Search

Abstract The soil conditions and the yield and quality of Rosa sp. var. Freedom were determined following the incorporation into the soil of rose waste composts, with or without fertigation; the effects of these treatments were compared with those of non-stabilised chopped rose wastes + fertigation (FWF). The growing conditions were those of a commercial greenhouse. The use of the composts, alone or combined with fertigation, increased the available P and K contents of the soil with respect to FWF. However, only the compost + fertigation treatments improved, in general, the soil fertility regarding the organic matter (OM), nitrogen and available micronutrient concentrations, in comparison to FWF. When the composts were added alone, irrigation with alkaline water increased the soil pH and, in consequence, reduced the availability of micronutrients. Overall, the combined use of compost and fertigation increased the cut rose yield and quality relative to the application of compost alone and FWF. Principal component analysis indicated that the OM, available Cu, Mn and Zn and total N contents and the pH of the soil were the principal soil parameters determining the yield and quality of the roses. This analysis classified the treatments in three groups: the compost + fertigation treatments; the treatments with compost alone; and the FWF treatment. The compost + fertigation treatments gave the highest net income (average for these treatments = 80388.92 US dollars ha−1). Therefore, the compost + fertigation treatments were highly beneficial with regard to increasing soil fertility and cut rose yield, quality and profitability. Highlights • The use of rose waste composts combined with fertigation improved soil fertility. • Compost + fertigation treatments were the most suitable for cut rose production. • The highest net incomes were achieved with the compost + fertigation treatments. [ABSTRACT FROM AUTHOR]

In Mediterranean ecosystems, post-fire forestry management practices are often used to improve forest structure and to reduce the risk of fire in coppices of resprouting species. Such practices enhance tree growth (i.e., height), probably because they release resources. On the one hand, resource release may stimulate reproduction. On the other hand, tree species that are regenerating after a fire may already face a delay in reproduction, and this delay may be lengthened if species mainly invest these additional resources in growth. Within this theoretical framework, it is poorly understood how different forest management practices affect the reproductive abilities of forest species. In this study, we analyzed the effect of two post-fire forestry treatments (selective thinning of resprouts and selective thinning of resprouts plus understory clearing) on a Mediterranean coppice dominated by the resprouter species Arbutus unedo L.; in particular, we examined how the treatments affected this species’ reproductive ability (flower and fruit production at the tree and stand level, as well as fruit characteristics). Our results show that the treatments had no effects on the number of flowers and mature fruits per individual. Meanwhile, mature fruit dry mass and seed set were greater in plots that had been both thinned and cleared than in control plots and plots that had only been thinned. This pattern was reversed for seed abortion rate: it was lower in plots that had been thinned and cleared. The dry mass of developed seeds did not differ among treatments. At the stand level, the percentage of strawberry trees that flowered, the percentage of strawberry trees that bore fruit, the dry biomass of mature fruits per hectare, and the number of developed seeds per hectare were not affected by these treatments. Other studies have shown that these two forest management practices can improve the vertical and horizontal structure of A. unedo coppices that are regenerating post fire; this study demonstrates that selective thinning does not modify the species’ reproductive success and, such practice when combined with understory clearing might enhance it. Consequently, these forestry practices might ensure the natural regeneration of populations of this species, as well as the availability of food for local fauna. It is thus highly recommended that such practices be used to manage coppices dominated by resprouter species following fire, especially in situations where the growth of the forest canopy has stagnated and/or reproduction of forest species has been delayed. [ABSTRACT FROM AUTHOR]

Scheduled production of ornamentals has facilitated the development of novel crop lines that can be sold in flower over an extended period, thereby maximising sales potential. Research activities have aided the development of protocols for these 'forced' crops, but little attention has been given to knowledge of how such protocols affect subsequent garden performance. The aim of this study therefore, was to investigate the influence of different production factors (cutting size, temperature, photoperiod and time of propagation) on flower induction both with respect to the main marketing stage, but also in terms of 'after-sales' performance. The short-lived herbaceous perennial Coreopsis grandiflora cv. Flying Saucers was used as a model subject. When exposed to five diurnal temperatures (14, 20, 24, 27 and 31°C) and grown at four photoperiods (8, 11, 14 and 17h), time to first open flower was optimal at 27°C (42 days). Speed of flowering was aided by longer photoperiod (approximately 5 days earlier at 17h than at 14h). Greatest numbers of flowers produced overall though was associated with the 14°C/14h regime. Comparisons based on original cutting size demonstrated that large cuttings, rooted under long-day photoperiods produced plants with greater flower numbers than other cutting treatments. Once planted out, however, plants from all treatment combinations had similar floral performance (mean of 160 flowers per plant). Time of propagation/planting-out also had no overall effect on the numbers of flowers produced within the lifespan of the plant. It was concluded that conditions during production and planting time did not influence garden performance over the longer term. [ABSTRACT FROM AUTHOR]

