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International audience; The oak barrel maturation step is nowadays strongly rooted in the production of quality wines. Two main physico-chemical phenomena contribute to the modification and improvement of wine: the solubilisation of volatile and non-volatile wood compounds concomitant with the dissolution of oxygen from the air into the wine. Indeed, wood is a porous material and gas transfer (especially oxygen transfer, expressed as oxygen transfer rate or OTR) through oak barrels, is an intrinsic parameter which ensures wine oxygen supply during maturation. Due to its oenological impact, it has been actively studied over recent decades using several approaches based on the same principle: the monitoring of oxygen in a model wine solution in the barrel. This project aimed at assaying barrel OTR by using a new tool based on the theoretical knowledge of gas transfer through porous materials. An oxygen concentration gradient was created on each side of a barrel kept in an airtight stainless-steel tank. The concentration of the oxygen in the atmosphere around the barrel was monitored in order to quantify oxygen transfer, thus the avoiding common drawbacks of interactions between dissolved oxygen ingress kinetics and the consumption of oxygen in the liquid phase by wood components. This study reports for the first time, the diffusion coefficient of entire oak barrels (Q. sessilis) to be between 10(-10) and 10(-9)m(2)/s, and it contributes to increasing knowledge on the complex phenomena driving oxygen ingress during the maturation of wine in barrels kept in cellar conditions. The results highlight the important role of wood moisture content in oxygen transfer, and provides a simple and reliable parameter to monitor it: the weight of the barrel. Following methodology developed by the authors, the OTR of a new oak barrel was found to be 11.4 mg/L per year. Taking into account the oxygen released through the wood pores, a new barrel will contribute 14.4 mg/L per year of oxygen to the wine, of which 46 % in the first three months of aging.

International audience; How cellular and molecular structure of raw fruits impact puree’s texture is still an unresolved question. Texture variations of purees obtained from four apple cultivars of contrasted texture (Braeburn, Gala, Golden Delicious, Granny Smith) and two modalities (mealiness, fruit load) after two contrasted processes were investigated. Although puree’s viscosity strongly varied between cultivars (562–1368 mPa s), it did not correlate with apple firmness, except for Granny Smith. This cultivar had the firmest fruits (3.2 N) and the most viscous purees (1368 mPa.s), in accordance with large particles (around 650 μm), high pulp wet mass and serum viscosity. Mealy Braeburn apples showed lower puree’s viscosity (562 mPa.s) than their not-mealy homologues (779 mPa.s). This was due to reduced cell adhesion, maybe because of lower (arabinose + galactose)/rhamnose ratio, leading to smaller particles during processing. Process also impacted puree’s viscosity (692–939 mPa s), with more viscous purees obtained with the high temperature-low shear process.

International audience; Worldwide dairy processing plants produce high volumes of dairy processing sludge (DPS), which can be converted into secondary derivatives such as struvite, biochar and ash (collectively termed STRUBIAS). All of these products have high fertilizer equivalent values (FEV), but future certification as phosphorus (P)-fertilizers in the European Union will mean they need to adhere to new technical regulations for fertilizing materials i.e., content limits pertaining to heavy metals (Cd, Cu, Hg, Ni, Pb, and Zn), synthetic organic compounds and pathogens. This systematic review presents the current state of knowledge about these bio-based fertilizers and identifies knowledge gaps. In addition, a review and calculation of greenhouse gas emissions from a range of concept dairy sludge management and production systems for STRUBIAS products [i.e., biochar from pyrolysis and hydrochar from hydrothermal carbonization (HTC)] is presented. Results from the initial review showed that DPS composition depends on product type and treatment processes at a given processing plant, which leads to varied nutrient, heavy metal and carbon contents. These products are all typically high in nutrients and carbon, but low in heavy metals. Further work needs to concentrate on examining their pathogenic microorganism and emerging contaminant contents, in addition to conducting an economic assessment of production and end-user costs related to chemical fertilizer equivalents. With respect to STRUBIAS products, contaminants not present in the raw DPS may need further treatment before being land applied in agriculture e.g., heated producing ashes, hydrochar, or biochar. An examination of these products from an environmental perspective shows that their water quality footprint could be minimized using application rates based on P incorporation of these products into nutrient management planning and application by incorporation into the soil. Results from the concept system showed that elimination of methane emissions was possible, along with a reduction in nitrous oxide. Less carbon (C) is transferred to agricultural fields where DPS is processed into biochar and hydrochar, but due to high recalcitrance, the C in this form is retained much longer in the soil, and therefore STRUBIAS products represent a more stable and long-term option to increase soil C stocks and sequestration.

Regulation of water flow in the pedicel–fruit system may generate a diurnally regulated uptake of sugar and prevent water loss by a system of fruit xylem-to-phloem and phloem-to-apoplast recirculation., We develop a model based on the biophysical representation of water and sugar flows between the pedicel, fruit xylem and phloem, and the fruit apoplast and symplast in order to identify diurnal patterns of transport in the pedicel–fruit system of peach. The model predicts that during the night water is mainly imported to the fruit through the xylem, and that fruit phloem–xylem transfer of water allows sugar concentrations in the phloem to be higher in the fruit than in the pedicel. This results in relatively high sugar transport to the fruit apoplast, leading to relatively high sugar uptake by the fruit symplast despite low sugar concentrations in the pedicel. At midday, the model predicts a xylem backflow of water driven by a lower pressure potential in the xylem than in the fruit apoplast. In addition, fruit xylem-to-phloem transfer of water decreases the fruit phloem sugar concentration, resulting in moderate sugar uptake by the fruit symplast, despite the high sugar concentration in the pedicel. Globally, the predicted fruit xylem–phloem water transfers buffer the sugar concentrations in the fruit phloem and apoplast, leading to a diurnally regulated uptake of sugar. A possible fruit xylem-to-apoplast recirculation of water through the fruit phloem reduces water lost by xylem backflow at midday.

Recent works revealed that bark is able to produce mechanical stress to control the orientation of young tilted stems. Here we report how the potential performance of this function changes with stem size in six Amazonian species with contrasted bark anatomy. The potential performance of the mechanism depends both on the magnitude of bark stress and the relative thickness of the bark. We measured bark longitudinal residual strain and density, and the allometric relationship between bark thickness and stem radius over a gradient of tree sizes. Constant tensile stress was found in species that rely on bark for the control of stem orientation in young stages. Other species had increasing compressive stress, associated with increasing density attributed to the development of sclereids. Compressive stress was also associated with low relative bark thickness. The relative thickness of bark decreased with size in all species, suggesting that a reorientation mechanism based on bark progressively performs less well as the tree grows. However, greater relative thickness was observed in species with more tensile stress, thereby evidencing that this reduction in performance is mitigated in species that rely on bark for reorientation., During ontogeny, species that rely on bark for posture control maintain thick bark and constant tensile stress, while other species have relatively thinner bark and increasing compressive stress.

A model formulation that reduced carboxylation capacity to optimize water costs for carbon gain successfully predicted stomatal behaviour for species from six plant functional types, irrespective of water availability or leaf ontogeny., The primary function of stomata is to minimize plant water loss while maintaining CO2 assimilation. Stomatal water loss incurs an indirect cost to photosynthesis in the form of non-stomatal limitations (NSL) via reduced carboxylation capacity (CAP) and/or mesophyll conductance (MES). Two optimal formulations for stomatal conductance (gs) arise from the assumption of each type of NSL. In reality, both NSL could coexist, but one may prevail for a given leaf ontogenetic stage or plant functional type, depending on leaf morphology. We tested the suitability of two gs formulations (CAP versus MES) on species from six plant functional types (C4 crop, C3 grass, fern, conifer, evergreen, and deciduous angiosperm trees). MES and CAP parameters (the latter proportional to the marginal water cost to carbon gain) decreased with water availability only in deciduous angiosperm trees, while there were no clear differences between leaf ontogenetic stages. Both CAP and MES formulations fit our data in most cases, particularly under low water availability. For ferns, stomata appeared to operate optimally only when subjected to water stress. Overall, the CAP formulation provided a better fit across all species, suggesting that sub-daily stomatal responses minimize NSL by reducing carboxylation capacity predominantly, regardless of leaf morphology and ontogenetic stage.

