Water Sensitive Periods during the Reproductive Growth Phase of Glycine max L. II Establishing Water Stress Sensitivity

The water sensitivity of soybeans was determined on a day-to-day basis from the onset of flowering to physiological maturity by correlating daily leaf water potential values of 50 different soil water regimes with corresponding grain, vegetative and biomass yields. Days, and consecutive days forming periods, during which significant negative correlations were obtained were regarded as water sensitive periods during the reproductive growth phase of the soybean crop.
Water deficits during flowering significantly inhibited vegetative and biomass production but inhibited grain yields only when occurring during early flowering. During pod elongation and seed development the sensitivity of the soybean plant to water stress was present but diminished in time with regard to vegetative and biomass yields. The effect on grain yields was restricted to pod elongation and to later seed development stages. Water stress affected grain yields to a far greater extent than vegetative growth during seed filling and physiological maturity.     

Growth Analysis in Relation to Pigeonpea Improvement

An attempt was made to assess possible constraints to higher production, with respect to partitioning of total dry matter to reproductive sinks in early pigeonpea. Growth, dry matter accumulation and yield components were determined in four diverse genotypes under four dates of sowing and different plant densities. Data on growth characteristics, dry matter accumulation (vegetative and reproductive) were obtained for three sowings, while the data on yield components were obtained for two dates of sowing. Growth analysis showed that the total dry matter was low upto 30 days after sowing and increased linearly upto 120 days. Coversely, LAD was high for the first 30 days and reduced at later stages of growth. The mean LAI of genotypes did not very much at initial stage of growth. However, it has given interesting picture during 70 to 90 days of growth. The higher biological yield and seed yield were attributable to high LAI and LAD coupled with thick stem, more effective branches, more pods per plant and larger raceme length. Harvest index was the maximum with increased plant populations in all sowings. Indeterminate varieties under high plant density and narrow row spacing (50 cm) developed a large leaf area and were presumably able to make better use of light. Growth and branching of individual plants were reduced at the higher plant population, but on per unit basis more dry matter was produced. It is suggested that breeding should be concentrated to improve an inability to accumulate adequate vegetative dry matter for the maintenance and filling of pods, may force the plant to continue vegetative production into the reproductive dry matter to support production of ultimate seed yield.     

播期对雨养旱地春玉米生长发育及水分利用的影响

为了解决陕西渭北旱塬地区玉米播种期干旱缺水造成出苗不全、不整齐,导致产量低而不稳的问题,设置6个不同播期,研究对春玉米生长发育、干物质生产、产量形成、水分利用及环境因子的影响。结果表明,随着播期的推迟,玉米的生育期明显缩短,营养生长期、营养生长与生殖生长并进期变化范围为2~19 d,生殖生长阶段则相对稳定,变化范围仅为?3~5 d。在一定的时间范围内,不同播期处理间的单株干物质生产没有明显差异,但由于受播期调整后的土壤含水量变化影响,适宜播期的玉米花后雌穗干物质积累量、籽粒产量及水分利用效率分别较早播和晚播提高4.0%~23.6%、3.9%~24.5%和6.6%~14.5%。早播影响产量的主要因素是播种期土壤含水量低而造成的出苗差,实际收获穗数不足;晚播影响产量的主要因素是生殖生长期后移,有效积温和日照时数减少造成的花后干物质积累减少、千粒重下降。适期播种可以增加田间实际收获穗数,促进雌穗花后干物质积累,提高玉米的水分利用效率。结合该区生态因素,5月4日以前适墒播种是玉米高产的有效避旱播期。研究结果可为该区春玉米抗逆避旱高产栽培提供有效的技术参考。     

Lint Yield Compensatory Response to Main Stem Node Removal in Upland Cotton (Gossypium hirsutum)

