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为了研究产量关键期干旱胁迫对玉米物候及产量和产量组成的影响,评估作物生长模型对干旱胁迫下玉米物候和产量模拟的效果,基于锦州农业气象试验站2011-2015年分期播种试验玉米产量和产量组成观测资料,尤其是2014年和2015年天然干旱胁迫试验数据和2015年玉米开花、吐丝物候加密观测资料,分析了产量关键期干旱胁迫对玉米物候及产量和产量组成的影响,评估了CERES-Maize模型对不同降水年型玉米产量和产量组成的模拟效果,提出了模型改进的方向。结果表明,2014年和2015年辽宁省西部地区在玉米开花期前后经历了较严重的干旱胁迫过程,干旱胁迫导致玉米吐丝延迟程度大于开花,90%以上的植株能到达开花阶段,但仅有45%~88%的植株能到达吐丝阶段,直接影响株籽粒数(不同播期下的玉米株籽粒数相差32%)及最终产量(产量下降33%~78%)。CERES-Maize模型对正常年玉米产量及产量组成的模拟效果较好,对干旱年的模拟效果较差,部分原因在于模型在模拟玉米物候时不对开花和吐丝期加以区别,只考虑了温度对花期的影响,而没有考虑干旱胁迫下玉米因开花-吐丝间隔增大、雌穗发育异常、物候期推迟而造成的减产作用。因此,玉米产量关键期干旱胁迫直接影响玉米物候(开花-吐丝期),进而影响玉米穗粒数及最终产量;为提高干旱胁迫下作物模型的模拟评估能力,亟待开展干旱胁迫下基于冠层吐丝动态的玉米产量模拟研究。 相似文献
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不同栽培方式和营养液磷钾水平对万寿菊生长和开花的影响 总被引:6,自引:0,他引:6
为了探讨万寿菊对静止水培的适应性以及营养液不同磷、钾水平对其生长和开花的影响,本研究以常规基质培为对照,设置了不同磷、钾浓度的营养液静止水培万寿菊。结果表明:万寿菊在供试的4种营养液配方中静置水培均能正常生长,整株生物量、植株氮磷钾含量、根活力和开花数目均显著优于基质栽培;静止水培时,提高钾浓度或同时提高磷、钾浓度,能促进根系的生长,使万寿菊开花一致,且花朵直径较大。 相似文献
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Models can play an important role in agricultural planning and management. Thermal time accumulation is a common way of describing phenological development in crop models, but the sensitivity of this concept to water stress is rarely quantified. The effect of pre-anthesis droughts on the timing of anthesis and physiological maturity was assessed for quinoa (Chenopodium quinoa Willd.) var. ‘Santa Maria’, with the help of two field experiments (2005–2006 and 2006–2007) in the central Bolivian Altiplano. Various treatments with different sowing dates and irrigation applications were considered. To evaluate the effect of drought stress on crop development, drought stress during the first 60 days after sowing was assessed with three different stress indicators: the number of days that the soil water content of the root zone was above a threshold, the average relative transpiration, and the sum of daily actual transpiration, standardized for reference evapotranspiration (∑(Ta/ET0)). The best indicator to quantify the effect of pre-anthesis drought stress on phenological development was ∑(Ta/ET0) cumulated until 60 days after sowing. This indicator showed a significant logarithmic relation with the time to anthesis and time to physiological maturity. Correlations of the drought stress indicator with thermal time accumulation were better than with calendar time accumulation. Due to an effect of post-anthesis droughts, the correlations of the drought stress indicator with the time to anthesis were stronger than with the time to physiological maturity. It was also demonstrated that deficit irrigation can contribute to a better agricultural planning due to a better control of the phenological development of quinoa. The proposed relations can be used for modeling phenological development of quinoa in drought prone regions and for efficient deficit irrigation planning. 相似文献
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[目的]为红芙蓉山茶和七星红山茶的促成栽培提供技术参考。[方法]采用复合激素涂抹剥离外部鳞片的2种山茶花蕾,统计始花时间、始花温度、平均花茎、整株花期、花蕾大小,观察花鲜艳程度、花开放程度、阴冷天花开放程度。[结果]结果表明,GA 800 mg/L+Spd 70 mg/L处理七星红山茶的效果较好,BA 150 mg/L+NAA 60 mg/L次之;GA 500 mg/L+BA 120 mg/L处理红芙蓉山茶的效果较好,GA800 mg/L+NAA 80 mg/L对红芙蓉山茶有一定的促进作用。[结论]外施复合激素可以使红芙蓉山茶和七星红山茶提前开花。 相似文献
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The influences of the anthesis date and the fruiting branch positions on parameters of cotton fiber quality and super-molecular structure were studied. Fiber quality parameters, such as cotton fiber length, micronair, maturity and fiber strength deteriorated with postponing the anthesis date and decreasing temperature. When anthesis happened on the same date, the fruiting branch positions affected the fiber quality parameters, and the fiber quality parameters of the lower portion turned out to be higher than that of the upper portion, although the difference was insignificant. The super-molecular structure of the lower portion turned out to be superior to that of the upper portion at the early anthesis date and high temperature, which is in accordance with what was mentioned above, but the fruiting branch positions did not affect the impact of the anthesis date on the super-molecular structure. 相似文献
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Modelling the risk of cross-pollination between maize crops can help to define efficient isolation methods to reduce the risk of gene flow between these crops. However, the use of such models over the pollen emission season is limited by poor estimations of pollen emission. In this study, we present a model that predicts hourly pollen emission fluxes over the pollen season and that accounts for effects of both meteorological conditions and crop variety. It consists of two sub-models that predict: (i) the seasonal pattern on a daily basis and (ii) the normalized diurnal pattern on an hourly basis.To assess the variability of pollen emission, ten field experiments were carried out in July and August over four years using three crop varieties. The model was built from (i) a parameterisation of the measured diurnal and seasonal patterns of pollen emission followed by (ii) a quantification of the relationships between parameter values and meteorological conditions. Total production of pollen was fairly constant for a given variety over years and sowing dates, while patterns of emission varied with meteorological conditions. The pollen emission season was longer when temperature was low and humidity was high. In most cases, the diurnal pattern was unimodal: the onset and the peak of emission were delayed when relative humidity was high or wind speed was low. In some cases, a second peak of emission occurred during the afternoon. This was observed more frequently when temperatures were high. 相似文献