N uptake is positively correlated with photosynthetic capacity in ryegrass. The N sink strength of leaf meristems increased in response to defoliation. C and N reserves were remobilized only under severe defoliation., In grassland plant communities, the ability of individual plants to regrow after defoliation is of crucial importance since it allows the restoration of active photosynthesis and plant growth. The aim of this study was to evaluate the effects of increasing defoliation intensity (0, 25, 65, 84, and 100% of removed leaf area) on sugar remobilization and N uptake, remobilization, and allocation in roots, adult leaves, and growing leaves of ryegrass over 2 days, using a 15N tracer technique. Increasing defoliation intensity decreased plant N uptake in a correlative way and increased plant N remobilization, but independently. The relative contribution of N stored before defoliation to leaf growth increased when defoliation intensity was severe. In most conditions, root N reserves also contributed to leaf regrowth, but much less than adult leaves and irrespective of defoliation intensity. A threshold of defoliation intensity (65% leaf area removal) was identified below which C (glucose, fructose, sucrose, fructans), and N (amino acids, soluble proteins) storage compounds were not recruited for regrowth. By contrast, nitrate content increased in elongating leaf bases above this threshold. Wounding associated with defoliation is thus not the predominant signal that triggers storage remobilization and controls the priority of resource allocation to leaf meristems. A framework integrating the sequential events leading to the refoliation of grasses is proposed on the basis of current knowledge and on the findings of the present work.

The aim of this work was to evaluate the chemical composition of some plantation wood and the assessment of their compatibility with plaster. A quantitative analysis of the chemical composition each of the species (Eucalyptus saligna, Cupressus lusitanica and Eucalyptus paniculata) was carried out, followed by chemical compatibility evaluation using different types of wood particles. The quantitative analyses were carried out on wood powder of size between 0.27 and 0.30 mm. The results obtained were 2.4, 3.4 and 1.6% for ethanol–benzene extract (EAB); 2.6, 3.2 and 2.4% for hot water extract (EE); 12.4, 21.6 and 12.1% for 1% sodium hydroxide extract (ES); 48.6, 48.4 and 40.4% for cellulose content (C); 34.8, 34.3 and 36.3% for lignin content (L); then 0.1, 0.6, 0.3% for ash content (CE) respectively of E. saligna, C. lusitanica and E. paniculata. Chemical compatibility CA was measured from hydration temperature curves as a function of time using the area method. The results showed that compatibility CA decreased from 100 to 68% as the wood content in the composite increased up to 15% for all species and types of particles used. At this minimum value, the species was still considered as highly compatible in accordance with literature. Although compatibility is good, it decreased in the order E. paniculata followed by E. saligna and then C. lusitanica, the least compatible due to the inhibiting action of extractives.

Highlight Temperature and relative humidity occurring during prolonged storage of freshly harvested Arabidopsis seeds control dormancy cycling and the expression of molecular regulators of this process., The changes in germination potential of freshly harvested seeds of Arabidopsis thaliana stored in various combinations of temperature and relative humidity were investigated over 63 weeks of storage. Seeds of the wild type Col-0 and of two mutants displaying low and high levels of dormancy, cat2-1 and mtr4-1, respectively, were stored at harvest in 24 different environments including a combination of eight relative humidities, from 1 to 85%, and four temperatures (10, 15, 20, and 25 °C). These mutations did not influence behaviour of seeds during storage. Primary dormant seeds did not germinate in darkness at 25 °C but acquired the potential to germinate at this temperature within 7 weeks when stored in relative humidities close to 50% across all temperatures. Sorption isotherms and Arrhenius plots demonstrated that the seed moisture content of 0.06g H2O/g dry weight was a critical value below which dormancy release was associated with reactions of negative activation energy and above which dormancy release increased with temperature. Longer storage times when relative humidity did not exceed 75–85% led to decreased germination at 25 °C, corresponding to the induction of secondary dormancy. Dormancy release and induction of secondary dormancy in the dry state were associated with induction or repression of key genes related to abscisic acid and gibberellins biosynthesis and signalling pathways. In high relative humidity, prolonged storage of seeds induced ageing and progressive loss of viability, but this was not related to the initial level of dormancy.

International audience; Carob (Ceratonia siliqua L.) fruit pulp from 12 wild and 8 domesticated trees from 15 Moroccan localities were investigated for their polyphenols contents: total polyphenols content (53.22 - 118.04 mg and 57.46 - 183.31 mg), total flavonoids (1.41 - 4.83 mg and 1.62 - 7.46 mg) and condensed tannins (1.47 - 7.36 mg and 1.85 - 6.66 mg) in one carob fresh pulp for wild and domesticated trees, respectively. Fruit pulp from trees in the same region shows variable contents in polyphenols, flavonoids and condensed tannins.

In order to isolate polyphenols from Douglas fir outer bark, this latter was mechanically fractionated by means of knife and ball millings. The sieving of the resulting powder gave rise to a set of fractions with different particle sizes and shapes. The particles ranging from 0.56 to 0.16 mm size were mainly composed of tannins (46%) while, taxifolin was located in the coarser fraction (83%) with particles size above 1 mm. The isolated phenolic compounds are suitable of upgrading to higher value products.

The present work investigates the interactions between soil content, rootstock and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS) and Pinot Noir (PN) varieties were grafted either on Riparia Gloire de Montpellier (RGM) or 110 Richter (110R) rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake by the plants, and N content both in vegetative and reproductory organs. Rootstock, variety and year affected berry weight at harvest, while nitrogen did not affect significantly this parameter. Grafting on RGM consistently increased berry weight compared to 110R. PN consistently produced bigger berries than CS. CS berries were heavier in 2014 than in 2013, but the year effect was less marked for PN berries. The berries were collected between veraison and maturity, separated in skin and pulp, and their content was analyzed by conventional analytical procedures and untargeted metabolomics. For anthocyanins, the relative quantitation was fairly comparable with both LC-MS determination and HPLC-DAD, which is a fully quantitative technique. The data show complex responses of the metabolite content (sugars, organic acids, amino acids, anthocyanins, flavonols, flavan-3-ols/procyanidins, stilbenes, hydroxycinnamic and hydroxybenzoic acids.) that depend on the rootstock, the scion, the vintage, the nitrogen level, the berry compartment. This opens a wide range of possibilities to adjust the content of these compounds through the choice of the roostock, variety and nitrogen fertilization.

Highlight The earliest events in ripening are decreases in turgor, softening, and increases in abscisic acid. Later events integral to regulating colour development include growth, further increases in abscisic acid, and sugar accumulation., Along with sugar accumulation and colour development, softening is an important physiological change during the onset of ripening in fruits. In this work, we investigated the relationships among major events during softening in grape (Vitis vinifera L.) by quantifying elasticity in individual berries. In addition, we delayed softening and inhibited sugar accumulation using a mechanical growth-preventing treatment in order to identify processes that are sugar and/or growth dependent. Ripening processes commenced on various days after anthesis, but always at similarly low elasticity and turgor. Much of the softening occurred in the absence of other changes in berry physiology investigated here. Several genes encoding key cell wall-modifying enzymes were not up-regulated until softening was largely completed, suggesting softening may result primarily from decreases in turgor. Similarly, there was no decrease in solute potential, increase in sugar concentration, or colour development until elasticity and turgor were near minimum values, and these processes were inhibited when berry growth was prevented. Increases in abscisic acid occurred early during softening and in the absence of significant expression of the V. vinifera 9-cis-epoxycarotenoid dioxygenases. However, these increases were coincident with decreases in the abscisic acid catabolite diphasic acid, indicating that initial increases in abscisic acid may result from decreases in catabolism and/or exogenous import. These data suggest that softening, decreases in turgor, and increases in abscisic acid represent some of the earliest events during the onset of ripening. Later, physical growth, further increases in abscisic acid, and the accumulation of sugar are integral for colour development.

