Influence of Variable Amounts of Irrigation Water and Nitrogen Fertilizer on Growth, Yield and Water Use of Grain Sorghum

Sorghum hybrid CSH-6 was grown in fields in Delhi, India between July–November 1986 in order to study the effect of nitrogen nutrition and irrigation on dry matter accumulation, grain yield and water use. The treatments included 40 Kg Nha⁻¹ combined with two irrigations (30 DAS, 60 DAS), one irrigation (60 DAS) and no irrigation respectively. Rainfall during the crop season was only 17 cm. The unirrigated plants were considerably water stressed and exhibited very low leaf water potential, less leaf area, delayed anthesis, longer crop duration but shorter grain filling duration. The ears showed sterility and yield was only 0.41 t ha⁻¹ without nitrogen fertilization. Addition of nitrogen fertilizer had no significant effect on yield in unirrigated plants. A single irrigation 60 DAS increased yield due to increase in both grain number and grain weight per ear in fertilized and unfertilized crop respectively. Two irrigations in the unfertilized crop increased the yield to 2.2 t ha⁻¹ while similar treatment in the fertilized crop did not increase the yield significantly. Irrigation increased the WUE for grain yield. The results indicate that nitrogen stress and water stress reduced grain yield primarily through grain number rather than grain weight. Irrigation relieved both water stress and nutrient stress. Nitrogen nutrition was not beneficial under severe water stress conditions but was considerably helpful under mild stress. Biomass, grain yield and harvest index show significant correlation with preanthesis water use.     

The Interaction of Sowing Date and Water Availability in Determining Plant Architecture, Fruiting Pattern and Yield Components of Soybean (Glycine max L. Merr.)

A 2-year trial has been carried out in northern Italy on soybean (cv. Hodgson) grown in lysimeters, comparing three soil water regimes (well-watered conditions and water stress during vegetative and reproductive stages) at two sowing dates. Plant evapotranspiration and water uptake depth were calculated from volumes of water independently supplied to eight lysimeter layers; at harvest, plant architecture, yield components and fruit distribution along the main stem and lateral branches were evaluated.
Although water stress intensity was not severe, crop evapotranspiration and water uptake depth were severely restricted by water shortage. Both low water-availability and late sowing significantly modified the architecture of plants, decreasing total height, number and length of internodes and lateral branches. Seed allocation along the stem was shifted downwards both by delaying the sowing date and by reducing the water supply; the component most responsible for yield decrease was the number of pods per plant, while unit seed weight was only slightly affected by water stress. Grain yield reduction was higher when water availability was inadequate during the reproductive phase in the early-sown crop and during the vegetative stage in the late-sown crop. This suggests that the intensity of the water shortage, plant phenological stage of stress application, as well as the date of stress application within the growing season determine the yield response of soybean.     

Influence of Water Stress on Grain Yield and Vegetative Growth of Two Cultivars of Bean (Phaseolus vulgaris L.)

Lack of water during vegetative and/or reproductive growth stages is one of the most limiting factors for bean growth. The purpose of this study was to evaluate the effects of water stress applied during two phenological stages (flowering and pod filling) on growth, yield and yield components. Two genotypes of bean ( Phaseolus vulgaris L.) were used in this study, cv. Carioca, an indeterminate Brazilian landrace, and cv. Prince, a determinate cultivar grown in Europe. Carioca appears to be generally stress-tolerant while Prince is intolerant. Plants were grown in large plastic pots covered with a black plastic sheet to protect the soil from rain and evaporation. The water stress treatments were: control (well-watered plants), WSFS (water stress during flowering stage) and WSPFS (water stress during pod-filling stage). Water stress reduced yield and yield components at both flowering and pod-filling stages. The parameters affected were seed weight, number of seeds per plant and number of pods per plant. Number of seeds per pod and seed weight were not affected. No effects of water stress were detected on harvest index. Time to maturity was slightly prolonged, especially for WSFS. Water stress at both stages resulted in lower accumulated water loss compared to the control plants. Water stress during both phenological stages reduced other growth parameters, the number of trifoliate leaves, stem height, number of main branches and number of nodes on the main stem.     