Hail storm damage to the cotton (Gossypium hirsutum L.) plants can destroy vegetative and reproductive structures, modify canopy architecture and impact lint yield. Field studies were conducted at University of Arizona Maricopa Agricultural Center in 2011, 2012 and 2013 to examine cotton plant architecture changes and compensatory growth in response to removal treatments of uppermost nodes on main stem (terminal bud removal, 2 node removal and 4 node removal) as simulation of hail damage at the node 2, 4, 8, 12, 16 and 24 growth stages. Main stem node removal caused significant decrease in leaf area and biomass, especially at early growth stages. However, significant lint yield reduction only occurred by removing 2 nodes at the node 4 stage and removing 4 nodes at the node 8 stage in 2011, removing terminal bud at the node 12 stage in 2012 and removing terminal bud, 2 nodes and 4 nodes at the node 8 stage in 2013. The lint yield reduction did not exceed 13 % in all three growing seasons. Yield loss due to main stem node removal was mainly compensated by increased boll number on the vegetative branches at early growth stages and on fruiting branches at late growth stages. Yield compensation from vegetative branches increased with number of main stem nodes removed. This study suggests that the cotton crop has a strong compensatory ability to plant structure damage due to its indeterminate growth and longer growing season in the region.     

水分胁迫对红麻生理特性和产量的影响

水分胁迫下,红麻叶片水势降低,游离脯氨酸含量大幅度上升,过氧化物酶活性增强,蒸腾速率减慢,用水效率提高,绿叶面积和净同化率变小,生长受阻。以上变化随水分胁迫程度加重而加剧。复水后红麻各项生理功能恢复很快。反映了红麻是一种耐旱性很强的作物。在红麻旺长后期水分胁迫对营养生长及干茎和生麻产量的影响大于旺长前期。但旺长后期水分胁迫后有促进生殖生长的趋势。因此,根据红麻不同时期对水分胁迫的反应及收获对象不同而采取相应的水分管理技术是十分重要的。     

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.     

黄淮海夏大豆干物质积累、转运及产量对播期的响应特征

为了明确播期对大豆干物质积累,花前、花后同化物转运及产量的影响,促进大豆新品种推广及高产稳产.以'菏豆37'为试验材料,设置6月5日(D1)、6月15日(D2)、6月25日(D3)3个播期处理,用Logistic曲线方程,对数据进行分析.D2播期下大豆营养器官、生殖器官及单株地上部进入干物质快速积累起始时间均最早,分别...     

内陆河流域不同播期对春玉米土壤温度及生物量的影响

土壤温度是限制玉米高产的主要环境因子,为了寻求合理的播种时间,使玉米生长发育处于适宜的土壤温度环境中,从而保证干物质的积累和产量的形成。通过在内陆河流域代表区域武威开展不同播期对大田地膜春玉米进行试验,采用全生育期连续定点观测春玉米发育期、产量结构和20 cm、40 cm两个深度的土壤温度变化,分析了不同播期对春玉米生物量和土壤温度的影响。结果表明：营养生长期不同播期处理各层次地温均随生育进程的推进呈逐渐升高的趋势,拔节之后即进入生殖生长期,地温呈降低趋势。第二播期（4月20日）生长状况好,干物质累积量高,尤其是乳熟期和成熟期差异明显(P<0.05)。第二期产量构成优于第三期（4月30日）和第一期（4月10日）。第二播期处理,可以在苗期获得较高的地温,土壤增温明显,而在拔节期以后可保证适当较低的温度,从而保证干物质积累时间和产量结构的形成,是当地最适宜的地膜春玉米播种期。第一播期生物量则表现最差,说明正常情况下作物适当提前播期,延长生长期的做法在玉米的生产上是有一定风险的。     

甜荞品种‘牡丹荞’季节性栽培对产量的影响

甜荞(Fagopyrum esculentum Moench)的生长生育过程受自然因素影响很大,光照、温度条件和水分条件的季节性变化对其产量影响明显。通过对‘牡丹荞’品种在不同季节的栽培种植,以播期、成熟期、全生育期、株高、主茎节数、主茎分枝、单株粒重、千粒重、小区产量为研究指标,通过数理统计的方法建立回归方程,揭示甜荞在某个区域的最适播期以及播期对主要产量性状的影响。研究结果表明：甜荞品种‘牡丹荞’在太原地区栽培对光照不敏感,对水分要求不严格,只对热量要求较严。出苗到开花期的 平均温度高则全生育期缩短,主茎分枝减少,单株粒数增加,单位面积甜荞产量提高。播种到出苗阶段,同其他作物一样,温度越高出苗越快。灌浆期最适温度为18~22℃。太原地区种植甜荞的最佳时期为7月7—20日。     

