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1.
The yield results of six field experiments with bulb onions are presented and it is concluded that : (1) The total yield of ripe bulbs increased with increasing number of plants per sq. ft. until an optimum was reached and thereafter the yield declined.

(2) At the optimum plant densities for total yield the bulbs were too small for normal market purposes but were of a suitable size for pickling whole.

(3) Some varieties of onion would not produce large bulbs even when grown at low plant densities; thus the choice of varieties for ware bulb production is of paramount importance.

(4) The fitting of a mathematic model to the density/yield data showed that if varieties were ranked for yield at anyone plant density this ranking would remain the same at all other plant densities. Absolute yield differences between varieties were, however, greatest at low plant densities.

(5) Decreasing the distance between rows at a given plant density increased the total yield of bulbs. At 7 plants per sq. ft., a density suitable for commercial dry bulb production, reducing the row spacing from 18 in. to 9-12 in. increased yield by 10 to 30%.

  相似文献   

2.
Five experiments carried out over three years are described in which the effects of irrigation at various growth stages on the yield of peas from plants grown at different plant densities were determined. Results showed that, irrespective of the density at which the plants were grown, plants irrigated at the start of flowering and again as the pods were swelling produced significantly higher yields than unirrigated plants. Yield of peas per plant was consistently reduced as density increased but yield per unit area did not show a consistent relationship with plant density from year to year. The results indicated that, even when irrigation is available, plant densities of five to six plants per sq. ft. should not be exceeded.  相似文献   

3.
A study was made of the effects of plant density, plant arrangement and row orientation on the yield of bulbs and flowers from small offsets of narcissus var. King Alfred left in the ground for 2 years. Over the density range of 2–14 plants per sq. ft., flower number increased from 2 to 12 per sq. ft. and stem length increased from 29 to 35 cm. Total bulb yield per unit area increased with density from 171 to 696 gm. per sq. ft.; the weights in each of four commercial bulb grades also increased. When the ratio of the between-row distance to the within-row distance was increased, bulb yield declined in E-W rows, but not in the N-S rows.  相似文献   

4.
In experiments over the period 1962–64 in southern England the effects of runner size, planting time and in-row spacing were compared with regard to the yield of one-year strawberry plants. Planting time had the greatest effect. Early planting markedly increased yield, though runner size interacted with it. In August, runner size had no effect, very small runners yielding as well as large ones but, from September planting, large runners outyielded smaller runners. Plots with spacing of six inches in the row outyielded those with spacing of twelve inches.

The experimental treatments did not have a marked effect on the yield of large berries in 1962, but in 1963, when growth was less vigorous, treatment effects were similar to those on overall yield. The yield of very early, ripe fruit was greatest from the September-planted runners. Plant spacing had no effect on time of ripening.

The difference in growth and crop between the two years was probably related to the soil and to air-temperature differences each autumn after planting.

In the second season of each trial, plant spacing was doubled, by removal of alternate plants. The original planting treatments had few significant effects on the yield from the spaced, two-year old plants. From both one-and two-year-old plants Cambridge Favourite outyielded Cambridge Rival, but the latter gave more early ripe fruit and less waste fruit.  相似文献   

5.
Summary

Ashwagandha (Withania somnifera L. Dunal; Solanaceae) is being cultivated around the world mainly for its root which has rejuvenative properties. Field experiments during 1999–2001 under semi-arid tropical conditions of Hyderabad, India studied the effect of tillage depths (15 and 30 cm) and plant population densities (20, 40, 60 and 80 plants m–2) on root morphology, yield and quality and cultivation economics of ashwagandha. Preparatory tillage to 30 cm depth in combination with a density of 60 plants m–2 gave the highest root yield of 1.2 t ha–1 which was 50% higher than that following 15 cm tillage depth and the same density. This is attributed to the favourable effect of the former treatment leading to 33, 37 and 21% increases in plant height, number of branches per plant and shoot biomass yield, respectively. Further, this treatment produced most (68%) best quality root pieces. Main root length, length of lateral roots and diameter of lateral roots were significantly increased, while the diameter of main root and the number of laterals decreased. Furthermore, increase in plant density from 20–80 plants m–2 increased production of best quality roots from 42% to 59% under shallow tillage and from 53% to 71% of root yield under deep tillage. The implications of change in root morphology are discussed in the light of production of different grades of roots, their market preferences and economics. Deep tillage was equally advantageous for seed production, but plant population density for maximum seed yield (211 kg ha–1) was lower at 40 than at 60 plants m–2 for maximum root yield. Maximum gross and net returns and benefit-cost ratio occurred following the highest root yield.  相似文献   

