The components of yield in black currants

Examination of black currant data relating berry weight, seed number and position on the raceme indicates that there is an upper limit of berry weight (potential weight) for each position on the raceme. This limit may be a genetic character of the cultivar.A suitable combination of seed number and rate of development is necessary to reach potential berry weight and berries may be sub-maximal from deficiency in either or both factors arising from different causes.Berries seem to develop within a range of potential sizes so that differences in numbers of berries do not affect the mean size.Crop yields can be related to 5 variable components affecting fruit number and to 2 affecting fruit size, apart from the possible genetic limit. Of these components 5 operate in the pre-fruiting year ending with the termination of flower initiation, and 2 affect performance in the fruiting year.Partitioning the shortfall in numbers and size to the variable components can direct attention to deficiencies in particular phases of development causing reduced yields.     

Propagation of black currants by single-noded cuttings

Single-noded cuttings were taken from four regions of one-year-old black currant shoots in September 1966, before winter chilling had begun, and stored at 1 °C for 0, 4, 8 or 12 weeks before being inserted in seed trays and placed in a growth room at 20 °C, with continuous illumination. Cuttings from the lower half of shoots rooted and grew well with or without chilling, but cuttings from the upper middle quarter of shoots rooted better after 8 or more weeks in cold storage. Few cuttings from the top region rooted, even after 12 weeks of cold. Cold storage accelerated subsequent bud burst, as did 2 minutes’ treatment with GA₃ at 100 ppm.

In the field, dormancy of buds on intact plants increased after September and was pronounced in December. However, cuttings from all regions of shoots taken from plants in the field in January and immediately placed in the growth room rooted and grew well     

Plant spacing and cultivar affect melon growth and yield components

The objective of this study was to evaluate the effect of cultivars and in-row spacing on vegetative growth and yield components in melon (Cucumis melo L.). The cultivars ‘Early Dawn’ (ED), ‘Superstar’ (SS) and ‘Medoro’ (ME) were grown in rows 1.5 m apart at plant spacing 0.6, 0.9, 1.2 or 1.5 m. Cultivars ED and SS were grown in 1998 and 1999, while ED and ME were tested in 2000. The main vine length, diameter, number of leaves and lateral branches were highest at 1.5 m in-row spacing in 1999 and 2000, while there was no influence of plant spacing on observed growth parameters in 1998. ED performed better compared with other two varieties, mostly due to more fruit per ha and per plant. Yield was significantly decreased with increased plant spacing in all 3 years of research. At in-row spacing of 1.5 m yield was in average 25% lower than at 0.6 m spacing. Average fruit weight slightly increased with plant spacing up to 1.2 m, even though the differences were significant only in 1999. Small differences among cultivars were also found. Number of fruit per ha decreased linearly while number of fruit per plant increased linearly as plant spacing increased in all cultivars except SS in 1999.     

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.     

The influence of tree training and plant density on growth,yield components and yield of Arabica coffee cv. Ruiru 11

Assessment of tree growth and yield components of Coffea arabica L. cv. Ruiru 11, as influenced by tree training on single or two-stem systems at densities between 1600-4800 trees per ha during the first production cycle was carried out at Ruiru, Kenya over three years. Trees trained on the two-stem system tended to be taller than those on singlestems. Although the results were not clear, trees at low plant densities had thicker stems irrespective of the training system. The total number of primary branches was significantly higher on trees trained on the two-stem system. However, bearing primaries and productive wood were higher on the single-stem system during the first year of production. The number of bearing primaries and productive wood increased in subsequent production years on the two-stem system. Training trees on the two-stem system significantly depressed yields in the first production year by 245 to 842%, irrespective of plant density. Yields of clean coffee increased significantly with tree density irrespective of the tree training method. Yields over the production period increased by 33, 45,27 and 9% with increases in planting densities from 1600 to 2400, 2400 to 3200, 3200 to 4000 and 4000 to 4800 trees per ha, respectively. However, yields increased at a decreasing rate at densities above 3200 trees per ha. The proportions of the large grade ‘A’ sized coffee beans were not significantly affected by the treatments. It was concluded that it is possible to raise two stems during the first production cycle of ‘Ruiru 11’, although this might not be economical. Single stems would be preferred and a high plant density of between 3200-4000 trees per ha would be optimum during the first coffee production cycle.     