Dynamics of water and nitrogen stress along the grapevine cycle as affected by cover cropping

Cover cropping is developing in vineyards as it may induce numerous ecosystem services. However, soil cover also competes with grapevine for soil resources. This work aimed at evaluating both the period and intensity of the resulting water and nitrogen stress experienced by grapevine by comparing treatments with bare soil, permanent and non-permanent soil cover. The adopted stress indices were the Fraction of Transpirable Soil Water (FTSW) and the Nitrogen Nutrition Index (NNI).Cover cropping improved winter soil water refilling, but the grass transpiration during spring later led to similar water stress of grapevine among treatments. In dry years, summer water stress was not higher with non-permanent cover than with bare soil. The building of a critical nitrogen content curve for grapevine enabled to diagnose an early nitrogen stress, from budbreak to flowering, in cover cropped treatments. NNI dropped then in dry years, particularly in cover cropped treatments.The early growth limitation of grapevine observed in cover cropped treatments was the consequence of mild early nitrogen stress, which suggests that perennial nitrogen reserves were reduced because of an earlier competition with cover crop. After grapevine flowering, water appeared to be the most limiting factor for both grapevine growth and nitrogen availability.In water limited environment, nitrogen stress is highly dependant on water constraints. However, this work reveals the partial uncoupling of the dynamics of water and nitrogen stress during the grapevine cycle in water-limited cropping systems, which highlights the relevance of a co-ordinated management of water and nitrogen.     

温宿红葡萄生物学特性及果实性状多样性研究

摘要：【研究目的】温宿红是新疆温宿县地方优异葡萄品种,当地长期栽培中形成了丰富的葡萄种质资源多样性,本文通过对温宿红葡萄果实与形态性状多样性的研究,以期为筛选出适合当地条件的温宿红葡萄系列新品种（系）提供材料基础。【方法】通过田间观察,以果实特性为主要指标,植株形态特征为辅,研究温宿红葡萄品种多样性。【结果】温宿红葡萄植株生长势强,晚熟、丰产,果穗松紧适中、穗梗粗壮,果粒圆、大小一致,果肉硬脆,味甜,果皮红色鲜丽,符合人们的消费习惯, 有一定的耐贮运性,是较为理想的鲜食品种。温宿红自然群体中存在诸多变异类型,初步筛选出的7个形态与果实性状多样性植株在果穗、果粒形态,果实耐压力、耐拉力、可溶性固形物含量和种子数等方面均存在显著性差异。【结论】温宿红葡萄自然群体中存在变异类型,对该品种的深入研究及初选的多样性植株具有一定育种及利用价值。     

Compensatory Growth Responses During Reproductive Phase of Cowpea after Relief of Water Stress

Unpredictable drought affects growth and yield of dryland cowpea ( Vigna unguiculata [L.] Walp.) during rainy season. With the objective of identifying compensatory growth responses after relief of water stress, pot-grown plants (cv. C-752) were water-stressed at flowering, and physiological responses, short term dry matter partitioning upon relief of water stress, and productivity at maturity were studied. Water stress decreased, to varying degrees, leaf water potential, stomatal conductance, photosynthesis rate and transpiration rate. Recovery in assimilation lagged behind that in water relations. Assimilate supply seemed to be limiting early pod growth upon relief of water stress due to low photosynthesis rate, reduced leaf area per pod, and increased partitioning to leaf expansion. However, later pod growth was not limited by assimilate supply and final dry matter per pod was similar in both non-stressed and stress-affected plant. Cowpea exhibited the following growth responses during pod-fill stage upon relief of water stress: 1. increase in leaf area, 2. shift in dry matter partitioning in favour of leaf expansion, 3. extended green leaf duration, and 4. increase in pod number. These partially compensating physiological responses probably ensure reasonable productivity of dryland cowpea during rainy season.     

