Flowering,fruit set and development of the fruit and seed of sweet pepper (iCapsicum annuum L.) cultivated under conditions of high ambient temperature

Sweet pepper (Capsicum annuum L.) cvs E-84066 and Yolo Wonder were grown under ambient conditions in plastic covered greenhouses. Anthesis commenced five and six weeks after planting and rose to a peak of 39 (E-84066) and 19 (Yolo Wonder) flowers per week respectively after which there was a rapid fall. Temperatures throughout anthesis were high (>38°C (maximum) and >16°C (minimum)) and this is likely to have contributed to the magnitude of the flux. Fruit set was highest in the early stages of the crop, but subsequently declined as the majority of flowers aborted. Overall, fruit weight was correlated with seed weight and seed number, and declined throughout the life of the crop. By contrast, seed size and the percentage germination remained constant. The latter is of particular importance for seed crops where seed quality is of primary concern.     

Gibberellic acid and fruit set in sweet orange

A single GA₃-spray at petal-fall to the entire tree enhanced initial set in the ‘Navelate’ sweet orange (Citrus sinensis L. Osbeck), but this effect was transient and in most cases final yield was not increased. When followed by girdling, final yield was increased even in the most productive orchards, this effect being due to an increase in fruit number while fruit size was unaffected. The response was markedly dependent on the GA₃ concentration, 5 mg l^?1 giving the best results. Higher concentrations up to 20 mg l^?1 even reduced yield compared to the untreated control trees. Chlormequat reduced the number of fruits finally cropped without affecting their size, an effect which may be explained through a reduction in the endogenous gibberellin levels.     

不同授粉时间对西瓜坐果的影响

针对西瓜生产和育种中存在的花期不遇问题,采用5种不同的授粉方式,调查其对西瓜坐果的影响。结果表明,正常授粉效果表现最好,坐果率达90%;雌花蕾期授粉上午效果比下午好,上午授粉坐果率为70%,下午授粉为50%;未开放的雄花经冰箱存放或开放雄花在室温下自然存放24 h后花粉仍保有生活力,可用以授粉,坐果率为分别为43%和40%。     

Quality fruit improvement in sweet pepper culture by bumblebee pollination

The percentage of ovules that set seeds per fruit has been used to evaluate the bumblebee activity of a two campaigns greenhouse trial. The experiment was carried out with two commercial cultivars of sweet pepper, ‘bell’ type, called Bardenas and Vergasa. The averages of the percentages of seed set per fruit of the two campaigns were 49.8% (Bardenas) and 40.7% (Vergasa) on the pollination treatment, whereas the averages of the control (self-pollination) treatment were 27.5% and 25.7%, respectively. Percentages of seed set per fruit was strongly related with the number of bee visits, but weakly with duration of visits.     

Influence of fruit load on dry matter and N-distribution in sweet pepper plants

The influence of fruit load on the leaf characteristics and on the distribution of dry matter (DM) and nitrogen (N) in sweet pepper (Capsicum annuum L., cv. Cornado) plants was investigated under Mediterranean glasshouse conditions during a winter–spring production cycle (from December till June). DM weight of all organs (roots, stems + petioles, leaves and fruits) and N content were determined throughout the growing cycle over a 3-week interval. The results showed that the cyclic fruit load pattern (production flushes) was associated with strong variations of N-leaf content on an area basis and specific leaf weight, SLW. On a whole plant scale, the value of SLW dramatically decreased (≈30%) with increasing fruit load; the reverse held true as long as the fruit dry weight remained low (<30 g pl⁻¹). The decline in SLW was coincident with a shift in distribution of DM and N in the plant, both preferentially diverted to the fruits. The time evolution of DM and N fractions in organs exhibited periodic fluctuations, with a duration close to the length of a fruit growth cycle (about 70 days, from anthesis to harvest). Linear relationships were found between the fraction of dry mass and N in fruits, and those of the other organs. The slope of these relationships was considered as an indicator of the response and sensitivity of the organ growth to an increase in fruit load. The root dry mass fraction was the most affected by increases in fruit load (slope of −0.75), while the N fraction in roots and in leaves was affected to a similar extent (slope of −0.50 and of −0.40, respectively). We conclude that, in the sweet pepper, the cyclic pattern of fruit load induces opposite cyclic patterns of dry matter and N content in the other aerial organs as well as in the roots, thereby reflecting close shoot–root coordination in the allocation of carbon and nitrogen resources among the organs. Finally, we discuss the possible implications that could derive from these findings for modelling dry matter partitioning in plants subjected to continuous fruit harvesting.     

