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In a previous study, we showed that access to willow fodder decreased somatic cell counts (SCC) in the milk of local Mamber goats grazing in brushland at the end of lactation. To test whether the consumption of willow affects the cells of the immune system, Alpine crossbred dairy goats grazing in the same environment were either offered free access to freshly cut willow fodder (W, n = 24) or not (C, n = 24) for 2 weeks. The willow fodder contained 7.5 g/kg DM of salicin. The other major secondary compounds were catechin, myricitrin, hyperin and chlorogenic acid (2.2, 2.6, 1.0 and 0.75 g/kg DM, respectively). Udder health status was determined before the experiment, and each of the two groups included five (W) or six (C) goats defined as infected, as established by microbial cfu in milk, and 19 (W) or 18 (C) non-infected goats. Goats ingested, on average, 600 g of DM from willow (25% of food intake), resulting in minor changes in dietary quality compared to the controls, as established by faecal near-IR spectrometry. Throughout the 2 weeks of experiment, differences between groups in dietary CP contents were minor and affected neither by infection nor by access to willow; the dietary percentage of neutral detergent fibre (NDF) decreased in C and increased in W; dietary acid detergent fibre (ADF) increased; and the dietary tannin contents decreased for both treatments. However, milking performance and milk quality attributes in both W and C goats were similar. Initial SCC and milk neutrophil (cluster of differentiation (CD)18+ and porcine granulocyte (PG)68) cell counts were higher in infected than in non-infected goats; counts decreased significantly in W but not in C uninfected goats. The percentage of CD8+ T-cells increased in all C goats, while in the W group, a significant increase was found only for infected goats. The consumption of willow mitigated an increase in CD8+ in blood and triggered an increase in CD8+ in milk, suggesting an immune-regulatory effect independent of udder status. To our knowledge, this is the first report of a direct nutraceutical effect of fodder ingestion on the immune status of goats.

Willows (Salix), which are found worldwide, have secondary metabolites that are valuable as dietary supplements for animal feed. The objectives of the current study were to test the effects of irrigation source on the production of secondary metabolites and their potential to inhibit nematode exsheathment. Three willow ecotypes (Kishon, Meah Shearim, and Golan) were irrigated with Fresh Tap Water (FW) or Treated Wastewater (TWW). TWW irrigation resulted in a doubling of biomass production compared with FW, probably due to the presence of more nutrients, particularly nitrogen. The type of irrigation water (TWW vs. FW) did not affect the quantity and quality of secondary metabolites, such as phenols, in all three willow ecotypes, although there was a difference in the chemical profile of glycoside phenols between willow ecotypes. Biomass and secondary metabolite production differed greatly between ecotypes, which was evident in the differing concentrations of phenols and flavonoids. These varying concentrations in turned affected the inhibition of the exsheathment of larval L3 nematodes. The ethanol extract of the Kishon ecotype consistently resulted in more than 90% exsheathment inhibition when tested on the L3 larval stage, whereas extracts from Meah Shearim and Golan resulted in lesser inhibition. A sub-fraction of the ethyl acetate fraction obtained from Kishon had maximum activity with more than 90% exsheathment inhibition.

Juvenile and vegetative adult shoot apical meristems (SAM) are actively involved in acquisition of flowering competence, while the embryonic SAM is regarded as &ldquo, responsible&rdquo, only for germination. Comparative analyses of imbibed and stratified seeds of garlic Allium sativum show that only stratified seedlings produced bulbs and flower stems at the end of the season. Since the seed morphology of stratified and non-stratified seeds prior to sowing was similar, the differences are attributed to the molecular alterations in the embryonic SAM. Functional annotation analysis of 3000 differentially expressed genes suggests that seed imbibition reactivates the embryonic cell cycle, initiates the metabolism, and primes garlic seed germination. Stratification enhances DNA modifications, biosynthesis, cellular transport, and tissue development. Similar to vernalization of the vegetative buds, stratification of the embryonic SAM resulted in altered expression of meristem-identity and flowering homologs. Phase transitions from seed germination to flowering and bulbing in A. sativum are tightly connected, and possibly associated with downregulation of specific flowering repressor(s). The embryonic SAM plays an important role not only in seed germination, but in the entire plant life cycle, providing the foundation for the genetic regulation of major functional shifts in metabolism and development.

This research aimed at providing a first evaluation of willow tree (Salix acmophylla) irrigated by secondarily-treated wastewater as a fodder for goats. The nutrient and mineral contents in stems and leaves of two willow types (termed “red” and “white” for their bark color) and the concentration of secondary compounds were established. The adaptation of naive goats to willow forage and its effect on the milk composition of late lactating goats were also studied. Willow fodder was composed of 45% leaves and 55% stems, on a DM basis; the weighted content of CP, ME, NDF, Ca, and P were (on a DM basis): 13.6%, 1.8 Mcal, 44.9%, 1.1%, and 0.2%, respectively. Lead, nickel and cadmium were found below the detection threshold in willow fodder and the concentrations of metals did not exceed the recommended ranges in feed. Intake was higher for red than for white willow fodder. The adaptation rate to white willow was low (27 g/d) but steady and intake was similar to that of clover hay after one week. White willow contained 1.2-fold more salicin (P

