延迟收获对长江中游春玉米农艺性状及机收质量的影响     

刘志辉  展茗  梁如玉  王燕  刘永忠  黄益勤  杨仁能  尚春辉 《中国农业大学学报》2021,26(11):10-22

为探明长江中游玉米籽粒机械直收适宜品种与配套农艺措施，2018—2019年选用不同玉米品种，测定不同机收时间下玉米关键农艺性状、产量及机收质量指标。结果表明，收获时间对春玉米机收产量与机收质量均有显著影响。延迟1周收获后籽粒容重显著增加，机收产量显著提高，2年平均提高9.72%；而延迟2周收获则有降低机收产量的趋势。2年收获时杂质率总体≤3%，而机收籽粒破碎率与损失率均>5%，是该区域春玉米籽粒机收面临的主要问题。籽粒厚度、籽粒含水率和百粒重是影响机收籽粒破碎率的关键性状，三者与机收籽粒破碎率均呈显著的倒二次曲线关系；玉米的倒伏率、穗位高和重心高度是影响机收损失率的关键性状，倒伏率与机收损失率呈显著正相关，而穗位高和重心高度与机收损失率均呈显著的二次曲线关系。延迟收获能显著降低籽粒含水量，从而降低籽粒破碎率，但继续延迟收获有增加倒伏的风险。综上，长江中游春玉米成熟后适时延迟7~10 d收获，可有效降低籽粒含水量与机收籽粒破碎率，提高玉米籽粒机收产量。  相似文献   

Narbon Vetch (Vicia narbonensis L.): A Potential Feed Legume Crop for Dry Areas in West Asia     

A. M. Abd El  Moneim 《Journal of Agronomy and Crop Science》1992,169(5):347-353

Provision of feed supplies for the rapidly growing livestock population is essential in West Asia. Shortages can be alleviated by growing forage crops in the existing fallow lands.
Narbon vetch (Vicia narbonensis L.) is a leguminous species with high yield potential, drought tolerance and cold resistance. It could be used for grain and straw production as source for animal feed in dry areas. It is good source of protein with seeds contain 28 % protein yielding 364 kg per hectare protein, whilst straw contains 9 % protein and yields a similar amounts of digestible protein per hectare.
Nine promising lines of Narbon vetch developed at ICARDA were tested at two sites over four years under rainfed conditions. Since climatic conditions were considered to be of considerable importance, each site in each year was treated as a separate environment to give eight environments with annual rainfall varied from 195 to 504 mm.
Narbon vetch possessed high seedling vigour with rapid winter growth and negligible cold damage. Grain yield varied form 0.47 to 1.90 t/ha, with a harvest index varying from 30 to 40 %. The data indicated that below 300 mm rainfall the grain yield varied from 0.47 t/ha when rain fall was 195 mm to 1.4 t/ha when rainfall was 245 mm. Most of the lines had wide adaptation to dry areas in terms of both grain yield and stability. Climate, except early spring rains had little effect on biological and grain yields.  相似文献   

Spatial distribution of Lolium rigidum seedlings following seed dispersal by combine harvesters     

J M Blanco-Moreno  L Chamorro  R M Masalles  J Recasens†  & F X Sans 《Weed Research》2004,44(5):375-387

This paper considers the relationships between the dispersal of seeds and the distribution pattern of an annual weed. A comparative study of seed dispersal by combine harvesters, with and without a straw chopper attached, was established using Lolium rigidum, a common weed in Mediterranean cereal crops. Seed dispersal distance was quantified and the relationships between dispersal and fine‐scale seedling distribution evaluated. Primary dispersal of L. rigidum seeds occurs in a very limited space around the parent plants, but the density of seed is low because most seeds do not fall from spikes spontaneously. In contrast, many seeds are spread by combine harvesters. In this study the maximum dispersal exceeded 18 m from established stands in cereal fields, although the modal distance was close to the origin. In addition, the action of the combine harvesters tended to accumulate L. rigidum seeds predominantly under the straw swath, with some lateral movement. This action could explain the fine‐scale banded pattern of L. rigidum in cereal fields. Although the treatment of straw by the standard and straw chopper combines differed, the resultant seed distribution showed few differences.  相似文献   

Yield Performance of Wheat Isolines with Different Dosages of the Short Arm of Rye Chromosome 1          下载免费PDF全文