Effects of Temporary Water Stress After Anthesis on Grain Yield and Yield Components in Different Tiller Categories of Two Spring Wheat Varieties

Water stress might limit grain yields of cereals under humid conditions. The objective of this study was to investigate the effect of a temporary water shortage at three different stages after anthesis on the grain yield and yield components of different tiller categories in two spring wheat varieties. A pot experiment with controlled water supply and rain shelters was conducted in 1984 and 1985 in Kiel, N. W. Germany. The water stress (pF 2.9 to 3.4) was imposed either between anthesis to early milk development of the caryopsis (WS1) (EC 65 to EC 72 according to Z adoks scale), early milk development to late milk development of the caryopsis (WS2) (EC 72 to EC 77) and late milk development to maturity (WS3) (EC 77 to EC 92). The control had a constant water supply throughout the growing season of between pF 2.2 to 2.5.
The water stress treatment WS1 significantly reduced the single plant yield by 10 % (1984) and 15 % (1985) in one variety (Selpek), whereas the other variety was unaffected. The response of both varieties to the two later treatments was smaller and insignificant.
In the first year the yield decrease in the variety Selpek after the WS1 treatment was mainly caused by a lower number of ears per plant compared with the untreated control (WS0). In the second year (1985) additionally a lower grain weight of the second category shoots caused by a reduction of the number of kernels per ear contributed to the decrease of the single plant yield. The yield component thousand grain weight could not compensate for the reduction in the number of kernels per ear.     

盐逆境下缓/控释肥对水稻生长发育、产量和品质的影响

为探明盐逆境下缓/控释肥对水稻生长发育、产量和品质的影响，以南粳5055为材料开展盆栽试验。设置3个盐分水平：0.0g/kg(S0)、1.5g/kg(S1)、3.0g/kg(S2)和4种氮肥处理：常规尿素（F1）、有机缓释水稻专用肥（F2）、大颗粒尿素（F3）和硫包衣尿素（F4），各处理的施氮量和磷钾肥用量相同，以不施氮肥处理为对照（CK）。结果表明，盐逆境下，F2的最大茎蘖数、株高和成穗率均最高；在S0下，F2、F3和F4的产量比F1分别高出11.89%、5.58%和17.14%；在S1和S2下，F2的产量比F1分别高出30.28%和37.20%，而F3和F4的增产效果不佳。在盐逆境下，F2主要通过增加有效穗数、穗粒数和千粒重提高产量。盐逆境下穗粒重、一次枝梗的粒重、千粒重和结实率，二次枝梗的粒重和千粒重均以F2最高。盐逆境下，F2具有较高的糙米率、精米率、胶稠度和较低的直链淀粉、蛋白质含量。由本研究可得出，盐逆境下，F2的增产效果最佳，且对稻米品质具有一定的有利影响，在一定程度上能缓解盐逆境对水稻的危害。     

Genetic control of alfalfa seed yield and its components

Seed yield is of little agronomic importance in alfalfa (lucerne) but is critical in the marketing of varieties. In order to develop breeding criteria, the quantitative genetics of seed yield components must be studied. The objective of this study was (1) to evaluate combining ability for seed yield and its components and (2) to estimate the genetic control of these same characters. A 7 × 7 diallel mating design, including reciprocals, among parents from different varieties, and a 7 × 7 factorial design within the ‘Flamande’ population were evaluated. In the diallel design, where the progenies were evaluated over two growing seasons, a high genotype effect was found for seed yield and its components while genotype × year interaction was only significant for seed yield per plant. General combining ability (GCA) effects explained most of the variation due to genotype effect. Specific combining ability (SCA) and reciprocal effects were only significant for seed yield per plant. ‘Europe‐1’, ‘Rival‐5’ and ‘Medalfa‐7’ were the most promising parents, conferring the highest GCA for most of the characters evaluated, especially for seed weight per inflorescence. In the factorial design, seed weight per pod was the only character for which the year effect was not significant. Male and female effects were significant for all characters and these effects were larger than the male × female interaction variance for all the characters. These results were stable over the 2 years for most characters. Additive variance was larger than dominance variance, for all traits. This resulted in high narrow‐sense heritabilities, especially for seed yield per plant, seed weight per inflorescence and number of seeds per pod. Seed weight per inflorescence and number of seeds per inflorescence were highly correlated with seed yield per plant among the full‐sib (FS) families, in both experiments. Increase in seed yield potential in alfalfa could be achieved by the use of seed weight per inflorescence as a selection criterion.     