Willow (Salix spp.) is grown for energy biomass in temperate regions and is also a promising source of feed for ruminants. Willow fodder contains high concentrations of beneficial plant specialized metabolites (PSMs). We investigated the efficacy of ensiling willow fodder in 1.5 L jars without (control-C) or with silage additives (lactobacilli-LAB, molasses-M, or the combination MLAB), and the effects on nutritional attributes of ensiling willow in 60 L drums with LAB. We also assessed the effect of ensiling willow fodder on PSMs by liquid chromatography / time-of-flight / mass spectrometry (LC-TOF-MS). Exact or tentative compound identification was established, depending on availability of appropriate standards. In jars, LAB-supplemented silages reached lowest pH (4.2). M-supplemented silages had lower aNDF and aADF contents. IVDMD was higher in M than in C, and the contents of crude protein (CP) were not affected by silage treatments. Ensiling in drums did not affect the major nutritional components of willow fodder. Even though phenylalanine, arginine, tyrosine, histidine, and methionine, but not tryptophan, were increased 3.8–7.9-fold by ensiling, the finding is of low importance, as free amino acids are totally degraded in the rumen. In contrast, the main PSM, i.e., the salicinoid salicin was 74 % de-glycosylated, concomitantly with a ten-fold increase in salicylic acid concentration and with the appearance of acetyl-salicylic acid; likewise, the flavonoids hyperin and rutin were 66 % de-glycosylated, consequent with a 48-fold increase in quercetin concentration. As the bio-availability of the quercetin aglycone is inferior to that of its glycosylated counterparts, ensiling might affect the nutraceutical value of willow fodder. Likewise, catechin, gallocatechin and epicatechin were totally metabolized by ensiling. Overall, ensiling willow fodder (with LAB) does not affect the nutritional attributes of willow fodder but it greatly alters its PSM concentrations and, possibly impairs its nutraceutical value. However, as anti-oxidative activity is supposed to increase, following de-glycosylation, further research is needed to evaluate a possible trade-off on nutraceutical value between the glycosylated and aglycone forms of phenolics contained in willow fodder.

Establishment of seedlings of economic crops is often reduced if there is not a steady supply of water. Essential oils (EO) from plants are increasingly used instead of synthetic chemicals to protect plant and animal products against biotic and abiotic stresses. We investigated priming radish seeds by soaking or by matriconditioning with synthetic or natural compounds as a means of inducing resistance to drought stress, thus maintaining crop yield. Priming radish seeds for two hours in solutions of essential oils (EO) thymol and carvacrol derived from Origanum syriacum, with “oregano natural product” (ONP; a solution of the residue remaining after EO extraction), or with the gibberellin synthesis inhibitor trinexapac ethyl (TE), was much more effective in inducing drought resistance than was matriconditioning with the same compounds in sawdust for two days. The latter treatment induced considerable fungal and bacterial infection in treated seeds if the substrate-matrix was not heat-treated beforehand. The increase in specific leaf area in plants from treated seeds was mostly consistent with an increase in leaf water content. Seed treatments with EO, ONP, and especially TE led to a three-fold increase in radish seedling survival compared with water-treated controls, when 21 day-old seedlings were irrigated after 6 days of drought. Under drought conditions, seedlings from treated seeds had a 2–3-fold increase in relative water content increased 2–3-fold, while membrane permeability decreased 20–50-fold as a result of the treatments. However, the physical benefits of the treatments often did not correlate with treatment-induced increases in physiological parameters such as pigments (chlorophyll, carotenoid, anthocyanin), pigment ratios (chlorophyll a/b, carotenoid/chlorophyll), or antioxidant activity. Seed treatments with biostimulants can be as effective as treatments with synthetic compounds in inducing drought resistance in seedlings.

The yield (kg ha −1 ) and quality (weight, total soluble solids (TSS%), TSS:acid ratio, antioxidative activity in juice and peel) of “Sweetie” ( Citrus maxima × C. paradisi , also known as oroblanco) fruit grown on the non-traditional ‘Poorman’s Orange’ rootstock were similar to and often better than that of “Sweetie” grown on the commercial standard sour orange rootstock, which is susceptible to tristeza. Yield and quality of fruit grown on ‘Swingle’ citrumelo rootstock were inferior to that of sour orange. Fruit grown on ‘Marsh’ grapefruit as a rootstock were of similar or slightly lesser quality than ‘Poorman’. “Sweetie” fruit grown organically were higher in TSS% and titratable acidity than those grown in a conventionally-managed grove, but with a significant decrease in yield, regardless of rootstock.

Seed priming has been used to achieve enhanced and uniform emergence of many horticultural crops. Controlled seed rehydration induced by priming triggers metabolic processes associated with early stages of germination. Compounds employed in priming can be large and charged, such as hormones or acidic molecules, or small and neutral osmolytes such as sugars and polyols. Priming with water, osmolytes such as proline or mannitol, hormones such as gibberellin or brassinosteroids, or biological solutions such as salicylic acid or essential oils can enhance seedling or mature-plant tolerance to abiotic stresses. The treatment effectiveness may depend on methodology, crop, and/or seed structure. Beneficial effects of priming for abiotic stress tolerance are often associated with enhanced antioxidant activity in the seedling, as expressed by increased enzyme activity and/or concentrations of protective compounds. Although the beneficial effects of seed priming can be significant, they are not observed consistently. This may be related to the duration of the protective action of priming. Protection afforded by priming is often more effective if stress is present at the time of sowing, germination, or emergence. Delaying sowing after priming can result in impaired germination, while protective effects of the treatment do not always persist with plant maturation. Future research on seed priming for abiotic stress resistance should emphasize development of treatments that are effective even after treated seeds are stored, persist during most or all of plant maturation, and behave similarly in different cultivars of the same crop and ideally in a range of crops.