播期对大豆生长状况及产量的影响

了解不同播期对大豆生长状况及产量的影响,对寻求适宜播期及优质高效生产有重要意义。以黑龙江省哈尔滨市大豆主栽品种为试验材料,通过3个播期处理(S1为5月1日,S_2为5月10日,S_3为5月21日),研究不同播期条件下大豆生长状况及产量的变化规律。结果表明:S_1、S_2处理生育期日数延长;S_1、S_2处理在鼓粒期—成熟期干物质积累与分配及生长率明显高于S_3处理,干物质积累向果实转移量增大,其产量分别增加230.6、317.7 kg/hm~2;S2处理在3个处理中最优,水热等气候资源利用程度高。哈尔滨市大豆适宜播期为5月8—10日,但适播期应考虑春季土壤水分或春季首场透雨,促进大豆生长发育,显著提高产量。     

不同生育时期遮阴对大豆形态性状和产量的影响

间套作是提高土地利用率,促进农作物高产的重要技术,而遮阴限制间套作大豆产量,且间作和套作大豆被遮阴的生育时期不同。为明确不同生育时期遮阴对大豆形态性状和产量的影响,2010-2012年用透光率50%的遮阳网对桂夏2号、南豆12、南冬抗22、E61和C103遮阴处理,结果表明,不同生育时期遮阴对各形态指标影响程度不同,前期遮阴(VER1和VER2)对主茎长、主茎长/茎粗等主茎形态性状有(极)显著影响,主茎长、主茎长/茎粗比值平均比对照分别高45.75%,93.64%;后期遮阴(R1R8和R2R8)对分枝数和底荚高度等形态性状有(极)显著影响,分枝数平均比对照低29.97%,底荚高度平均比对照高28.59%;各品种产量受前后期遮阴影响程度不同,R/V比值低于1.4的品种产量受前期遮阴影响更大,R/V比值大于等于1.5的品种产量受后期遮阴影响更大;相关分析和通径分析结果表明,主茎长、第一节间长、分枝高、主茎长/茎粗比值和主茎长/分枝数比值与单株产量呈极显著负相关,分枝数与单株产量呈极显著正相关,主茎长/茎粗比值和主茎长/分枝数比值是间接反映大豆产量高低的重要指标。     

Water-Sensitive Periods during the Reproductive Growth Phase of Glycine max L. I. Regression Model for estimating daily leaf water potential

To establish the exact duration of critical periods for plant water stress during the reproductive growth stage of soybeans it is necessary to draw correlations between daily leaf water potential values and crop growth and yield. Different sets of daily leaf water potential values can be induced by different sets of irrigation applications. It is, however, imperative that water stress values are available for each day over the growing season of a large number of irrigation treatments. Since these values were not available, it was decided to calculate it by establishing a relationship between leaf water potential as determined by potential evapotranspiration and soil water content as well as soil water potential for various layers of the root zone. The most reliable regression formula was found to be:      

