不同生育时期干旱对花生根系生理特性及产量的影响

采用旱棚土柱栽培法,研究了不同生育时期干旱对花生根系生理特性及产量的影响。结果表明:干旱胁迫下,花生根系变长,直径变小,表面积增大,根尖数增多,根系活力下降,根系总吸收面积、根系活跃吸收面积增大,根干物质量、根冠比增大。不同生育时期相比,花针期和结荚期干旱对根系生长发育和根系活力的影响明显大于苗期和饱果期干旱,而根系总吸收面积和活跃吸收面积增幅显著低于苗期和饱果期,表明花针期和结荚期对干旱反应敏感;不同时期干旱明显降低了花生荚果产量,结荚期减产最大,其次为花针期和饱果期,苗期减产最小。     

膜下滴灌追肥时期对花生干物质及氮素积累和产量的影响

为确定膜下滴灌适宜的追肥时期和追肥次数,以花生品种青花7号为供试材料,以不灌水不追肥作为对照,在总施肥量相同的前提下,设置7种追肥方式,研究膜下滴灌追肥时期和追肥次数对花生干物质及氮素积累和产量的影响。结果表明:不同时期追肥较对照均能增加花生营养和生殖器官干物质积累、含氮量、氮积累量、荚果和籽仁产量。以花针期+结荚期配合追肥效果最好,花针期次之,饱果期追肥效果最差。其中,生育期间只追1次肥,增加花生营养和生殖器官干物质积累、含氮量、氮积累量、荚果和籽仁产量的表现为花针期追肥效果最好,其次为结荚期,饱果期效果最差。生育期间追2次肥,增加营养和生殖器官干物质积累、含氮量、氮积累量、荚果和籽仁产量则以花针期+结荚期追肥效果最好,花针期+饱果期追肥效果次之,结荚期+饱果期追肥效果最差。分次追肥效果较1次追肥效果好,但生育期间追3次肥的效果不是最好的。与对照相比,花针期+结荚期追肥在所有处理中对花生生长及氮素积累和产量形成的促进效果为最优。说明追肥时期早、前期追肥量大和分次追肥有利于促进花生生长和氮素吸收积累,从而提高荚果和籽仁产量。在本试验条件下,研究认为花针期+结荚期的追肥方式更适用于花生生产。     

干旱胁迫对花生生长发育和光合产物积累的影响

采用人工控制条件下的防雨棚土柱栽培试验,以不同抗旱类型花生品种为材料,设置充分灌水和中度干旱胁迫处理,对苗期、花针期、结荚期、饱果期和成熟期(播种后30d、50d、75d、103d和132d)5个生育时期地上部不同器官和根系物质积累的影响进行了研究。结果表明,随生育期的进行,除花育22号在全生育期干旱胁迫条件下呈渐升趋势至成熟期最大外,花育23号和花育25号2品种根系干物质积累量均呈"抛物线型"变化趋势。干旱胁迫使花育23号根系干物质积累量峰值出现在结荚期,而花育25号峰值滞后到饱果期。3品种根重和荚果干物质积累量大小顺序均表现为:花育25号花育22号花育23号;通过Logistic方程能很好地拟合各品种地上部各器官、根系及植株生长发育情况。干旱胁迫使花育22号和花育23号两品种最大生长速率(Vm)明显降低,花育25号明显升高,但3品种地上部植株物质积累最大速率出现的时间(Tm)均明显滞后;地上部叶片和茎Vm降低,Tm延长;干旱胁迫使花生光合作用降低,光合产物积累缓慢,植株生长发育迟滞。3品种表现出对干旱胁迫适应性的差异,花育23号品种对水分较为敏感,抗旱性较差,花育25号具有较强的抗旱性。     

花生主要光合性状对产量形成的重要性差异分析

为了明确不同光合性状在花生产量形成过程中的重要性差异,选择苗期、花针期、结荚期、饱果期和成熟期气孔导度、羧化效率、最大光化学效率、实际光化学效率、单株绿叶面积等主要光合性状与产量进行了灰色关联度分析。结果表明,在苗期、花针期和结荚期,羧化效率与花生产量的关联度最大,光合暗反应限制着光合产量的形成;而在饱果期和成熟期,气孔导度与花生产量的关联度最大,气孔张开的程度限制着花生产量的形成。     

不同生育期干旱对花生衰老特性及产量的影响

在防雨棚池栽和盆栽条件下,通过人工控水研究了不同生育期干旱对花生衰老特性和产量的影响。研究表明,不同生育期干旱均导致花生叶片叶绿素含量、净光合速率、SOD、POD、CAT活性和花生根系活力的降低,致叶片MDA含量提高,其中花针期和结荚期干旱对花生衰老特性影响最大。干旱处理均导致荚果产量、生物产量降低,花针期和结荚期干旱对花生产量形成影响最大。     