Citron (Citrus medica, L.) fruits (“etrog” in Hebrew; plural “etrogim”) are used ritually in the Jewish holiday of Sukkot (Tabernacles), and can command as much as US$100/fruit, depending on quality. The etrog is unique among citrus fruits in that only the external attributes are of commercial importance. Maintaining physical fruit quality mandates the use of protective cushioning on the tree, at harvest, and in packaging. Growers use a wide range of chemical treatments post-harvest to reduce to a minimum the possibility of disfiguring insect or disease infestations. Most etrog varieties are highly susceptible to chilling injury if stored at less than 12°C. Etrogim lose water readily during storage, so fruit are stored and almost always marketed in plastic bags that limit water loss. Skin color is regulated with applications of ethylene or gibberellin, depending on whether specific markets prefer fruit that are greener or more yellow.

We investigated the morphological and physiological bases of drought tolerance in rocket (Eruca sativa) and lettuce (Lactuca sativa) seedlings as induced by pre-exposure to different ratios of red (R) and blue (B) LED light. Seedlings were grown for 17–18 days under white (control), 100R:0B, 75R:25B, 50R:50B, 25R:75B, or 0R:100B LED lighting at 156 μmol/m2/s. All seedlings were moved under white fluorescent lights 17–18 days after sowing. Half the seedlings were then droughted for 7 days, followed by re-irrigation for 7 days, while the other seedlings remained fully irrigated. Exposure to combined red and blue wavelengths promoted morphological development (leaf area, number of open leaves, leaf specific weight), as well as pigment (chlorophyll, carotenoids) and secondary metabolite (flavonoid) biosynthesis in both species. Morphological and physiological characteristics were more enhanced by monochromatic red or blue light exposure in lettuce than in rocket. Rocket grown under combined R:B lighting, and lettuce grown under 100 % red or blue LED light suffered most from drought (in the form of lower relative water content (RWC) and increased membrane leakage), despite increased ABA concentrations and antioxidant activity at mid-drought. In lettuce, but not in rocket, there was a positive residual effect of LED pre-treatment on fresh weight of droughted and re-irrigated plants. Increased concentrations of antioxidant metabolites did not correlate with tolerance to drought. All combined R:B light treatments increased stomatal density in both rocket and lettuce. All LED regimes which resulted in increased stomatal aperture area per unit leaf area (AALA) (μm2 aperture/cm2 leaf) resulted in decreased RWC at the end of drought. Stomatal AALA was negatively correlated with end-drought RWC (r = -0.89, p = 0.02) in rocket, but not in lettuce. The relationship between stomatal development and antioxidant activity on drought tolerance appears to be species-specific. The benefits provided to two leafy green species when grown under LED lights must be balanced against the resulting vulnerability to drought.

Nutrition, especially wheat consumption, is a major factor involved in the onset of type 1 diabetes (T1D) and other autoimmune diseases such as celiac. While modern wheat cultivars possess similar gliadin proteins associated with the onset of celiac disease and T1D, alternative dietary wheat sources from Israeli landraces and native ancestral species may be lacking the epitopes linked with T1D, potentially reducing the incidence of T1D. The Non-Obese Diabetic (NOD) mouse model was used to monitor the effects of dietary wheat sources on the onset and development of T1D. The effects of modern wheat flour were compared with those from either T. aestivum, T. turgidum spp. dicoccoides, or T. turgidum spp. dicoccum landraces or a non-wheat diet. Animals which received wheat from local landraces or ancestral species such as emmer displayed a lower incidence of T1D and related complications compared to animals fed a modern wheat variety. This study is the first report of the diabetogenic properties of various dietary wheat sources and suggests that alternative dietary wheat sources may lack T1D linked epitopes, thus reducing the incidence of T1D.

The leaves, inflorescences, and fruit bunches of date palm trees develop at the crown, which is the apex of a single trunk that can be up to 25 m tall. Because palm trees are monocots, the leaves and inflorescences are generated deep within the trunk from a single meristem—the palm heart—and are inaccessible for direct bioregulator treatments. We followed the effects of two growth regulators, paclobutrazol and uniconazole-P, on the vegetative growth of young date palm seedlings. Both growth regulators constrained the elongation rate of the leaves and reduced the leaf length. Microscopic analysis of dissected palm hearts revealed that the growth retardants did not affect the generation of new leaves. However, the treatments did change the dimensions of the developing embryonic leaves as well as the shape of the apical meristem. The results suggest the possible future use of growth retardants to reduce trunk height, enabling cheaper, safer, and more efficient management of date palm trees.

Treatment of plants with abscisic acid (ABA) can enhance resistance to environmental stresses in general and to preharvest sprouting in particular. Inhibitors of gibberellin (GA) synthesis have been reported to enhance the metabolic activity or effectiveness of ABA. Wheat seeds(Triticum aestivum L., cv. Bet Hashita) were soaked for 2 h in100 μm ABA, in 1250 ppm trinexapac-ethyl (TE, anacylcyclohexanedione-based GA synthesis inhibitor), or in a combination of the two. After drying, seeds were imbibed 24 h in water and the protein in heat-stable extracts from embryos was examined. Treatment with ABA alone increased expression of dehydrin and of a 37 kDa protein. Treatment with TE more than doubled protein concentration in the embryo and enhanced expression of dehydrin and of proteins weighing 37, 20, and15 kDa. Combined treatments of TE and ABA led to enhanced expression of dehydrin and of a 15 kDa protein.