Seasonal and cultivar differences in salt-induced changes in antioxidant system in tomato

Salt stress has been applied to improve the quality of tomato, but detailed information about the changes in antioxidant systems in salt-stressed fruit is not available. In this study, we examined the effect of salt stress on oxidative parameters, antioxidant content and antioxidant enzymes in two tomato cultivars during two cropping seasons. Salt stress was applied by adding 100 mM NaCl to the nutrient solution. We show that tomato fruits have antioxidant systems to protect themselves from salt-induced oxidative stress. This finding is supported by the lipid peroxidation and hydrogen peroxide levels, which remained unchanged under salt stress conditions. However, these antioxidant systems depend on cultivars and cropping seasons. In the summer crop, the antioxidant systems in salt-stressed ‘House Momotaro’ can be attributed to the enzymatic reactions of ascorbate peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2), while those in salt-stressed ‘Mini Carol’ can be attributed to their non-enzymatic reactions of ascorbate and glutathione. In the winter crop, the antioxidant systems were not influenced by salt stress in either cultivar. However, the proline content increased in both cropping seasons and cultivars. The seasonal and cultivar differences of salt-induced changes in the antioxidant systems may result from cultivar differences in antioxidant capacities and the interaction between salt stress and growth conditions such as temperature and solar radiation.     

种植密度对辣椒DU01光合特性及产量的影响

以适于一次性采收的辣椒新品种DU01为试验材料,设置5个种植密度,对DU01的光合特性及产量构成因素等进行研究.结果表明,盛果期后,DU01的叶面积、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)随着密度的增加而降低,叶绿素a(Chla)、叶绿素b(Chlb)、类胡萝卜(Car)和总叶绿素(Chlt)含量随...     

The influence of photoperiod and plant density on yield of winter-grown gladioli in Queensland

The yields of inflorescences, corms and cormlets, and the inflorescence quality of winter-grown gladioli in south-east Queensland, were studied under 2 daylength regimes, 3 plant densities (150 000, 300 000 and 450 000 corms ha^?1) and 3 plant arrangements (bed, double row and single row). The daylength treatments were the natural daylength (12.3–14.5 hours) and a 24-hour photoperiod treatment in which natural daylengths were extended using incandescent light of an intensity of 150 lux. Two cultivars were used.Extending the photoperiod to 24 hours delayed flowering by approximately 15 days, and increased the number of inflorescences harvested from low, medium and high density treatments by 20, 91 and 169%, respectively, when compared to the inflorescence yield from these density treatments under natural daylengths. The quality of the inflorescences from the high-density treatment receiving the 24-hour photoperiod was similar or superior in all quality characteristics to that of inflorescences grown under the most favourable density treatment under natural daylengths (150 000 corm ha^?1). Plant arrangement had little effect on the number of days to flowering or inflorescence yield but inflorescence quality was improved when plants were grown in a double-row arrangement compared to those from the bed or single-row arrangements. Extension of the photoperiod had no effect on the number of new corms per plot. However, the average weight of new corms and the weight of cormlets per plot and per corm were reduced by approximately 32, 71 and 63%, respectively, when compared to the results obtained from plants grown under natural daylengths. These results suggest that flowers compete for available photosynthates with corms and cormlet development.The economic feasibility of extending photoperiod for the commercial production of winter-grown gladioli in south-east Queensland is discussed.     

The effect of 4 storage treatments on seed yield components of 3 onion inbreds

Onion bulbs of 3 inbred lines were stored during the winter in 4 different storage temperature regimes. Traits directly and indirectly associated with seed production were studied the following summers. The inbred lines differed in their responses and many traits were affected by the storage treatments. The storage treatment of 10°C for 12 weeks followed by 2° C for 12 weeks resulted in a significantly higher seed yield than did storage at 2° C throughout the entire period. Inbred 2399 had a higher seed yield than the other inbreds. Associated with high seed yields of 2399 was early flowering, a high number of leaves/bulb, tall seed stalks and a high number of florets/bulb.     

常山胡柚皮中挥发性成分分析

为进一步研究常山胡柚皮中挥发油和挥发性化学成分的不同,采用水蒸气蒸馏法和有机溶剂提取法分别制备常山胡柚皮中的挥发油和挥发性成分,利用气相色谱-质谱联用仪,结合计算机检索标准数据库对其化学成分进行分离和鉴定,并对浙江常山胡柚果皮的49种挥发油和挥发性成分进行了比较。发现这2种组分中只有7种化合物相同;鉴定成分多为萜烯类化合物,共有26种,占总量的50%以上。     

The influence of illumination levels of daylength extension on yield of winter-grown gladioli in Queensland

