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.     

日光温室基质袋培番茄东西垄向栽培模式研究

在滑盖式现代节能日光温室采用基质袋培方式开展了番茄东西垄向栽培模式研究,通过分析番茄不同垄向栽培的冠层小环境、植株长势、产量、品质指标,探讨日光温室番茄东西垄向栽培模式产量形成影响因素。结果表明:当栽培密度相同时,与南北垄向相比,东西垄向番茄冠层辐射量和冠层空气温度较高。东西垄向EW-4处理(2.9株· m~(-2))、南北垄向SN-1处理(2.9株· m~(-2))和SN-3处理(2.9株· m~(-2))的茎粗、叶面积、叶面积指数及地下部干质量无显著差异。EW-4处理株高比SN-3处理显著提高13.07%;地上部干质量为473.10 g,分别比SN-1和SN-3处理显著降低19.26%和6.86%;平均单果质量和单位面积产量均显著高于SN-1和SN-3处理;果实可溶性固形物含量高于SN-1和SN-3处理。东西垄向不同栽培密度处理中,EW-1处理(2.2株· m~(-2))植株冠层辐射量较高,EW-4处理冠层空气温度较高。EW-5处理(3.3株· m~(-2))的株高和叶面积指数明显高于其他处理;EW-4处理叶面积及地上部干质量较大;EW-1处理地下部干质量显著高于其他处理。产量方面,EW-3处理(2.6株· m~(-2))的平均单株产量和单位面积产量分别为3.68 kg ·株~(-1)和9.57 kg · m~(-2),明显高于其他处理。各处理番茄果实可溶性糖、有机酸、VC含量和糖酸比均无显著差异。通径分析结果表明平均单果质量和平均单株产量对不同垄向袋培番茄单位面积产量有直接影响。综上,在滑盖式日光温室内,基质袋培番茄采用东西垄向栽培时产量高于南北垄向,以东西垄向栽培密度为2.6株· m~(-2)进行生产可得到较高产量。     

生物腐熟技术在温室黄瓜栽培上的应用效果

在温室黄瓜栽培中应用秸秆生物腐熟技术的研究结果表明:在冬春季节,日平均地温(20cm)可提高4~7℃,CO2浓度达到713~2275μL/L,为对照的178%~558%,基本上满足了黄瓜生育的需要。处理区黄瓜幼苗壮苗指数明显高于对照;有机质含量增加,黄瓜根系发达,植株生长健壮,发病率明显降低;始收期提前7~15d,前期产量增加40.3%,早熟效应显著;商品率明显提高,品质改善,采收期延长,黄瓜总产量提高32.6%~44.9%。     

The Relative Importance of Stem and Root in Determining Rootstock Influence in Apples

Young clonal cacao trees have been grown under controlled soil moisture conditions for 20 months in a glasshouse. Weighable soil containers were used, and water was added to restore the soil to field capacity each time the total available water, which was about 40 lb. for each plant, had been depleted to 85% (wet treatment), 50% (medium treatment) or 15% (dry treatment). Plants were either given one of these treatments for the whole experiment, or one treatment was given during the natural dry seasons and another during the natural wet seasons.

Plants given a dry treatment at any time lost their apical dominance and flushed vigorously about 10 days after each watering, though many flushes subsequently withered. The other plants flushed normally, except that the continuously wet plants ceased to flush towards the end of the experiment. The mean expanded area of each leaf was greatest during wet and least during dry periods, and plants which had suffered the least soil moisture deficit throughout growth had the greatest net leaf area and dry weight accumulation. There was little difference in the rate of transpiration per unit leaf area between plants during periods of high compared to medium soil moisture, but the rate was less during dry periods. Dry weight increases both per unit of water transpired and per unit of net leaf area were greatest in the wettest plants.

There was little difference between the effects of the wet and the medium treatments on flower production or setting or on cherelle wilt, though ultimately slightly more pods ripened on the wet plants. Plants in a dry period developed few flowers, but initiation was apparently stimulated, for in a subsequent wet or medium period flowering was exceptionally heavy ; setting was poor and cherelle wilt high, however.

It is concluded that irrigation on a greater scale than is practised at present is likely to be beneficial to the growth and yield of cacao.     

Initial Crown Diameter of Transplants Influences Marketable Yield Components of Two Strawberry Cultivars in Annual Hill Production System

Abstract

Influence of initial transplant size on yield components was investigated using two strawberry cultivars over a three-year period. Plants were sorted into three groups according to crown size each fall before transplanting.