Dear Editor, We read with interest the article by Gorelick et al. [1], who assayed the diabetogenic potential of two ancestral wheat landraces (Triticum turgidum ssp. dicoccoides and spp. dicoccum), compared to a modern wheat cultivar (T. aestivum) in NOD mice. [...].

The citron (Citrus medica L.) is one of the three primordial citrus fruit (the others being pummelo and mandarine) from which most other citrus originated. It is an evergreen tree, ranging in height from 3 to 5 m, with fruit borne on thorny branches in 2–3 waves during the year. The tree is relatively short-lived (up to 15–18 years) and is sensitive to many insects and soil diseases, as well as to high and low temperatures. Fruit range in size from 200 to 800 g, although they can grow much larger. Fruit attain their size while the peel is still green, and then ripen to yellow or even orange. Although raw citron peel and extracts are highly regarded in Asia for their many medicinal uses (ranging from Alzheimer’s to cancer to diabetes to ulcers to intestinal parasites) and as an insect repellent, the majority of fruit grown in the Mediterranean Basin are used for Jewish ritual during the autumn harvest festival of Sukkot (Tabernacles). Specific varieties of etrog (pl. etrogim), as such citrons are called, are grown under meticulous conditions of orchard care, harvest, and postharvest handling so that only fruit of the highest quality reach the religious market. Other uses for citrons in the Mediterranean region are as an ingredient in perfumes, as sweetened and/or brined peel for confectionery and baking, and as flavoring for candy and alcoholic beverages.

Wheat (Triticum aestivum L.) varieties with the dwarfing Rht (reduced height) alleles have reduced sensitivity to endogenous or exogenous gibberellin (GA). The Rht isolines are also less sensitive to the effects of chlormequat and other compounds which cause dwarfing by depressing GA synthesis. Abscisic add (ABA) inhibits cereal seed germination and is in dynamic tension with GA, which enhances germination. Tetcyclacis is a cytochrome P450 mono-oxygenase inhibitor of GA synthesis. It also inhibits ABA hydroxylase, thus extending ABA activity. In preliminary experiments, wheat varieties differing in Rht complement responded differently to ABA and/or tetcyclacis. We therefore investigated the effect of seed applications of ABA (100 μM), with or without tetcyclacis (25 μM), on germination and initial growth of Rht wheat isolines Rht-B1b, Rht-B1a (dwarf); Rht-B1b,Rht-D1b (dwarf); Rht-B1b + Rht-D1b (double-dwarf); and Rht-B1a, Rht-D1a (tall) to determine a possible genetic basis for the observed varietal differences. Treating seeds with ABA, tetcyclacis, or both, delayed emergence by 1, 1.8, or 3.7 d, respectively, compared with controls. ABA had little or no effect on final emergence, shoot height, or fresh weight, but led to a slight reduction in dry weight of Rht-D1b and Rht-B1b+D1b. Tetcyclacis reduced growth rate (mm/ d), shoot height, fresh weight, and percentage dry weight in proportion to Rht dosage, as is typical of GA synthesis inhibitors. Synergistic effects of ABA and tetcyclacis were not detected for any parameter measured, except for rate of emergence. ABA did not exert a profound effect on seedling germination or initial growth of the Rht wheat isolines examined in this study.

'Golden Delicious' apples were held at 38C for 0 or 4 days and treated with 0 or 0.14 mol L -1 CaCl 2 2 H 2 O, stored at 0C for six months, and then held at 20C for 7 days. Texture and quality were measured by nondestructive sonic vibration, Magness-Taylor (MT) puncture and axial compression of tissue specimens using a force/deformation testing instrument, and sensory evaluation by untrained panelists. Prestorage treatment with heat, calcium, or the combination significantly improved the poststorage firmness over that of untreated control fruit. MT firmness values and crispness scores were higher for heat-treated apples than for controls, but the Ca and combination treatments resulted in significantly higher values. Calcium infiltration significantly increased sensory hardness and overall acceptability scores, as well as the location of the maximum force in compression, regardless of heat treatment. Apples exposed to heat before storage were sweeter than those not heated. Only the controls were scored in the unacceptable range for crispness and overall acceptability. Crispness mean scores could be predicted by the destructive puncture and compression tests (r 2 = 0.93) and to a moderate level by the nondestructive sonic vibration test (r2 = 0.72). None of the instrument measurements adequately predicted acceptability scores. Although calcium infiltration resulted in the best poststorage quality, prestorage heat treatments may provide a practical, economical means of improving poststorage quality of apples.

Cuttings of both `Rehovot' and `Tzfat' land-races of myrtle, when sampled throughout the year, had a significant temporal variation in the percentage of successful rooting. The rooting percentage of cuttings taken during December–February reached 70%, while only 20% of the cuttings taken during May–August successfully rooted. The `Rehovot' type was sensitive to aeration in the rooting medium, while the `Tzfat' type rooted equally well in all media. Treating cuttings with 2,6-dihydroxy-acetophenone before dipping in rooting hormone (IBA) did not enhance rooting of `Rehovot', but increased rooting in `Tzfat' myrtle by an average of 6%.

