遥感图像时空分析的数据处理系统设计     

沈建中  杨俊泉  莫伟华  陈尚文  吴英  何立 《林业资源管理》2002,(6):58-61,67

简单介绍了配准后的NOAA-AVHRR图像数据的空间格局时序分析的数据处理系统设计。主要分析了系统目标,介绍了数据处理的数学模型和相应的技术措施,提出了数据处理结果正确性检查机制及对反演多样化数学模型变更作出快速反应的方法,同时还探讨了时空数据物理设计的有关问题。  相似文献   

白跗平腹小蜂对主要森林害虫抑制力研究     

方惠兰  廉月琰 《浙江林业科技》1994,14(2):1-3

１９８７～１９９２年连续６年研究结果表明，白跗平腹小蜂Ａｎａｓｔａｔｕｓａｌｂｉｔａｒｓｉｓ对马尾松毛虫Ｄｅｎｄｒｏｌｉｍｕｓｐｕｎｃｔａｔｕｓ、柳杉毛虫Ｄｅｎｄｒｏｌｉｍｕｓｌａｔｉｐｅｎｎｉｓ、水青蛾Ａｃｔｉａｓｓｅｔｅｎｅｎｉｎｇｐｏａｎａ等１３种主要森林害虫卵有较明显的抑制作用。在林间，该蜂对马尾松毛虫第１、２代卵的自然抑制力分别力１６．５５％和２２．２９％，对柳杉毛虫越冬代卵的自然抑制力为２３．４５％；对水青蛾第１、２代卵的抑制力分别力５．４９％和２．６３％；在林间，人为释放白跗平腹小蜂对第１代马尾松毛虫卵的校正抑制力为３３．５％，在室内１２．３～２８℃范围内，每头雌峰对马尾松毛虫、水青蛾和柞蚕剖腹卵的日破坏数（寄生数）分别力１５、１８和２６粒，一生破坏数分别为５６、９１和２０８粒。即使虫卵即将孵化，该峰同样亦能寄生，并羽化出正常的子代白跗平腹小蜂。  相似文献   

松毛虫CPV、B.t.林间防治第一代马尾松毛虫试验初报   总被引：1，自引：3，他引：1  

李红征  侯佩华  简国林  吴仁贵 《江西植保》2003,26(1):37-38

用松毛虫CPV和B.t.进行喷雾防治马尾松毛虫试验，试验表阴：药后18d两种生物药剂的防治效果均在70%以上，B.t.达86．98％，CPV与B.t.的混合使用防效达85．04％。  相似文献   

Fungi associated with esca disease in grapevine     

P. Larignon  B. Dubos 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(2):147-157

Cross sections of woody stems of 309 diseased grapevines collected in France showed two kinds of necrosis typical of esca: a) A central light-colored necrosis of soft consistency, consisting of three zones, preceded by a centrally discolored wood, and b) a sectorial light-colored necrosis composed of two zones preceded by a sectorial brown necrosis. Isolations showed that different microflora was associated with each necrosis. Phaeoacremonium aleophilum and Phaeoacremonium chlamydosporum occurred in the discolored wood and the zones bordering the central decayed wood. Eutypa lata was the main fungus isolated from sectorial brown necrosis and the zones adjoining the decay wood. Phellinus punctatus was isolated from the sectorial and central decayed wood. Stereum hirsutum was present in decayed wood of 15 grapevines with esca symptoms not inhabited by P. punctatus. Wood decay tests and pathogenicity tests showed that S. hirsutum and P. punctatus were responsible for the decayed wood. Phaeoacremonium chlamydosporum and S. hirsutum produced a centrally discolored wood similar to that found in esca-affected vines. Phaeoacremonium aleophilum caused a sectorial brown necrosis of soft texture. From these studies, it was found that esca is a complex disease involving several microorganisms whose role in the process leading to wood degradation is discussed.  相似文献   