灌溉方式和播期对地膜春玉米产量和水分利用效率的影响

为了缓解气候变化加剧的水资源短缺危机和生态风险,寻求合理高效节水灌溉方式,提高农田作物水分利用效率的适应性。通过不同灌溉方式和不同播期对大田地膜春玉米进行试验,采用全生育期连续定点观测春玉米发育期、产量结构和水分利用效率,分析了不同灌溉方式和不同播期对春玉米产量和水分利用效率的影响。结果表明：滴灌、喷灌和漫灌3种灌溉方式中滴灌最有利于春玉米干物质积累、第二播期生长状况好,干物质累积量高,尤其是乳熟期和成熟期差异明显(P<0.05)。滴灌、喷灌较漫灌根系多;喷灌根系长而粗,与滴灌、漫灌差异极显著(P<0.01)。滴灌、喷灌果穗长、果穗粗好于漫灌,滴灌秃尖最短,籽粒重和百粒重呈现为滴灌>喷灌>漫灌,且差异显著(P<0.05)。第二期产量构成优于第三期和第一期。滴灌产量高,耗水少,水分利用效率最高,而产量较高耗水最少的第三期水分利用效率高,差异显著(P<0.05)。总之,滴灌是最适宜于干旱区的抗旱、节水、节肥和增产的灌溉方式;第二期是最适宜的播种期,且气候变暖有利于晚播、晚熟品种的推广和获得高产。     

The Effect of Air Temperature on Growth and Alkaloidal Yield of Hyoscyamus muticus L.

The effect of natural air temperature on the vegetative growth and alkaloidal yield of H. muticus L. was studied. The highest number of branches, diameter, fresh and dry weights of stem and roots occurred in September sowing at full-flowering and fruiting stages. Relatively higher temperature in Sept. sowing favoured leaf growth (number, area and dry weight). Hyoscyamine yield in different organs of the plants sown in Sept., excessively exceeded all other sowings during flower budding and full-flowering stages. Hyoscine yield was quantitatively very small as compared with that of hyoscyamine and even could not be detected in the leaves of winter sowings during full-flowering stage.     

有机耕作对大豆土壤-植株氮磷吸收及品质的影响

通过常规与有机大豆土壤-植株氮磷吸收规律和产品品质比较,为区域农业发展提供决策依据。研究以常规与有机大豆为研究对象,分析土壤-植株氮磷吸收规律,大豆产量与品质差异。结果表明,常规与有机耕作模式下土壤全氮、全磷含量差异均不显著。不同生育时期常规与有机大豆土壤全磷含量差异显著,均表现为成熟期最大,花期最小。常规与有机大豆植株氮素、磷素吸收均为花期最大,成熟期最小。与常规大豆相比,有机大豆产量和蛋白质产量分别提高13.7%和17.1%,油脂产量降低9.1%。由此得出,有机和常规大豆土壤-植株氮磷吸收特征基本相同,但有机大豆种植过程中由于充分利用土壤自身调节能力,改善了土壤养分均衡供应,使得产量及品质均显著高于常规大豆。     

水条播对寒地水稻农艺性状和产量构成因素的影响

随着劳动力的短缺,直播水稻具有省工省力的优点逐渐受到重视,因此筛选适宜水条播（直播）的水稻品种是极其重要的。为此,以29份寒地水稻为材料,采用随机区组试验设计,研究水条播对寒地水稻农艺性状、产量构成因素和产量的影响。结果表明,水条播对寒地水稻单位面积穗数的影响为偏正向,对株高、穗长、穗重、一次枝梗数、二次枝梗数、穗粒数、成粒率、千粒重、生物产量、经济系数和理论产量的影响都是偏负向的。水条播提高了穗重、一次枝梗数、二次枝梗数、单位面积穗数、穗粒数、成粒率、千粒重、生物产量、经济系数和理论产量的变异程度,而千粒重的变异系数较小。穗重、成粒率和生物产量对水条播反应较敏感的材料,一般其理论产量对水条播的反应也较敏感。     

播期对高蛋白大豆籽粒品质及产量的影响

旨在确定探明不同高蛋白大豆品种的最佳播期。本试验以黑龙江省三江平原主栽的4 个高蛋白大豆品种分7 个播期进行栽培，研究了播期对高蛋白大豆品质及产量的影响。结果表明：4 个高蛋白大豆品种在各播期蛋白质含量均值变化范围为39.14%~45.26%，最大变化幅度为15.64%；脂肪含量均值变化范围为18.82%~20.30%，最大变化幅度为7.86%；产量变化范围为2064.2~3068.1 kg/hm2，蛋白质产量均值变化范围为807.2~1377.9 kg/hm2，产量和蛋白质产量均随播期变化呈先增高后降低的趋势，并在A2 播期达到最大值，播期显著影响大豆蛋白质含量、脂肪含量、产量和蛋白质产量。因此，适期播种能够提高大豆产量和蛋白质产量，适合当地高蛋白大豆品种的最佳播期是5月4日左右。     