The viability of Penicillium expansum Link conidia in sporulating culture declined rapidly when exposed to 38 °C, and when conidia were exposed to 38 °C prior to inoculation of apple fruits (Malus ×domestica Borkh.), the resulting lesions were smaller than those on fruit inoculated with nonheated conidia. `Gala' apples were heated after harvest (38 °C for 4 days), pressure infiltrated with a 2% solution of CaCl2, or treated with the antagonist Pseudomonas syringae van Hall, alone or in combinations to reduce postharvest decay caused by Penicillium expansum. After up to 6 months in storage at 1 °C, no decay lesions developed on fruit that were heated after inoculation with P. expansum, or any combination of P. expansum, antagonist, or Ca. Parallel lots of heat-treated and nonheated fruit that were either infiltrated or not infiltrated with Ca were stored up to 6 months. They were then inoculated with P. expansum alone, or with the antagonist followed by P. expansum. Prior heat treatment did not influence lesion size. Calcium alone, the antagonist alone, and heat plus Ca all reduced the incidence of decay by ≈25%, whereas heat plus the antagonist reduced it by 70%. Calcium plus the antagonist or Ca plus the antagonist and heat reduced decay incidence by 89% and 91%, respectively. The integrated strategy of heat-treating fruit, followed by Ca infiltration and then treatment with an antagonist, may be a useful alternative to controlling postharvest decay with fungicides.

SummaryMango (Mangifera indica L. cv. Nam Dokmai) fruits chilled for 21 d at 48C were firmer than non-chilled fruits during subsequent ripening at 258C. The cell wall contents of chilled fruit contained less water-soluble pectin, more ammonium oxalate-soluble pectin and less alkali-soluble pectin than non-chilled fruits. The increase in ammonium oxalate-soluble pectin was at the expense of the alkali-soluble pectin and correlated with high pectinesterase activity in the fruit from low-temperature storage. Polygalacturonase and b-galactosidase activities were inhibited in chilled fruits. The relationships between delay in loss of firmness, and differences between activity of cell wall enzymes and pectin content of chilled and non-chilled fruits are discussed.

Mango fruits (Mangifera indica L. cv. Nam Dokmai) were held for 3 days at 38°C and then transferred to 20°C. Fruits placed directly at 25°C after harvest reached their peak ethylene production after 4 days, while the heated fruit took 9 days (6 days after the end of the heat treatment). The 1-aminocyclopropane-1-carboxylic acid (ACC) content paralleled that of ethylene production in unheated fruits, with highest content occurring on day 4. In heated fruit, ACC content continued to increase for 8 days following the heat treatment. The 1-aminocyclopropane-1-carboxylic acid synthase (ACS) activity in unheated fruit was also highest on day 4. In heated fruit the activity was undetectable following heat treatment, but recovered partially during the ripening period. Initial ethylene production from discs with peel was 6-fold higher in unheated fruit than heated, although afte r6ho fincubation the production from both was similar. Activity of 1-aminocyclopropane-carboxylic acid oxidase (ACO) in the discs also showed an 8-fold difference in initial activity in heated versus unheated discs with peel. This difference disappeared during incubation of the discs. In heated discs without peel, both ethylene and ACO activity remained lower than in discs with peel, and the differences between heated and unheated fruit discs were more pronounced. We conclude that the inhibition of ethylene production found during heat treatment is due to inhibition of both ACS and ACO. ACO recovers full activity following heat, while ACS activity recovers only partially, but enough to allow the heated fruit to achieve an ethylene peak. © 1999 Elsevier Science B.V. All rights reserved.

Postharvest heat treatments have been proposed as non-chemical means for enhancing storage of fruits and vegetables. Various regimes of time and temperature in either hot air or hot water maintain fruit firmness and diminish the incidence and severity of pathological diseases. Treatment with calcium, alone or in combination with heat, has similar beneficial effects. Little attention has been paid to the organoleptic effect of these treatments, upon which consumer acceptability ultimately rests. We heated (38°C, 3 d) mature-green or pink tomatoes (Lycopersicon esculentum, L., cv. 'Daniella') and measured overall consumer preference after the fruit were stored at 12°C for 10 d. Heated and non-heated fruit were rated similarly for acceptability by a taste panel, with no off-flavours being detected. Apples (Malus domestica, Borkh., cv. 'Golden Delicious') were infiltrated with 2% calcium chloride, or heated (38°C, 4 d), or heated and then infiltrated prior to 6 months' storage in air at 0°C. A range of flavour and texture attributes were then rated by tastes panellists. Heated and/or calcium-treated fruit were perceived as crisper, sweeter, and overall more acceptable than untreated fruit. We conclude that, in addition to conferring physiological benefits on stored tomatoes and apples, heat and calcium treatments do not damage and may even improve consumer acceptability.

The efficacy of a prestorage dry heat treatment and a hot water dip was investigated for reducing storage rots on bell peppers and tomatoes. The best results were obtained with hot air at 38°C for 48 to 72 h or hot water at 50 to 53°C for 2 to 3 min. Under these conditions in vitro germination and growth of Alternaria alternata and Botrytis cinerea were weakened or prevented. The effect of the heat treatment in vivo was more pronounced, and fungal development was prevented on inoculated fruits. Following the heat treatment the produce could be stored at low temperature without developing chilling injury. The dry heat treatment was also effective in preventing the development of insect pests such as Ceratitis capitata Weidmann (medfly). This is the first report of a single heat treatment being able to control fungal and insect pests and beneficially affect fruit physiology.

