The Relation Between the Rate of Respiration of an Apple Fruit and its Content of Protein: I. The Value of this Relation Immediately After Picking

Tomato plants of two varieties (Potentate and Immuna) were grown for four seasons with different combinations of magnesium and potassium sulphate in heated glasshouses. Magnesium sulphate was applied either to the soil or as a foliar spray, with untreated plots as controls ; these treatments were combined factorially with two levels of soil potassium. The effects of the treatments on the magnesium and potassium contents of the soil, as extracted by 0 5N-acetic acid, are recorded.

Chlorosis of the leaves was widespread where magnesium was not applied. Foliar spraying effectively controlled the deficiency symptoms; treatment of the soil with magnesium sulphate was only partially successful in the first season but increasingly satisfactory thereafter.

In only one of the four seasons was there a significant increase in yield J due to the correction of magnesium deficiency. In that year (1959) the yields at the higher level of potassium were increased by 15%and 12%by the soil and spray treatments respectively (P=0·001).

The magnesium treatments slightly improved fruit quality as assessed by visual grading, mainly at the very low level of potassium in the last two seasons. The dominant factor affecting fruit quality was potassium, however, which markedly increased the proportion of uniformly coloured fruit and reduced the incidence of ripening disorders.

It is suggested that magnesium deficiency should be controlled by supplying this nutrient rather than by reducing the application of potassium salts below the quantity necessary for high fruit quality.

Variety Immuna gave higher yields and better quality fruit than Potentate throughout the trial.     

A Supplementary Note on Fruit Spraying With A Glyoxalidine Preparation in 1948

An instrument is described for measuring the compression of tomatoes under a known weight. This has been used to study the effect of some of the many factors likely to influence the firmness of tomatoes. The measurements of compression were made along the axis from the calyx to the stylar scar.

The compressibility of the fruit increased threefold during ripening from the mature green to the fully red condition. The firmness of the fruits of two varieties increased with the number of locules per fruit.

Comparison of the fruits of eight varieties showed marked differences in firmness; the even-ripening form of Potentate (Potella) was the firmest variety tested, and Harbinger the softest. The compression readings were significantly and negatively correlated with the percentage of walls and placentae, and with the thickness of the fruit as measured along the axis of compression. Fruit size and the percentage of walls were themselves positively correlated.

Both lime and potash significantly increased the firmness of the fruit of variety Moneymaker. Phosphate had a slight beneficial effect, but no significant response was found to nitrogenous fertilizer.

Tomatoes of two varieties, grown with different combinations of shading, day temperature and watering, were examined. Fruits grown at a day temperature of 85° F. (29-5° C.) were 30% softer than those grown at 65° F. (18-3° C.). Some evidence was obtained that heavy watering softened the fruit, particularly under hot, shaded conditions.

Freshly-picked tomatoes of three varieties approaching the fully red condition continued to soften rapidly during storage (74° F.), the effect being highly significant even within three days.

The effect of fruit size on the compression readings, and on percentage compression, is discussed.     

The Effects of Nitrogen,Phosphorus, Potassium,Magnesium and Lime in Factorial Combination on the Size and Shape of Glasshouse Tomatoes

The effects of nutrition on tomato fruit size and shape are summarized, based on the results of a factorial trial in heated glasshouse borders. The varieties grown were Potentate, J168 and Moneymaker.

The average weight per fruit, calculated from total weights and numbers, was decreased by potassium and magnesium sulphates. Both high nitrogen (760–830 lb. N per acre) and low nitrogen (30–150 lb. N) decreased the weight per fruit as compared with the intermediate nitrogen level (300–380 lb. N). The weight per fruit of varieties J168 and Moneymaker, grown for two seasons, was decreased significantly by high phosphorus in one year and increased by lime in both years.

The uniformly coloured and regularly shaped fruits were graded into four commercial-size categories. Expressed as percentages of the sum of these four grades, the proportion of large fruits showed nutritional responses generally similar to those for average weight per fruit, with opposing trends in the smaller size categories.

The proportion of somewhat irregularly shaped fruit in the uniformly coloured categories, studied for six seasons, was appreciably affected by nutrition. Fruit shape was improved by high potassium and magnesium, and also by nitrogen deficiency. High phosphorus affected the shape adversely. Liming improved the shape of fruit of variety Potentate in three out of four seasons, but the opposite effect was found with J168 and Moneymaker in the final season.

The relation of fruit size and shape to soil salinity is discussed.     

Pollination and Environmental Factors Affecting Fruit-Setting in Spencer Sweet Peas,Lathyrus Odoratus L.