Ultrasonic acoustic emission (UAE) methods have been applied for the detection of freeze–thaw-induced embolism formation in water conduits of tree species. Until now, however, the exact source(s) of UAE has not been identified especially in angiosperm species, in which xylem tissues are composed of diverse types of cells. In this study, UAE was recorded from excised branches of walnut (Juglans regia cv. Franquette) during freeze–thaw cycles, and attempts were made to characterize UAEs generated by cavitation events leading to embolism formation according to their properties. During freeze–thaw cycles, a large number of UAEs were generated from the sample segments. However, the cumulative numbers of total UAE during freeze–thawing were not correlated with the percentage loss of hydraulic conductivity after thawing, suggesting that the sources of UAE were not only cavitation leading to embolism formation in vessels. Among the UAEs, cumulative numbers of UAEs with absolute energy >10.0 fJ strongly correlated with the increase in percentage loss of hydraulic conductivity. The high absolute energy of the UAEs might reflect the formation of large bubbles in the large lumen of vessels. Therefore, UAEs generated by cavitation events in vessels during freeze–thawing might be distinguished from other signals according to their magnitudes of absolute energy. On the other hand, the freezing of xylem parenchyma cells was followed by a certain number of UAEs. These results indicate the possibility that UAE methods can be applied to the detection of both freeze–thaw-induced embolism and supercooling breakdown in parenchyma cells in xylem.

Titratable acidity and pH are important chemical traits for organoleptic quality of banana since they are related to sourness and sweetness. Banana fruit has the particularity of being ripened out of the plant after harvest and during postharvest maturation titratable acidity and pH of the pulp continue to change until consumption. A modeling approach was used to understand the mechanisms involved in changes in titratable acidity and pH of the pulp during maturation. Changes in pH were modeled by solving a set of equations representing acid/base reactions. Changes in titratable acidity were modeled by taking organic acid content (citrate, malate, oxalate, and phosphate) and mineral content (potassium, magnesium, chlorine) into account. The two models were built using data from three dessert banana cultivars with contrasting acidity. For each model, calculated values were compared to observed values. Sensitivity analysis was used to study the influence of the model parameters on pH and titratable acidity. These models allowed fairly good predictions of pH and titratable acidity, and shed some light on the determinants of acidity changes during banana maturation.

Highlight text A mutation in the plum auxin-receptor encoded by PslAFB5, which acts as a negative regulator of auxin responses, results in inactive Pslafb5 protein causing accelerated fruit-ontogeny events associated with auxin hypersensitivity., Ethylene has long been considered the key regulator of ripening in climacteric fruit. Recent evidence showed that auxin also plays an important role during fruit ripening, but the nature of the interaction between the two hormones has remained unclear. To understand the differences in ethylene- and auxin-related behaviours that might reveal how the two hormones interact, we compared two plum (Prunus salicina L.) cultivars with widely varying fruit development and ripening ontogeny. The early-ripening cultivar, Early Golden (EG), exhibited high endogenous auxin levels and auxin hypersensitivity during fruit development, while the late-ripening cultivar, V98041 (V9), displayed reduced auxin content and sensitivity. We show that exogenous auxin is capable of dramatically accelerating fruit development and ripening in plum, indicating that this hormone is actively involved in the ripening process. Further, we demonstrate that the variations in auxin sensitivity between plum cultivars could be partially due to PslAFB5, which encodes a TIR1-like auxin receptor. Two different PslAFB5 alleles were identified, one (Pslafb5) inactive due to substitution of the conserved F-box amino acid residue Pro61 to Ser. The early-ripening cultivar, EG, exhibited homozygosity for the inactive allele; however, the late cultivar, V9, displayed a PslAFB5/afb5 heterozygous genotype. Our results highlight the impact of auxin in stimulating fruit development, especially the ripening process and the potential for differential auxin sensitivity to alter important fruit developmental processes.

International audience; Sourness and sweetness are major drivers of consumer preference for banana fruits and are mainly linked to the presence of citrate and malate. The objectives of the present work were to determine how agro-environmental and genotypic factors affect the concentrations of citrate and malate in banana pulp during growth and postharvest ripening. Changes in citrate and malate concentrations in the pulp during the development of the fruit were investigated in relation to fruit age, fruit load, and potassium fertilization in three cultivars of dessert banana presenting contrasted acidity at the eating stage. Major differences in the pattern of citrate and malate accumulation were found in the three cultivars both during growth and postharvest ripening. The fruit growth rate was greater when the fruit load was reduced, but this treatment had no effect on the accumulation of organic acids in any of the three cultivars. A high potassium supply increased fruit growth but had no effect on organic acid accumulation in any of the three cultivars. Late harvested fruits had higher citrate and lower malate concentrations in the pulp at the eating stage. Our results showed that the concentration of organic acids in banana pulp is mainly controlled by genotype and that this may be an interesting trait to target in breeding programs to improve the organoleptic quality of new cultivars. The physiological mechanisms likely to control the accumulation of citrate and malate during banana fruit development are discussed. (C) 2014 Elsevier B.V. All rights reserved.

International audience; The performance of oil expression from Jatropha curcas L. (Jatropha) seeds using a pilot scale continuous screw press was studied. The influence of seed pre-treatment, i.e. whole, crushed and deshelled seeds, screw-press operational settings (shaft rotational speed and press cake outlet section) was investigated. For each experiment, the material flows (seeds, press cake and crude oil) were measured and analysed for their oil, water and solids contents. The behaviour of oil expression was very sensitive to seeds preparation. It was shown that for whole seeds, a good reproducibility was obtained, whereas for crushed or deshelled seeds, heterogeneity of the feed led to unsteady pressing conditions and important discrepancies in the performance. The presence of seed shells contributes to build a porous solid matrix which favours oil flow through the press cake. For whole seeds, a correlation between oil recovery and seed throughput was proposed. The mass balance consistency was carefully analysed and oil yield was determined using a direct and an indirect method. A good linear correlation between seed and press cake throughputs was observed: the seed throughput is always divided in a stream of crude oil and a stream of press cake in the same proportion. This important result shows that the residual oil in press cake and the amount of solids carried by the oil are directly related and determine the efficacy of the separation. Thus, for a given screw press and feed material, the oil sediment content can be predicted knowing the oil recovery. The energy consumption during pressing was measured and modelled as a function of oil recovery and seeds oil content. The specific mechanical energy for oil expression was less than 5% of the energy content of the oil and a minimum mechanical energy requirement was generally observed at oil recoveries between 70% and 80%.

International audience; We analyzed how changes in BnNrt nitrate transporter gene expression induced by nitrate are associated with morphological changes in plantlets and osmotic water flow for growth. We hypothesized that in a Petri dish system, reduction in transpiration should induce conditions where nitrate and water fluxes for growth depend directly on nitrate transporter activity and nitrate signaling. Rape seedlings growing on agar plates were supplied with increasing external K15NO3 concentrations from 0.05 to 20 mM. After 5 d of treatment, morphological switches in plantlet growth were observed between 0.5 and 5 mM nitrate supply. Root elongation was reduced by 50% while the cotyledon surface area was doubled. These morphological switches were strongly associated with increases in 15NO3- and water uptake rates as well as 15N and water allocation to the shoot. These switches were also highly correlated with the upregulation of BnNrt1.1 and BnNrt2.1 in the root. However, while root expression of BnNrt2.1 was correlated linearly with a shoot growth-associated increase in 15N and water uptake, BnNrt1.1 expression was correlated exponentially with both 15N and water accumulation. In low transpiring conditions, the tight control exercised by nitrate transporters on K15NO3 uptake and allocation clearly demonstrates that they modulated the nitrate-signaling cascade involved in cell growth and as a consequence, water uptake and allocation to the growing organs. Deciphering this signaling cascade in relation to acid growth theory seems to be the most important challenge for our understanding of the nitrate-signaling role in plant growth.

