不同负载量对金陵黄露桃产量和果实品质的影响

为探讨不同负载量对桃产量和果实品质的影响，以自然开心形树形的金陵黄露桃为试材进行了连续3年的试验。试验采用随机区组设计，设4个处理：T1，留果约150个/株；T2，留果约250个/株；T3，留果约300个/株；T4，留果约350个/株，单株重复，每处理重复6次。结果表明：T4处理产量较高，但单果重最低；T1处理产量最低，但单果重最高；T2处理产量相对较低，但单果重相对较高；T3处理产量相对较高，但单果重相对较低。T1处理果实可溶性固形物含量和糖酸比均较高。T2和T3处理果实内在品质均略低于T1处理。负载量对果实着色程度影响不显著。可见，盛果期金陵黄露桃负载量为每株约150个果实时（每667 m2产量约1 300 kg），产量较低，但可生产出较大果个的果实，品质较好；每株250～300个果实时（每667 m2产量2 000～2 400 kg），可保证较高的产量和较大的果个。     

龙泉一号枇杷留果量研究

以6年生龙泉一号枇杷为材料，研究不同留果量和结果母枝对枇杷单果重、果形指数、可食率、种子数和可溶性固形物含量等品质果实的影响。结果表明，各指标处理间差异显著，根据加权平均数的综合评价，无论长结果母枝还是短结果母枝，留1～2个栗的商品～率最高。只要结果母枝数量足够，产量也不会下降。     

不同留果量对龙眼枝梢成花及产量效益的影响

以结果习性好的龙眼立冬本为试材,研究不同留果量对枝梢成花及产量、效益的影响.结果表明,每穗果实60～70粒,穗重0.81 kg左右,果穗数量以32％最为适宜,果实均为单果重13 9以上的优质果；营养枝粗度、长度和复叶数分别为8.46 mm、26.35 cm和19.60个,次年枝条成花率77.130％,与对照差异均不显著,属优良结果母枝；大小年平均株产最高(55.32 kg),效益最好(936.0元/株),大小年幅度最小(5.94％),是龙眼立冬本生殖生长与营养生长相对平衡的适宜留果量.留果量38％～48％均出现不同程度的大小年结果.     

玫瑰香葡萄修剪试验

6年生玫瑰香葡萄,株行距1.25×2米,单篱架扇形整枝。 经冬剪对母校留4芽、6芽、8芽、10芽不同芽段处理(每处理6株,重复4次)调查,以留6个芽段处理获得的产量最高,平均比留4、8、10芽段的单株分别高13.8%、5%、74%,树势也最强,果实品质最佳。 不同冬剪芽段在不同粗度的母枝上芽眼前发率和结实力反应是;随着冬剪长度的增 加而降低,随着母枝粗度增加而相应提高。不过决定结实力的关键因素还是结果母枝的健壮程度。 根据留6个芽段冬剪的单株产量,树势、品质最好,并结合以往实践经验,认为玫瑰香葡萄在单篱架栽培中应以中(4-6芽)短(2-3芽)梢修剪为…     

介绍几种确定苹果留果量的方法

科学地疏花疏果,使树体合理负载,不仅可减少树体不必要的营养消耗,提高坐果率,增加果实产量,增进果实品质,而且还能促使树体健壮生长,促进花芽分化,增强抗逆性,实现丰产稳产。因此科学合理地确定留果量,搞好疏花疏果是非常重要的,下面介绍几种确定苹果留果量的方法,供参考。1以产定果法就是先根据品种、树龄、树势以及栽培管理水平等,确定667m2的产量,再根据产量和单果重确定每667m2的留果量。如一般盛果期苹果树每667m2产量应控制在3000～3500kg,因此每667m2的留果量,元帅系品种为1.2万～1.4万个果(单果重250g),富士系留1.0万～1.2万个果(…     

不同留果距离对金晶梨果实的影响

以金晶梨为试材,开展不同留果距离对梨果实品质的影响试验。结果表明,金晶梨留果距离为25 cm时,平均单果重为267.15 g,显著高于对照的239.82 g;200 g以上果比例达95.41%,显著高于对照的89.03%;单株产量达25.88 kg,与对照差异不显著;果实可溶性固形物含量达10.4%。     