D. C. Maheepala  B. Ehdaie  J. G. Waines 《Journal of Agronomy and Crop Science》2015,201(2):152-160

Translocations of the short arm of rye (Secale cereale L.) chromosome 1 (1RS) in wheat (Triticum aestivum L. cv. Pavon 76) are known to increase root biomass. Such an increase enhances water and nutrient uptake and may improve grain yield. Two greenhouse experiments and a field experiment were carried out at the University of California, Riverside, in 2012 and 2013 under well‐watered and terminal drought treatments to evaluate phenotypic characters associated with varying dosages of 1RS, including grain yield. The genotypes used were cultivar Pavon 76 (R₀), Pavon 76/Pavon1RS.1AL (F₁ hybrid) with a single dosage of 1RS (R₁A), Pavon 1RS.1AL with two dosages of 1RS (R₂A), Pavon 1RS.1DL (R₂D) also with two dosages of 1RS and Pavon 1RS.1AL‐1RS.1DL (R₄AD) with four dosages of 1RS. There was a significant positive correlation between number of dosages of 1RS and root biomass. However, no correlation was found between root biomass and grain yield per plant. Drought in the field experiment reduced grain yield significantly. Under well‐watered field conditions, grain yield of R₂A (215.9 g plant^?1) was significantly greater than those of R₂D (191.8 g plant^?1) and R₄AD (161.7 g plant^?1). Also, grain yield of R₄AD was significantly less than those of F₁, Pavon 76 and R₂D under well‐watered conditions. Under drought field conditions, no significant differences were found among the genotypes for grain yield was found between F₁ (14.7 g plant^?1) and R₄AD (12.4 g plant^?1). Harvest index was significantly greater in well‐watered (44.2 %) than in drought (34.6 %) field conditions. On average, genotypes F₁ (42.3 %) and R₂A (40.6 %) had higher harvest index than R₂D (38.3 %) and R₄AD (35.5 %) in the field. Also, Pavon 76 (40.2) and R₂D (38.3) had higher harvest index than R₄AD. Drought tolerance was lowest for R₄AD due to its relatively lower grain yield potential. In general, Pavon 1RS.1AL carrying two dosages of 1RS showed higher grain yield under wet treatments. Pavon 1RS.1AL‐1RS.1DL carrying four dosages of 1RS produced the largest shoot and root biomasses, but the least grain yield.  相似文献   

Some Agronomic Strategies for Organic Quinoa (Chenopodium quinoa Willd.)          下载免费PDF全文

S.‐E. Jacobsen  J. L. Christiansen 《Journal of Agronomy and Crop Science》2016,202(6):454-463

Quinoa is a potential new seed crop for protein feed and human consumption in Europe, with tolerance to a range of abiotic stresses. For this purpose the study was planned to analyse the effect of important agronomic strategies like nitrogen level, N application strategy, row spacing and harvest time on yield and quality of quinoa. The experiments took place in the field of the experimental station of the Faculty of Science, University of Copenhagen. Three levels of organic nitrogen from slurry was used (60, 120 and 180 kg N ha^?1), supplied either all at once at sowing, or split between sowing and beginning of the reproductive phase. The effect of row spacing and harvest time was studied by harvesting seeds at seed maturity, which occurred 2–3 weeks prior to the mechanical harvest by threshing, and a couple of months after. Yield increased significantly (P ≤ 0.05) with an application up to 180 kg N ha^?1, reaching 2200 kg ha^?1. Increasing N also caused a significantly increased seed weight (up to 3.3 mg) and protein content (up to 17 %). N level did not affect number and amount of weeds. Split application with part of the N applied at bud formation did not have a significant effect on yield. Delayed harvest had a negative influence on seed weight, whereas protein content was stable after harvesting even a month after seed maturity. A late harvest significantly reduced seed germination, being reduced by 50 % after a 2‐month delay. A conclusion from this study is that both yield and protein content of seed can be manipulated by N level and application strategy. Harvest time is important for securing a high seed quality measured as seed germination, seed weight and protein content. A fast germination of quinoa is an important characteristic demonstrating that the crop has good possibilities for being well‐established in the field when free from weeds at the time of sowing. The choice of row spacing is important and depends on weed control method. Weed control strategy should be developed based on modern precision tools.  相似文献   

不同密度紧凑型油菜的源库特征及与收获指数的相关研究     

王学芳  田建华  董育红  关周博  杨丽 《中国农学通报》2020,36(18):33-38

旨在为油菜株型育种和机械化栽培提供理论和技术依据。选用3个不同类型的紧凑型油菜常规品种,以松散型油菜杂交种‘秦优7号’为对照,研究了在15万、30万、45万、60万、75万、90万株/hm²密度下各品系的库源特征及其与收获指数的关系。结果表明,紧凑型油菜单株在不同密度下的库源特征与对照松散型相同,单株根、茎、枝、壳干重,角粒数和单株角果数随种植密度的增加而降低,且低密度显著高于高密度;千粒重随密度的变化不大。紧凑型油菜的生物学产量和经济产量随种植密度的增加而增加,松散型油菜随种植密度的增加而下降。说明紧凑型油菜适宜密植和机械化收获。收获指数对密度的响应在两类型品种表现一致,最低密度15万株/hm²增加到30万株/hm²时达到峰值,以后随着种植密度的继续增加而降低。收获指数与茎+枝+壳干重之和,与库性状角粒数、角果数、千粒重、单株产量,与库源关系的粒根比、粒茎比、粒枝比、粒壳比显著正相关,说明要提高收获指数不仅要扩“源”增“库”,还要协调库源的合理分配比例。  相似文献   