Fruits were harvested once a week over a ten-week period each year. There were marked differences between ‘Chandler’ and ‘Camarosa’ cultivars. Transplants of the ‘Chandler’ cultivar with larger crown diameters produced significantly greater early and total marketable yield than transplants with smaller crown diameters. Regression analysis of yield components against initial crown diameter revealed a positive relationship between total fruit numbers produced per plant and initial crown size for both cultivars. Total weight of marketable fruit produced per plant was positively associated with initial crown diameter of transplants. Relationships between initial crown diameter and early yield components were not as consistent among the two cultivars tested. Early yield components of ‘Chandler’ were all correlated to initial crown diameter of transplants. The size of the transplant did not influence early yield components of ‘Camarosa’ except for fruit size. There was a significant relationship between the postharvest dry weight of plants and initial crown diameter of transplants.     

Influence of slip size,deslipping and decrowning on the ‘Sugarloaf’ pineapple

Definitions: Crown = the short stem and leaves growing from the apex of the fruit. Slip = leafy branch, attached below the fruit, developed from axillary bud on the peduncle. Happa = branch arising from axillary bud at the point of junction of peduncle and stem.Large-slip plants of ‘Sugarloaf’ pineapple (Ananas comosus) (L.) Merr.) were more vigorous than small-slip plants initially; however, plants from smaller slips caught up in size within a year after planting. Large-slip and medium-slip plants produced more slips and happas than small-slip plants. Smaller slips produced heavier and larger crowns, delayed both flowering and fruit maturity, reduced fruit size and yield, and recorded a higher incidence of sunburn. Slip size did not influence sucker development, peduncle size, and % TSS, % acidity and TSS/acidity ratio of the fruit.Deslipping, and decrowning and deslipping together produced significantly more suckers than control and decrowning-treatments. Deslipping-, and decrowning and deslipping together produced the maximum fruit weight and yield, whilst deslipping produced the longest fruits. Sunburn was greatest on decrowned and deslipped fruits, followed by deslipped fruits and then by control and decrowned fruits. Pruning did not influence happa production, peduncle size, fruit maturity, and % TSS, % acidity and TSS/acidity ratio of the fruit.No significant interaction between slip size and pruning was found.     

The production of egg-plant,Solanum melongena L., under surface and subsurface systems of irrigation in Tanzania

An area irrigated by a drip or trickle subsurface irrigation system produced bigger, healthier plants, more fruits and higher fresh and dry weight yields than a similar area that was surface irrigated. Yields without fertilizer were greater with the subsurface system, and optimum fertilizer levels were higher under the subsurface than the surface irrigation system.     

Effect of interplanted rice on the growth of tomato in deep solution culture and on the response to salinity

Summary

Tomatoes were grown for 66 d in deep solution culture (a) without aeration, (b) with interplanted rice and (c) with air bubbled through the solution, in factorial combination with two electrical conductivities (4 and 8 mS cm^?1). Root growth was seriously restricted in the poorly aerated solutions (a) and (b). Interplanted rice stimulated shoot growth compared with the un-aerated treatment, and increased the total dry weight, leaf area and fruit yield (fresh weight) by up to 26, 34 and 22% respectively. The total dry weight of plants grown with rice was only 60% of that of the aerated ones but the area of corresponding upper leaves was 73%. Water and nutrient uptake were reduced by poor aeration but, after allowing for the uptake by the interplanted rice, only the uptakes of P and Ca by tomatoes in that treatment were significantly higher than those of the un-aerated plants. The higher salinity reduced growth and the uptake of nutrients. No interaction between aeration and salinity was found.     

Effect of the plant raising environment,transplant weight and date of transplanting on the subsequent growth and development of leeks (Allium porrum L.) grown for early production

Leek transplant weight at planting was greater for a given period of growth at 23°C than at 9°C but was unaffected by nutrition. A single line fitted to all the data, using a time-scale based on ‘effective day-degrees’ (with a base of 4°C and an upper limit of 23°C) accounted for over 76% of the variance in transplant weight at planting. Plant weight at harvest was positively related to transplant weight and fitting straight lines to each of the early and late harvest data sets from all the experiments accounted for 75% of the variance in plant weight at harvest. There were no ‘carry-over’ effects of temperature or nutrition from the plant-raising phase other than those on transplant weight. It was calculated, using data from two of the experiments where transplanting date was a factor, that yields fell by between 0.4 to 1.61 ha“1 for each week’s delay in planting over the period early April to mid-June. This loss in yield could be compensated by planting larger plants; 300 g plants could be produced in early August by planting 0.6 g, 0.9 g and 1.7 g plants in mid-April, mid-May and early/mid-June, respectively. The number of plants with flower initials at harvest increased with an increase in transplant weight and exceeded 10% with transplants of 0.5 g fresh weight or more and, for comparable transplant weights, was substantially greater from plants raised at 9° than 12°C. Flower initials were present even in crops from plants raised at 23°C. Transplants raised at 9°C produced up to 30% bolters at harvest but bolters were almost completely absent in crops established from plants raised at 12°C, 18°C or 23°C. Small plants (<0.4 g fresh weight) with 2-3 visible true leaves responded to cold.     