Postharvest heat treatments were applied to three apple (Malus domestica Borkh.) cultivars: `Anna', `Golden Delicious', and `Jonathan'. The temperatures ranged from 38 to 50 °C and from 5 to 96 hours. The temperatures of 50 °C for 5 or 10 hours and 46 °C for 10 hours controlled all developmental stages of San Jose scale on `Golden Delicious' and `Jonathan' fruit. Blue mold germination was prevented by 46, 42, and 38 °C after 28, 34, and 42 hours, respectively. The time needed to control the fungus was longer than that required to kill the insect. Apples were damaged by a 50 °C treatment but could withstand at least 12 hours at 46 °C and at least 24 hours at 42 °C. At 38 °C no damage was found on preclimacteric apples even after 96 hours, but if postclimacteric fruit were heated at 38 °C heat damage occurred. The treatments that did not cause damage maintained the fruit firmness during post storage ripening. The results are discussed in the context of developing integrated postharvest heat treatments.

Summary The relationship between softening, pectic substances, polygalacturonase (EC 3.2.1.15), pectinesterase (EC 3.1.1.11) and β-galactosidase (EC 3.2.1.23) during ripening of heated and non-heated mango (Mangifira indica L.) fruits cv. Nam Dokmai was investigated. Fruit softening was accompanied by a progressive increase in water-soluble and ammonium oxalate-soluble pectin and a progressive decrease in alkali-soluble pectin. Polygalacturonase and β-galactosidase activities increased while pectinesterase activity decreased continuously during softening. Heating fruits for 3 days at 38 °C resulted in an increase in softening, ammonium oxalate-soluble pectin and activity of β-galactosidase, and a decrease in alkali-soluble pectin and activities of polygalacturonase and pectinesterase, while heating had no pronounced effect on water-soluble pectin. Softening of ripening mango fruits was more closely related to changes in β-galactosidase activity than to polygalacturonase and pectinesterase activities. The possibility that softening of Nam Dokmai fruits is affected by mechanisms other than involvement of only polyglacturonase and solubilization of the polygalacturonide backbone of the pectin is discussed.

Sodium bicarbonate (SBC) inhibited in vitro mycelial growth of A. alternata, Fusarium spp. and R. stolonifer. SBC action was fungistatic rather than fungicidal. Coating commercially harvested ‘Galia’ and ‘Ein-Dor’ melons with wax containing 2% SBC reduced decay incidence after storage and shelf life simulation by four to seven-fold, to a commercially acceptable level of 6–7%, compared to untreated or waxed-treated controls. This treatment also maintained the fresh and blemish-free appearance of the fruit at harvest. Higher concentrations of SBC (3%) were phytotoxic and significantly reduced general fruit appearance. A trial shipment by sea transport to Europe demonstrated that 2% SBC incorporated into a wax coating maintained the marketability of ‘Galia’ melon fruits compared to that of untreated fruit. SBC can be an alternative biocide to the fungicide imazalil, thus eliminating unwanted residues on melon fruits.

`Golden Delicious' apples (Malus domestica Borkh.) were treated after harvest with heat (air at 38 °C for 4 days or 42 °C for 1 day) or 2% CaCl2 (w/v; applied as a dip or pressure-infiltrated) or a combination of the two and stored at 0 °C for ≤6 months. Decay caused by Botrytis cinerea Pers.:Fr. after inoculation to a depth of 2 mm with a conidial suspension virtually was eliminated in stored fruit heated at 38 °C, regardless of Ca treatment. Apples punctured to a depth of 0.5 mm (but not 2 mm) and inoculated with B. cinerea on removal from storage were almost completely protected from poststorage decay if they had previously been pressure-infiltrated with 2% CaCl2, regardless of the heat regime. Heating fruit at 42 °C and dipping in 2% CaCl2 were only partially effective in preventing decay from either pre- or poststorage inoculations. Fruit firmness was not related to resistance to decay.

Golden Delicious apples (Malus domestica Borkh) were heated for 4 days at 38 °C and then dipped in 2% CaCl2, or dipped in the solution without prior heating. Scanning electron micrographs of the fruit wax layer after three days of 0 °C storage showed that the heated apples had areas of amorphous wax and fewer surface cracks than unheated apples. There was less wax on the surface of heated than on unheated apples. Electron density scan of apple wax showed more calcium in outer than inner wax area of undipped but heated apples, while the opposite obtained in unheated apples. Dips in calcium raised the wax calcium level of the unheated apples more than the heated ones. Plasma emission spectrometry of calcium in apple peel and flesh after 5 months storage at 0 °C showed greater penetration of calcium from the dips into unheated apples, compared to heated apples. It is suggested that during the heat treatment the wax softens and fills in cracks while water loss pulls calcium towards the fruit surface. This continuous wax layer on heated fruit decreases the ability of external calcium to move into the apple.

Penicillium expansum is one of the main postharvest pathogens of apples in Israel. Heating apple fruit inoculated with P. expansum for 96 h at 38°C completely inhibited decay development. Fruit held for 24 h at 42°C or 12 h at 46°C had significantly reduced decay after an additional 14 days incubation at 20°C, compared with unheated inoculated control fruit. Mycelial growth and percentage spore germination in vitro were inversely proportional to length of time of exposure to various temperatures. The ET50 for spore germination was 42, 34 and 20 h at 38, 42 and 46°C, respectively, while the ET50 for mycelial growth was 48, 44 and 36 h at those temperatures. When Penicillium spores were incubated on crude extract prepared from the peel of apple fruits held 4 days at 38°C, germ tube elongation was significantly reduced, while the walls of the tubes were thicker, compared with germ tubes from spores incubated on crude extract prepared from peel of non-heated fruit. The evidence presented here supports the hypothesis that the effect of heating on the decay of apples caused by P. expansum is not only the result of direct inhibition of fungal germination and growth by high temperature, but is also partly due to the formation of an inhibitory substance in the heated peel.