留果量和结果部位对莲雾优系农科二号果实品质的影响

以莲雾优系农科二号为试材,采用人工疏果方式设不同留果量和结果部位处理,研究其对单果重、果长、果顶宽和可溶性固形物含量的变化。结果表明:穗留果量为2、3个时,单果重、果长、果顶宽、可溶性固形物含量均极显著高于对照;穗留果量为4个时,单果重、果长均显著高于对照,可溶性固形物含量极显著高于对照。树冠内膛果实较外围果实大而长,单果重、果长差异极显著,果顶宽差异显著,可溶性固形物含量差异不显著。树冠外围中、下部果实的单果重大于上部,且果顶显著宽于上部;中、下部果实显著或极显著长于上部;上部果实可溶性固形物含量极显著高于中、下部。由此可见,疏果有利于果形、单果重和内在品质的形成,建议每穗留果2~4个,选择树冠内膛和外围中部结果为主。     

单株留果数量对厚皮甜瓜果实发育、品质及产量的影响

为了探讨单株留果数量对厚皮甜瓜果实发育、品质及产量的影响,选用了不同类型的厚皮甜瓜品种进行了单株留果数量研究。结果表明:小果型品种众天翠玉、中甜1号和中果型品种一品红2号以单株留2个果产量、效益较好;中果型品种新世纪、海蜜2号和海蜜5号以单株留1个果的产量、效益较好。     

“蜂糖李”幼果期不同留果量对着果率、产量及品质的影响

为研究蜂糖李幼果期不同留果量对蜂糖李着果率及果实品质的影响，在花后1个月，疏除整株幼果的1/5(T1)、1/4(T2)、1/3(T3),以不疏果处理为对照。结果显示，不同处理之间的着果率、单果质量、单株产量显著高于对照。T3处理的着果率和单果质量最高，分别为76%和77.93 g。T1、T3、T2的单株产量分别为24.54、23.24、17.95 kg,显著高于CK的13.21 kg。疏果处理能提高果实的纵横径，而对果形指数无影响，各处理的可溶性固形物含量和固酸比显著高于对照。疏除全株幼果的1/3处理效果最佳，能显著提高着果率、单果质量及产量，对果实外观品质和内在品质都有提升作用。     

留果数对浮宫1号杨梅果实性状的影响

分析了不同结果枝留果数对浮宫1号杨梅果实单果重及可溶性固形物含量的影响。结果表明,留果数及结果枝长度对杨梅果实单果重影响显著,对果实可溶性固形物含量影响较小。在浮宫1号杨梅栽培过程中,短果枝可保留1个果;中等长度结果枝粗枝可保留3个果,中枝保留2个果,细枝保留1个果;长果枝留3个果可达到一级果标准,留2个果则达到特级果标准。     

Optimum leaf area index in T-bar trained kiwifruit vines

Summary

The effect of leaf area index (LAI) on canopy growth, light interception, yield, fruit growth and quality and return bloom of kiwifruit were examined in 1990 and 1991. Different LAIs were obtained in the 1990 season with defoliation treatment made precociously at different intensities, in a diffuse way, uniformly in the whole canopy. At the end of canopy development LAIs of 3.6,3.3,3.1,2.6 and 1.8 were obtained and evaluated. The kiwifruit vines with a bud load of 680?700 and LAIs of 3.3 and 3.6 in 1990, showed an optimum and constant yield (>90 kg per vine), good average fruit weight (>100 g) and high fruit quality in both years, and also good return bloom the following season. The reduction of LAI to 2.6 and 1.8 drastically reduced, in the year of LAI imposition, both yield (?18.5% and ?30%, respectively) and mean fruit weight (?18.6% and ?29.1%, respectively) compared with vines with an LAI higher than 3.1. In the same treatments, the soluble solids concentration in the fruit was significantly decreased and a great reduction in numbers of fruiting shoots and numbers of fruits per fruiting shoot were observed in the year following the LAI imposition. In vines with the same bud load, fruit number and an LAI of 3.1, small variations in yield and fruit weight in the year of defoliation treatments were recorded, but in the following season the yield was significantly reduced (?14 kg per vine) due mainly to a decrease in the number of fruiting shoots (?14%). In kiwifruit vines with low LAI (2.6 and 1.8) nearly all fruits present in the canopy ripen, with no significant fruit drop. At low LAI, the sink strength of the fruit was greater and more extended so that vine growth and the plants reserves were restricted. Under the conditions of this experiment, an LAI higher than 3.3, corresponding to a leaf area-fruit ratio higher than 600 cm² per fruit, is necessary to obtain regular vine growth and yield, optimum fruit size and quality and return bloom the following season.     

