Production variability in apple crops

The problem of year-to-year variation in English apple crops was studied for the cultivar ‘Cox's Orange Pippin’ by analyzing data collected from similarly-managed commercial blocks of trees. In the period 1971–1975 yields, in each block of trees, moved in the same direction each successive year. In low-average yield years the variation in yield tended to be as extensive as in high-average yield years. Over the period studied, no relationships between climatic factors during the blossoming-period and subsequent yield could be determined. The most important factor linked with low-average yield was found to be above-normal temperatures in the pre-blossom stage.It was postulated that in order for a tree to carry a crop to its full potential, a decisive vernal temperature impulse is needed. If this dormancy break does not occur, because of above-normal temperatures, a full crop cannot be carried, even though subsequent weather conditions are optimum. Yield failures are attributed to some hormonal or other physiological imbalance occurring due to the lack of the normal decisive vernal dormancy break.It was shown that the alternate-year bearing pattern evident in apple crops in the United Kingdom, The Netherlands and Belgium between the years 1971 and 1975 could be explained by this hypothesis.     

保加利亚的苹果生产与研究

保加利亚气候条件非常适宜苹果生长.1968年保加利亚苹果种植面积为3.04万hm2,但近年由于土地改革,苹果种植面积持续减少,现仅存5393hm2.笔者介绍了目前保加利亚苹果的种植面积、产量、主栽品种、砧木、树形及研究状况.     

Physical properties of media for container-grown crops. II. Peat mixes

The effect of addition of sand, perlite, polystyrene and pumice in half and quarter proportions and in various particle sizes, on physical properties of peat mixes was studied. Coarse sand had no effect on air space (AS), while fine sand reduced AS and at the higher rate the value fell to an unsatisfactory level. At the higher rate of coarse sand addition, easily available water (EAW) fell to an unsatisfactory level. Fine sand increased EAW. Total porosity (TP) and water-buffering capacity (WBC) were generally reduced as a result of sand addition. The addition of coarse perlite at the higher rate increased the AS, while fine perlite at both rates and medium perlite at the high rate reduced AS. The effect of addition of coarse and fine perlite on EAW was similar to sand addition. Total porosity was reduced by coarse perlite and by medium perlite addition at the higher rate. The addition of polystyrene increased AS, but decreased EAW and the value fell to an unacceptable level at the high rate of application. Bulk density, WBC and TP were decreased by the addition of polystyrene. The addition of a standard grade of pumice had no effect on AS, but the EAW, WBC and TP were reduced. However, only in the case of WBC was the reduction below the critical level.     

Some aspects of crop variation in ‘Golden Delicious’ apple trees

Fruit-set of ‘Golden Delicious’ apple trees was found to be largely independent of seasonal differences and much more closely related to the initial number of blossom clusters, when compared with many other apple cultivars under English conditions. In one young orchard, yield became increasingly a function of trunk girth during the first 3 cropping-years, but the trees then abruptly developed a biennial rhythm. Thereafter, blossom production was negatively correlated with the number of clusters in the previous year rather than with the number of fruits.Applications of daminozide or GA₃ appeared to increase or decrease, respectively, the amount of return bloom without altering the negative correlation with the number of clusters in the previous year. Chemical fruit-thinning with a mixture of carbaryl and NAA also appeared to be effective in increasing return bloom.     

The effect of irrigation and crop load on stem water potential and apple fruit size

Summary

The effect of irrigation rate under various crop loads on the fruit size of apple (Malus domestica Borkh cv. Golden Delicious) was investigated in three field experiments in 1993–1995. During the first two years the field experiments evaluated the effects of various crop loads on yield, fruit size and midday stem water potential under 40% deficit irrigation. In 1995, the effects of five irrigation levels (0.42–1.06 of USDA Class A evaporation pan) and four crop loads (100–450 fruits per tree) were studied in a factorial experiment. Midday stem water potential increased with irrigation level and decreased with crop load in 1993 and at the lowest irrigation level in 1995. Daily fruit growth rate decreased with midday stem water potential in 1993 and at the lowest irrigation level in 1993. The effect of crop load on fruit growth rate was associated with limited soil water availability. A reduction in yield and average fruit size were associated with midday stem water potentials lower than –1.3 MPa. Taking an additional 0.1 MPa as a safety factor, –1.2 MPa could serve as a reasonable threshold for irrigation control in the orchard.     