6.
陈娟  王一鸣  唐建  宋锐  缪鑫 《蔬菜》2023,(6):23-25
为确定紫甘薯新品种“内渝紫2号”最佳种植株距,为新品种的示范推广提供技术依据,设置5种不同株距(20、25、30、35、40cm),对不同株距条件下紫甘薯“内渝紫2号”的植株性状、产量性状进行调查分析。结果表明：加大株距有利于提高茎蔓长度、分枝数、单株结薯数、单株鲜薯质量和大中薯比例;在30～40 cm范围内,缩小株距,有利于提高鲜薯产量、茎叶产量和薯干产量;30 cm株距时鲜薯产量和薯干产量最高,667 m2产量分别为1 722.67 kg和480.63 kg。综合考虑,建议“内渝紫2号”栽培株距为30 cm,可获得较为理想的鲜薯产量。  相似文献   

7.
Carnations, cultivar ‘White Sim’, were planted on 17 January, 12 March, 11 July, 12 September and 7 November, at densities of 12.9, 25.8, 51.7 and 103.3 plants m?2. For each planting-date, yields within a year from planting were asymptotically related to plant density. The mid-winter plantings gave the highest yields and the July planting the lowest.Yield patterns, derived from a weighted moving average, were affected by both the date and the density of planting. At high density, a major part of the year's yield came from the first flush, accounting for 48% of the total yield in the September planting and 75% in the March planting. At the low density, the first flush was only 26–31% of the year's yield. After the first flush, crop yields were suppressed more at higher densities, especially in the November, January and March plantings. Densities of 25.8 and 51.7 plants m?2 gave the best continuity of production per unit area, whilst the lowest density gave the best continuity of production per plant.The suppression of flower initiation was related to the amount of light; in November less than 20% of the incident light penetrated the canopy of a high-density September planting. Continuous light did not materially increase the number of shoots per plant that initiated flowers, its greatest effect being to produce earlier initiation.  相似文献   

8.
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.  相似文献   

9.
Variations in final plant density (number of plants per square foot) lead to variations in yield in onion variety trials and often complicate the interpretation of the results. These variations in plant density may be caused by differences in germination and in seedling survival. Such differences were obtained from several lots of genetically similar seed of the onion variety Cambridge No. 10 which had been produced under different environmental conditions, viz. in different places and years. It was found, however, that variations in yield produced by these environmental effects on the seed could be allowed for within limits by using a statistical method based on the regression of final plant density on yield.

Where seed of one stock of this variety was produced in each of three years by harvesting the seed heads at various stages of maturity and drying them at either 25° C. or 35° C., all except one lot of seed gave variations in yields of onions which were related to final plant densities. The exceptional lot, consisting of the least mature seed dried at 35° C., gave not only poor germination and seedling survival but also less vigorous surviving plants than those from the other lots.  相似文献   

10.
通过植株密度的单因素、5水平处理试验,研究了天鹰椒栽植密度对天鹰椒的产量、单株结椒数和单株椒重的影响作用。结果表明,天鹰椒在每hm^2种328747株的密度下,达到了最高干椒产量3987．3kg／hm^2,比常规密度条件下的增产42．2％。  相似文献   