Thresholds,sensitive stages and genetic variability of finger millet to high temperature stress

Finger millet [Eleusine coracana (L.) Gaertn.] is an important coarse cereal crop grown in the arid and semi‐arid regions and often experiences high temperature (HT) stress. The objectives of this research were (i) to quantify effects of season‐long HT stress on physiological and yield traits, (ii) to identify the developmental stages most sensitive to HT stress and (iii) to quantify the genetic variability for HT stress tolerance in finger millet. Research was conducted in controlled environment conditions. HT stress decreased the chlorophyll index, photosystem II activity, grain yield and harvest index. Maximum decrease in number of seeds per panicle and grain yield per plant was observed when stress was imposed during booting, panicle emergence or flowering stages. Maximum genotypic variation was explained by panicle width and number of seeds per panicle at optimum temperature (OT) and grain yield per plant at HT and number of seeds at HT. Based on the stress response and grain yield, tolerant or susceptible genotypes were identified. Finger millet is sensitive to HT stress during reproductive stages, and there was genotypic variability among the finger millet genotypes for number of seeds per panicle and grain yield under HT, which can be exploited to enhance stress tolerance.     

水氮胁迫对冬小麦籽粒灌浆速率影响的模拟研究

为定量分析水氮胁迫对冬小麦籽粒灌浆速率的影响,以‘济麦22’为材料,于2016—2017和2017—2018年度开展施氮试验。结合2017—2018年度试验资料,通过分析水氮胁迫对冬小麦籽粒灌浆速率的影响规律,引入氮素和水分影响因子,构建水氮胁迫对冬小麦籽粒灌浆速率影响的模拟模型S_(j,t)=S_(W3N300,t)×(1+F_N)×(1+F_W)。经2016—2017年小麦生长数据检验,除绝对误差占实测值比率d_ap略高外,RMSE值、平均绝对误差d_a以及相关系数r均显示模拟值和实测值有较高的一致性,说明实测值与模拟值吻合程度较好,所建模型可较好模拟水氮胁迫对冬小麦籽粒灌浆速率的影响。     

The Influence of Plant Water Stress on Net Photosynthesis and Yield of Sunflower (Helianthus annuus L.)

The effect of plant water stress on net photosynthesis, leaf growth, yield and yield-related components were investigated in a single experiment in order to determine in which way water deficits affect sunflower yields.
Sunflower plants, grown under controlled temperature regimes, were stressed during budding, anthesis and seed filling by withholding water until the leaf water potential reached -1600 and -2000 kPa. Leaf area of unstressed plants significantly exceeded that of plants under severe stress during all growth stages investigated. The CO₂ uptake rate per unit leaf area as well as the total uptake rate per plant, significantly diminished with stress, while this effect drastically increased during the reproductive phase of the plant. Although this resulted in significantly smaller heads and kernels, it did not affect the number of seeds borne in the inflorescence. Severe stress during anthesis and seed filling resulted in more empty kernels. Moderate and severe stress during budding significantly lowered both grain and oil yields while plants that experienced moderate stress during anthesis and seed filling significantly outyielded those under severe stress.     