Hand pollination, flower-shaking or tripping of the keel petals, was necessary to obtain adequate self-pollination of Spencer type sweet peas in glasshouses.

The effect of low light intensities on fruit-setting was studied by growing plants under muslin of different weaves. During long days a small but significant increase in the fertility of a summer-flowering variety of sweet pea occurred on plants shaded by thin muslin, provided that high temperatures and minimal soil watering were maintained. The more intense the shading treatment, the greater was the amount of flower-bud abortion and this abortion was responsible for lower yields of fruits per plant. A significantly smaller number of flowers set fruit as a result of a heavy watering treatment that led to a slight waterlogging in the pots.

By comparing the fruit-setting rate with temperatures which prevailed in a series of five-day periods in spring and summer, it was found that, for unit rises of temperature, the setting rate increased exponentially. A regression equation was computed for the prediction of setting rates.

Low temperatures in the week before anther-dehiscence were found to depress fertility, no matter how favourable the post-pollination temperatures.     

Effects of shading and thidiazuron + oil treatment on dormancy breaking,blooming and fruit set in apricot in a warm-winter climate

Overcoming dormancy represents one of the major limitations to fruit tree production in warm areas. High temperatures during the chilling period have a negative effect on breaking of dormancy. Shading of trees reduces the incidence of radiation and the temperature. Previous works on shading did not take into account the stage of dormancy. The aim of this work was to evaluate the effects of shading during different periods of endodormancy, in an area having relatively warm winters, and the effects of a treatment of thidiazuron ([TDZ] N-phenyl-N-1,2,3-thiodiazol-5-il-urea) and winter oil, on apricot blooming, fruit set and ripening. The study was carried out during three years which showed marked differences regarding chilling accumulation. Autumn shading did not affect blooming or harvesting. Regarding harvest date, 2–3 days of precocity were achieved by shading during endodormancy, relative to the control. The TDZ + oil treatment increased blooming percentage, made blooming more uniform and brought forward the blooming (by 7–14 days) and ripening (3–8 days) dates. However, pistil abortion percentage was strongly increased by using TDZ and winter oil when there was low chilling accumulation, which led to reduce fruit set percentage. Shading during late endodormancy produced 5 days precocity for the harvest date in the year with lower chill accumulation. Shading of trees during endodormancy and TDZ + oil treatment could be suitable for increasing precocity in warm-winter climates. Significant year-to-year variation has been shown for blooming, pistil abortion, fruit set and fruit/bud percentages. Correlations among these variables are also discussed. Under conditions of marginal chill accumulation, the distribution of chilling during autumn and winter had an important role in the overcoming of dormancy, blooming and fruit set.     

遮阴对日光温室柑橘生长及生理特性的影响

以4年生枳砧砂糖橘为试材,研究不同遮阴处理对温室柑橘树冠微环境、柑橘生长及叶片生理特性的影响。结果表明:未遮阴的日光温室条件下,中午光合有效辐射强、温度高、相对湿度低,柑橘叶片净光合速率日变化呈"双峰型",有明显的光合"午休"。遮阴可显著降低光合有效辐射,降低柑橘树冠温度,增加树冠相对湿度,柑橘叶片净光合速率日变化表现为"单峰型"。遮阴处理对新萌发夏梢生长表现出抑制作用,随着透光率的降低,柑橘枝长、枝粗、枝条数降低。遮阴处理使柑橘叶片单叶面积增大,叶片变薄。遮阴使叶绿素b含量增加,随着透光率的降低,叶绿素a/b值变小。一层遮阴柑橘幼果坐果率比对照提高了16.44%,二层遮阴处理坐果率为0。     

Effect of overhead shading on yield and fruit quality of kiwifruit (Actinidia deliciosa)

Summary

Kiwifruit vines (cv. Hayward) were shaded from early spring until fruit harvest at levels of 100% (control), 70% or 45% full sun. Although shoot growth during the early part of the season was not significantly affected by the shading, the percentage bud burst was reduced and the time of full bloom appeared to be slightly delayed. The mean fresh weight of individual fruits was significantly reduced by shading, and fruit on shaded vines reached commercial harvest maturity of 6.2% soluble solids two to three days later than those on unshaded vines. During cool storage, fruit from vines grown under 45% full sun were slightly but consistently less firm and had lower soluble solids concentrations than unshaded fruit. No differences in the starch or total sugar contents were found between shaded or unshaded fruit, either at harvest or after cool storage. Shading vines did not affect either the colour (HunterLab values) or the chlorophyll concentration of fruit. Possible implications of these results for commercial orchards are discussed.     