International audience; Titratable acidity and pH are important chemical traits for the organoleptic quality of banana since they are related to the perception of sourness and sweetness. Banana fruit has the particularity of having separate growth and ripening stages, during which pulp acidity changes. A modeling approach was used to understand the mechanisms involved in changes in acidity during pulp growth and post harvest ripening. Changes in pH and titratable acidity were modeled by solving a set of equations representing acid/base reactions. The models were built using data from growth and post harvest ripening of three dessert banana cultivars with contrasting acidity. For each model, calculated values were compared to observed values. These models allowed the prediction of pH (R-2 = 0.34; RMSE = 0.75, biais = 0.05) and of titratable acidity (R-2 = 0.81, RMSE = 2.05, biais = -1.44) during fruit growth and post harvest ripening. The sensitivity analyses showed that among acids, malic, citric and oxalic acids are the main contributors to banana pulp acidity, and that among soluble minerals, potassium also plays an important role. Studying the factors that affect the accumulation of organic acids (citric, malic, and oxalic acids) and potassium in banana pulp could be a relevant area of research with the objective of modifying banana fruit acidity.

The product. Coconut water (Cocos nucifera L.) is an ancient tropical beverage whose original properties have drawn the attention of manufacturers as a natural functional drink. Preservation. This refreshing liquid comes mainly from immature coconuts which are difficult to collect, store and thus to commercialise. Nevertheless, some studies, mostly from Asian countries, tend to prove that the shelf life of immature coconut fruits could be prolonged thanks to post-harvest treatments. Processing. Coconut water itself, extracted from the nut, is obviously easier to handle but is also very sensitive to biological and chemical injuries. Thermal treatment combined with chemical additives are already used by the industry but other technologies such as micro- and ultrafiltration are not yet available on an industrial scale. Whatever the process, taste, aroma and colour (linked to enzymatic activities) are still difficult to control. Discussion. Results of former and recent investigations are discussed. Finally, suggestions are made for further research to increase our knowledge of this original tropical juice.

International audience; To check if bunch trimming improves quality traits of banana, its effect on the dry matter content of the pulp and peel of two banana cultivars (Grande Naine, and a hybrid named Flhorban 924) were investigated during fruit growth. For both cultivars, bunches with six hands (controls) were compared with trimmed bunches with only two hands at two fruit development stages, one early fruit pruning treatment at 160 degree days (dd) and one late fruit pruning treatment at 540 dd. Early bunch trimming increased fruit weight by more than 25%. An allometric relationship of type Y = aX b was found between fruit and pulp dry weight, in which the coefficients mainly depended on the cultivar concerned. In the allometric relationship between the weight of water in the fruit and the pulp,coefficient b was the same in the two cultivars. During fruit growth, the dry matter content of the pulp and peel increased rapidly between 160 and 600 dd, then continued to increase, but more slowly, to reach maximum at between 600 and 800 dd depending on the cultivar, and finally declined slowly until the end of growth. The early bunch trimming treatment led to an increase of 1 g 100 g − 1 in the dry matter content of the peel. However, the dry matter content of the pulp was not affected by bunch trimming irrespective of when the treatment was carried out. In conclusion, this common cultivation practice did improve fruit weight but had no significant impact on the dry matter content of the banana pulp at harvest.

International audience; Trees will have to cope with increasing levels of CO2 and ozone in the atmosphere. The purpose of this work was to assess whether the lignification process could be altered in the wood of poplars under elevated CO2 and/or ozone. Young poplars were exposed either to charcoal-filtered air (control), to elevated CO2 (800 μl l−1), to ozone (200 nl l−1) or to a combination of elevated CO2 and ozone in controlled chambers. Lignification was analysed at different levels: biosynthesis pathway activities (enzyme and transcript), lignin content, and capacity to incorporate new assimilates by using 13C labelling. Elevated CO2 and ozone had opposite effects on many parameters (growth, biomass, cambial activity, wood cell wall thickness) except on lignin content which was increased by elevated CO2 and/or ozone. However, this increased lignification was due to different response mechanisms. Under elevated CO2, carbon supply to the stem and effective lignin synthesis were enhanced, leading to increased lignin content, although there was a reduction in the level of some enzyme and transcript involved in the lignin pathway. Ozone treatment induced a reduction in carbon supply and effective lignin synthesis as well as transcripts from all steps of the lignin pathway and some corresponding enzyme activities. However, lignin content was increased under ozone probably due to variations in other major components of the cell wall. Both mechanisms seemed to coexist under combined treatment and resulted in a high increase in lignin content.

International audience; Spring geophytes produce larger storage organs and present delayed leaf senescence under lower growth temperature. Bulb and leaf carbon metabolism were investigated in Erythronium americanum to identify some of the mechanisms that permit this improved growth at low temperature. Plants were grown under three day/night temperature regimes: 18/14 degrees C, 12/8 degrees C, and 8/6 degrees C. Starch accumulated more slowly in the bulb at lower temperatures probably due to the combination of lower net photosynthetic rate and activation of a 'futile cycle' of sucrose synthesis and degradation. Furthermore, bulb cell maturation was delayed at lower temperatures, potentially due to the delayed activation of sucrose synthase leading to a greater sink capacity. Faster starch accumulation and the smaller sink capacity that developed at higher temperatures led to early starch saturation of the bulb. Thereafter, soluble sugars started to accumulate in both leaf and bulb, most probably inducing decreases in fructose-1,6-bisphosphatase activity, triose-phosphate utilization in the leaf, and the induction of leaf senescence. Longer leaf life span and larger bulbs at lower temperature appear to be due to an improved equilibrium between carbon fixation capacity and sink strength, thereby allowing the plant to sustain growth for a longer period of time before feedback inhibition induces leaf senescence.

The maintenance in the long run of a positive carbon balance under very low irradiance is a prerequisite for survival of tree seedlings below the canopy or in small gaps in a tropical rainforest. To provide a quantitative basis for this assumption, experiments were carried out to determine whether construction cost (CC) and payback time for leaves and support structures, as well as leaf life span (i) differ among species and (ii) display an irradiance-elicited plasticity. Experiments were also conducted to determine whether leaf life span correlates to CC and payback time and is close to the optimal longevity derived from an optimization model. Saplings from 13 tropical tree species were grown under three levels of irradiance. Specific-CC was computed, as well as CC scaled to leaf area at the metamer level. Photosynthesis was recorded over the leaf life span. Payback time was derived from CC and a simple photosynthesis model. Specific-CC displayed only little interspecific variability and irradiance-elicited plasticity, in contrast to CC scaled to leaf area. Leaf life span ranged from 4 months to >26 months among species, and was longest in seedlings grown under lowest irradiance. It was always much longer than payback time, even under the lowest irradiance. Leaves were shed when their photosynthesis had reached very low values, in contrast to what was predicted by an optimality model. The species ranking for the different traits was stable across irradiance treatments. The two pioneer species always displayed the smallest CC, leaf life span, and payback time. All species displayed a similar large irradiance-elicited plasticity.

Aims: The aim of this work was to study the dynamics of the sludge particles during wine fermentation in liquid phase.Methods and results: Ninety L of Sauvignon blanc enriched with 1.8% (v/v) of sludges, inoculated with a commercial strain of S. cerevisiae, were fermented in a transparent 100 L-fermentation tank. Results showed that the physical behavior of the sludge particles is dependent on the yeast CO2 production activity. Sludge dynamics can be divided in three phases clearly linked to the yeast fermentative activity. Although a complete dispersion of the sludges occurred during the fermentation, it could be observed that either at the surface or at the bottom of the tank, the medium turbidity never ranges the initial turbidity level, due to the disruption of the medium/gross particles into fine particles during the growth phase. Fine particles rapidly re-aggregated into medium/gross particles during the stationary phase.Conclusions: From these results, it appears that the evolution of must turbidity during fermentation is much more complex than previously expected. Sludges are only dispersed in the fermenting must during a very short phase after the initiation of cell growth.Significance and impact of the study: This study raises the questioning of the relationship between initial must turbidity and nutrient availability in trouble musts, since sludges are completely deposited at the onset of both cell growth and fermentation. Further research works are therefore needed to study the factors which can impact sludge particle size modification and consequently sludge nutrient accessibility for yeast growth.