马尾松毛虫的主要防治措施     

周继伟 《北京农业》2011,(6):82

浙江省龙泉市植物资源极其丰富,有松木林面积4.66万hm2,马尾松毛虫是为害马尾松林的大敌,防控马尾松毛虫发生为害任务十分艰巨。  相似文献   

保安湖乌鳢渔获群体结构及生长特性     

谢从新  夏增东 《华中农业大学学报》1997,16(4):367-373

依据１９９２年和１９９３年４－５月收集的标本，分析保安湖乌鳢渔获体系结构和生长特征。年龄由Ⅰ－Ⅶ龄构成，Ⅰ－Ⅺ龄分别占渔获总尾数的１２．３７％，２４．７４％、４１．２４％和１７．５３％。Ⅴ－Ⅶ龄极少公占４．１２％。优势体长为３１－４２ｃｍ；优势体重为３５０－９５０ｇ。体长与体重关系为Ｗ＝０．００７９９１Ｌ＾３．１６０２。ＶｏｎＢｅｒｔａｌａｎｆｆｔｙ生长方程为Ｌｔ＝７７．３（１－ｅ＾－０．１９８８  相似文献   

Effects of Water Temperature on Sock Grading of Sub-Marketable Channel Catfish,Ictalurus punctatus,in Earthen Ponds     

《Journal Of Applied Aquaculture》2013,25(1-2):95-103

Abstract

The passive sock grading method used by commercial channel catfish, Ictalurus punctatus, farmers to grade and reduce the number of under-sized fish delivered to processing plants was assessed on an experimental scale. The assessment was conducted at the Aquaculture Research Station at the University of Arkansas, Pine Bluff in 0.1-ha earthen ponds. A rectangular holding sock was fabricated with dimensions of 0.9 m in width, 2.4 m in length, and 1.2 m in depth. The mesh size of the sock was 4.4 cm and the mesh material was nylon netting, 0.64 cm in diameter. Seventeen groups of channel catfish, were graded, with group weights ranging from approximately 115 to 370 kilograms. Fish were held in the sock for approximately three hours (±0.27 hours). The water temperature during the trials ranged from 7.3°C to 28.7°C. The percent removal of fish less than 0.45 kg during the three-hour holding period ranged from 27.6% to 73.3%. Overall, sock grading efficiency increased with increasing water temperature and at water temperatures above 15°C a greater percentage of fish less than 0.45 kg were not retained in the socks.  相似文献   

补充寄主提高林间松毛虫卵寄生率的研究     

童新旺  倪乐湘  劳先闵 《中国生物防治》1988,(3)

研究表明:在松林内,14种松毛虫卵寄生蜂中有9种能寄生柞蚕卵。利用柞蚕卵作为马尾松毛虫卵寄生蜂的补充寄主是可行的。补充寄主的林地,卵蜂种群密度比对照提高0.68～1.43倍,而长年补充又比阶段补充增加1.37倍,比对照区增加2倍。林间补充寄主后提高了平腹小蜂和白角小蜂的种群密度。第一代松毛虫卵期总寄生率补充寄主区较对照区提高5.16～28.96％,第二代提高3.62～24.97％;第三代提高8～17.99％。根据卵蜂在不同生态条件下的消长规律,补充寄主的方法应有所不同,在地被物稀少的松林中补充寄主的次数应多一些,而在地被物丰富的松林中,补充寄主的次数可相应减少。  相似文献   

应用CPV林间防治越冬代马尾松毛虫试验     

彭龙慧  曾文文  吴仁贵  扬立生  邱火林 《江西植保》2005,28(3):120-121,119

应用CPV林间进行越冬代马尾松毛虫防治试验,结果表明不同剂量CPV与1/100000的20%氰戊菊酯乳油复配能显著提高CPV的林间杀虫效果。林间以CPV2.4×106~1.5×105多角体/ml与1/100000的20%氰戊菊酯乳油复配防治越冬代马尾松毛虫为宜,13天幼虫死亡率可达85%以上。  相似文献   

祟仁余干两地封山育林控制松毛虫效果初探     

许永青  彭龙慧  罗俊根  吴平文  曾志杰 《江西植保》2007,30(2):86-88

本文通过对祟仁、余干两地封山育林控制马尾松毛虫效果的研究。揭示了封山育林是一种安全、经济、有效的控制松毛虫的技术措施,通过封山育林,改变了松林生态环境,增加了松林的生物多样性,提高了松林的抗虫能力。  相似文献