11.
Summary

This study addresses vegetative growth and the uptake of nutrients and their accumulation in the vegetative and reproductive tissues of pepino (Solanum muricatum Ait.). The study was conducted in soilless plastic house conditions, with a planting density equivalent to 25.000 plants ha–1 during two seasons (1997–98 and 1998–99). The plants were sampled, fractionated into leaves, stems, fruits and roots, then dried and weighed and the macronutrient content was analysed every 30.d for 300.d after transplanting. The yield obtained was 2.kg of fruit per plant, which is 30% of the total dry weight. The relative growth rate (RGR) ranged from 0.0028 to 0.0451.d–1. The highest N, K, Ca and Mg concentrations were recorded in the leaves, and the highest P concentration in the roots. The nutrient accumulation of this yield was 10.64, 1.12, 16.06, 10.0 and 1.58.g of N, P, K, Ca and Mg per plant respectively. The highest accumulation of all nutrients was found in the leaves. The nutrient with the highest specificuptake rate was K, which ranged from 0.0037 to 0.0838.g g–1 d–1.  相似文献   

12.
研究了不同定植密度对淮安红椒超越2009生长发育及产量的影响。试验结果表明，较低的定植密度有利于淮安红椒叶片鲜质量、单果质量增加，定植密度对产量的影响可能主要是通过影响单果质量而实现，定植密度52500株/hm2和60000株/hm2处理，单位面积产量较其他密度处理显著增加。综合分析认为，红椒超越2009定植密度以52500~60000株/hm2较适宜，其中52500株/hm2最好，红椒单果质量最大、产量较高。  相似文献   

13.
Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.  相似文献   

14.
种植密度对不结球白菜叶面积指数动态变化及产量的影响   总被引：1，自引：0，他引：1  
以不结球白菜"春油5号"为试材,设置不同种植密度(667m^2种植13 340、16 675、17 787、22 233株),研究了不同种植密度对不结球白菜叶面积指数动态变化及产量的影响,以期为不结球白菜的合理密植提供参考依据。结果表明:在整个生长季节供试的不同种植密度不结球白菜的叶面积指数、单株质量及产量的发展均呈"S"型变化,播种后41d各指标缓慢增加;播种后41～54d各指标呈指数型增长,各种植密度间差异显著;后期到达最高点后保持不变甚至出现下降,处理间差异消失。相关分析表明,种植密度与叶面积指数和产量呈正相关,与单株质量呈负相关,综合不结球白菜单株质量、产量考虑,适宜栽培株行距为20cm×20cm(667m^2种植16 675株),适宜的叶面积指数为3。  相似文献   

15.
为加快泡渍豇豆专用品种推广,实现节本增效栽培,以成豇9号为试验材料,研究3种不同种植密度与生产常规密度对豇豆农艺性状、产量与效益的影响。结果表明:随着密度加大,生长势强的处理叶片随之加大,产量反而降低、病虫害增加、成本加大;处理3(每667 m~2种植9 000株,1 800穴,行穴距170 cm×45 cm)的产量、产值最高;处理1(每667 m~2种植9 000株,1 500穴,行穴距170 cm×50 cm)成本最低,产量较高。综合分析,处理1最适宜成豇9号栽培,节本增效,综合比较效益最优。  相似文献   

16.
Summary

The influence of plantation age and plant density on pseudostem size, canopy cover and vegetative growth characteristics of banana cv. Williams was investigated over four cropping cycles at Burgershall Research Station, in the subtropical Eastern Transvaal. Densities were 1000, 1250, 1666 and 2222 plants ha?1. Over all densities, pseudostem height, lamina area, numbers of functional leaves at flowering and LAI increased with plantation age up to the second ratoon (R2). This increase in canopy cover caused vegetative and total cycle intervals to be extended progressively from plant crop to R3. Within cycles, higher density had little effect on plant height or lamina length, but induced thinner plants with significantly narrower leaves than at low density. Peak ratoon LAI at flowering almost doubled between 1000 and 2222 plants ha?1. At 1000 plants ha?1, four cropping cycles were completed in the same period as three cycles at 2222 plants ha?1. Annual leaf emergence rate was significantly reduced by up to five leaves with an increase in plant density from 1000 to 2222 plants ha?1, which was also accompanied by a 3–4°C reduction in pseudostem temperature. Up to six more leaves per plant were produced at 2222 plants ha?1 and only 14% of the available radiation was transmitted through the primary canopy compared with 30% at 1000 plants ha?1. Crop cycle interval is an important component of annual yield at different densities.  相似文献   