International audience; Whereas the effects of water and nitrogen (N) on plant Delta C-13 have been reported previously, these factors have scarcely been studied for Delta O-18. Here the combined effect of different water and N regimes on Delta C-13, Delta O-18, gas exchange, water-use efficiency (WUE), and growth of four genotypes of durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] cultured in pots was studied. Water and N supply significantly increased plant growth. However, a reduction in water supply did not lead to a significant decrease in gas exchange parameters, and consequently Delta C-13 was only slightly modified by water input. Conversely, N fertilizer significantly decreased Delta C-13. On the other hand, water supply decreased Delta O-18 values, whereas N did not affect this parameter. Delta O-18 variation was mainly determined by the amount of transpired water throughout plant growth (T-cum), whereas Delta C-13 variation was explained in part by a combination of leaf N and stomatal conductance (g(s)). Even though the four genotypes showed significant differences in cumulative transpiration rates and biomass, this was not translated into significant differences in Delta O-18(s). However, genotypic differences in Delta C-13 were observed. Moreover, similar to 80% of the variation in biomass across growing conditions and genotypes was explained by a combination of both isotopes, with Delta O-18 alone accounting for similar to 50%. This illustrates the usefulness of combining Delta O-18 and Delta C-13 in order to assess differences in plant growth and total transpiration, and also to provide a time-integrated record of the photosynthetic and evaporative performance of the plant during the course of crop growth.

International audience; The leafhopper Scaphoideus titanus is the vector of a major phytoplasma grapevine disease, Flavescence dorée. The vector’s distribution is in Eastern and Northern Europe, and its population dynamics varies as a function of vineyard latitude. We tested the hypothesis that hatching dynamics are cued by cold temperatures observed in winter. We exposed eggs from a natural population to simulated “cold” and “mild” winters and varied the exposure time at 5 °C from 0 to 63 days. We show that temperature cooling mainly affected the onset of hatching and is negatively correlated to the cold time exposure. The majority of hatchings occurred more quickly in cold rather than in mild winter simulated conditions, but there was no significant difference between the duration of hatching of eggs whatever the cold time exposure. In agreement with the Northern American origin of the vector, the diapause termination and thus the timing regulation of egg hatching require cold winters.

We aimed to define a more robust indicator for banana harvest date that ensures an optimal fruit green life (GL). Our hypothesis was that development rather than growth would account for GL more accurately. To this end, five indicators were compared: one related to fruit size (i.e., growth, expressed as the diameter of fruit); two related to fruit age [i.e., development, expressed as the age of fruit measured in the number of days or in degree days (°Cd) from inflorescence emergence]; and two related to metabolism during maturation (i.e., the concentrations of malate and citrate in the pulp). Different treatments (e.g., fruit removal, leaf shading, bunch bagging, defoliation, water deficit, and flooding) were applied to modify the fruit growth rate. On different dates between the emergence of the inflorescence and harvest, fruit GL and the five indicators were measured. The results showed that there was a decreasing exponential relationship between GL and accumulated °Cd from inflorescence emergence (r2 = 0.77). This was more reliable than the relationships between GL and fruit diameter (r2 = 0.39), or between GL and fruit age, expressed in days (r2 = 0.39). Relationships were also established between GL and malate or citrate concentrations, but they were not sufficiently reliable to estimate GL. The results illustrate that GL is related to fruit development, and that °Cd is a more reliable criterion for harvest date than the number of days, or fruit diameter, because it is less sensitive to different fruit growth rates. Banana growers in the French West Indies usually use fruit diameter and age in days to determine harvest date. However, they face problems of fruit ripening during transportation. The use of °Cd as an indicator may help to determine the optimum harvest date more accurately.

International audience; The grape berry microclimate is known to influence berry quality. The effects of the light exposure of grape berry clusters on the composition of berry tissues were studied on the "Merlot" variety grown in a vineyard in Bordeaux, France. The light exposure of the fruiting zone was modified using different intensities of leaf removal, cluster position relative to azimuth, and berry position in the cluster. Light exposures were identified and classified by in situ measurements of berry temperatures. Berries were sampled at maturity (> 19 Brix) for determination of skin and/or pulp chemical and metabolic profiles based on (1) chemical and physicochemical measurement of minerals (N, P, K, Ca, Mg), (2) untargeted H-1 NMR metabolic fingerprints, and HPLC targeted analyses of (3) amino acids and (4) phenolics. Each profile defined by partial least-square discriminant analysis allowed us to discriminate berries from different light exposure. Discriminant compounds between shaded and light-exposed berries were quercetin-3-glucoside, kaempferol-3-glucoside, myricetin-3-glucoside, and isorhamnetin-3-glucoside for the phenolics, histidine, valine, GABA, alanine, and arginine for the amino acids, and malate for the organic acids. Capacities of the different profiling techniques to discriminate berries were compared. Although the proportion of explained variance from the H-1 NMR fingerprint was lower compared to that of chemical measurements, NMR spectroscopy allowed us to identify lit and shaded berries. Light exposure of berries increased the skin and pulp flavonols, histidine and valine contents, and reduced the organic acids, GABA, and alanine contents. All the targeted and nontargeted analytical data sets used made it possible to discriminate sun-exposed and shaded berries. The skin phenolics pattern was the most discriminating and allowed us to sort sun from shade berries. These metabolite classes can be used to qualify berries collected in an undetermined environment. The physiological significance of light and temperature effects on berry composition is discussed.

Mealiness, mechanical breakdown and cell wall chemical structure of a mealy (cv ‘Cameron’) and a juicy (cv ‘Quest’) tomato ( Lycopersicon esculentum Mill.) variety were studied over several weeks during the harvest period. A set-up was designed to break tomato pericarp tissue while measuring the rupture energy. For ‘Cameron’, the rupture energy was high and decreased over the harvest period. For ‘Quest’, the rupture energy was low and did not vary throughout the study. The particles in the pulp after breakdown were characterized by image analysis. For ‘Cameron’, intact cells were always recovered from the pulp. Many cell fragments were obtained in the case of ‘Quest’. At the end of the harvest period, ‘Quest’ had a higher content of intact cells. The chemical composition and structure of cell walls in pericarp tissue were determined by biochemical analysis, mid-infrared and solid-state NMR spectroscopy. Cell walls of ‘Cameron’ pericarp tissue were richer in neutral sugars and uronic acid than those of ‘Quest’. The pectin content of ‘Cameron’ samples decreased over the harvest week and was compensated for by protein. ‘Quest’ was richer in mobile arabinan pectic side-chains than ‘Cameron’. Mealiness was correlated with rupture energy, size of recovered particles and mid-infrared data. The data are discussed with regard to cell adhesion and rigidity.