Field plots for the practical estimation of potential yield

Field bean (Vicia faba minor), tulip (Tulipa sp.) and calabrese (Brassica oleracea var. italica) were grown in the field under conditions where constraints on growth were minimised as far as was reasonably possible. Their growth and yield were compared with those of plants grown in adjacent plots with normal good husbandry practice.

Yields of total dry matter from the highly fertile “measured-maximum” (MM) yield plots of field bean, tulip and calabrese, (20, 18 and 12 t/ha, respectively) were 34, 44 and 49% greater than from the controls. Differences in harvest index (ratio of dry weight of economic unit to total plant dry weight) resulted in yields of economic product of 7.3, 42 and 20 t/ha fresh weight for field bean, tulip and calabrese, respectively, which represented increases over the control yields of 12, 61 and 67%.

It is suggested that the method provides an inexpensive and easy way of establishing a good estimate of potential total dry-matter yield for a particular locality. Such an estimate is a good criterion with which to compare growth from other experimental treatments and may provide a guide for deployment of research resources.     

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。     

The effects of irrigation on the establishment and yield of lettuce and leek transplants raised in peat blocks

The establishment and yield of lettuce and leeks were not reduced by transplanting dry (—0.06 to —0.09 MPa) as compared to saturated peat blocks (3.2 cm cube), provided irrigation was applied immediately after transplanting during the summer. When irrigation was withheld until eight days after transplanting the marketable yield of lettuce was reduced by 30% and 38% when transplanted in saturated and in dry blocks respectively. These reductions were due to reduced survival during establishment and to the more extensive trimming required to produce marketable heads rather than to a reduction in total fresh weight per plant at maturity. The marketable yield of leeks was reduced by 16% and 24% when saturated and dry blocks respectively were transplanted without irrigation, the reduction being largely due to a lower mean shoot weight. Measurements of block and soil water after transplanting suggested that even when the soil was irrigated immediately after transplanting, it was urmble to supply water directly to the blocks for more than a few days.     

不同水肥配比对加工型马铃薯产量与品质的影响

研究了水肥耦合效应对加工型马铃薯经济性状及品质的影响,结果表明,在最优化水肥处理（每1hm2灌水2520．00m3,施尿素457．50kg,磷酸二氢铵825．00kg,硫酸钾247．50kg）条件下,马铃薯植株株高、茎粗、地上部干质量、块茎质量、单株块茎质量和产量等性状上表现最优,且产品干物质含量最高,还原糖含量最低,维生素C含量最高,马铃薯的品质最佳,更利于对其加工的要求。     

Water relations and yield of lysimeter-grown strawberries under limited irrigation

The effects of partial root-zone drying (PRD), as compared to deficit irrigation (DI) and full irrigation (FI), on strawberry (cv. Honeoye) berry yield, yield components and irrigation water use efficiency (WUE_I) were investigated in a field lysimeter under an automatic rain-out shelter. The irrigation treatments were imposed from the beginning of flowering to the end of fruit maturity. In FI the whole root zone was irrigated every second day to field capacity viz. volumetric soil water content (θ) of 20%; while in DI and PRD 60% water of FI was irrigated to either the whole or one-half of the root system, respectively, at each irrigation event. In PRD, irrigation was shifted from one side to the other side of the plants when θ of the drying side had decreased to 8–11%. Compared to FI plants, leaf water potential was significantly lower in DI and PRD plants in 3 out of 10 measurement occasions, while stomatal conductance was similar among the three treatments. Leaf area, fresh berry yield (FY), individual berry fresh weight, berry water content, and berry dry weight (DW) were significantly lower in DI and PRD plants than those of FI plants; whereas the total number of berry per plant was similar among treatments. Compared with FI, the DI and PRD treatments saved 40% of irrigation water, and this led to a 28 and 50% increase of WUE_I based on berry FY and DW, respectively, for both DI and PRD. Conclusively, under the conditions of this study PRD had no advantage compared to DI in terms of berry yield and WUE_I. DI and PRD similarly decreased berry yield and yield components and thus cannot be recommended under similar conditions.     