Effect of Irrigation and N-Fertilization (Fertigation) Scheduling on Tomato in the Jordan Valley

Tomato ( Lycopersicon esculentum mill. cv. Petopride ) is the most important vegetable crop in Jordan; its production is characterized by inadequate irrigation and fertilization practices, especially under open field conditions. A field study was carried out to determine the effect of different irrigation intervals and different N-fertilizer doses on water use, tomato yields and residual soil nitrogen.
Results indicated significant differences in water use and tomato yields between irrigation treatments. Highest yield (51.4 ton ha⁻¹) was obtained under three irrigations per week with 504 mm total water supply, whereas under irrigation once a week 35.3 ton ha⁻¹were produced with 353 mm total water supply. There were no significant differences in yield between fertigation with ten equal time intervals and fertigations with intervals as per crop requirements, the yields were 47.1 ton ha⁻¹ and 44.5 ton ha⁻¹, respectively. However, yield was significantly lower with three fertigations at equal intervals and equal doses (35.8 ton ha⁻¹) throughout the season. There were no significant differences between mineral nitrogen forms in terms of yield effects. Significant irrigation effects were observed on total soil nitrogen. Residual soil N was 0.052% in the surface layer (0–30 cm), and 0.030% in the subsurface layer (30–60 cm).     

Yield and Agronomic Characters of Tropical Maize (Zea mays L.) Cultivars under Different Irrigation Regimes

Drought spells are unpredictable under tropical conditions and can occur at every growth stage of the maize plants. Little is known about the reactions of tropical maize cultivars to water shortage. A set of Thai cultivars was examined in the field during the dry season. Three stress situations were imposed: prolonged stress throughout the growing season, pre- and post-anthesis stress. Pre-anthesis water stress delayed flowering and especially the data of silking. Thus, the anthesis-silking interval was wider. Prolonged water stress decreased grain yield mainly due to a low number of kernels and/or thousand kernel weight (TKW). Post-anthesis stress mainly reduced TKW grain set per ear. Relief from pre-anthesis stress increased grain yield by a grater number of kernels and higher TKW as compared to prolonged stress. Genotypic differences were high for the anthesis-silking interval following pre-anthesis stress. Low yielding, early but generally drought-stable cultivars existed as well as cultivars which were generally high yielding even under water stress because of a good residual yield. Some cultivars were resistant to pre-anthesis stress but not to post-anthesis stress and vice versa. It can be concluded that ample genotypic variability exists for adaptation to varying situations of pre-and post-anthesis stress within tropical maize cultivars.     

旺长期干旱胁迫对红麻生长发育、产量及效益的影响

为探讨干旱胁迫对红麻生长及产量的影响,寻找最佳节水灌溉临界值,以红麻品种杂红992为试验材料,通过盆栽控水法研究不同干旱胁迫强度和时长对红麻生长发育指标（叶片数、株高、茎粗和地上干物质量）、产量和经济效益的影响。结果表明,干旱胁迫显著降低了红麻生长量,减缓了生长速度,且降低幅度与胁迫强度和时间呈正相关。干旱胁迫后的红麻在复水后将会进行补偿性生长。与正常灌溉相比,短时（5d）的轻度（土壤含水量控制在60%～65%）或中度（土壤含水量控制在40%～45%）干旱胁迫不仅可以节水45%～73%,而且提高产量8%～14%,综合经济效益提高2445～3729元/hm2。但重度（土壤含水量控制在20%～25%）或长时间（>15d）干旱胁迫降低了补偿效应甚至产生伤害。因此,从红麻生产的高产、高效出发,确定土壤含水量占田间最大持水量的40%～45%作为红麻旺长期增产、增效的水分临界指标。     

Comparative Effects of Salt and Water Stress on Seed Germination and Early Embryo Growth in Two Cultivars of Sweet Sorghum