International audience; Red-purple pitahaya (Hylocereus sp.) is a promising crop grown commercially in dry regions of Central America. Both its skin and flesh are characterized by being a glowing, deeply red-purple color. Materials and methods. The main physicochemical characteristics of three commercial cultivars of red pitahaya were assessed, including total phenolic compounds contents, total betacyanins, vitamin C and oxygen radical absorbance capacity (ORAC). Thermal stability of betacyanins at different temperature and pH was also assessed. Results and discussion. Pitahaya fruit has a low vitamin C content ranging from (116 to 171) µg·g-1 of fresh pulp without seeds, but it is rich in betacyanins [(0.32 to 0.41) mg·g-1 ] and phenolic compounds [(5.6 to 6.8) µmol Eq gallic acid·g-1 ]; it has a high antioxidant ORAC value of (8.8 to 11.3) µmol Eq Trolox·g-1. Visible spectra of aqueous fruit extracts were very similar to that of pure betacyanin. Indeed, the characteristic color of juice diluted to 1% presents a high hue angle (H° = 350º ± 3) and high chroma values (C* = 79 ± 2). Thermal stability of pitahaya betacyanin decreases with pH, but it remains compatible with industrial utilization as a colorant (half-time = 22.6 min at 90 °C at pH = 5 of the fruit) and was found to be very similar to that previously reported for beetroot. Conclusions. Pitahaya juice combines the functional properties of a natural food colorant with high antioxidant potency.; La pitahaya rouge (Hylocereus sp.) est une culture pleine de pro-messes qui est exploitée commercialement dans des régions sèches de l'Amérique centrale. Sa peau tout comme sa chair se caractérisent par leur couleur d'un rouge profond. Matériel et méthodes. Les principales caractéristiques physico-chimiques des fruits de trois cultivars com-merciaux de pitahaya rouge ont été évaluées, dont leur teneur totale en composés phénoliques, leur teneur totale en bêtacyanines et en vitamine C, ainsi que leur capacité d'absorbance du radical oxygène (ORAC). La stabilité thermique des bêtacyanines à différentes températures et pH a été également évaluée. Résultats et discussion. La pitahaya a une faible teneur en vitamine C comprise entre (116 et 171) µg·g-1 de pulpe fraîche sans graines, mais elle est riche en bêta-cyanine [(0,32 à 0,41) mg·g-1 ] et en composés phénoliques [(5,6 à 6,8) µmol Eq d'acide galli-que·g-1 ] ; elle a une valeur élevée en antioxydant ORAC : (8,8 à 11,3) µmol Eq Trolox·g-1. Les spectres visibles des extraits aqueux de fruits ont été très semblables à celui de la bêtacyanine pure. En effet, la couleur caractéristique du jus dilué à 1 % a une forte tonalité (H° = 350º ± 3) et des valeurs élevées de chromas (C* = 79 ± 2). La stabilité thermique de la bêtacyanine de pita-haya diminue avec le pH, mais elle demeure compatible avec une utilisation industrielle comme colorant (demi période = 22,6 min à 90 °C au pH = 5 du fruit) et elle s'est révélée très semblable à celle précédemment rapportée pour les betteraves. Conclusions. Le jus de pitahaya combine les propriétés fonctionnelles d'un colorant alimentaire normal accompagné d'un pouvoir antioxydant élevé. Amérique centrale / Nicaragua / Hylocereus / colorant alimentaire / bétaïne / antioxydant

International audience; An in vivo experimental system-called the 'berry-cup' technique-was developed to study sugar phloem unloading and the accumulation of sugar in ripening grape berries. The berry-cup system consists of a single peeled grape berry immersed in a buffer solution in a cup prepared from a polypropylene syringe. A small cross-incision (2 mm in length) is made on the stylar remnant of a berry during its ripening phase, the skin of the berry then being easily peeled off, exposing the dorsal vascular bundles without damaging either these or the pulp tissue of the berry. The sites of sugar phloem unloading are thus made directly accessible and may be regulated by the buffer solution. In addition, the unloaded photoassimilates are easily transported into the buffer solution in the berry-cup. With the berry-cup technique, it takes 60 min to purge the sugar already present in the apoplast, after which the amount of sugar in the buffer solution is a direct measure of the sugar unloading from the grape berry phloem. The optimum times for sampling were 20 or 30 min, depending on the type of experiment. Sugar phloem unloading was significantly inhibited by the inclusion of either 7.5 mm NaF or 2.5 mm PCMB in the buffer solution. This study indicates that sugar phloem unloading in ripening grape berries is via the apoplastic network and that the process requires the input of energy. The system was shown to be an appropriate experimental system with which to study sugar phloem unloading in ripening grape berries, and was applied successfully to the study of berry sugar unloaded from grapevines subjected to water stress. The results showed that water deficiency inhibits sugar unloading in grape berries

National audience

International audience; (1) This paper analyses the frugivorous diet of Cercopithecus cephus through one annual cycle in comparison with variations in fruit species availability, fruit morphology and nutrient and mineral content of fruit. (2) Among the whole spectrum of fruiting species available, a small fraction (termed edible species) is included in the monkeys' diet. (3) Among these edible species, some are more frequently sampled by monkeys than expected by their density, whereas several abundant species are only occasionally eaten. Overall, twenty species (35% of those sampled) contribute to 85% of the diet; among them, only three are included in the list of the twenty most abundant plant species in the study site. (4) According to their selection ratio (percentage sampled/percentage abundance), fruit species have been classified into three categories: preferred, neutral and avoided species. These three categories differ by their nature, their colour and their chemical composition. (5) Brightly coloured fruits possessing either a succulent pulp or arillated seeds are largely eaten: they possess either a high water content and a high sugar content (succulent pulp) or a high protein content and a high fatty acid content (arils). (6) Dull-coloured fleshy fruits are avoided: they possess a relatively low nutritive value and a high concentration of fibres. (7) The most preferred species exhibit a high acidity content. (8) We discuss the different levels of selection exerted by monkeys and underline the difficulties involved in the assumption that fruits constitute a superabundant food resource or alternatively are a limiting resource in tropical rain fore

International audience; By mobilizing the socio-technical approach to innovation and semi-directive survey of 31 stakeholders, this paper analyzes the value chains that ensure the valorization of apricot pit by-products and the dynamics of their actors. Beyond the technical knowledge on the recovery of apricot by-products and their potential uses, this paper shows a multitude of strategies but also challenges that are barriers to this innovative sector development. It also highlights some of the drivers that these value chains can rely on for their further development. The results of this work show real economic opportunities that are available to operators in these sectors depending on the nature of the by-product but also the market targeted by them. It also shows that the diffusion of these innovations must be better coordinated on the market. To do so, the socio-economic and environmental interests related to the valorization of apricot pit by-products must be highlighted.

International audience; Sensory methods applied to ornamental plants enable studying more objectively plant visual qualitykey drivers of consumer preferences. However, management upkeep of a trained panel for sensory profile is time-consuming, not flexible and represents non-negligible costs. The present paper achieves the proof of the concept about using morphometrical descriptors upkeep of a trained panel for sensory profile is time-consuming, not flexible and represents non-negligible costs. The present paper achieves the proof of the concept about using morphometrical descriptors integrating 2D image features from rotating virtual rose bush videos to predict their visual appearance according to different sensory attributes. Using real plants cultivated under a shading gradient and imaged in rotation during three development stages, acceptable prediction error of the sensory attributes ranging from 6.2 to 19.8% (normalized RMSEP) were obtained with simple ordinary least squares OLS) regression models and linearization. The most accurate model obtained was for the flower quantity perception.Finally, a secondary analysis highlighted in most of the studied traits a significant influence of defoliation, stressing herefore the impact of the leaves on plant architecture, and thus on the visual appearance.

International audience; In many agri-food companies, food quality is often managed using expertise gained through experience. Overall quality enhancement may come from sharing collective expertise. In this paper, we describe the design and implementation of a complete methodology allowing an expert knowledge base to be created and used to recommend the technical action to take to maintain food quality. We present its functional specifications, defined in cooperation with several industrial partners and technical centres over the course of several projects carried out in recent years. We propose a systematic methodology for collecting the knowledge on a given food process, from the design of a questionnaire to the synthesis of the information from completed questionnaires using a mind map approach. We then propose an original core ontology for structuring knowledge as possible causal relationships between situations of interest. We describe how mind map files generated by mind map tools are automatically imported into a conceptual graph knowledge base, before being validated and finally automatically processed in a graph-based visual tool. A specific end-user interface has been designed to ensure that end-user experts in agri-food companies can use the tool in a convenient way. Finally, our approach is compared with current research.