辽宁抚顺‘寒富’苹果生产现状

对辽宁省抚顺地区120个‘寒富’苹果园进行了调查。结果表明,抚顺地区‘寒富’苹果园立地条件差,果园基础设施差,砧穗组合以寒富/GM256/山定子为主,人均管理面积为1.07 hm2,管理水平不高,树形不规范,不施基肥的果园占63%。常用的杀菌剂依次是多菌灵、代森锰锌、甲基硫菌灵,最常用的杀虫剂为高效氯氰菊酯,其次是吡虫啉。     

果园间作不同绿肥春季增殖害虫天敌的调查

早春果园间作的3种绿肥上节肢动物类群有3-8种,其中植食性生物以蚜虫和叶螨为优势种。毛叶苕子上优势天敌为东亚小花蝽,三叶草为瓢虫,紫花苜蓿为东亚小花蝽和蜘蛛。到苹果生理落果期,毛叶苕子上天敌种群密度东亚小花蝽45-130头/m2,瓢虫15-25头/m2,蜘蛛15-42头/m2;三叶草上瓢虫43-72头/m2,蜘蛛15-32头/m2,东亚小花蝽,6-10头/m2,蚜茧蜂15-72头/m2;紫花苜蓿上东亚小花蝽15头/m2,蜘蛛15头/m2,瓢虫7头/m2左右。果园间作毛叶苕子更利于叶螨天敌东亚小花蝽的春季繁殖。     

Contrasting effects of host crops and crop diversity on the abundance and parasitism of a specialist herbivore in agricultural landscapes

Landscape Ecology - Landscape complexity affects herbivores in agroecosystems, but consequences on pest control services are variable. Carryover effects of landscape composition in previous years...     

Responses of fruit growth,quality, and productivity to crop load in apple cv. Ultra Red Gala/MM111

The effects of three crop load densities (4, 6 and 8 fruit per cm² of the cross-section of each tree branch, BCSA) on fruit growth, yield, fruit quality and vegetative growth were studied in apples (Malus × domestica Borkh) Ultrared Gala/MM111, from the fourth leaf (2006–2007 season) to the sixth (2008–2009 season). The maximum fruit growth rate was reached between 90 and 108 days after full bloom (DAFB), with values above 2.6 g day⁻¹. Accumulated yields to the sixth leaf reached 181, 157 and 123 Mg ha⁻¹ in the high, medium and low crop loads, respectively. Mean fruit weight decreased with increasing fruit crop load but the yields of fruit weight over 194 g were similar in all crop loads; the highest crop load exceeded the lowest crop load by 18.8 and 27.5 Mg ha⁻¹ of fruit weight of more than 172 and 154 g, respectively. The yields of harvested fruit exceeding 75% with red coloring did not show major differences, while fruit classified as 50–75% with red coloring were less common in the low crop load. No major differences were found at the end of the study in vegetative growth in the different seasons, nor in plant size. The reduction in mean fruit weight and in the percentage of fruit with good coloring was compensated by the increase in yields, thus not resulting in an effective reduction in the quality of the harvested fruit. The level of plant development reached with a semi-vigorous rootstock and high fruit loads allowed obtaining high fruit yield earlier and of good quality.     

Characterization of variability and genetic similarity of European pear using microsatellite loci developed in apple

Seven microsatellite loci (SSR) developed in apple were used for the identification of 63 European pear cultivars. A total of 46 fragments were amplified, with an average of 6.6 alleles per SSR. Only one microsatellite amplified more than one locus. The mean expected and observed heterozygosities over the six single-locus SSRs averaged 0.68 and 0.44, respectively, and the number of effective alleles per loci was 3.43. The amplified fragments produced 61 different fingerprinting patterns that allowed to unequivocally distinguish all the varieties analyzed. Only two varieties, which derive from mutations, could not be distinguished from the original variety. Cluster analysis of the estimated genetic similarity, grouped the varieties according to their pedigree and their geographic origin. The variability detected with the SSRs in European pear varieties was low when compared with the variability detected in other fruit crops in the Rosaceae.     