Cuticular cracking in pepper fruit. I. Effects of night temperature and humidity

Summary

The objective of the present study was to characterize some of the anatomical and physiological characteristics of fruit cracking in bell pepper (Capsicum annuum L.). Scanning-electron micrographs show that initiation of fruit cracking in bell pepper is by formation of mini-cracks on the cuticle layer; these then enlarge into cracks and traverse the epidermal cells. Pepper cultivars differ in their sensitivity to cracking, partly because of differences in fruit pericarp thickness. Limitation of night transpiration by high humidity or low temperature increased the turgor potential of the fruit pericarp and enhanced cracking. Likewise, leaf pruning suppressed night transpiration and concomitantly increased cracking. Fruit cuticle transpiration was found to be low in the early stages of fruit development and to increase as the fruit became susceptible to cracking. Environmental conditions which enhanced cracking also increased cuticle transpiration in a sensitive pepper cultivar but not in a less sensitive one. We suggest that fruit cracking in bell pepper occurs because reduction in night transpiration causes high turgor pressure in the fruit. As the cuticle becomes permeable to water, the inner turgor pressure causes the cuticle to crack. Differences in cultivar sensitivity may be partly due to differences in pericarp thickness and cuticle properties, but additional factors may be involved.     

几种措施对新次郎甜柿坐果率和果实品质的影响

试验结果表明，以新次郎甜柿为试材，盛花期喷1次80mg／L赤霉素或与禅寺九品种自然授粉，均可显著提高新次郎甜柿的坐果率；盛花期主干环剥0．5cm后的坐果率与对照无显著差异。喷赤霉素、环剥和自然授粉各处理的果实可溶性固形物、维生素C和单宁含量与对照无显著差异，但喷赤霉素可明显减小单果重。     

不同授粉条件对'南果梨'坐果率的影响

‘南果梨’风味独特,品质优良,是海城地区优良的地方品种,栽培历史悠久。但是‘南果梨’自花结实率低,而且不同授粉条件下其坐果率也相差悬殊。‘南果梨’自花结实率究竟是多少,授粉的适宜温度是多少？不同授粉方法的坐果率是否一样？为了解‘南果梨’自花授粉坐果率和不同的授粉条件对坐果率的影响,我们进行了此项试验,以便为优化授粉条件,提高坐果率提供指导意见。     

不同倍性雄株对软枣猕猴桃坐果及果实性状的影响

【目的】了解不同倍性的雄株对软枣猕猴桃坐果及果实性状的影响,为生产上授粉雄株的选配提供依据。【方法】选用二倍体、四倍体、六倍体雄株花粉分别为四倍体软枣猕猴桃‘红宝石星’授粉。授粉30 d后,统计各授粉组合的坐果率。果实收获后,调查单果质量、果形指数、果肉颜色、可溶性固形物含量、种子数、种子质量等性状。【结果】用二倍体中华猕猴桃雄株为四倍体软枣猕猴桃‘红宝石星’授粉,落果严重,坐果率很低(4.7%~6.1%);用四倍体中华猕猴桃‘磨山4号’授粉,雌株坐果率有所增加但仅有18.6%;而用六倍体美味猕猴桃雄株的花粉授粉后,雌株坐果率为52.4%~86.3%,与用四倍体的软枣猕猴桃雄株花粉授粉的坐果率相近。用四倍体的中华猕猴桃‘磨山4号’和六倍体的美味猕猴桃‘陶木里’花粉授粉,‘红宝石星’的单果质量、果肉色调角显著减小,果实中种子千粒重均减少,其中‘磨山4号’授粉处理引起种子千粒重显著减少。【结论】不同倍性的雄株显著影响了猕猴桃的坐果状况及果实的单果质量、果肉颜色、种子千粒重等性状。用二倍体中华猕猴桃雄株花粉为四倍体软枣猕猴桃‘红宝石星’授粉,坐果率很低(4.7%~6.1%),难以满足生产上需求。用四倍体中华猕猴桃雄株花粉授粉时,雌株坐果率有所提高(18.6%)。用六倍体美味猕猴桃雄株花粉授粉时,坐果率高达86.3%,与用四倍体的软枣猕猴桃雄株花粉授粉的坐果率相近,但果实鲜质量显著减小。     

Effects of CPPU on fruit set and fruit growth in Japanese persimmon

The effects of hand-pollination and spraying with N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit set and fruit growth of ‘Matsumoto-Wase-Fuyu’, which is a member of the pollination-constant, non-astringent group of persimmons (PCNA) were investigated. Staminate flowers of pollinizers in the orchard were eliminated before anthesis. Hand-pollination was carried out at full bloom (FB). Without prior hand-pollination, CPPU at 5 or 10 mg 1⁻¹ was sprayed 11 days after FB. Hand-pollination and spraying with CPPU increased fruit set before thinning of fruits by hand. The number of fruits after thinning did not differ among treatments. The yield of marketable fruits after hand-pollination was similar to that after treatment at 5 mg 1⁻¹, but was higher than that for untreated trees. Formation of a sunken fruit apex, which was observed in about 30% of fruits from untreated trees, was suppressed by application of CPPU. CPPU also delayed coloration of fruit. There were no differences among treatments in firmness or soluble solids concentrations of marketable fruits.     