The Effects of Nitrogen,Phosphorus, Potassium Magnesium and Lime in Factorial Combination on Ripening Disorders of Glasshouse Tomatoes

The effects of nutrition on the incidence of fruit ripening disorders are described, based on studies of three varieties of tomato (Potentate, Moneymaker and J168) grown with 72 combinations of fertilizers in heated glasshouse borders. The treatments included three levels each of nitrogen and potassium in factorial combination with two levels of phosphorus, magnesium and lime.

Potassium sulphate markedly decreased the overall percentage of unevenly ripened fruit from all three varieties. Magnesium sulphate had a similar but smaller effect; the response to magnesium was greatest at low levels of potassium. The higher level of phosphorus increased the proportion of unevenly ripened fruit, the combination of low potassium and high phosphorus having a particularly adverse effect. The responses to nitrogen were complex and differed between varieties. Lime increased the proportion of unevenly coloured fruit from varieties Moneymaker and J168, significantly in the high nitrogen plots. Numerous other interactions between nutrients were found.

The effects of the treatments on specific forms of ripening disorder were recorded, including greenback, yellow and green blotch, and waxy fruit. Potassium decreased the incidence of all forms of ripening disorder. High phosphorus increased the proportion of blotchy and waxy fruit, but significantly decreased the incidence of greenback in variety Potentate.

Although the intermediate level of potassium in this trial (871 lb. K₂ 0 per acre) had previously been found sufficient for maximum yield, significant improvements in fruit quality were obtained at the highest level (1,742 lb. K₂O per acre).     

夏季遮阴对猕猴桃园生态因子和光合作用的影响

以中华猕猴桃翠玉和美味猕猴桃米良一号为试材,研究高温季节(7月初-9月底)不同遮阴强度(0、25%、50%、75%)对猕猴桃园生态因子和光合作用的影响。结果表明:未遮阴的自然条件下,猕猴桃叶、果表面温度极高,蒸腾强烈,叶片光合作用出现严重的"午休"现象,表明树体处于严重的胁迫状态;遮阴可在一定程度上降温增湿,改善猕猴桃冠幕微环境,大大降低叶温和果温,有效消除叶片光合作用的"午休"现象。翠玉适宜的遮阴强度约为25%,米良一号约为50%。遮阴对翠玉叶片蒸腾速率无显著影响,但对米良一号的影响较大。可见,适度遮阴能有效缓解夏季高温强光对猕猴桃的危害,但过度遮阴有负面影响。     

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.     

番茄不同生育阶段遮荫对光合作用与产量的影响

 研究了番茄夏季不同生长阶段午间遮荫对光合作用、干物质分配和产量构成的影响。结果表明,不同时期遮荫使番茄初花期、盛花期和末花期午间气孔导度(Gs) 和胞间CO2 浓度(Ci) 增加, 75%遮荫显著降低净光合速率(Pn) , 但盛花期中度遮荫( 40%遮荫) 的Pn 随着遮荫时间的增加逐渐上升, 在末花期阶段表现尤为明显, 8 d 平均Pn 比对照增加22%, 蒸腾速率也显著增加。在初花和盛花期, 重度遮荫( 75% 遮荫) 显著降低根、茎干样质量, 但中度遮荫使末花期的根、茎干样质量分别比对照( 不遮荫) 增加43%和22%, 叶干样质量的增加不明显。初花期遮荫对果实产量影响不明显, 但盛花期75%遮荫的总产量和有效产量显著降低; 在末花期, 与对照相比, 40%的遮荫使总产量和有效产量显著增加, 单果质量亦增加35%。这些结果表明, 末花期午间适度遮荫有利于提高光合作用, 增加干样质量和经济产量。     

Thinning apples via shading: an appraisal under field conditions

Summary

Fruit development and the fate of fruits was followed on ‘Imperial Gala’ apple (Malus × domestica Borkh.) trees thinned chemically or using shading. The percentage fruit drop, fruit growth rates using callipers and electronic gauges, and whole tree gas exchange rates were measured before, during, and after covering with a shading cloth that blocked 90% of solar radiation, applied for 1 week starting 30 d after full bloom (DAFB). While fruits were thinned to similar crop loads and all reached a similar size at harvest, their growth patterns reflected the treatments applied, with fruit growth slowing down and fruit dropping sooner in chemically-thinned trees which were treated earlier, than in the shading treatment, which took place later. Daily fruit growth patterns changed and were greatly reduced under shading, as were the net carbon exchange rates (NCER), both in total per tree and per unit of light intercepted by the trees. Regression analysis of the NCER per unit of light intercepted revealed no difference between the two treatments before and after shading, but a significantly lower relationship during shading. This work supports the hypothesis that C-starvation may induce fruit abscission at approx. 30 DAFB. Fruit growth patterns, and their changes during shading, were consistent with this hypothesis. This method of thinning, may be of interest to reduce the use of chemicals, and in organic fruit growing. However, before it can be adopted, a method to estimate the length of the period of shading is required.     