The water requirement of the mushroom crop

Experiments are described in which it was attempted to quantify the water requirement of the mushroom crop for maximum yield.The amount of water applied was positively correlated with crop weight from about the second week of cropping and increasing the amount of water applied reduced the drying of the compost and casing during cropping. The watering treatments affected the character of the mushroom mycelium developing in the casing layer.The amount of water required to maintain the percentage water content of compost and casing unchanged throughout cropping can be calculated from an equation representing the overall balance of water applied to, and lost from, the mushroom trays.     

Studies in the Development of the Strawberry: II. Stolon Production by First-Year Plants in 1952

Studies were carried out on the assumption that incompatibility and dwarfness of budded citrus trees result from impaired carbohydrate movement through the bud union. During autumn and winter, carbohydrates move from the tree tops to the roots and accumulate there as starch. The starch level can therefore serve as a measure of this movement.

This study included seven rootstock varieties all budded with Shamouti orange scion. Unbudded rootstocks were included for purposes of comparison.

The starch level was determined in the winter at three locations along the trunk, below and above the bud union.

No clear indication was found of impaired carbohydrate movement through the bud union of stock-scion combinations showing very low growth vigour.

The starch level in bark and wood in the rootstock portion of trunks of budded trees was found to be negatively correlated with tree size. This indicates that the level of starch in the trunk results from the growth vigour of the tree and is not a factor which affects it.

No relation was found between starch level in the scion and tree size. Based on these findings the conclusion was reached that incompatibility and low growth vigour in citrus do not seem to result from impaired carbohydrate movement through the trunk and starvation of the roots.     

Soil pH in fruit trees in relation to specific apple replant disorder (SARD). II. The first five years at the Wageningen research plot

Field plots were established with 4 target pH values, viz. 4, 5, 6 and 7, to study the effect of pH on specific apple replant disorder (SARD). The target pH levels were not stable and frequently showed fluctuations. Although no significant differences have been found on tree performance, the development of the trees on the plots with the lowest pH level was better than those at higher pH levels.     

静宁苹果市场的特点

在世纪之交．苹果市场波动很大,导致大面积苹果园被毁。据统计,2001-2005年全国苹果园净减100万hm^2。而甘肃静宁始终保持苹果快速发展态势,苹果栽培面积已由改革之初的零星种植发展到目前的4．67万hm^2。其中一个重要的原因是静宁苹果市场很独特．逐渐成熟完善的苹果产地交易市场．促进了静宁苹果面积的快速扩大和种植效益的大幅提升。现将静宁苹果批发交易市场的特点总结如下。     

Response of evergreen perennial tree crops to gibberellic acid is crop load-dependent: II. GA3 increases yield and fruit size of ‘Hass’ avocado only in the on-crop year of an alternate bearing orchard

Despite problems of low fruit set, small fruit size and alternate bearing, the Hass cultivar dominates commercial avocado production worldwide. To increase yield and fruit size, gibberellic acid (GA₃) (25 mg L⁻¹) was applied at different stages of ‘Hass’ avocado tree phenology: (i) mid–late April (flower abscission), end of June–beginning of July (fruit abscission and beginning of the exponential phase of fruit growth), and mid-January (beginning of pre-harvest fruit drop); (ii) end of June–beginning of July; and (iii) mid-September (near the end of the major fruit abscission period; period of exponential fruit growth). In both years of the research, applications of GA₃ in April and June–July were within the periods of intense flower and fruit abscission, respectively; fruit abscission was low in September and January. Maximum air temperature was not related to flower or fruit abscission. In the on-crop year (391 fruit per untreated control tree), a single application of GA₃ at the end of June–beginning of July significantly increased total yield (kilograms only) and yield of commercially valuable fruit (178–325 g/fruit) (as kilograms and number per tree) compared with the control (P < 0.0001). GA₃ applied in September increased total yield (kilograms only) and yield of commercially valuable fruit (kilograms and number per tree) to values intermediate to and not significantly different from all other treatments, except trees receiving multiple applications of GA₃. This treatment reduced total yield and yield of commercially valuable fruit (kilograms and number per tree) relative to all treatments (P ≤ 0.0002). In contrast, during the off-crop year (32 fruit per control tree), no GA₃ treatment had a significant effect on yield or fruit size compared with the control and all other GA₃ treatments. For ‘Hass’ avocado, there was no negative effect from applying GA₃ at the end of June–beginning of July in both the off- and on-crop years; 2-year cumulative total yield and yield of commercially valuable fruit were increased by 27 kg (128 fruit) and 22 kg (101 fruit) per tree, respectively, above the yield of untreated control trees (P < 0.0001).     

