苹果增产菌对苹果霉心病的防治效果

于苹果幼芽萌动期、开花前１～２天、坐果期、幼果期、果实迅速膨大期和成熟前期喷施１０００倍液苹果增产菌。经对幼果心室、萼筒分离培养表明：处理后果实心室和萼筒的有害微生物群落比对照少。成熟期和贮藏期调查表明：成熟期霉心病发病率可降低３．０％～１０．０％，病情指数降低６．７％～３３．２％；贮藏１个月后发病率降低１０．０％～２２．３％，病情指数降低１５．６％～４３．３％。     

采后浸钙对库尔勒香梨果实Ca、Mg、K含量及萼端黑斑病的影响

2012～2013年研究采后浸钙处理对库尔勒香梨果实Ca、Mg、K含量及萼端黑斑病发生的影响。结果表明,浸钙处理提高了香梨果皮和果肉中的Ca、Mg含量和Ca/Mg,其中6%CaCl2处理对提高Ca含量的效果更显著,同时,浸钙处理降低了K含量和K/Ca,其中6%CaCl2处理对降低K/Ca的效果更显著。浸钙处理,能够明显降低萼端黑斑病的发生,在3个处理中,以4%CaCl2溶液处理对防治萼端黑斑病的效果最好,发病率为0,6%CaCl2和8%CaCl2溶液处理的发病率比对照分别降低74.4%和79.3%。     

Incidence,Growth, and Inactivation of Listeria monocytogenes in Cooked and Peeled Cold-Water Shrimp

ABSTRACT

Cooked and peeled cold-water shrimp (Pandalus jordani) naturally contaminated with Listeria monocytogenes were obtained from a processor for a series of studies to determine the level of contamination and growth characteristics of this bacterium in the naturally contaminated product. L. monocytogenes was isolated from every 25-g sample of individually quick frozen (IQF) shrimp that was tested. The level of contamination in each composite sample ranged from 5 to 16 colony forming units (CFU) per 25 g. When individual shrimp taken from the 25-g sample portions were tested separately, samples positive for L. monocytogenes ranged from 1 of 12 to 5 of 15 shrimp tested. The project also evaluated the effectiveness of three methods to inactivate the bacterium: ozone, chlorine dioxide, and steam as possible product reconditioning strategies. Ozone and chlorine dioxide were both found to be ineffective reconditioning treatments for shrimp naturally contaminated with L. monocytogenes. Experiments with steam conducted at the laboratory and later at the shrimp processing plant verified that shrimp contaminated with L. monocytogenes could be safely reconditioned by steam pasteurization. Steam was used successfully to pasteurize several thousand pounds of contaminated shrimp in the processing plant. When the naturally contaminated product was packaged in either oxygen-permeable or impermeable films and stored at 5°C and 10°C, the product was deemed spoiled by sensory evaluation after 9 days of storage, at which time the L. monocytogenes population were 3 × 10⁴ CFU per g. By comparison, when an isolate (strain 4311) from naturally contaminated shrimp was inoculated onto the pasteurized shrimp at a concentration of 12 cells /25g, the L. monocytogenes population reached 3.0 × 10⁸ per g after 9 days of storage. The pasteurization process used in this study would not be effective in inactivation of Clostridium botulinum. Ready-to-eat-shrimp must therefore be stored below 3°C or frozen.     

广西桑树品种资源材料对赤锈病的抗性鉴定

【目的】测定广西桑树品种资源材料对赤锈病的抗性水平,为育种部门提供抗性材料。【方法】采用涂抹法和覆盖法接种桑赤锈病病菌,鉴定7个桑树品种资源材料对赤锈病的抗性;同时,对桑园赤锈病田间自然发病情况进行调查。【结果】测定的7个桑树品种材料均发病,其中伦教40发病相对较轻,其余6个品种发病较重。不同年份、季节、地势的桑树品种材料赤锈病发生程度不同;4月上旬为赤锈病始发期,10～11月为发生高峰期;旱坡地桑树赤锈病发病较轻,水田、低洼地发病较重。【结论】伦教40赤锈病发病较轻,抗病能力较强,可作为抗性育种中间材料或亲本加以利用。     