水分调控对核桃叶片结构和产量的影响

 测定了沟坡梯田核桃园采用不同水分调控措施后, 核桃叶片结构指标和单株产量。结果表明,灌水225 kg/ 株、灌水150 kg/ 株、覆膜、覆草处理对核桃叶片结构影响显著, 灌水225 kg/ 株处理使核桃增产43. 1 % , 中度修剪和覆草处理增产29 %以上。     

Effects of summer day-time temperature on sugar content in several portions of watermelon fruit (Citrullus lanatus)

Summary

Effects of temperature on the sugar content of watermelons were investigated in the outer, middle and central portions of the fruit, respectively. Cubic boxes covered with transparent plastic ®lm (designated as the ®lm covering) and well ventilated wooden slats (designated as the shading), were put on watermelon fruits from 0500 to 1800 hours for 10.d from day 30 after anthesis (daa). Flesh temperature at all portions was highest in the ®lm covering and the lowest in the shading. Rind thickness was least in the shading. Sucrose content was high in the middle portion of the fruit in the shading, but was low in the ®lm covering. Glucose and fructose content was high in the central portion of the fruit in the shading but low in the ®lm covering. Watermelon fruit with thin rind and high sugar content can be produced by lowering the day temperature by shading only the fruits.     

Historical Milestones,Current Methods,and Strategies Resulting in Year-Round Strawberry Production in Belgium

ABSTRACT

Strawberry production in Belgium has evolved from being a June-harvested crop grown in soil to a year-round crop grown in multiple production systems, as a result of the development of new cultivars and production techniques. Strawberry cultivation used to be one aspect of diverse family enterprises, but now strawberry farms are specialized. In the beginning, strawberries were only harvested in June. Covering the crop with plastic tunnels allowed the harvest to advance to May. Subsequently, an important innovation was the use of cold-stored plants in year-round plantings, which also allowed later production. This evolution in combination with the development of various cultivation systems using peat substrates (including table-tops, plastic greenhouses, and glasshouses) resulted in a strawberry production period from March until December–January. Recently, interest in assimilation lighting in glasshouses has increased. At first, this allowed advanced production in February, but now even winter production is possible, resulting in fresh Belgian strawberries 365 days a year.     

草莓果实发育过程中花色苷和黄酮醇类物质的形成

以‘赛娃’草莓为试材,研究了果实中花色苷和类黄酮类物质的形成机制。在‘赛娃’果实中共检测到12种花色苷和7种黄酮醇类物质。幼果期(盛花后15～25 d)果实内没有花色苷的积累,但黄酮醇类物质大量积累;随着果实成熟,花色苷含量逐渐增加,黄酮醇类物质含量降低;遮光导致花色苷和黄酮醇类物质的积累降低了70％～90％,尤其是花青素糖苷和槲皮素糖苷的含量降低了90％以上,表明遮光抑制草莓花色苷和黄酮醇类物质的积累,且对花青素、槲皮素合成的抑制明显高于花葵素和山奈酚。草莓果实类黄酮类物质代谢在发育前期主要向双氢槲皮素方向合成,果实成熟期主要向花葵素方向合成。     

Some Experiments to Investigate the Control of Apple Sawfly,Hoplocampa Testudinea (Klug), by Concentrate Sprays

Eight-year-old trees of Laxton’s Superb apple on M.II rootstock growing on loamy fine sand of low moisture retention were used to study growth and crop responses to different soil moisture conditions from 1953 to i960 inclusive. Water was applied when soil moisture tensiometers set at 1 ft. depth indicated tensions of : A, 10 cm. Hg ; B, 20 cm. Hg ; C, 50 cm. Hg. Treatment D was unwatered.

Water was applied to an area 12 ft. in diameter around each tree, which was about one-third of the ground area available to each tree. The average amount of water required by each treatment during a season was equivalent to : A, 4-1 ; B, 3-5 ; C, 2-1 inches over its whole area.

Comparison of soil moisture deficits in the unwatered plots in the very dry season of 1959 with amounts of water applied to the other trees suggested that the rate of water loss throughout the experiment was not seriously affected by the treatments applied.