播种量对冀北地区2个荞麦品种产量的影响

试验于2018-2019年连续进行2年,采用裂区设计,以甜荞品种冀甜荞1号和苦荞品种冀苦荞1号为材料,设置5个播种量处理,研究了播种量对不同荞麦农艺性状及产量的影响。结果表明,播种量对冀甜荞1号的株高、主茎节数和千粒重影响不大,对主茎分枝数、花序数、单株粒数、单株粒重以及产量有一定影响,播种量在120万~180万粒/hm²之间均能达到高产,适宜播种量为120万粒/hm²。不同播种量对冀苦荞1号的主茎节数和千粒重影响不大,对株高、主茎分枝数、花序数、单株粒数、单株粒重以及产量都有一定影响,播种量在90万~150万粒/hm²之间均能达到高产,适宜播种量为90万粒/hm²。     

Establishment of a crop evapotranspiration calculation model and its validation

In order to contribute knowledge on the method used to calculate the actual crop evapotranspiration, soil, crop, atmosphere, and water spatial structure were integrated into a complete system. Based on the energy balance equation and aerodynamic equation, the meteorological data was reduced and the crop physiological parameter was increased, then the crop evapotranspiration calculation model under natural conditions was derived. The crop evapotranspiration calculation model was verified by the water balance formula using data generated from corn, potato, and flue-cured tobacco grown under field conditions for three consecutive years from 2017 to 2019. The results showed that: from 2017 to 2019, the average root mean square error for measured and calculated evapotranspiration of corn, potato, and flue-cured tobacco at different growth times were 0.5948, 0.4753, and 0.3326, respectively, the mean deviation, mean absolute error, and mean relative error were small, and the coefficient of determination and consistency index were both greater than 0.9100. The measured and calculated crop evapotranspiration of the selected crops increased at first and then decreased gradually as the crops matured, and finally decreased to harvest evapotranspiration, showing a parabolic trend. The crop evapotranspiration calculation model not only reflects the actual evapotranspiration of crops at different growth time but also reflects the change law of actual crop evapotranspiration. The model does not need the correction of soil moisture content, irrigation method, and crop coefficient and can directly calculate the actual crop evapotranspiration. It has the characteristics of consistency between the calculated value and the measured value, strong applicability, simple calculation process, and high accuracy and has the best effect on monitoring soil moisture and crop water shortage sensitivity. The model is significance in that it guides for monitoring soil moisture, determining actual crop evapotranspiration, crop water shortage index, and high yield and efficiency under water-saving conditions.     

播期对白燕7号在黑龙江省中西部地区产量的影响

为探究播期对皮燕麦生长特性和产量的影响,设置6个播种时期,研究了不同播期对皮燕麦品种白燕7号生育进程、形态指标、光合特性等指标的影响,分析了不同播期处理气候因子和皮燕麦生长的相关性。结果表明：随着播期的推迟,皮燕麦的生育期缩短,分蘖数先减少后增加,株高逐渐升高;光合性能降低、叶面积指数在营养生长期逐渐升高,在生殖生长期则相对降低;各阶段光合势总体呈降低趋势;收获穗数、千粒重、穗粒数显著减少,子粒产量呈下降趋势。气候因素中日照时数对子粒产量影响最大。在其他因子不变的情况下,积温每增加1℃,子粒产量减少1.158kg/hm ²;降雨量每增加1mm,子粒产量减少0.738kg/hm ²;日照时数每增加1h,子粒产量增加24.101kg/hm ²。为获得子粒高产,黑龙江省大庆地区皮燕麦播种日期选择在4月13日前后为宜。