In semiarid regions of the Mediterranean basin, water and salinity stresses restrict crop establishment. The effects of salt and water stress on seed germination and early embryo growth (radicle and shoot growth) were investigated in laboratory in two cultivars of sweet sorghum [Sorghum bicolor (L.) Moench] – cv. ‘90‐5‐2′ and cv. ‘Keller’ – to verify how these stresses may limit crop growth during the very early stages of growing season. Six water potentials (ψ) of the imbibition solution (from 0 to ?1.0 MPa) in NaCl or polyethylene glycol (PEG) for salt and water stress tests, respectively, were studied. Daily germination was recorded, and radicle and shoot lengths and dry weights (DWs) were measured 2 days after initial germination. Seed germination was reduced (8–30% lower than control) by water stress at ψ 相似文献   

Effects of Salinity and Soil–Drying on Radiation Use Efficiency,Water Productivity and Yield of Quinoa (Chenopodium quinoa Willd.)

Drought and salinity reduce crop productivity especially in arid and semi‐arid regions, and finding a crop which produces yield under these adverse conditions is therefore very important. Quinoa (Chenopodium quinoa Willd.) is such a crop. Hence, a study was conducted in field lysimeters to investigate the effect of salinity and soil–drying on radiation use efficiency, yield and water productivity of quinoa. Quinoa was exposed to five salinity levels (0, 10, 20, 30 and 40 dS m^?1) of irrigation water from flower initiation onwards. During the seed‐filling phase the five salinity levels were divided between two levels of irrigation, either full irrigation (FI; 95 % of field capacity) or non‐irrigated progressive drought (PD). The intercepted photosynthetically active radiation was hardly affected by salinity (8 % decrease at 40 dS m^?1) and did not differ significantly between FI and PD. Radiation use efficiency of dry matter was similar between salinity levels and between FI and PD. In line with this, no negative effect of severe salinity and soil–drying on total dry matter could be detected. Salinity levels between 20 and 40 dS m^?1 significantly reduced the seed yield by ca. 33 % compared with 0 dS m^?1 treatment owing to a 15–30 % reduction in seed number per m², whereas the seed yield of PD was 8 % less than FI. Consequently, nitrogen harvested in seed was decreased by salinity although the total N‐uptake was increased. Both salinity and drought increased the water productivity of dry matter. Increasing salinity from 20 to 40 dS m^?1 did not further decrease the seed number per m² and seed yield, which shows that quinoa (cv. Titicaca) acclimated to saline conditions when exposed to salinity levels between 20 and 40 dS m^?1.     

甘白远缘杂交新材料单株产量与农艺性状的相关性分析

为了明确甘白远缘杂交新材料各性状对单株产量影响,促进新材料在育种中的应用,对133个远缘杂交BC₁F₄后代株系的农艺性状,进行了变异分析、相关分析、通径分析和主成份分析。结果表明,远缘杂交后代农艺性状中主序无效角果数变异最大,株高的变异最小。单株产量与株高、分枝高度、主序有效长度、一次分枝数、主序无效角果数、每果粒数和千粒重呈正相关,其中与株高呈极显著关系。影响单株产量的主要性状为株高、分枝高度,二次分枝角果数和主序有效角果数。主成份分析可将相关性状综合为5大类,其中第一、三为产量控制性状,其余依次为株高控制性状、主序控制性状和分枝控制性状。因此,本研究中甘白远缘杂交后代的单株产量主要受株高、分枝高度、二次分枝角果数和主序角果数的影响。本研究结果对于充分利用甘白杂交后代优良性状,选育优良品种提高有价值参考。     

串叶松香草种子产量构成因子分析

采用方差分析、相关分析、通径分析和逐步回归分析对串叶松香草种子产量构成因子进行了研究,结果表明:在串叶松香草株高、每株生殖枝数、每株花序数、每花序种子数、千粒重和单株种子产量这6个产量因子中,除株高和千粒重在不同生长年限之间不存在显著差异外,其它因子均存在显著差异;每株花序数和每花序种子数与单株种子产量间存在极显著相关,是串叶松香草种子产量的主要影响因子;串叶松香草单株种子产量的回归模型为:Y=-87.50047+0.14578X3+4.19497X4(F=23.51,Pr0.0001)。