农田杂草抗药性检测鉴定方法

化学除草剂的大面积使用,解决了农田草害的主要问题,极大的推动了农业生产和除草剂化学工业的发展。但是,随着除草剂使用面积和用量的不断提高,杂草抗药性已日益成为除草剂应用和农业生产面临的一个突出问题。目前对抗药性杂草的发生和分布、生物学特性、抗性机理、鉴定技术以及抗药性杂草的综合治理等方面进行了大量的研究。其中,杂草抗药性的鉴定是其综合治理的前提,因此也是最为重要的内容之一。本文对杂草抗药性的鉴定方法,如温室整株植物测定法、生理生化测定法以及DNA分析技术等进行介绍,并对这些技术的优缺点进行分析。     

水草收割机明轮推进器的建模与仿真分析

为进一步研究水草收割机在乌梁素海生态治理中有效控制湖泊富营养化的问题,针对水草收割机明轮推进器的运动特性,运用MATLAB中SQP法优化明轮的结构尺寸;根据优化的结构尺寸,通过Pro/E软件建立与物理样机相同的明轮推进器三维实体模型,装配后模拟其真实运动情况,并进行干涉检验.通过Pro/E和ADAMS的专用接口模块MECH/Pro将实体模型导入到ADAMS软件中,运用动力学分析软件ADAMS对明轮推进器进行运动仿真,获得有效数据,为水草收割机系列产品设计研究提供参考数据.     

稻田周围杂草地生境节肢动物群落的物种丰富度、优势度及多样性

2001年5-9月对福建省古田县单季稻田周围杂草地生境的节肢动物群落进行系统调查.结果表明:(1)稻田周围的杂草地生境贮存着丰富的天敌资源,对稻田害虫天敌种群的保存和发展有重要作用;(2)杂草地生境节肢动物群落的物种丰富度、个体数量和多样性呈现出在水稻生长前期(拨节期前)降低,在水稻生长后期增高的趋势.     

Performance of Bangladesh indigenous rice in a weed infested field and separation of allelopathy from resource competition

This study aimed to identify the potential allelopathic indigenous rice (Oryza sativa L. ssp. indica) varieties from Bangladesh using a performance study in a weed‐infested field and to assess the extent of allelopathic interference relative to resource competition in a glasshouse experiment. Six varieties – namely, “Boterswar,” “Goria,” “Biron” and “Kartiksail” as the most allelopathic, “Hashikolmi” as weakly allelopathic and “Holoi” as nonallelopathic – were raised following a nonweed control method. The infestation levels of weed species were calculated using Simpson's Diversity Index (SDI), which ranged from 0.2 to 0.56. However, a significant correlation coefficient (0.87, P < 0.001) was obtained from these field data compared with the root inhibition percentage from the laboratory bioassay, and the “Boterswar” variety was the most allelopathic. The interactions between the allelopathic variety “Boterswar,” weakly allelopathic variety “Hashikolmi” and Echinochloa oryzicola via a target (rice)‐adjacent (E. oryzicola) cogrowth culture were determined in a hydroponic arrangement. The relative competitive intensity (RCI) and the relative neighbor effect (RNE) values showed that the crop–weed interaction was facilitation for “Boterswar” and competition for “Hashikolmi” and E. oryzicola in rice/E. oryzicola cogrowth cultures. The allelopathic effects of “Boterswar” were much higher than the resource competition in rice/E. oryzicola cogrowth cultures. The converse was observed for “Hashikolmi.” Moreover, the mineral content of E. oryzicola was severely affected by “Boterswar”/E. oryzicola cogrowth cultures’ exudate solution. Therefore, the allelopathic potential of “Boterswar” variety might be useful for developing the weed‐suppressing capacity of rice, which will likely have a significant influence on paddy weed control.     

贵州省稻茬免耕油菜田杂草的发生情况

为弄清贵州省稻茬免耕油菜田杂草发生情况,对贵州省油菜主产区田间杂草发生情况进行了初步调查.结果表明:杂草的发生种类有16科50种,其中,油菜田内发生杂草26种,田埂及田边侵入性杂草24种.利用相对频率、相对均度分析方法对贵州省稻茬免耕油菜主产区油菜移栽期和开花期杂草发生情况调查结果进行分析:油菜移栽期田间以棒头草、蘩缕、毛茛等杂草为优势种群杂草,同时在部分油菜田还残存有水稻田遗留部分杂草,如久雨花、节节菜等.在调查区域内,油菜开花期不同区域田间主要优势种群杂草有一定差异.棒头草、蘩缕、毛茛、小飞蓬、稻搓草等为调查区域稻茬免耕油菜田田间共性杂草.     

莠去津的环糊精包合物对稗草幼苗除草效果的影响

以稗草为指示材料,用水培法研究了三嗪类除草剂莠去津的环糊精包合物对稗草幼苗除草活性的影响.试验结果表明:用不同浓度的β-环糊精(β-CD)包合物浸种处理后,能抑制稗草根系发育,达到提高除草效果和缓释的作用.当莠去津与β-CD包合物浓度均为6.5 mg·mL-1时,抑制效果达到最好,对稗草主根长、根鲜重、芽长和芽鲜重的抑...     

几种除草剂防除玉米田杂草的田间药效对比

为选择能防除玉米田杂草且对玉米安全的理想除草剂,促进玉米高效安全生产,对40%乙.莠.氰草津SC、15%甲基磺草酮SC等5种除草剂进行玉米田杂草防除药效试验。结果表明:40%乙.莠.氰草津SC、23%烟嘧.莠去津SC对玉米田单、双子叶杂草有较好的防效,防治效果分别达90.76%、91.60%。两种除草剂杀草谱广,持效期长,对玉米苗安全,是理想的玉米地除草剂。     

苯噻酰·吡嘧防除稻田杂草对田间光照和水稻产量的影响

采用田间试验和仪器测定分析方法研究了40.3%苯噻酰.吡嘧泡腾颗粒剂对水稻田间主要杂草的防除效果、杂草防除后田间不同高度层的透光率变化以及水稻产量的变化。结果表明,施用40.3%苯噻酰.吡嘧泡腾颗粒剂能有效控制水稻田间杂草,对稗草、异型莎草、鸭舌草的综合密度防效为91.56%～99.80%,综合鲜重防效为93.02%～99.82%;施用40.3%苯噻酰.吡嘧泡腾颗粒剂后,水稻田间的透光率显著提高,有效改善了田间光照条件,增产效果显著。40.3%苯噻酰.吡嘧泡腾颗粒剂防除稻田杂草的推荐剂量为241.8～483.6 g/hm2。