苹果大年业内分析今年苹果产量增加、质量提高、价格稳中有降

日前，记者从青岛召开的2006全国的苹果产销形势分析和市场协调会议上了解到：今年是苹果大年，如果后期没有大的自然灾害，苹果增产已成定局，全国产量预计将比去年增产约25％，总产量将达到2500万吨左右，质量也将好于往年，收购价格与上年相比将稳中有降。     

世界果品生产贸易新趋势（下）

2.2世界果品贸易流向的改变 随着阿根廷向巴西不断增大苹果、梨的出口，同时更多的巴西热带水果销往阿根廷，南美自由贸易协定国间的贸易迅速增加。1991年，在南美自由贸易协定签订之前，阿根廷、巴西、巴拉圭、乌拉圭等国间的关税较高，随关税下调，更多消费者能够承受进口果品的价格，因此刺激了市场需求。智利最近加入南美自由贸易组织后也获得了效益，智利现在新鲜果蔬出口总额的20％以上是运往拉丁美洲地区，而1993/94年度出口拉丁美洲的量仅占总量的16％。 尽管这些南半球国家果品、蔬菜生产季节与美国和欧洲季节相反，但仍然存在出口…     

Relations between the concentration of diffusable and extractable gibberellin-like substances and the alternate-bearing behaviour in apple as affected by chemical fruit thinning

The levels of diffusable and extractable gibberellin-like substances (GA_s) of apple fruits were investigated in the alternate-bearing ‘King of the Pippins’ and the regularly fruiting ‘Golden Delicious’, using the barley endosperm bioassay. During 1977 and 1978 there were marked differences between the two cultivars in both the chronological appearance and the absolute amounts of diffusable GA_s. The application of fruit-thinning chemicals (carbaryl, ethephon, NAAm) to ‘King of the Pippins’ suppressed the early increase of GA_s in diffusates, which normally occurs during the second week after full bloom. The following year, the thinned trees exhibited heavy flower- and fruit-set, while the untreated control trees showed a very poor bloom. The later appearance of the GA peak in diffusates from fruits of ‘Golden Delicious’ (5 weeks after full bloom), was not accompanied by a similar inhibitory effect on subsequent flowering.In contrast to their effect on the levels of diffusable GA_s, the thinning-treatments caused no real change in the amount of extractable GA_s, which was very similar in fruits from both cultivars.     

The use of peroxidase polymorphism in the identification of apple scion cultivars

Polyacrylamide gel electrophoretic separations of peroxidase isoenzymes from shoot bark tissues of apple show patterns that are consistent for cultivar and independent of season, age or eco-physiological condition of the plant. This permits cultivar identification both throughout the year and during the juvenile phase of growth. Based on peroxidase zymograms, 108 apple cultivars from collections at the National Fruit Trials, Brogdale, and East Malling Research Station were reproducibly classified into 26 phenotypic groups.     

The response of the mushroom crop to the pattern of watering

When trays were given the same total amount of water, the manner in which it was apportioned throughout the pre-cropping and cropping periods had significant effects on the mushroom crop.Delaying the start of watering, without affecting the total amount given, retarded the start of cropping slightly, reduced yield and allowed more mushroom mycelium to cover the casing layer. Where the casing was covered extensively with mycelium, fruiting was reduced even when subsequent watering removed some of the mycelial covering. In the more productive areas of the trays with excessive mycelial overlay the mushrooms were closely packed and thus of poor quality and difficult to pick.Comparison of various ways of apportioning the total amount of water applied between pre-cropping and cropping showed that yield was optimum when watering was spread regularly and evenly throughout pre-cropping and cropping.Cased trays which were not watered produced in 6 weeks a yield of mushrooms about two-thirds of that from trays watered regularly, thus showing that there is a considerable reserve of water in the compost and casing on which the crop can draw.