葡萄品种霜霉病抗性的田间自然鉴定

葡萄霜霉病(Downy mildew)是发生最为广泛、危害最为严重的真菌病害之一.于葡萄霜霉病发病盛期,对在陕西省杨凌区新引进栽培的不同葡萄新品种霜霉病抗性进行田间自然鉴定,摸清不同葡萄品种抗病性,为葡萄霜霉病的田间防控和葡萄抗病育种提供理论依据.通过对新引进的38个葡萄品种叶片的田间发病情况统计,并对霜霉病的抗病指数...     

江西甘蔗花叶病田间调查

2007年9-10月对江西甘蔗花叶病(sugarcane mosaic disease)进行了多点田间调查,结果表明江西甘蔗普遍发生花叶病,其中红皮甘蔗花叶病重于青皮甘蔗,两者病丛率分别为59.8%和19.2%,赣北、赣中、赣南3大地区之间的甘蔗花叶病发生轻重无明显差异。     

闽北山区西瓯农业生态系统结构因素的灰色关联分析

采用灰色关联分析法分研究了闽北山区农业生态系统结构因素之间的关系。全村工农业总收入主要受农业发展的影响，其中农业收入由种植业、养殖业、林果业、渔业等组成，相互间分别为0．8575、0．9277、0．9252和0．9128。对作物总产量影响最大的是劳力、灌溉面积、耕地面积以无机和有机肥投入等5个因素。因而应当进一步合理调整生产结构，以利于充分发挥山区型生态农业的优势。     

倒春寒与杨树烂皮病发病的关系

对辽宁省1997-2010年倒春寒分为轻度、中度偏轻、中度和重度等4级,并对不同等级倒春寒与辽宁省杨树烂皮病Valsa sordida发病的关系进行了分析。结果表明：倒春寒与杨树烂皮病年发生总面积呈正相关（P〈0.05）,与中、重度发病面积呈正相关（P〈0.01）,与轻度发病面积关系未达到显著水平（P〉0.05）;与轻度病害所占比率呈负相关（P〈0.01）,与中、重度病害所占比率呈正相关（P〈0.01）。倒春寒发生越严重的年份,相应的杨树烂皮病发病面积越大。倒春寒发生程度越重,中、重度病害发生的面积和比率增加越明显。     

沼气发酵液防治甘薯软腐病的效果

甘薯软腐病是甘薯储藏期间常发生的主要病害之一。本课题连续两年利用沼气发酵液对2500公斤甘薯进行室外窖藏与室内试验,取得比较明显的防治效果。窖藏试验表明,到出窖时,1990年和1991年的薯块发病率,沼液处理比对照分别下降了61.20％和47.74％,平均下降54.47％。pH8.0的沼液比pH6.5的薯块发病率下降了8.08％。通沼气于窖中,薯块发病率下降:53.11％。实验室试验,沼液处理比对照,10天内薯块发病率下降了44％,30天时下降了22％。     

基于DEA的陕西省土地集约利用评价

以陕西省11个辖区为研究对象,选用投入导向型变动规模报酬的数据包络分析方法(DEA法)测度土地集约利用效率,并运用灰色斜率关联度对有效决策单元进行排序分析,寻求供给侧土地资源集约利用的发展方向,以更好地提高土地集约利用效率。结果表明:各辖区中7个地区表现为DEA有效,其土地利用集约水平由高到低依次为商洛市、安康市、渭南市、汉中市、西安市、榆林市、杨凌示范区;铜川市、宝鸡市、咸阳市和延安市4个地区为DEA无效,影响其无效的原因包括房屋建筑面积冗余、单位GDP能耗过多、能源利用效率较低、社会商品销售额偏低以及天气优良天数偏少等。针对上述情况,为更好地发挥土地在供给侧结构性改革中的作用,提出了相关的意见和建议。