Variability in the components of yield of black currant cultivars

Examining the components of yield of black currant cultivars in 2 successive years indicated that the number of flowers per raceme, racemes per flower bud, and mean potential berry weight, although variable between cultivars, tended to vary little within any cultivar. These components combined gave a potential berry weight per bud which appeared to be relatively stable, and may be a genetic characteristic.Year-to-year variation in yield of single cultivars was closely correlated with changes in the number of fruiting buds per bush (the product of number of shoots and fruit buds per shoot). These components are determined at different times in the year before harvest and may indicate critical phases in development of the crop.In each year, all cultivars produced roughly the same proportion of their potential crop as actual crop, although the proportion was different in the 2 years. Thus the differences between cultivars in crops harvested were related to differences in crop potential developed in the pre-fruiting year, which are considered to be due to quantitative genetic differences in potential yields per bud and differences in response to conditions affecting fruit bud formation.     

Cane and bud number effect on yield components of non-irrigated grapes cv. ‘Yaghooti’

An experiment was conducted with non-irrigated vines (Vitis vinifera), in which the number of buds per cane and the number of canes per vine were varied. With increasing canes per plant the percentage bud-burst decreased. Cluster number and total yield increased with increasing the number of buds per vine. Cluster weight and sugar content decreased when vines were overloaded. Yield was positively correlated with cluster number and negatively correlated with sugar content. The position of the pruning-cut affected the percentage bud-burst only near the cut.     

Carbohydrate content of inflorescent buds of defruited and fruiting pistachio (Pistacia vera L) branches in relation to biennial bearing

Summary

Changes in carbohydrate content of inflorescent buds of fruiting and defruited branches of the same tree were measured in 1994 and 1995 in the period before and during bud abscission in pistachio (Pistacia vera L. cv. Aegenes) to investigate its relationship to inflorescent bud abscission. HPLC was used for soluble sugar analysis, while starch was hydrolyzed to glucose enzymatically and the amount of glucose was then determined using the glucose oxidaseperoxidase method. The effect of fruit on leaf net photosynthesis (Pn), chlorophyll a and b (Chl (a+b)) in leaves and specific leaf weight (SLW) was also investigated in 1995. Starch concentration was initially similar in buds of fruiting and defruited branches but became greater in buds of defruited branches from early June 1994 (57 d after full bloom (AFB)) and 20 June 1995 (61 dAFB), resulting in higher starch contents. Glucose and fructose concentrations were similar in flower buds throughout the whole period of measurement; inositol and sucrose (the most abundant sugar in flower buds) both became much lower in fruiting branches from early July 1994 (83 dAFB) and mid July 1995 (88 dAFB). The rapid decrease in sucrose concentration coincided with rapid seed growth and the greatest period of bud abscission in fruiting branches. During the same period, total sugar and total carbohydrate concentrations and contents were greater in buds of defruited branches. The presence of fruit increased Chl (a+b) content in leaves while decreasing SLW between 43 and 61 dAFB. During this same period, leaf Pn rates were greater in fruiting shoots than in defruited ones.     

Thidiazuron increases current-year fruit size and production in Actinidia deliciosa without decreasing return bloom

Summary

The effects of whole-crown application of thidiazuron (TDZ), applied two weeks after full bloom, at the concentrations of 0 (control), 2 or 10 ppm, on vine yield, fruit quality and on next-season potential yield of Actinidia deliciosa ‘Hayward’ were evaluated in 1998–99. Fruit growth increased rapidly after TDZ application. Fruit fresh weight and yield increased by about 13% and 22% with the 2 and 10 ppm concentration, respectively. These responses were associated with only small changes in fruit shape, with 10 ppm-treated fruits slightly rounder than the control. During ripening, TDZ did not affect fruit soluble solid content, flesh firmness or concentration of non-structural carbohydrates. No effect was observed on the amount of winter pruning, entity of bud burst, percent of fertile buds, number of inflorescences per fertile bud or percent of vegetative buds. These results show that TDZ can be applied to the whole crown to increase fruit size and yield, without affecting fruit quality or the next-season’s crop.     