The yields of inflorescences, corms and cormlets, and inflorescence quality of winter gladioli were studied under varying illumination levels of 12 hour daylength extension ranging from 0 to 333 lux. The illumination level of the daylength extension for each plot depended on its distance from 2 tungsten halogen light sources mounted at 6 m above ground on poles spaced 8 m apart. The lamps were adjusted for wide beam distribution and aimed at points on the ground 8 m from the base of the poles.Inflorescence yield was increased by increasing the illumination level of daylength extension. The relationship between horizontal illumination level in lux (x) and number of inflorescences (y) was described byy=27.3?10.9 exp(?0.02x)Ninety-seven % of maximum inflorescence yield was obtained at a daylength extension illuminance of 144 lux, while 97% of the maximum number of florets per spike and the other flower quality characteristics were obtained at a daylength extension illumination level of approximately 100 lux. Ninety-seven % of the maximum number of days to flowering was approached at a daylength extension illuminance of 45 lux.There was no clear relationship between the illumination level of daylength extension and number and weight of new corms, or the average weight of each new corm. However, the weights of cormlets per plot and per new corm were higher from plants which received no daylength extension.The commercial application of tungsten halogen lamps to provide daylength extension for winter gladioli production is discussed.     

Combining-ability for yield and its components in tomato

In a line × tester analysis in tomato (Lycopersicon esculentum Mill.), the adequacy of 4 testers for combining-ability has been studied. The general and specific combining-ability (GCA and SCA, respectively) variances indicated that the role of non-additive gene action for most of the characteristics and heterosis breeding for the improvement of these traits have been enhanced. LE.758 among the lines and LE.68 among the testers were identified as the best general combiners for yield and its important components. A close agreement between GCA and per se performance was observed among the testers. For selection of hybrids, per se performance as a reliable parameter in preference to SCA effect is indicated.     

优质加工型苹果品种瑞丹早期丰产栽培技术

瑞丹（JUDAINE）为法国制汁专用苹果品种,我校于2000年从山东农业大学引进栽培。通过6年的试验观察,认为该品种栽培容易,早果丰产,果实含糖量高、含酸量极高,是一个适宜本地栽培的优良制汁专用苹果新品种。2005年为江苏省丰县各果汁加工厂提供了近110t优质苹果,有力促进了当地果汁加工出口企业的发展,提高了当地果农发展加工型苹果的积极性。     

The influence of soil moisture stress and plant populations on the yield of pickling cucumbers

A 2-year study was conducted on the effects of irrigation and plant populations on yield of pickling cucumbers (Cucumis sativus L). The main plot treatments were no irrigation or irrigation at a frequency necessary to prevent the available soil moisture (ASM) from falling below 25 or 60%. The sub-plots consisted of 49 000 plants/ha (multi-harvest) or 123 000, 185 000 and 247 000 plants/ha (once-over harvest). Irrigation substantially increased the yield and improved the grades of both multi-harvest and once-over harvest pickling cucumbers. Highest yields were obtained from the multi-harvest operation with irrigation at 60% ASM level. Maximum yields were obtained with irrigation at 25% ASM level in the once-over harvest operation. All population densities of the once-over harvest operation produced similar yields when not irrigated. Increasing plant populations from 12 to 25 plants m^?2 did not significantly affect yields under irrigated conditions.     

花后温度和湿度条件对台农1号杧坐果率的影响

为探索杧果坐果率与开花后温度和湿度条件的关系,以台农1号杧为试材,应用生物统计学方法计算分析了80个温度和湿度自变量与不同时期坐果率的相关关系。结果表明:(1)花后14d的坐果率受温度和湿度条件影响最大。(2)花后7d两性花坐果率与花后1～6d平均空气相对湿度呈显著直线线性负相关,与花后1～2d、1～4d、1～6d的平均最高温度、平均温度、平均最低温度、>10℃积温无显著相关关系。(3)花后14d坐果率与花后6～10d的平均最高温度、4～10d平均温度、2～10d平均最低温度、4～14d>10℃积温呈显著或极显著的直线相关;与花后1～14d平均最高温度、平均温度呈显著的多项式线性相关;与花后1～14d平均空气相对湿度呈极显著的直线线性负相关。(4)花后25d坐果率与花后1～10d的平均最高温度、平均温度、>10℃积温以及花后1～14d平均最高温度呈显著的多项式线性相关。(5)有利于花后14d坐果的花后4～14d的下限平均温度为20.6℃,最适温度为24.7℃。     

The effect of intensity of nutrient supply on growth,yield and leaf composition of black currant grown in sand culture

Black currants were grown from cuttings in sand culture to study the effect of intensity of nutrient supply on growth, yield and leaf composition of the plants. An increase in frequency of nutrient supply gave an increase in the amount of fruiting wood produced in 1966 and in the yield of fruit in 1967. Leaf phosphorus concentrations ranged from 0·48-1·61% as the intensity of nutrient supply increased; fractionation of phosphorus in leaf samples showed that the largest part of this variation was accounted for by differences in the inorganic phosphate content of the leaf. Leaf concentrations of N, K, Ca, Mg, Fe, Cu, Mn and Zn were little affected by the experimental treatments.     