17.
Two field experiments were carried out to investigate the effect of method of propagation (including two proposed new methods) and plant density on the growth, mineral uptake and yield of dasheen (Colocasia antiquorum, Schott.).Planting different pieces of “seed” resulted in a higher percentage germination, higher percentage efficiency of solar energy conversion and better growth characters of the plant, in the order: cormel, apical, half-apical, corm piece and quarter-apical piece, respectively.Increasing the plant density decreased the growth characters of the plant and increased the percentage efficiency of solar energy conversion.The nitrogen, phosphorus and potassium concentrations were not affected by types of dasheen seeds, whereas the absolute amount per plant followed the same pattern of change as the dry matter content.Distance between plants had no statistically significant effect on the concentrations of nitrogen, phosphorus and potassium in the plant tissues. However, the absolute amounts of these minerals per plant decreased as the plant population was increased.Planting with the cormel resulted in the highest total yield. However, the difference in total yield between planting with the apical and half-apical pieces was not statistically significant. A similar situation was found when planting with quarter-apical and corm pieces. Therefore, it is recommended that the apical piece is cut into two equal halves in order to use a given amount of apicals to reduce the corm pieces when planting.Increasing the plant population, by reducing the distance between plants from 45 to 30 cm, resulted in an increased yield per hectare. However, reducing the distance between plants to 15 cm resulted in a decrease in yield.  相似文献   

18.
为了研究马铃薯在相同种植密度下高产优质最佳的行株距,采用37 500和60 000株 ? hm-2两种密度,通过扩大行距缩小株距,分别设置4个和7个行株距比处理,研究其对马铃薯茎叶干物质积累、光分布、光合特性、叶绿素荧光特性、产量及块茎淀粉、蛋白质、维生素C、还原糖含量的影响。结果表明：行株距比在低密度下为1.5、高密度下为2.5时,可提高茎叶干物质量、叶面积指数、叶绿素含量、净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、最大光能转化效率（Fv/Fm）、实际光化学量子效率（PSⅡ）、光化学猝灭系数（qP）、鲜薯产量及其淀粉、维生素C、可溶性蛋白含量,而胞间CO2浓度（Ci）、非光化学猝灭系数（NPQ）和还原糖含量的变化规律与之相反。‘青薯9号’高产优质的行距/株距在37 500和60 000株 ? hm-2种植密度下,分别为63.3 cm /42.2 cm和64.6 cm /25.8 cm。  相似文献   

19.
The growth and cropping of two virus-infected strawberry varieties was compared with that of clones the virus content of which had been reduced by heat therapy.

The heat-treated clones of both Cambridge Favourite and Early Cambridge were considerably more vigorous, bearing more crowns than their untreated counterparts. In the first year after planting, both clones of each variety produced similar total yields, but the heat-treated clones produced a higher percentage of large fruit. Plants of the heat-treated clone of Cambridge Favourite flowered and ripened their fruit later than plants of the untreated clone in the second year, but gave a greater yield. However, the two clones of Early Cambridge gave similar yields, the increased potential of the heat-treated clone provided by a greater number of crowns being offset by reduced inflorescence formation.

In order to establish whether reduction of vigour would lessen the tendency of some heat-treated clones to form barren crowns, spring planting was compared with autumn planting. Spring planting, which reduced plant size and yield of both varieties in the first season but had less effect on size and none on yield in the second season, failed to check partial barrenness in the heat-treated clone of Early Cambridge.

At the end of the first growing season the heat-treated clones of both varieties showed a greater incidence of Verticillium wilt than the untreated clones but this difference was not maintained in the second year.  相似文献   

20.
郭赵娟 《长江蔬菜》2013,(20):19-21
为完善胡萝卜优良品种郑参丰收红栽培技术,特进行了秋季单垄双行栽培密度试验。试验结果表明,随着密度的减小,产量有降低的趋势,而商品根率有增大趋势;最佳垄株距可选择50cm×10cm,60cm×10cm;种植密度为2．67万株／667m2时,产量最高,密度为1．28万-2．22万株／667m2时,既高产,商品根率又高。  相似文献   

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