International audience; AbstractKey messageThis paper presents a greenhouse study for assessing the genetic variation in maritime pine (Pinus pinasterAiton) in response to pinewood nematode (Bursaphelenchus xylophilus(Steiner et Buhren) Nickle), which is a causal agent of pine wilt disease. Fifteen out of 96 half-sib families were selected as less susceptible. This experiment is an important first step for creating a resistance breeding program.ContextPine wilt disease is caused by the pinewood nematode (Bursaphelenchus xylophilus (Steiner et Buhren) Nickle), a quarantine pest, and is a concern to maritime pine (Pinus pinaster) in Portugal due to its economic, environmental, and social impacts. This disease is regarded as a major threat to European forests.AimsThis paper aimed to evaluate the genetic variation in maritime pine families that were inoculated with pinewood nematode, identify the most resistant families, and establish the guidelines for a resistance improvement program.MethodsTwo-year-old half-sib progenies obtained from 96 plus trees were inoculated. The plants were monitored for survival on four different dates. The statistical analysis followed the mixed model theory.ResultsGenetic variability of the susceptibility to pine wilt disease was observed. At 157 days after inoculation, the 15 highest genetic ranking families out of 96 were selected, having a predicted survival mean of 15.6% instead of 11.0% on average for the all 96 families.ConclusionThis study allows for the implementation of an improvement program to help control pine wilt disease.

Aim: This paper aimed to address the relationship between grapevine disease, pest occurrences and climate. The extremely large extension of viticulture worldwide offers the possibility to evaluate the impacts of climate variability on many aspects of the grape growing system. For this, we initiated a global survey to retrieve the most important diseases and pests in many grape growing regions worldwide and to identify the risk of exposure to pests and diseases of viticulture as a function of climate.Methods and results: Based on the answer of respondent about the main reported diseases/pests in their region, a severity index was calculated. Each region was geolocalised and data were compared to the WorldClim gridded climate database to document the range of climate conditions (growing season temperature and rainfall) associated to the main diseases/pests. The potential climatic-induced changes of grapevine disease and pest geography by 2050 are assessed using agro-climate projections from the ARPEGE CNRM model, using the RCP 4.5 scenario. The preliminary results allow to determine the distribution of diseases as function of agroclimatic indicators.Conclusion: While the distribution of diseases differs according to the region of the world, the current analysis suggests that mildews remain the major phytosanitary threat in most of the regions. Powdery mildew, trunk diseases and viruses were reported in extremely diverse climatic conditions, including intermediate and wet regions. Significance and impact of the study: This paper present an original methodology to address the relationship between grapevine disease and pest occurrences and climate. Such documentation is scarce in the current literature. Further analysis is currently being performed, including additional survey answers, climate indices and supplementary data collected (spatial extension, frequency of treatments…) to better depict the challenges of grapevine phytosanitary management in a changing climate.

The first commercialization of seedlings inoculated with truffle fungi occurred in 1973. Over the last 40 years, considerable progress has been made relative to quality control for inoculated seedlings. A recently published paper by Andr,s-Alpuente and colleagues (Mycorrhiza 24:29-37, 2014) reviewed and tested the different methods of mycorrhization assessment currently used in Europe. The aim of this paper is to augment their findings by adding information to the discussion about the most important steps in seedling quality control. Additionally, the history of seedlings inoculated with truffles, procedures currently used in France for seedling control quality, and a reflection on future research aimed at increasing truffle production will be presented.

International audience; To reduce the use of pesticides, innovative studies have been developed to introduce the plant as the centre of the crop protection system. The aim of this paper is to explain how architectural traits of plants and canopies induce a more or less severe epidemic and how they may be modified in order to reduce disease development. In particular, it focuses on three key questions: i) which processes linked to epidemics can be influenced by architecture ii) how can architecture be characterized relative to these modes of action, and iii) how can these effects be explored and exploited? The roles of plant/canopy architecture on inoculum interception, on epidemic development via the microclimate and on tissue receptivity are discussed. In addition, the concepts of disease avoidance, canopy porosity and an ideotype unfavourable for disease development are described. This paper shows that many advances have already been made, but progress is still required in four main fields: microclimatology, mathematical modelling of plants, molecular genetics and ideotype conception.

Disease is one of the most complex and challenging research topics in biology. At every level of organization, from molecular interactions through the physiology of plant–pathogen interactions to population genetics and ecology, the relationship between hosts and parasites is a potent driving force for evolution by natural selection and the generation of biological diversity. Parasites exploit a huge range of features of their hosts while, in turn, plants defend themselves by recognizing the presence of parasites, disabling functions essential for pathogenicity. Disease and responses to antagonists are thus closely integrated with many other aspects of an organism’s biology. It is not surprising, therefore, that as research on pathogenicity and disease resistance has accelerated in recent years, it has become apparent that these processes involve a wide range of trade-offs with other traits. The study of fitness in plant disease is also a subject of increasing practical relevance. As early as 1963, Vanderplank raised the concern that selection for higher yield in the absence of disease may lead to evolution of lower levels of what he called horizontal resistance, which is nowadays more often called partial or quantitative resistance. Over the last 40 years or so, production of arable and horticultural crops has benefitted from protection by effective, systemic fungicides. Disease resistance in crop varieties is now increasingly seen as essential rather than desirable, as many pathogens have evolved insensitivity to important pesticides, fewer new modes of action are being developed and public opinion favours greater restrictions on applications of pesticides to crops. The agricultural and horticultural industries now face the challenge of producing varieties which combine resistance with many other essential characteristics such as quality, yield and a wide range of agronomic properties. Plant breeders in particular must maintain and improve resistance to ever-changing populations of parasites without incurring significant costs in terms of other crucial traits. This supplement on ‘Fitness Costs and Trade-offs in Plant Disease’ brings together fundamental biology with applications to disease control. Some of the costs and trade-offs described here have a long history in the plant pathology literature while others are newly discovered ways in which disease and defence are integrated with other biological processes. The papers span the range from molecular evolution of hosts and parasites to the large-scale evolution of populations. In between, they report the diverse and often surprising ways in which costs of pathogenicity and defence affect parasites, their hosts and the interactions between them. They cover fungal, bacterial and viral diseases; crops and model plant species; fundamental research and applications to the plant breeding and agrochemical industries; and a wide range of disciplines including molecular biology, physiology, genetics and ecology. It will be evident that research on the costs and trade-offs involved in disease touches on very many other areas of plant and pathogen biology. It is fitting, although it was unintentional, that this supplement appears on the fiftieth anniversary of Vanderplank’s (1963) seminal work, which has done so much to stimulate both research on fitness costs and consideration of the relevance to crop production. Whilst there are inevitably some notable omissions, this supplement has brought together, for the first time, papers covering a wide range of topics in this area which, it is hoped, will stimulate advances in research by plant pathologists and others.

Developing and implementing alternatives to the ‘pesticide only’ approach requires improvements in current pest control methods (using Decision Support Systems, longer rotations, more robust cultivars, mixed crops, crop management...), but also the generation of new knowledge that can be put to use in integrated and innovative crop production systems. Innovative studies are now needed that place the plant at the centre of the crop protection system; and, to do so, analyse how plant architectural traits can be used to limit or suppress disease epidemics. This topic is not new: it was indeed an important field of research before the advent of the ‘pesticide only’ approach that has dominated the practise of plant protection since the 1970s. Today there is a renewed impetus, firstly because of the societal pressure to develop environmentally friendlier pest control strategies, but also thanks to the advances in experimental and modelling activities which now allow truly interdisciplinary work when tackling complex systems. This volume puts together the main keynote papers delivered to the conference “Plant and Canopy Architecture Impact on Disease Epidemiology and Pest Development”, held in Rennes, France, in July 2012. The papers illustrate disciplinary complementarities, by including contributions from plant pathologists, disease epidemiologists, entomologists, agronomists, plant and crop physiologists, bioclimatologists, plant geneticists and appliedmathematicians.Many papers are co-authored by specialists from different disciplinary origins, highlighting the integrative efforts that need to be made to tackle a problem that may appear at first to be relevant only to plant pathologists. Why is such an interdisciplinary research strategy actually required? Simply, because the question at Eur J Plant Pathol (2013) 135:453–454 DOI 10.1007/s10658-012-0112-4

N° ISBN - 978-2-7380-1284-5; International audience; This paper uses the capability approach to analyse the impact of urban and peri urban horticulture on development in Africa. Is horticulture, considered as an innovation, able to improve the capabilities of people? This paper states that it is not the practice of horticulture which increases the capabilities of farmers but the level of capabilities that increases the chances of adopting horticulture. In order to answer the above question we have attempted to understand the context in which the agricultural sector and the farmers evolve in Africa, characterized by the urban transition towards a majority of urban population and the rise of nonfarm incomes. It appeared important to understand the underlying prerequisites for horticultural practices, that is, expensive agrochemical inputs and credit requirements.