Processing yield of the carrot cultivar Esplanada as affected by harvest time and planting density

Cenourete^® is a minimally processed carrot root similar to the American product known as ‘baby-carrot’. This product is obtained through peeling and abrasion of cylindrical carrot root segments. The cultivar Esplanada is well suited for the production of Cenourete^® due to its characteristics of long length and cylindrical root shape as well as uniform dark orange root colour. For Cenourete^® production, the root should be less than 25 mm in diameter. However, it is well known that root size is influenced by planting density and harvest time. Therefore, the adjustment of the cultural practices would be necessary to increase root yield aimed for Cenourete^® processing. The recovery of Cenourete^® from ‘Esplanada’ was studied under two between-line spacings: 20 cm (5 transversal lines/m) and 12.5 cm (8 transversal lines/m). Roots were harvested at 80, 90, 100 and 110 days after sowing. Cenourete^® yield ranged from 2.39 ± 0.37 to 10.75 ± 1.07 t/ha depending on the combination of harvesting date and between-line spacing. These values corresponded, respectively, to a percent Cenourete^® yield recovery of 3.3 ± 0.7%–28.6 ± 2.8% in relation to the total root production. It was concluded that higher yield is obtained with 12.5 cm between-line spacing than with 20 cm between-line spacing and with earlier harvest (80–90 days) than with late harvest (100–110 days).     

A possible influence of pedicel dimensions on fruit size and yield in strawberry

During the investigation of factors affecting fruit size in strawberry, the physical characteristics of the fruiting structure were examined as a possible cause of size limitation in fruit. The greatest total weight of fruit which can be sustained at any one time on an inflorescence appeared to be related to the dimensions of the main peduncle. At this limit the fruit yield may be no more than half the potential fruit yield of the inflorescence, indicating that unless ripe berries are removed development of immature berries may be restricted or stopped.This implies that under conventional management high yields will require frequent picking to achieve full potential. Once-over cropping, as in mechanical harvesting, may entail accepting yields one half or less of those now being obtained by conventional hand picking.It is suggested that if evaporative losses from ripe berries can be reduced, as by cloching, tunnelling, windbreaks, or plant breeding for less permeable cell walls, increased yields might be expected.     

Relationships between yield components in first cropping year and average yield of short-day strawberries over two main seasons

Fruit productivity of the garden strawberry, Fragaria × ananassa Duch., is a result of interrelationship of yield components contributing to it directly or indirectly. The main aim of the investigation was to find out whether there exists any general regularity, connecting relationships between main yield components in first cropping year to average yield of two main seasons. Two successive studies which primarily included 23 genotypes, differing in yield components and productivity, each, were planted in field conditions in spring 1999 and in spring 2000, respectively, and used for data collection to explore the material obtained in them. Four key yield components and average yields were measured in both cropping years, after which all possible ratios between the components were calculated to find out: first, the relationships to be influential on average yield of the two main seasons; second, type of the probable yield dependence upon the ratios; and, third, their values leading to high yields. Two ratios between the key yield components in first season, i.e.: inflorescence number per plant to branch crown number per plant, named ratio 1, and fruit weight (g) to flower count per inflorescence, named ratio 2, have been found to be related to average yield. An irregular surface, with a single peak falling approximately in its centre, describes average yield dependence upon the ratios. Values of the two ratios falling in the range of 1.0–1.6 each, provided that they are close, have enabled plants to produce high yields cumulatively over two first years. The paper highlights the most important differences in plant behaviour and yield dynamics of strawberry genotypes, depending on combinations of the ratios in first year, discerning those, which have been particularly advantageous to obtain very high yields, and are influenced by negative environmental factors least of all. Based on the findings, a method of predicting of average yield has been developed. Following this, usefulness of the method and possibilities of its using in strawberry breeding and variety trial are discussed.     

The effect of phosphorus applications on the strawberry cultivar Acadia

Total yields from the strawberry cultivar Acadia over a three-year period were not influenced by applications of 20% superphosphate supplying up to 199.2 kg P/ha. Following an application of dolomitic limestone, 40 to 60 ppm P were found in the soil and 0.23 to 0.31% P in the leaves at flowering. These values were associated with optimum yields. In a greenhouse sand culture study plants receiving 5 ppm of nutrient P produced maximum top weight at leaf-P values below levels normal for other cultivars.