The water treatments stimulated trunk and shoot growth ; growth differences between differently treated trees could be adequately explained in terms of soil moisture tension and root-occupied soil volume. Evidence was found of serious leaching under the wettest treatment, and this may have caused a lower growth and crop response to treatment A than to B in the later years of the trial.

Crop increases were directly related to growth increases. Despite the marked effects of water treatments on shoot numbers and on crop increase the growth and crop relationship was virtually unchanged.

Treatments A, B and C increased total crops by 40%, 46% and 25% respectively, and marketable crops by 44%, 55% and 42% respectively. There was no marked effect of treatment on fruit size, though the increased proportion of fruit of a commercial size from the watered trees was of importance. Treatment B provided the largest total and marketable crops, but treatment C provided the greatest increase in marketable crop for each inch of water applied.     

Phytotoxic Effects of Phenylmercuric Compounds Upon Certain Pear Varieties

In trials at East Mailing Research Station, extending over the years 1952 to 1959, chlorotic spotting, associated with loss of chlorophyll, and distortion of leaves occurred following post-blossom application to four pear varieties of phenylmercuric salts at 0?003% elemental mercury concentration.

On Conference, serious crop losses occurred in five successive seasons after application of 0?005% phenylmercuric chloride (PMC), and in two seasons when the acetate, dimethyldithiocarbamate, basic nitrate, oxinate, or the salt of a “ fixtan ’’ acid was applied, each at 0?003% elemental mercury concentration. All these organomercurials caused losses on Doyenné du Comice in both seasons, but Laxton’s Superb and Williams’ Bon Chrétien were less affected.

Fruit-bud formation was reduced, on Conference only, by PMC in three successive seasons and by all the salts in one season.

Reducing the dosage reduced the loss of crop, but even at 0?0025% PMC significant reductions in crop and in fruit-bud formation occurred on Conference.

Pre-blossom applications appeared to add little to the effects caused by post-blossom applications.

Applying PMC in one dose at a given stage of development caused greater crop loss than applying the same dose divided equally over two successive stages. Other evidence supports the view that the effects are not cumulative.

In the light of rainfall and temperature conditions recorded on the days following each post-blossom application in each year, crop loss must be expected following post-blossom application of sufficient organomercurial for scab control in any season on Conference and Doyenné du Comice ; on Conference, reduction of fruit-bud formation may also occur.

Although pear leaves are obviously damaged by phenylmercuric salts, it is likely that the effects on cropping are largely due to direct absorption and/or translocation of some form of mercury into fruit-buds and fruitlets.     

The Field Performance of Cold-Stored Strawberry Runners in South-East England

After 4-5 months’ storage at 30° F. (-1° C.), runners of Redgauntlet and Cambridge Favourite strawberries established well when planted in June or July. In contrast to freshly lifted runners, stored plants runnered fairly freely in the year of planting and grew with an erect habit. In the year after planting, plant habit was normal but more stolons were produced early in the season.

Deblossoming cold-stored runners after planting, though not necessary for satisfactory establishment, increased the subsequent yield. Cold-stored runners planted in late July and deblossomed in August cropped well in the following year, the total crop and in particular the yield of large fruit (> ? in. diameter) being similar in amount to that from fresh runners planted in early August. The weight of early fruit harvested from Redgauntlet was appreciably greater from cold-stored than from early-planted fresh runners, but stored runners of Cambridge Favourite showed no gain in earliness. It is concluded that stored runners may satisfactorily be used as a substitute for fresh ones to obtain the recognized advantages of early planting.

Cold-stored Redgauntlet runners planted in June ripened a small crop of fruit in August. Reducing the inter-plant spacing from 18 in. to 9 in. doubled the initial yield and also increased the total amount of fruit harvested in the two succeeding years without lessening the quantity of large fruit.     

A Study of the Development of the First Inflorescence of Glasshouse Tomatoes

When seedlings of the Potentate variety of glasshouse tomato began growth at a time of year when the day-length was less than twelve hours and decreasing, development of the first inflorescence ceased at an early stage. When growth began at a time of year when the day-length was more than twelve hours, or less than twelve hours and increasing, normal development of the first inflorescence from initiation to ovary swelling occurred.

When these normal inflorescences reached antbesis and the ovaries began to swell at a time of year when the day-length was more than twelve hours, a large constant percentage of the buds reflexed their petals and nearly all such flowers set fruit. When the day-length became less than twelve hours anthesis and ovary swelling rapidly decreased and ceased.