高产夏直播花生干物质积累动态与产量形成规律

系统研究了麦收后夏直播地膜覆盖花生在３０万株／ｈｍ２密度下６０００ｋｇ／ｈｍ２产量水平的植株干物质生产和产量形成的规律。植株干物重和荚果干重动态可拟合成Ｌｏｇｉｓｔｉｃ方程。植株干物重最快增长期为出苗后４３～５１ｄ，最大生长速率０．７６８ｇ／（株·ｄ），最终生物量４０．８６ｇ／株。植株干物质积累量，结荚期占６４．６％，饱果成熟期占１２％。荚果干重最快增长期是出苗后７２～８１ｄ，幼果形成后３６～４５ｄ，最大增长速率０．８６７ｇ／（株·ｄ）。荚果干重增长量，结荚期占６６．４％，饱果成熟期占３３．４％。经济系数０．６。分配系数结荚期０．６２５，饱果成熟期１．７０７，产量形成期平均０．７９５。与春花生相比，生育前期叶面积发展快，干物质积累速度高。生育后期分配系数显著高于春花生。干物质和荚果产量主要在结荚期形成。     

不同生育时期膜下滴灌对花生生长发育及产量的影响

以花生品种山花7号为材料,研究了不同生育时期膜下滴灌对花生生长发育、产量及产量构成因素的影响。结果表明,膜下滴灌促进花生植株生长,其主茎高、侧枝长、分枝数、单株叶面积、生物量均大于CK;显著增加花生生育后期叶片叶绿素a/b值;对百果重、百仁重、单株结果数、出米率、荚果和籽仁产量有明显的促进作用。花针期滴灌、花针期和结荚期滴灌两处理花生荚果和籽仁产量增产幅度均在7%以上,而结荚期滴灌荚果和籽仁产量增幅仅分别为3.61%和5.08%。膜下滴灌有利于促进花生的生长发育,提高花生产量,在花针期进行膜下滴灌补水,增产效果较为明显。     

不同生育时期干旱处理对夏花生生长发育的影响

旱棚盆栽条件下研究了夏花生生长发育和生理性状对土壤干旱的反应，结果表明，水分胁迫使夏花生营养生长及干物质积累量下降，根系体积下降，叶片中叶绿素含量和脯氨酸含量提高。苗期干旱对营养生长影响最大，花针期和结荚期干旱主要影响生殖生长和产量形成，导致产量降低。     

控释氮肥对花生叶片蔗糖合成及产量的影响

本试验采用起垄地膜覆盖栽培方法,以花生品种山花9号为材料,研究了不同控释氮肥配比对花生蔗糖积累和产量的影响.结果表明,控释氮肥较普通氮肥在结荚后期叶面积指数高、叶片SPS活性和蔗糖含量高,利于提高百果重和饱果率,显著提高了荚果产量.掺混氮肥处理花生在苗期和花针期叶面积指数、SPS活性和蔗糖含量均较高,与普通氮肥处理无显著差异；生长后期不脱肥早衰,利于提高百果重和饱果率,荚果增产更明显.     

复合肥深施对花生生理和氮素吸收及产量与品质的影响

本试验探究不同施肥深度对花生生理特性和氮素吸收及产量与品质的影响，为花生机械化施肥设置合理施肥深度提供理论支持。采用大田栽培方式，设置施肥深度分别为0、5、10、15、20、25 cm,以不施肥作为对照，在花生苗期、花针期、结荚期、成熟期取样测定叶片抗氧化酶活性、营养器官氮素积累量、植株形态特征、产量及品质等指标。结果显示，除苗期外叶片POD、CAT活性随施肥深度增加呈先增后减的规律，深施15 cm能显著增加花针期和成熟期主茎高、侧枝长、总分枝数、主根长、叶面积指数和干物质量，提高成熟期饱果率、百仁质量、油酸含量及花生营养器官对氮素的积累，提高了整株氮素吸收效率，花生荚果产量和籽粒品质有所提高。试验得出深施15 cm为花生最佳施肥深度。     

Simulation of soybean growth and yield in near-optimal growth conditions

SoySim is a new soybean (Glycine max, L. Merr) simulation model that combines existing approaches for the simulation of photosynthesis, biomass accumulation and partitioning with several new components: (i) flowering based on floral induction and post-induction processes, (ii) leaf area index based on logistic expansion and senescence functions, (iii) integration of canopy photosynthesis using a beta function, and (iv) yield simulation based on assimilate supply and seed number. Simulation of above ground dry matter (ADM) and seed yield by SoySim were validated against data from field studies at Lincoln (NE), Mead (NE), Whiting (IA), and West Lafayette (IN) that included 147 site-year-cultivar-planting date-plant-plant population combinations. In each of the four field studies, agronomic management other than planting date and plant population was optimized to achieve growth with minimal limitation from pests, nutrients, or other controllable factors. SoySim requires just two genotype-specific and two crop management-specific input parameters and yet provides reasonable accuracy in simulating growth and yield under optimum growth conditions across a wide range of sowing dates, plant population, and yield (2.5–6.4 Mg ha⁻¹) in the North-Central U.S. Corn Belt. Simulated seed yield had a RMSE of 0.46 Mg ha⁻¹. Few cultivar-specific parameter input requirements, lack of requirements for specification of key developmental stages, and mechanistic treatment of phenological development, canopy photosynthesis, and seed dry matter accumulation give several advantages to SoySim for use in research and for use as a decision-support tool to evaluate the impact of crop management options on yield potential in favorable environments.     