1-甲基环丙烯对甜樱桃果实褐变的影响(英文)

在预实验基础上,(24±1)°C,RH80%-90%条件下,采用1μL/L甲基环丙烯(1-MCP)对甜樱桃处理24h,后置于(0±0.5)℃条件下冷藏18d,对果实的褐变参数及相关酶活性进行检测。结果表明,1μL/L1-MCP明显抑制甜樱桃果实L觹和H°值的下降及苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)和过氧化物酶(POD)活性的上升。(0±0.5)℃贮藏18d后,1-MCP处理的果实风味和口感无明显变化,色泽和综合评分明显优于对照(P<0.05)。     

Flower emasculation accelerates ovule degeneration and reduces fruit set in sweet cherry

Flower emasculation is commonly used to make flowers unattractive to pollinating insects and to carry out controlled pollinations. In sweet cherry, we have observed recurrent low fruit set after flower emasculation and compatible pollination without apparent causes. This led us to evaluate its effect on the progress of the reproductive phase and on fruit set in this species. Flower emasculation reduced by more than a half the fruit set obtained in crosses made during two consecutive years. This effect could be traced back to the first week after anthesis where weight increase of pistils from emasculated flowers was smaller and ovule degeneration was accelerated compared to pistils from non-emasculated flowers. Pollen tubes, which behaved similarly at the stigma-style level in emasculated and non-emasculated flowers, lost their directionality in the area close to the degenerated ovule in the ovary. While flower emasculation is valid to evaluate pollen tube performance in the style and to determine incompatibility relationships, the lower fruit set registered after emasculation alerts on its use in fruit set experiments and breeding programs.     

Changes in physicochemical attributes of sweet pepper cv. Domino during fruit growth and development

The effect of harvesting sweet pepper ‘Domino’ fruit at different stages of growth and development on physicochemical attributes was studied. The suitability of fruit fresh weight, diameter and length, weeks from anthesis, total soluble solids (TSS), fruit colour change, firmness, internal CO₂ and C₂H₄ concentrations as well as fruit respiration and ethylene production as maturity indicators were evaluated. Fruits were harvested weekly until fully red ripe. Fruits took 8 weeks after anthesis (WAA) to reach harvest maturity and a further 2–3 weeks to reach full ripeness (11 WAA). Fruits exhibited a sigmoid growth pattern. Hue angle (change in colour from green to red) declined with time while chroma (colour intensity) values increased with fruit maturity, as did TSS. An increase in PⁱCO₂ and PⁱC₂H₄ accompanied the decrease in hue angle. The association between fruit ripening and the significant increase in PⁱC₂H₄ indicates that ethylene may be responsible for ripening of this cultivar of sweet pepper. Colour change and TSS were reasonable indicators of maturity of sweet pepper fruit complemented with fruit firmness.     

几种秸秆基质对辣椒生长及果实品质的影响

菊芋是青海高原的特色经济作物,地上部秸秆生物量大,为解决其综合利用问题,将发酵完全的菊芋、小麦、油菜及玉米的秸秆复配羊粪、商品基质土、蛭石和珍珠岩作为辣椒的栽培基质,采用槽式无土栽培,通过对辣椒不同时期生长情况的监测来分析作物秸秆对辣椒生长、品质及产量的影响。结果表明,添加作物秸秆对辣椒生长、品质及产量都有正向影响,尤其是添加了菊芋秸秆的栽培基质在株高、茎粗、株幅等生长指标中都优于对照,果实的可溶性总糖、维生素C含量也都高于其他处理,有效增加了辣椒生物量,提升了果实品质,并且辣椒产量较对照增加了3%~5%。综合试验结果,添加菊芋秸秆可以提高辣椒的生物量、果实品质和产量。     

花期喷激素对红灯樱桃坐果率的影响

以9年生红灯樱桃为试材,于花期喷赤霉素和细胞分裂素,研究对坐果率的影响.结果表明,盛花期喷施赤霉素能显著提高甜樱桃坐果率,以30～40 mg/kg效果较佳;赤霉素与细胞分裂素配合喷施,对提高坐果率的效果优于单喷赤霉素,20mg/kg 6-KT与30mg/kg赤霉素配合施用效果最佳,坐果率比单喷赤霉素和自然坐果分别提高6.8和21.2个百分点.     