基于鲁棒反馈线性化的联合收获机割台高度控制策略   总被引：3，自引：0，他引：3  

庄肖波  李耀明 《农业机械学报》2020,51(11):123-130

谷物联合收获机割台高度控制非常重要，有效的割台高度控制有助于提高喂入量的稳定性、降低整机各环节的负荷波动。本文提出一种基于鲁棒反馈线性化的割台高度控制策略，该方法可以使割台跟随地面起伏进行俯仰控制调节。首先，基于割台结构和动力学分析建立系统数学模型，选取正弦角度的近似约简条件，将多变量的复杂非线性系统线性转换为典型的非线性系统；通过分析传统的反馈线性化控制研究可控仿射的模型构建方法，在集成鲁棒优化设计控制器基础上，提出鲁棒反馈线性化（Robust feedback linearization，RFL），通过构建灵敏度方程、选取增益来稳定系统；选取液压控制机构，根据控制液压输出的电流参数设计为基于鲁棒反馈线性化控制系统的控制器。将传统的PID控制和本文提出的鲁棒反馈线性化控制进行对比实验，结果表明，在不同行驶速度、地形正弦振幅和地形周期条件下，鲁棒反馈线性化控制下的高度误差均小于传统的PID控制；以3种不同行驶速度在同一起伏地面上行进，鲁棒反馈线性化控制下的高度误差受行驶速度增加的影响小于传统的PID控制。  相似文献   

特定黄瓜品种果实发育过程中品质变化     

刘峻蓉 《安徽农业科学》2017,45(1)

[目的]研究中农19号和中农29号这2个品种的最佳采收期。[方法]选取中农19号、中农29号2个黄瓜品种,研究其在果实发育过程中果实纵径、横径及可溶性蛋白、可溶性糖、维生素C含量变化,确定这2个品种的最佳采收期。[结果]中农19号、中农29号第5~10天生长最快,果实纵径、横径随时间延长逐渐变长、变粗;可溶性蛋白及维生素C含量变化:中农19号在第8天达到最高,随后又下降并趋于稳定;中农29号则是在第8天达到最高,后先下降又升高。中农9号可溶性糖含量先升高后下降再升高,而中农29号则出现2次高峰。[结论]综合考虑生理指标和形态指标,确定中农19号、中农29号均在开花后第8天为最佳采收期。  相似文献   

高产棉花太阳辐射能利用率及干物质分配规律研究   总被引：6，自引：0，他引：6  

潘学标  邓绍华  蒋国柱  吴同礼  董占山  崔秀稳  潘晓康  龙腾芳 《棉花学报》1992,(Z1)

通过对1988～1989年高产棉花栽培试验结果进行分析发现,棉花的太阳辐射利用率在叶面积系数小于2.0时随叶面积系数的增加而线性增加,大于2.0时增加变缓。从生育时间看,7月中旬前太阳辐射利用率指数上升,7月中旬至8月底相对稳定在1.2～1.4克/兆焦左右,9月以后又不同程度线性下降。生长季内子棉太阳辐射经济效率1988和1989年分别为0.14和0.15克/兆焦。收获指数与最大叶面积系数呈显著负相关;盛花期之前棉株各器官之间的同伸关系或明显,盛花期后器官的生长相互间无明显的确定性关系。如能调节密度与叶面积系数的关系,使得既提高5～6月的辐射能利用率,同时使7～8月叶面积系数维持在3.0～3.5的适宜范围内,9～10月群体又不早衰,则有利于获得高产。  相似文献   

基于视景仿真技术的联合收割机牵引及加载性能研究     

王曦  张晓亮  刘志刚  高珍冉 《农机化研究》2015,(7):236-239

随着农业机械化的不断发展,联合收割机的应用越来越普遍,大大地提高了农业生产效率。然而,在联合收割机使用中还存在一些驾驶员视域不开阔、可视环境差等不安全因素。针对这些问题,本文引入了视景仿真技术概念,通过构建基于视景仿真技术的联合收割机牵引及加载性能模型,对联合收割机的牵引及加载性能进行仿真分析。结果显示,将视景仿真技术应用与联合收割机,方便了驾驶员及时掌握实地信息,提高了牵引性能和加载性能,降低了驾驶危险系数。  相似文献