SummarySeeds of wheat (Triticum aestivum L.) were coated with a range of vegetable oils before sowing, in an effort to provide a hydrophobic coating that would only dissolve or wash away in the presence of sufficient water to maintain continued seedling growth. Germination of oil-treated seeds was reduced by 20–50% and time to 50% emergence was increased by two to five days. Treating pesticide-coated seeds with vegetable oil further decreased germination and extended time to emergence. Oil treatment did not decrease water uptake or affect seed respiration. Degree of saturation and linoleic acid:oleic acid ratio were not correlated with the effects of the various oils. The decreased germination and delayed emergence associated with the oil treatment were probably due to physiological rather than physical factors.

Pectin methylesterase activity and the degree of methyl esterification of cell wall pectins were measured in Golden Delicious apples after a 4 day heat treatment at 38° and after subsequent storage at 0° of heated and unheated apples. Enzyme activity increased similarly during storage in both heated and unheated apples, although heated fruit softened much less than unheated. During storage, the degree of esterification decreased in both heated and unheated apples in water- and CDTA-soluble pectin, but not in insoluble pectin. In a comparison of three methods of determining methyl groups, similar values were obtained for degree of bulk esterification of apple cell walls, regardless of treatment. Results presented do not confirm a role for pectin methylesterase or for de-esterification in apple fruit softening.

Sanosil-25 is a universally applicable disinfectant compound that is highly effective against pathogenic bacteria, fungi, algae, viruses and amoebae. The compound contains 48% hydrogen peroxide (H 2 O 2 ) and 0.05% silver ion (Ag + ) as a stabilizing agent. The ED 50 for spore inhibition in vitro was 0.09% and 0.18% for Botrytis cinerea and Alternaria alternata , respectively. Germination was completely inhibited at concentrations of 0.5% and 0.7% for B. cinerea and A. alternata , respectively. The ED 50 values for mycelial growth inhibition were 0.6% and 0.7% for B. cinerea and A. alternata , respectively, but for complete inhibition the effective concentrations were 1.5% and 2.0%. The effective exposure time of fungal spores was inversely related to the concentration used. Dipping commercially harvested eggplants and sweet red peppers in 0.5% Sanosil-25 reduced decay development after storage and shelf-life to a commercially acceptable level compared with an untreated control.

Prestorage heating (38° for four days) of apples (Malus domestica, cv Golden Delicious) leads to enhanced retention of fruit firmness during stor

Mature green tomatoes (Lycopersicon esculentum) were held at 38°C for 3 days and then placed at 12°C for 2 weeks or 2°C for 3 weeks, before being removed to 20°C for 5 days. During the heat treatment, ethylene production, lycopene synthesis, chlorophyll and cell wall degradation were all inhibited, while respiration was enhanced. The tomatoes held at 12°C ripened during storage and the heat-treated tomatoes ripened faster. At the end of storage and shelf-life the heated tomatoes were redder and had higher soluble solids content than control tomatoes. The tomatoes held at 2°C did not ripen during storage. After removal to 20°C, control tomatoes developed chilling injury, while heated tomatoes ripened normally. Prestorage heat treatment of mature green tomatoes permits storage for longer periods of time and at lower temperatures than currently recommended with no loss of their ability to ripen normally.

Commercial, ecological, and agrotechnical considerations have recently renewed interest in the use of physical rather than chemical means to maintain postharvest quality of horticultural crops. This review discusses prestorage heat treatments that protect against physiological disorders, enhance natural resistance to pathogen infection, reversibly inhibit fruit ripening, and permit flexibility in storage temperatures.

Apples (Malus domestica Borkh. cv. Anna) were treated at harvest by a dip in 3% CaCI2 solution, heated for 4 days at 38C, or the two treatments combined, before being placed in OC storage. After removal of the apples from storage and holding them for 1 week at 20C, the combined treatment maintained fruit quality best. The fruit remained firmer than with either treatment separately, and peel yellowing and decreased titratable acidity caused by the heat treatment were less pronounced. Heat treatment alone maintained fruit firmness, while CaCI2 alone had no effect on fruit quality, although it raised the fruit calcium level more than the combined treatment in most experiments. Altering the temperature (0, 20, or 38C) of the CaCl2 dip did not change its efficacy. There was less soluble and more insoluble pectin in cell wall extracts of apples from the combined treatment than from other treatments. In addition, proportionally less Ca was present in the water-soluble pectin fraction of the combined treatment compared to other treatments, indicating different binding properties in the cell wall.

The maximum storage life ‘Triumph’ persimmons in modified atmosphere (MA) packs of 0.08 mm low-density polyethylene was 8 weeks when packed under vacuum and 20 weeks when packed under nitrogen. The storage life could be extended to 7 months by storing ggibberellin-treated fruit in air at −1C°C prior to MA packaging. The factor which limited further extension of the storage life of the fruit under these conditions was the accumulation of ethanol and acetaldehyde, which caused development of off-flavors and tissue browning, respectively.