MAP贮藏对甜樱桃品质的影响

对甜樱桃的贮藏保鲜试验表明,MAP与专用保鲜剂结合可有效地保持果实的鲜食品质,减少果实的腐烂和褐变,降低果实的呼吸强度,延长果实的贮藏期.‘红灯‘甜樱桃贮藏保鲜80 d果实的腐烂率为3.62%;对照果实只贮藏了40 d.‘雷尼‘甜樱桃贮藏保鲜110 d果实的腐烂率为2.1%,褐变率为0,果柄抽干率为0.32%;对照果实只贮藏了50 d.     

甜椒的无公害生产技术

我们南张特菜基地生产甜椒已有6年的光景，甜椒及其他蔬菜已申请了绿色食品证书。我们在生产和管理上严格把关，全部施用有机肥，杜绝了高毒和高残留化学合成农药的使用，在病虫害防治上广泛使用人工、生物防治接术，保证了蔬菜品质，基本上达到了绿色食品标准。现将我们的做法总结如下。     

Effects of pre-blossom temperatures on flower development and fruit set in apricot

The influence of pre-blossom temperatures on flower development and fruit set is ascertained in apricot (Prunus armeniaca L.), a species without previous records on the effect of pre-blossom temperature on fruit set, but that is particularly prone to erratic fruit set. A polyethylene cage was used during pre-blossom development of flower buds to increase maximum temperatures by 6–7 °C and mean temperatures by 3 °C in orchard conditions. This increase in temperature accelerated flower bud development, caused a hastening in flowering time and following hand-pollination, reduced fruit set. At anthesis, flowers that had developed in warmer conditions weighed less and showed less development of the pistil than control flowers. Pistil growth of flowers under warm conditions did not differ from that of the control flowers when both the populations were compared on a real time scale in spite of the fact that warmed buds were at an advanced external phenological stage. Thus, hastening of external floral development by warm pre-blossom temperatures was not accompanied by advance in pistil development. This lack of synchrony resulted in premature flowering of flowers with underdeveloped pistils that had a reduced capability to set fruit. The results are discussed in terms of flower quality and its implications in fruit set and subsequent crop load.     

Gas exchange and antioxidant response of sweet pepper to foliar urea spray as affected by ambient temperature

This paper analyses the effect of different air temperatures (10, 20 and 30 °C) on the response of sweet pepper plants (Capsicum annuum L. cv. Herminio) to foliar urea applications after growing plants for 20 day with and without nitrogen (N) applied to the growing substrate. Leaf CO₂ assimilation, chlorophyll fluorescence, root respiration, lipid peroxidation and antioxidative enzymes were analysed. Spraying plants with urea increased leaf CO₂ assimilation of N-deficient plants when applied at 20 or 30 °C, compared with non-sprayed plants. When plants were sprayed with urea at 10 °C chlorophyll fluorescence of leaves was similar to that of plants that were supplied with full N in the nutrient solution. Root respiration was not affected by urea sprays whilst leaf NO₃⁻ concentration was increased by urea but only when it was sprayed at 10 or 20 °C. Lipid peroxidation and ascorbate peroxidase in N-deficient plants were reduced significantly by urea sprays, especially when plants were sprayed at 20 °C with N-limitation in the growing substrate. This study shows that N-limitation in the growing substrate induces a temperature-dependant increase in the activities of antioxidant enzymes in leaves of pepper and applications of foliar urea can be optimised, when applied at the appropriate temperature, to partly replace the N supplied to the roots of sweet pepper.     

Effects of temperature and seed coat treatments on germination of sweet pea

Tests on seeds of sweet pea (Lathyrus odoratus L.) were set up to examine responses to temperature during germination and to investigate the effects of mechanical and chemical treatments on the permeability of the seed coat to water.Optimum temperatures for germination occurred at about 21 °C, and higher temperatures resulted in the production of fewer seedlings. Although temperatures below c. 15 °C also reduced the numbers of seeds which germinated, even at 2 °C more than 50 % germinated within 60 days.Treatments with concentrated sulphuric acid or the mechanical removal of part of the seed coat by filing greatly increased permeability to water and under some conditions improved germination responses. Filing, followed by exposure to excess free water, reduced germination rates, possibly as a result of loss of solutes from the seed during imbibition.