几种除草剂与莲子草假隔链格孢混用防除空心莲子草的初步研究

在测定使它隆、农达、农思它、盖草能等除草剂对莲子草假隔链格孢(Nimbyaalternantherae)菌丝生长和孢子萌发抑制作用的基础上,研究了使它隆和农达与莲子草假隔链格孢混用防除空心莲子草的可能性实验结果表明:在1000倍的浓度下几种除草剂对该菌菌丝生长的相对抑制率依次为农思它(955%)>盖草能(80%)>使它隆(694%)>农达(445%);对孢子萌发则只有农思它稍有抑制作用(174%),其它3种均无抑制作用;2000倍的使它隆和农达分别与40g/L菌丝(湿重)的莲子草假隔链格孢菌丝悬浮液等量混合比单纯使用除草剂或菌丝悬浮液的除草效果好     

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.     

闽北毛竹林密度变化相关因子的动态规律研究

本文针对１９８５年及１９９２年森林资源二类调查资料，采用列联表方法，对毛竹林立竹密度与海拔及林分平均胸径对毛竹林分布的影响进行卡方检验、剩余分析和ｌｏｇ－线性模型拟合，得出：闽北毛竹林密度多在１８００株／ｈｍ２以下，胸径为第四级（８ｃｍ）以下，海拔最适分布区为４００－１０００ｍ；现实毛竹林密度及平均胸径偏低，应提高毛竹林经营水平，促使林分达到合理结构以实现速生丰产的目标。     

马尾松造纸工艺林合理造林密度的研究

５年生马尾松造纸工艺林密度试验结果表明：平均树高受造林密度的影响较小，在一定密度范围内平均胸径随造林密度的增大而减小；单位面积的材积、生物量随造林密度的增大而增大；综合林分生长、生物量结构和经济效益等因素，马尾松造纸工艺林造林密度３３３３株／ｈｍ２较为经济合理。     

早春小拱棚黄瓜栽培,何时定植好? 怎样使其缓苗快,长势旺?

1小拱棚黄瓜栽培特点塑料薄膜小拱棚早熟栽培黄瓜的适宜定植期为3月下旬。定植后黄瓜缓苗快慢、长势好坏是由许多环境因素共同作用的结果,其中最主要的是根系生长得好坏。实际上,每当观察地上部生育状态时,应当首先想到根系发育如何,有些症状表现在地上的冠部,但问题的根源却存在于地下部的根系上。     

Robotic weeders can improve weed control options for specialty crops

Specialty crop herbicides are not a priority for the agrochemical industry, and many of these crops do not have access to effective herbicides. High‐value fruit and vegetable crops represent small markets and high potential liability in the case of herbicide‐induced crop damage. Meanwhile, conventional and organic specialty crop producers are experiencing labor shortages and higher manual weeding costs. Robotic weeders are promising new weed control tools for specialty crops, because they are cheaper to develop and, with fewer environmental and human health risks, are less regulated than herbicides. Now is the time for greater investment in robotic weeders as new herbicides are expensive to develop and few in number, organic crops need better weed control technology and governments are demanding reduced use of pesticides. Public funding of fundamental research on robotic weeder technology can help improve weed and crop recognition, weed control actuators, and expansion of weed science curricula to train students in this technology. Robotic weeders can expand the array of tools available to specialty crop growers. However, the development of robotic weeders will require a broader recognition that these tools are a viable path to create new weed control tools for specialty crops. © 2019 Society of Chemical Industry     

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.