棉蚜的鉴别与防治探讨     

龚义彬 《商界．城乡致富》2014,(4):23-26,62

介绍了棉花虫害棉蚜不同虫态的形态特征及为害特征,并与相似虫害棉长管蚜、苜蓿蚜、菜豆根蚜、拐枣蚜等进行比较。同时总结了其发生规律和生活习性。然后从农业防治、物理防治、生物防治、化学防治等方面总结了该虫害的防治方法,并着重介绍了化学防治的用药时期及用药量。  相似文献   

5种油菜粉蝶类害虫的识别与防治     

夏红明 《商界．城乡致富》2014,(4):27-30

从形态特征、为害症状及分布等方面介绍了5种油菜粉蝶类害虫菜粉蝶、云斑粉蝶、大菜粉蝶、东方粉蝶、褐脉粉蝶的区别,并从农业防治、生物防治、物理防治、化学防治等方面总结了菜粉蝶类害虫的防治方法。  相似文献   

陕西地区烟粉虱的寄主种类与危害程度调查     

赵瑞华  邓振山  贺晓龙 《安徽农业科学》2015,(28):88-91

2013 ～ 2014年对陕西省烟粉虱的寄主植物进行了调查、鉴定,并应用危害指数对烟粉虱危害程度进行了评价.调查结果表明:陕西地区烟粉虱寄主植物达28科73种(变种),主要集中在5科植物(葫芦科、十字花科、茄科、豆科和菊科),其中蔬菜上危害达4级的寄主有7种.全省以陕南受害最重,寄主种类较多,陕北受害较轻,并依据寄主植物的分布情况分析了烟粉虱在陕西省的发生现状,预测了发展趋势.  相似文献   

果蔬运输受振动·冲击作用研究进展   总被引：3，自引：0，他引：3  

王芳  魏星  魏巍  赵满全  韩媛媛 《安徽农业科学》2015,(26):326-329

介绍果蔬在运输过程中的振动、冲击损伤,综述了果蔬振动冲击碰撞试验在实验室模拟时所需考虑的因数,并探讨了果蔬振动冲击损伤体积与各可控因素之间的相关性,此外,也对目前果蔬碰撞参数指标进行了简要说明.研究可为振动冲击作用下果蔬损伤机理的探究做出参考,也为果蔬的运输包装业提供理论依据.  相似文献   

Surgical Considerations in the Emergent Small Animal Patient     

Jennifer J. Devey 《Veterinary Clinics of North America: Small Animal Practice》2013

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Quantifying pesticide overuse from farmer and societal points of view: An application to Thailand     

《Crop Protection》2013

The rapid growth in pesticide use is a significant problem for Thailand, as it is in many other developing countries with an intensifying agriculture. The objective of this study was to quantify how much of the total quantity of pesticides is overused. The novelty of this research resides in the fact that it considered the social rather than the private optimum by including negative pesticide externalities in determining levels of overuse. Marginal benefits of pesticides are quantified by estimating Cobb–Douglas production functions with an exponential damage control specification. The marginal costs are calculated as the sum of private and external costs with the latter quantified using the Pesticide Environmental Accounting (PEA) tool. The method is applied using farm- and plot-level data from one intensive upland vegetable production system in northern Thailand. The findings show that about 80% of the applied pesticide quantity is used in excess of the social optimum, while the difference between the private and social level of overuse is small for this particular case study. Therefore results from the study area suggest that internalizing pesticide externalities into the price of pesticides would only have a small effect on reducing pesticide overuse.  相似文献   

Effects of phosphate fertilizer levels on cowpea pod-sucking bug populations and damage     

Olufemi O. R. Pitan  J. A. Odebiyi  G. O. Adeoye 《国际虫害防治杂志》2013,59(3):205-209

The effect of different application levels of phosphate fertilizer on cowpea pod-sucking bugs [Clavigralla sp., Riptortus sp., Anoplocnemis., Mirperus sp. and Negara sp. (Heteroptera)] was studied using 0 (control), 20, 40 and 60 kg/ha of single super-phosphate. The results showed that the bug densities decreased significantly with increase in rate of application. At 40 and 60 kg/ha, grain yields were significantly higher than at the lower rates of application. Crude protein, fibre, oxalate, phytin, potassium and magnesium contents as well as seed hardness also increased with increase in the rate of fertilizer application.  相似文献   

Effect of morphological traits of plant, head and seed of sunflower hybrids on house sparrow damage rate     

Abolghasem Khaleghizadeh 《Crop Protection》2011,30(3):360-367

Birds are important key pests of sunflower crops in many countries. In this study, 615 heads and 5429 seeds of 31 sunflower hybrids (single cross, three-way cross and introduced hybrids) were randomly selected and rates of bird damage were estimated at the Plant Breeding Research Institute of Karaj during the summer of 2004-2005. The Spearman correlation test showed a significant relationship between bird damage rate and some plant characteristics such as height of plant head above the ground (r = 0.100), inter-head distance or distance of heads from stems (r = −0.195), distance of petiole (nearest leaf) from head (cm) (r = −0.113), head diameter (r = −0.213), head angle to the horizon (r = 0.217) and seed density in sunflower heads (r = 0.320) (p < 0.01), but there was no significant correlation between bract length (r = 0.047), the sterile area to head surface ratio (r = −0.020), achene length (r = 0.267) and hull thickness (r = −0.002) and the rate of bird damage (p > 0.05). The Kruskal-Wallis non-parametric test showed significant differences of bird damage rate to hybrid plants, for head shapes, bract orientation in relation to the head surface and achene colors (p < 0.01) but no significant for stem hanging forms and degree of striping on the achene (p > 0.05). In conclusion, the sunflower heads suffering lower bird damage rates had traits such as greater diameter, flat and convex shape (edges curled outside), fewer angles to the horizon, more down-faced heads, open and longer bracts, longer distances between adjacent stems or heads, longer distance of petiole from head, and lower seed density. In considering the results of the present and previous studies, there was a degree of inconsistency of findings across all studies, but not for each sunflower trait. Future studies are still necessary for height of head above the ground surface, stem hanging form, head shape, bract length and orientation, sterile area ratio, seed density, achene length, color and striping, and hull thickness. Nevertheless, plant breeding trials should bear in mind these results to pursue the understanding of relevant characteristics in morpho-genetic studies in relation to bird damage.  相似文献   

吉林省烟草害虫及天敌名录(1992～1996)   总被引：1，自引：0，他引：1  

崔泳汉  伊伯仁  康芝仙  千兴权  路红 《延边大学农学学报》1999,(1)

１９９２年～１９９６年在吉林省进行了烟草害虫及天敌的种类、发生、为害、分布情况调查，结果发现了７５种害虫，５３种天敌．  相似文献   

高等级公路中U型桥台易破损的探讨   总被引：5，自引：0，他引：5  

黄子玉  李世文  郝秀丽  熊家财 《东北林业大学学报》2000,28(2):74-75

通过调查对高等级公路中Ｕ型桥台的破损进行探入研究，找出其易破损的主要原因，并从设计、材料和施工方面提出切实可行的技术措施，解决宽Ｕ型桥台在高等级公路中的应用问题。  相似文献