Mature-green tomato (Lycopersicon esculentum Mill.) fruit, when kept for 3 days at 36, 38, or 40C before being kept at 2C for 3 weeks, did not develop chilling injury, while unheated fruit placed at 2C immediately after harvest did. When removed from 2 to 20C, the heated tomatoes had lower levels of K+ leakage and a higher phospholipid content than unheated fruit. Sterol levels were similar in heated and unheated fruit while malonaldehyde concentration was higher in heated fruit at transfer to 20C. The unheated tomatoes remained green, and brown areas developed under the peel; their rate of CO2 evolution was high and decreased sharply, while ethylene evolution was low and increased at 20C. In contrast, the heat-treated tomatoes ripened normally although more slowly than freshly harvested tomatoes: color developed normally, chlorophyll disappeared, and lycopene content increased, CO2, and ethylene evolution increased to a climacteric peak and K+ leakage increased with time. During prestorage heating, heat-stress ethylene production was inhibited, protein synthesis was depressed, and heat-shock proteins accumulated. There appears to be a relationship between the “heat shock response” and the protection of tomato fruit from low-temperature injury.

Anna' and 'Granny Smith' apples (Malus domestics Borkh.) that were held at 38C for 4 days before storage at 0C not only were firmer than controls upon removal from storage, but also softened more slowly during shelf life at 17C. Skin yellowing and loss of acidity attendant upon the heat treatment were not prevented by dipping fruit in 2% CaCl2 before heating. Both heat-treated and control fruit softened at the same rate upon exposure to ethylene at 100 µl·liter -1 upon removal from storage. The insoluble pectin content of cortical tissues was higher in heat-treated fruit than in controls after 10 days at 17C, while soluble pectin levels were lower. Arabinose and xylose levels were lower in cell walls from heat-treated cortical tissue, but the treatment had no effect on loss of galactose residues during shelf life. Previous researchers have noted that heating apples at 38C for 4 to 6 days after harvest retarded or inhibited fruit softening while maintaining most other aspects of storage quality (Liu, 1978; Porritt and Lidster, 1978). The exception was a slight yellowing of the skin and a decrease in titratable acidity in comparison with unheated fruit. Calcium treatments also extend the storage life of apples, primarily by reducing the rate of metabolic activity (Bangerth et al., 1972}, thus reducing senes- cence phenomena such as fruit softening, yellowing, and loss of acidity (Ferguson; 1984; Glenn et al., 1988). Since uptake of Ca by pear cells was specifically enhanced by heating cells at 38C (Klein and Ferguson, 1987), we endeavored to determine if heating Ca-treated apples could synergistically inhibit loss of fruit firmness in storage, without associated problems of acid loss and skin yellowing. The specific objectives of this research were to increase the effectiveness of postharvest Ca dips by use of a heat treatment, while simultaneously counteracting the disadvantages of heat treatment alone (loss of acidity and yellowing). Since heat treat- ment inhibits ethylene production by apples (Klein, 1989), we investigated whether softening could be reinduced by exposing heat-treated fruit to ethylene at 100 µl·liter -1 upon removal from storage. We also studied whether the decrease in apple fruit softening after a prestorage heat treatment is due to changes in the neutral sugar and pectin composition of the cell wall in cortical tissue.

Additional index words. Malus domestics, color, firmness, acidity, soluble solids concentration, ethylene, respiration Abstract. The benefits conferred by a prestorage heat treatment on poststorage quality of apples (Malus domestics Borkh.) were measured on 'Anna', a non-storing early cultivar, and 'Granny Smith', a long-storing late cultivar. The major benefit was a decrease in rate of apple softening, both during OC storage and during simulated shelf life at 20C. Soluble solids concentration was not affected by heat treatment, but titratable acidity was reduced. Ethylene production after heat treatment and storage was similar to or higher than that of control apples, but respiration was lower. The optimum temperature and time combination for prestorage treatment of both cultivars was 4 days at 38C. High temperatures have been reported to inhibit ripening of many-fruits "(Mitchell, 1986). If held for too long above 35C, fruit will fail to ripen normally when returned to lower temper- atures. However, pears and apples have been reported to ripen normally if held at 40C for up to 6 days and then returned to 20C (Maxie et al., 1974; Liu, 1978). Liu examined ripeness indices of four cultivars of apples after 2 or 4 days at 40C and found that, compared to control, the heat treatment lowered titratable acidity, retained firmness, and had no effect on soluble solids concentration (SSC). Porritt and Lidster (1978) reported similar changes after storage of heat-treated apples. We have examined this prestorage treatment on 'Anna' apples, a non- scoring early cultivar, and 'Granny Smith,' a long-storing late cultivar. We determined how long the effects persisted in stored apples by examining their rate of ripening, ethylene production, and respiration after various durations of storage. We also de

Apples (Malus domestica Borkh.) were heated for 4 days at 38°C immediately after harvest and then placed at 20°C for 7–10 days. Protein synthesis, ethylene production and fruit softening were reversibly inhibited by the heat treatment. Fruit respiration, membrane permeability and chlorophyll degradation in the fruit peel were enhanced during the treatment. The heat-treated apples ripened normally but more slowly than untreated apple We hypothesize that heat treatment differentially affects processes which normally increase simultaneously during fruit ripening, by inhibiting those processes which require tie novo protein synthesis and enhancing those that do not.

A pre-storage heat treatment of 38°C for four days applied to apples (Malus domestica cv. ‘Granny Smith’) before standard storage in air at 0°C was found to inhibit the development of superficial scald. Apples stored for three months after heat treatment had superficial scald levels similar to those of apples dipped in diphenylamine (DPA), while all control apples had scald. This inhibitory effect was no longer apparent after five months of storage. The heat treatment inhibited the accumulation of α-farnesene and conjugated trienes in apple cuticle while DPA inhibited only a-farnesene oxidation. Heat treated apples also had lower polyphenoloxidase activity in the peel than untreated apples. This treatment may be a substitute for chemical treatments for short-term storage of scald- susceptible apple varieties.