Aims: This paper presents a study of spatial and temporal variations in solar radiation for the Bordeaux winegrowing region, over a 20 year period (1986-2005).Methods and results: Solar radiation data was retrieved from the HelioClim-1 database, elaborated from Meteosat satellite images, using the Heliosat-2 algorithm. Daily data was interpolated using ordinary kriging to produce horizontal solar radiation maps at a 500 m resolution. Then using a digital elevation model, 50 m resolution daily solar radiation maps with terrain integration were produced for the period 2001-2005. The long term (20 year) analysis of solar radiation at low spatial resolution (500 m) showed a west to east decreasing gradient within the Bordeaux winegrowing region. Mean August-to-September daily irradiation values, on horizontal surface, were used to classify the Bordeaux winegrowing region into three zones: low, medium, and high solar radiation areas. This initial zoning was downscaled to 50 m resolution, applying a local correction ratio, based on 2001-2005 solar radiation from the inclined surface analysis. Grapevine development and maturation potential of the different zones of appellation of origin of Bordeaux winegrowing regions are discussed in relation with this zoning.Conclusion: Solar radiation variability within the Bordeaux winegrowing region is mainly governed by terrain slopes and orientations, which induce considerable variations within the eastern part of Bordeaux vineyards. Significance and impact of study: Solar radiation has a major impact on vineyard water balance, grapevine development and berry ripening. However, irradiation data is seldom available in weather stations records. This paper highlights the need for high resolution mapping of solar radiation that uses remote sensing and terrain effect integration for agroclimatic studies in viticulture.

Aims: Plant water status monitoring during the vineyard growth cycle constitutes a basic parameter for both harvest quality and vineyard management. Unfortunately, the plant water status measurement requires skills and heavy deviees which drastically limit the number of repetitions either in space or in time, Moreover, due to the significant spatial variability in viticulture, extrapolation of one local measurement to a larger scale, vine field or vineyard, is difficult. Therefore, the design of tools and methods to characterize and to assess the spatial variability of plant water status constitutes a big challenge. The aim of this paper is to propose an approach aJiowing the spatial variability of the plant water status to be assessed. Methods and results: This work proposes a complete literature review of previous works using different approaches toassess the vine water status. Based on this review, it.leads to a conceptual approach considering the Spatial (S) and Temporal (T) variability Of the plant water status assessment at a whole vineyard scale. This paper is divided into three sections: (i) description of plant water status reference methods based on direct measurements on the plant, (ii) plant water status assessment methods based on auxiliary information (Le. weather, soil and plant vegetative expression), and finally (iii) a proposal for combining local reference measurement and auxiliary information ta characterize the spatial variability of the vine water status at the vineyard scale, Conclusion:Taking into account restrictive assumptions, this paper points out the possibility to provide relevant spatial assessment of the vine water status, This possibility is illustrated with a simple example. Significance and impact of theresults: This work gives an answer to the significant problem of vine water status assessrnent over space. Il proposes an approach based on high spatial resolution auxiliary information ta extrapolate a measurement (PLWP or SWP) made at a given time on a reference site. This proposaI determines the different steps for further investigations aiming at proposing a spatial model of vine water status, Objectif: L'évolution de l'état hydrique de la plante au cours du cycle végétatif est un paramètre important pour la gestion du vignoble et de la qualité de la vendange. Malheureusement, cette mesure fait appel à des dispositifs spécifiques particulièrement contraignants, ce qui limite fortement le nombre de mesures réalisables. La résolution spatiale et temporelle des mesures d'état hydrique est donc généralement faible. Compte tenu de la forte variabilité spatiale observée en viticulture, l'extrapolation de quelques mesures ponctuelles à une zone plus large peut s'avérer délicate. La conception d'outils et de méthodes qui permettent de caractériser cette variabilité constitue à la fois un enjeu et un défi. L'objectif de ce travail est de proposer une approche permettant d'estimer la variabilité spatiale de l'état hydrique des plantes. Méthodes et résultats : Cette proposition s'appuie sur un état de l'art exhaustif des principes de mesures et envisage une approche de modélisation. L'article est divisé en trois parties: (i) une description des méthodes de référence, mesures directes effectuées sur la plante, (ii) une revue des méthodes d'évaluation indirecte, basées sur des informations auxiliaires (climat, sol, expression végétative) et finalement, (Hi) une proposition de combinaison des deux approches en vue de caractériser la variabilité de l'état hydrique des plantes à l'échelle du vignoble. Conclusion; Ce travail ouvre des perspectives relatives à l'utilisation de données auxiliaires à haute résolution spatiale pour estimer la variabilité spatiale de l'état hydrique des plantes. Cette perspective est illustrée à travers un exemple simple. Ce travail met également en évidence les limites et les hypothèses de base à formuler pour mettre en œuvre l'approche proposée. Signification et impact de l'étude: Ce travail propose une réponse au problème de l'estimation de l'état hydrique des plantes à l'échelle d'un domaine. Il envisage une approche basée sur l'utilisation de données à haute résolution pour extrapoler une mesure de référence (potentiel hydrique de base ou potentiel hydrique de tige) réalisée à un moment donné sur un site particulier. Cette proposition permet de mettre en évidence toutes les étapes de recherche nécessaires afin d'arriver à un véritable modèle spatial d'estimation de l'état hydrique des plantes

National audience; Our paper deals with the wise use of peat and substrates in France, from a horticultural point of view. Modern orticultural substrates have been used for many years now to grow potted plants, nursery plants in containers, bedding plants, cut flowers and vegetables. The substrate market is considerable at this time, at both the professional and home gardening level. Peat and peat mixtures represent the biggest part of substrates. However, France is not self-sufficient in terms of horticultural peat production. As a result, different products exist as an alternative to peat: composted bark, coir and wood fibres, green waste, expanded materials, mineral wool, etc. This paper discusses some major strategies concerning substrates, taking current trends in citizens' needs in modern society into account, including the social demand for an ecological approach towards a more environmentally-friendly agriculture, combined with effective technical and economic performance. Peat and peatland preservation as well as the contribution of horticulture to the ecological re-use of solid waste must be dealt with within the framework of horticultural substrates.

International audience; Peri-urban agriculture is still the subject of intense debate as regards its viability, its efficiency in urban food supply relative to rural production, and the rationale for the state to protect it from urban development. The paper investigates the role of urban horticulture in the supply of African and Asian cities and the importance of maintaining proximity between farmers and consumers of vegetables. It draws on insights of spatial economics as regards physical proximity and institutional economics as regards relational proximity. It is based on market surveys in various cities of Africa and South-East Asia, especially on the origin of food products, and the relationships between buyers and purchasers. The results show the importance of urban agriculture in the overall supply of the most perishable vegetables, i.e., leafy vegetables, and its complementarity with rural areas for other vegetables in seasonal supply. In addition to the advantage of quickly bringing fresh perishable products, proximity has advantages in terms of short marketing chains with low marketing costs. In some situations, it also helps in building confidence between farmers and consumers, in particular as regards vegetable safety. Finally it contributes to food sovereignty. The paper concludes by arguing why it is legitimate for the public sector to support a non-polluting multifunctional urban agriculture.