Potato growth in response to relative humidity

Potato plants (Solanum tuberosum L. cvs. Russet Burbank, Norland, and Denali) were grown for 56 days in controlled-environment rooms under continuous light at 20C and 50% or 85% RH. No significant differences in total plant dry weight were measured between the humidity treatments, but plants grown under 85% RH produced higher tuber yields. Leaf areas were greater under 50% RH and leaves tended to be larger and darker green than at 85% RH.     

除草剂污染堆肥用量对黄瓜生物有效性的影响

化学除草已成为确保现代农业生产不可或缺的技术，但因除草剂会在非靶标植物中残留，进
而导致堆肥和有机肥料产品被除草剂污染，为避免堆肥及其产品在不合理应用时对后茬植物的生长产生不
良影响，造成不可挽回的损失，本试验采用市售基质、普通堆肥和受除草剂污染的堆肥为试材，设置无污
染堆肥处理（C1）、氯氨吡啶酸污染堆肥处理（C2）和二氯吡啶酸污染堆肥处理（C3）3 个处理，在0、5%、
10% 和20% 堆肥不同用量条件下，以黄瓜的出苗率和播种后45 d 时植株的节间距、株高、茎粗、植株干质量、
叶片数、叶面积、叶片卷曲情况和壮苗指数为评价指标。结果表明，受除草剂污染的堆肥对黄瓜种子的萌
发有抑制作用，且堆肥用量越大，出苗率越低，而且黄瓜幼苗表现出严重的除草剂药害症状，植株纤弱，
叶片狭小、卷曲。两种除草剂污染堆肥对黄瓜的影响呈现不同的规律，在堆肥用量相同的条件下，氯氨吡
啶酸比二氯吡啶酸对黄瓜的药害严重，这表明越高效的除草剂随堆肥或有机肥的施用对后茬敏感植物的药
害风险越大。     

UV-B radiation and photosynthetic irradiance acclimate eggplant for outdoor exposure

Treatment of greenhouse-grown eggplant (Solanum melongena L. var. esculentum Nees. 'Burpee's Black Beauty') seedlings with supplemental photosynthetically active radiation from cool-white fluorescent lamps increased growth of plants subsequently transferred outdoors relative to growth of plants that received no supplemental radiation or were shaded to 45% of solar irradiation in the greenhouse before transfer outdoors. Eggplant seedlings transferred outdoors were placed under plastic tarps either to provide relative protection from solar ultraviolet-B (UV-B) radiation (280-315 nm) using Mylar film or to allow exposure to UV-B using cellulose acetate. Protection of seedlings from UV-B radiation resulted in greater leaf expansion than for UV-B-exposed seedlings, but no change in leaf or shoot dry weight occurred after 9 days of treatment. Specific leaf weight increased in response to UV-B exposure outdoors. Exposure of eggplant to UV-B radiation from fluorescent sunlamps in the greenhouse also decreased leaf expansion and leaf and shoot dry weight gain after 5 days of treatment. However, there were no differences in leaf or shoot dry weight relative to control plants after 12 days of UV-B treatment, indicating that UV-B treated plants had acclimated to the treatment and actually had caught up with non-UV-B-irradiated plants in terms of growth.     

加工型白皮洋葱引种栽培示范及效益分析

引进山东的白皮洋葱新品种"白B2006",采用露地直播、育苗移栽及大田验证试验,对其产量、品质及经济效益进行分析。结果表明:栽植密度为3.0~3.5万株/667m2,产量可达2 400~3 500 kg,鳞茎干物质含量21.34%,粗蛋白含量0.88%,可溶性糖含量12.40%,VC含量10.26 mg/100g;干物质含量高于山东产地的同品种4~9个百分点。"白B2006"洋葱表皮洁白,风味纯正,适宜脱水加工,经济效益显著,可在柴达木盆地德令哈市推广种植。     

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.     

The effect of intermittent irrigation with cold nutrient solution on the growth of tomato seedlings propagated in rockwool

Seedlings of tomato, cv. Counter, propagated in rockwool blocks were irrigated five times every 24 h with nutrient solution at 10°C or 18°C for up to three weeks. The mean block temperature was lowered by 3.5-4.0 degrees C by irrigation at 10°C. One week of irrigation at the lower temperature caused the seedlings to develop a characteristic dark purplish colour. This treatment reduced fresh weight and leaf area but not dry weight which suggests that water uptake was also reduced. Dry weight was reduced following two or more weeks of irrigation at 10°C. When seedlings which had been irrigated at 10°C were returned to irrigation at 18°C, the purple colour slowly disappeared and the percent dry matter decreased. When plants were grown on, the total yield of fruit was unaffected by these seedling treatments.