Lateral growth of a wheat dough disk under various growth conditions

Numerous studies have tried to understand and model bubble growth inside dough. Experimental studies are inconvenienced by the methods’ inability to capture the dynamic phenomena. In this paper, a versatile experimental method was developed to allow for macroscopic expansion of wheat dough. The study evaluates expansion of a dough disk under varying: moisture content (40, 41, 42, 43, and 44% wb), leavening acid concentration (30, 40, and 50% db), pressure schemas, pressurizing gas (compressed air and CO₂), and lubrication (Teflon^® film coating and Pam^® aerosol lubricant). Dough expansion increased 22.6% by increasing moisture content from 40 to 44%. Increased baking powder formulation (40% db) was used to enhance initial growth conditions and CO₂ production. ‘Pressure pulse’ and ‘pressure vacuum methods’ added pressurization alternatively with full vacuum. The former method included a rest period before vacuum application, and increased expansion by 10.8%. Teflon^® and Pam^® reduced friction between the dough and acrylic plate and increased the final expansion by 14.7% compared to no lubricant following the ‘standard pressurization method’. ‘Pressure pulse’ and ‘pressure vacuum’ experiments decreased expansion by 28.4 and 38.2%, respectively compared to ‘standard pressurization’ while using Teflon^® and Pam^®.     

Influence of the growth retardant B 995 on growth and yield of potatoes

Summary Stem elongation in a potato crop can be reduced by spraying the growth retardant B 995 on the foliage. This treatment generally did not change the total dry matter production. Only in the last period of growth did B 995-treated plots show a higher total dry weight than the untreated ones. This was caused by a slightly later senescence of the treated plots. The B 995 treatment caused a marked change in the dry matter distribution: stem weight was decreased and tuber weight increased, but leaf weight was generally not influenced. With plants showing considerable vegetative growth, these effects resulted in an increased tuber yield. High nitrogen plots treated with B 995 combined a long productive periode with a favourable dry matter distribution, producing a very high tuber yield at the end of the growing period.     

3种植物生长调节剂对棉种萌发及棉苗生长的影响

采用药剂浸种回干技术，分析了稀土微量元素、芸薹素、甲哌   3种植物生长调节剂浸种处理对棉花种子萌发、出苗及幼苗生长的影响，以期为棉花生产提供参考。结果表明：1 000 mg·L^－1稀土微量元素、0.01 mg·L^－1芸薹素、50 mg·L^－1甲哌   对棉花种子萌发和幼苗促生效果较好。     

Retardation of shoot growth and promotion of tuber growth of potato plants by paclobutrazol

The relationship between shoot growth and tuber yield in potato plants (Solanum tuberosum L. cv. Russet Burbank) was studied under greenhouse conditions using paclobutrazol [(2R,3R + 2S,3S)-1-(4-chlorophenyl)-4,4-dimethyl-2-(l,2-4-triazol-l-yl)-pentan-3-ol), PP333], a growth retardant. Concurrent with reduction of stem elongation by the application of paclobutrazol to base of the main stem was a decrease in the dry weight of the shoot and an increase in the dry weight of the tuber. The inhibitory effect of paclobutrazol on stem elongation was reversed by gibberellic acid A₃ (GA₃). Leaf content of raffinose sugar and chlorophyll increased upon paclobutrazol treatment.     

晚育晚插对超级稻生长发育的影响

以沈农602、秋光和辽粳9为研究对象,主要通过对干物质与产量的关系,叶面积与产量的关系,穗部性状、以及不同播期对各生育时期的影响进行分析,来确定短生育期品种沈农602的晚播晚插高产机理。试验的结果表明:较高的产量要以较高的干物质积累为基础;干物质转运开始的时间对最终的转运率有一定影响,从而影响到最终产量;应注意后期的施肥,过多或过少都不利于高产的形成;不同播期对每穗粒数的影响较小;通过晚播,沈农602可以缩短生育期18～21d。     

Seedling growth of four grasses

Investigations were conducted into the seed reserves, shoot and seminal root growth of Lolium perenne, Festuca arundinacea, Holcus lanatus and Poa trivialis. Data are presented for the caryopsis, palea and lemma weights of these species. Shoot lengths of Lolium and Festuca were very similar but seminal root lengths of Lolium were longer and emerged earlier than those of Festuca. The caryopsis in Lolium lost weight much more rapidly in germination than Festuca. Seedlings of Lolium and Festuca showed similar increases in shoot length but Lolium had more rapid rates of seminal root growth and weight loss from the caryopsis. It is suggested that poor field establishment of Festuca may be due to poor mobilization of seed reserves and consequential poor seminal root growth. The possibility of selecting for good seminal root development in Festuca to improve establishment is suggested.