Effects of defoliation on fruit growth,carbohydrate reserves and subsequent flowering of ‘Hayward’ kiwifruit vines

A partial defoliation study was carried out on ‘Hayward’ kiwifruit vines with the aim of evaluating effects on fruit yield, changes in concentration of carbohydrates, and return bloom. At full bloom, ‘Hayward’ kiwifruit vines trained to the pergola system were submitted to 0% (control), 50% and 75% defoliation in the 2.0 m wide central horizontal area of the canopy. This area represents the vine ‘replacement cane zone’ (RCZ), whereas the remaining external area represents the ‘fruiting zone’ (FZ). Removing 50% of the leaves resulted in a small (−9 g in the RCZ and −3.3 g in the FZ), but significant, reduction in fruit weight compared to the control vines. More severe defoliation (75%) reduced fruit weight by 13 g in the RCZ and 7 g in the FZ. The defoliation treatment reduced the concentrations of starch and total soluble carbohydrates (glucose + fructose + sucrose) in the shoots and starch in trunk bark compared to those in control vines. The treatments caused a large reduction in return bloom, expressed as number of flowers per winter bud, by about 25% and 53% in vines with 50% and 75% defoliation, respectively.     

Vegetative and yield component characteristics of micropropagated muscadine grape (Vitis rotundifolia Michx.)

SUMMARY

Evaluations were made of the field performance of micropropagated (tissue cultured axillary buds) versus conventionally rooted softwood cuttings of muscadine grape, Vitis rotundifolia Michx. Trunk cross-sectional area did not differ between treatments during three years of field evaluation following planting. There were no differences in leaf area and dry weight or shoot number in the two propagation types; leaf morphology was normal with no apparent juvenile characteristics. Yield components including flower number per shoot and inflorescence, fruit number, total fruit weight and yield efficiency were greater in micropropagated plants during the second year, the first year of cropping; differences diminished and yield components were not different in year three. Performance of tissue cultured plants was therefore as good as, or surpassed, conventionally propagated plants during early vine establishment.     

Strawberry fruit yield and quality responses to flower bud removal: A simulation of damage by strawberry blossom weevil (Anthonomus rubi)

Summary

The effect of flower bud severing (with scissors) on the yield and fruit quality of strawberry (cv. Elsanta) grown on raised, polythene-mulched beds varied with plant size and numbers of flower buds per plant. On very small plants (with an average of seven flower buds and yielding 105 g of fruit per plant) severing reduced yield in direct proportion to the proportion of flower buds severed, irrespective of whether severing included or did not include removal of the primary (first node) flower bud. There was no evidence of crop compensation. On larger plants (with 24, 70 and 117 flower buds and yielding 0.34 kg, 0.73 kg and 1.16 kg of fruit per plant respectively) severing up to 12 buds per plant did not significantly affect yield: mean berry weight increased by up to 11% and the percentage fruit (by number) in quality class I increased from 67% to 72% in response to severing. Two mechanisms of yield compensation were, apparent i) an increase in mean berry weight, and ii) the maturing of alternative replacement flower buds. Severing slightly delayed by 1–2 d the date by when 10% and 25% of fruit was picked. Implications for the economic damage threshold for flower bud severing by the strawberry blossom weevil are discussed.     

The influence of fruiting on the bud sprouting and flower induction responses to chilling in Citrus

Summary

The effect of chilling temperatures on bud sprouting and flower formation was compared on fruiting and non-fruiting ‘Owari’ satsuma mandarin (Citrus unshiu Marc) trees. On non-fruiting trees, bud dormancy was weak, and a significant proportion of buds were able to sprout at high temperatures without being chilled. Separate effects of low temperatures on bud sprouting and flower induction were demonstrated. On fruiting trees these two effects of low temperatures were also demonstrated on summer-flush buds, but not on older (spring-flush) buds. The spring-flush buds from fruiting trees scarcely sprouted without being chilled. These buds required a longer chilling period for dormancy release than for flower induction, and it was not possible to separate the effect of low temperature on flower induction from the effect on dormancy release. The presence of fruit reduced flower formation by reducing bud sprouting. Furthermore, fruit had a direct inhibitive effect on vernalization which resulted in increased formation of vegetative shoots. The effect of fruit and low temperature on flowering was unrelated to carbohydrate accumulation in the leaves or the roots.