Highlights: [•] Production curves relate yield to weight of planted corms over 3 years. [•] Corms above 30g gave 2.4 times stigma production of 11–15g corms over 3 years. [•] Progeny corms <10g predominate and best yield of corms >20g occurs in year 2. [•] Progeny corm size distribution varied for mother corm weight class in years 2 and 3. [•] Management cycle depends on the objective of flowers or corms. [Copyright &y& Elsevier]

Abstract: We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO2 and/or O3 on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO2 increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O3 also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO2 +O3) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO2 may have a largely positive impact on forest tree reproduction and regeneration while elevated O3 will likely have a negative impact. [Copyright &y& Elsevier]

Abstract: The effect of foliar application of cytokinin (benzyl-adenine, 150mgL−1) and gibberellin (GA4 +GA7, 150mgL−1) on growth and flower development of 5-year-old plants of two jojoba clones was studied. The plant growth regulators were applied on October 5, 1999 (spring) and the plants were evaluated 120, 240 and 360 days after application. Shoot length, total number of nodes and number of nodes with branching were statistically different between clones but not between the growth regulator treatments. The total number of flowers on both clones was significantly increased by treatment with benzyl-adenine (BA) and significantly reduced by treatment with gibberellin. The seed yields, evaluated 180 days after application, were not statistically different from the control due to an increase in flower abortion. One clone treated with gibberellin showed a significant decrease in number and weight of seeds, the other did not. Histology of axillary buds revealed that BA application on one clone (4.11.32) enlarged the flower meristem, differentiating multiple flower production. [Copyright &y& Elsevier]

Abstract: The current study presents phenology data for Rhizophora mangle from two equatorial mangrove stands with different salinity regimes in Brazil. Observations based on litter fall and individual shoot development were compared and related to environmental factors. Patterns observed in litter fall were consistent with results of direct monitoring. While both reproductive organs and leaves were produced throughout the year, rates of formation followed seasonal trends. Distinct differences in propagule production between low and high salinity sites and between years of observation were detected; main propagule release was, however, restricted to the wet season which offers enhanced conditions for propagule establishment. Emergence of flowers was linked to leaf production. While there was no obvious single peak in leaf production, it was reduced towards the end of the dry season at both high and low salinity sites. Time series analysis revealed an independent pattern of leaf development superimposed on this annual seasonal trend, indicating slower development of leaf primordia during periods of low light availability in the wet season. No significant difference in age structure was detected between sun and shade leaves; maximum leaf life-time was approximately 1 year. [Copyright &y& Elsevier]

Copyright of Basic & Applied Ecology is the property of Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Production of amaryllis (Hippeastrum spp.) flowers is highly affected by the bulb size. We studied the N and K fertilization interaction with CO2 enrichment on the development of Hippeastrum bulbs grown in the greenhouse. Bulbs of two initial diameters, 3.5 and 5.4 cm, were grown for 233 days in the greenhouse on dune sand, either enriched with 1000 ppm CO2 or with the ambient concentration. The plants were fertilized via the drip irrigation system with combinations of NH4NO3–N (0–25 mM) and K (0–6.4 mM), six levels of each nutrient. Carbon dioxide was applied during daytime to an insulated section of the greenhouse. The results indicated a significant contribution to either nutrients to bulb growth, but the optimal response of the larger bulbs was at a higher CO2 concentration, for the two nutrients. The response in growth to both nutrients’ concentration was curvilinear. Enrichment with CO2 yielded an increase in bulb diameter, but the relative contribution was higher with the smaller bulbs. [Copyright &y& Elsevier]

The size of apical growing points on four grades of sandersonia tuber (3–5, 5–7, 7–10 and >10 g) increased with increasing tuber weight (R2=0.71). These tubers were divided in two separate experiments to provide weights of 16.7, 33 and 50% and 50, 75 and 100% of the original grade size weights. Tubers were grown in the main season under standard forcing conditions. Harvested stem length was significantly greater with increasing tuber size, but declined with increasing severity of cutting treatment. Similar results also occurred with stem weight, flower number and vase-life. Regression analysis of stem length versus planted tuber size for the combined data from both experiments produced a significant relationship (R2=0.83), with the fitted line being: L=673.5−336.9×0.7626T (where L is the stem length, T the tuber planted weight and 673.5 is the upper asymptote). Stem size and flower number were influenced by tuber weight rather than by apical growing point size. [Copyright &y& Elsevier]