Relative abundance and damage of some insect pests of wheat under different tillage practices in rice–wheat cropping in India

Tillage changes the physical and chemical properties of soil and can also inhibit or enhance useful and harmful fauna. In agriculture, different tillage technologies are being tried to enhance crop productivity, but little concrete information seems to exist on their effects on pest abundance and damage. To address this lack of information, sowing of wheat was investigated under different tillage systems. In order to monitor pest abundance and damage in altered tillage systems, the present studies on the relative abundance and damage due to insect pests viz. pink stem borer (PSB, Sesamia inferens Walker), termites (Microtermes obesi Holmgren and Odontotermes obesus Rambur) and root aphid (Rhopalosiphum rufiabdominalis Sasaki) were undertaken in a rice–wheat cropping system during 2010–11 and 2011–12. Pest abundance and damage was monitored in four tillage systems i.e. conventional tillage (CT), zero tillage (ZT), ZT + mulch and rotary tillage (RT) under insecticide protected and unprotected conditions. The application of insecticide did not affect root aphid incidence or termite damage. However, significant differences in PSB damage in insecticide protected (0.9%) and unprotected (1.2%) conditions were observed. The investigations demonstrated that in CT, damage by PSB (0.6%) was minimum; however termite damage (2.2%) was maximum as compared to all other tillage conditions. In ZT, PSB damage (1.4%) was maximum and root aphid incidence (3.1 aphids/tiller) was minimum in comparison to other tillage conditions. ZT + mulch resulted in inter-mediate insect pest incidence/damage; however, RT was the least effective practice which showed relatively high incidence/damage of these three insects (1.2% PSB damage, 1.9% termite damage and 5.1 aphids/tiller). The insecticide × tillage interaction indicated that insecticide application is needed only in ZT and RT for PSB management.     

种公牛饲养管理中易被疏忽的几项细节管理

种公牛在养牛环节中具有非常关键的作用,本文就种公牛饲养管理中易被疏忽的几项细节进行了论述,在管理上应引起足够重视.     

三种处理的玉米秸型优化日粮肥育肉牛效果的研究

将15头草原红牛平均分成3组,1、2、3组依次饲喂青黄贮玉米秸型日粮、玉米秸饲料块型日粮和玉米酒糟型日粮,进行268d的饲养试验,然后屠宰。1、2、3组试验牛的日增重依次为1022g、1140g和1186g;屠宰率依次是57.44%、58.73%和58.31%;净肉率依次是48.35%、50.06%和49.45%。各种饲料和活牛价格按时价计算,经济效益最好的日粮是玉米酒糟型,其次是玉米秸饲料块型,青黄贮玉米秸型效益较差。     

银川国家湿地公园规划与建设的若干问题

结合银川国家湿地公园的现状,讨论了规划和建设中的一些重大问题,为园区湿地资源的开发利用和湿地环境的生态恢复与保护提供参考。     

Influence of Atrazine and Roundup pesticides on biochemical and molecular aspects of Biomphalaria alexandrina snails

The excessive use of pesticides in agriculture has sparkled the interest of scientists in investigating the harmful effects of these compounds. The present study evaluates the pesticides Atrazine and Roundup (glyphosate) on biochemical and molecular aspects of Biomphalaria alexandrina snails. The results showed that LC₁₀ of these two pesticides caused considerable reduction in survival rates and egg production of treated snails. Additionally, Atrazine proved to be more toxic to B. alexandrina snails than Roundup. In treated snails, glucose concentration (GL) in the hemolymph as well as lactate (LT) and free amino acid (FAA) in soft tissues of treated snails increased while glycogen (GN), pyruvate (PV), total protein (TP), nucleic acids (DNA and RNA) levels in snail’s tissues decreased. The activities of glycogen phosphorylase (GP), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), succinic dehydrogenase (SDH), acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and phosphatases (ACP and ALP) enzymes in homogenate of snail’s tissues were reduced in response to the treatment with the two pesticides while lipid peroxide (LP) and transaminases (GOT and GPT) activity increased (P < 0.001). The changes in the number, position and intensity of DNA bands induced by pesticides may be attributed to the fact that pesticide can induce genotoxicity through DNA damage. It was concluded that the pollution of the aquatic environment by Atrazine and Roundup pesticides, would adversely affect the metabolism of the B. alexandrina snails, and have adverse effects on its reproduction.     

黄土高原小杂粮生产可持续发展技术体系构建

针对黄土高原生态环境脆弱的现实情况,立足于小杂粮的资源特点和生产现状,构建的小杂粮生产可持续发展技术体系注重建设基本农田,改善耕地质量;强调保护性耕作和种植,加快小杂粮优良品种选育、繁殖和推广进程,辅以合理的轮作倒茬技术。同时应突出绿色产品产出,持续提高降水利用效率,促进加工增值增效,从而确保小杂粮生产实现高产、优质、高效,最大限度地降低对资源环境的负面影响,实现小杂粮生产的可持续发展。     

青海马铃薯地膜栽培技术十一注意

地膜马铃薯栽培是项技术性、科学性很强的一种新型栽培方式。针对青海当前马铃薯地膜栽培中存在的技术问题。从不同生态地区选择、地膜类型的选择、田块前茬选择、品种选择、施用有机肥、宜耕期起垄覆膜、精细播种、推广机械化、加强田管、及时收获加工、清理残膜十一个方面的技术问题进行了原理分析和具体操作措施的阐述。     

黄斑海蜇的生活史及几种钵水母类螅状体形态特征的比较

以北部湾采捕黄斑海蜇Rhopilema hispidum vanhoffen,1888为亲体,通过人工繁殖的方法获得浮浪幼虫。在实验室培育条件下,对浮浪幼虫、螅状幼体、横裂幼体、碟状幼体和幼水母等多次变态发育过程进行了系统观察,描述了各发育阶段形态变化。首次报告了这个种的生活史,并比较了几种钵水母类螅状体的形态特征。     

如何提高高职生英语听说能力——心理问题探析

本文从心理分析角度出发,探析了如何提高高职院校学生英语听说能力,并根据教育心理学、教育学原理提出了针对性措施及解决方案。     

统筹城乡 科学发展:学习十七届三中全会《决定》的思考

笔者在对<中共中央关于推进农村改革发展若干重大问题的决定>认真学习后认为,<决定>对"三农"形势分析定论准确,对解决"三农"问题措施有力,而且对搞好"三农"工作意义重大,任重道远.并提出了解决"三农"问题不但要强化认识、强化科技支撑,而且还要提高农民组织化水平,做到四个到位,念好"十子经".