花期提高枣树坐果率的措施

随着农业产业结构的调整,枣树已成为山西省主要的经济林树种.枣树抗干旱,抗盐碱,耐瘠薄,易繁殖,好管理,结果早,寿命长;枣果营养价值高,药用价值大,经济效益好而深受农民的喜爱,目前山西省枣树栽培面积已达30多万公顷.     

Effects of Tebufenozide on the Biological Characteristics of Beet Armyworm （Spodoptera exigua Hǖbner） and Its Resistance Selection

In this article, the selection of tebufenozide to beet armyworm （Spodoptera exigua Htibner） was studied by the treatments to alternative generations＇ 3rd-instar larvae with LC50 dose and to continuous generations＇ larvae with LC10 dose; the effects of tebufenozide on the biological characteristics of current and subsequent generations were examined by the treatments to 3rd-instar larvae and egg pods in different concentrations. After treatments with LC50 dose till F11, the toxicity of tebufenozide to beet armyworm had no significant change, whereas the pupation rate, pupal weight, and fecundity were reduced markedly. After treatments with LC10 dose till Fl9, the beet armyworm only developed 3.52-fold resistance, and the main biological characteristics were nearly accordant in each generation. The livability was reduced 72 h later after treatments to 3rd-instar larvae, respectively in 2.5-40 μg mL^-1, and larval duration, pupation rate, and pupal weight changed considerably with the increase in concentrations. The fecundity, larval livability, larval weight and pupal weight of subsequent generations were reduced as the dose increased over 10 μg mL^-1. The hatching rate of egg pods did not differ with that of the controls obviously after treatment in 10-300 μg mL^-1. But the larval livability, larval weight and pupal weight were reduced when eggs were exposed to 50 μg mL^-1 dose or more. The results indicated that tebufenozide had low resistance risk to the current and subsequent generations of beet armyworm even if tebufenozide had significant effects on the biological characteristics of this insect.     

枣尺蠖的发生与气象条件的关系

枣尺蠖的发生直接危害到枣产品的产量和品质,通过对澄城县1991～2005年15年虫害调查资料和气象资料对比分析,发现3月下旬至4月下旬的降水量和4月中下旬的气温是影响枣尺蠖危害程度的主要因子,据此提出防治枣尺蠖新的预测预报方法。     

吕梁红枣受灾直接经济损失将达1．2亿元以上

每年红枣成熟的季节,总有连绵不断的秋雨,以致去年吕梁红枣几近绝收。今年虽好一些,但9月21日～26日的持续降雨,仍使吕梁市沿黄河枣区的红枣大面积受灾,31％的红枣出现了裂果和霉变。面对红枣遭受的巨大损失,吕梁市迅速启动了枣区防阴雨应急预案,特别是沿黄河枣区的兴县、临县、柳林、石楼等4县各级党委、政府,积极组织群众抢收并联系客商收购青枣,     

辽宁枣树适栽品种及抗寒栽培技术

针对辽宁地区限制枣生产的幼树期冻害问题,筛选出适于该地区栽培的枣树品种,并总结出一套较为完整的枣抗寒栽培技术。     

枣树不同杂交组合花粉萌发情况的荧光显微观察

以冬枣和雄性不育3号为母本,大叶无核枣等品种为父本进行品种间授粉,在荧光显微镜下观察人工授粉后柱头上花粉的黏附、萌发和花粉管生长情况。结果表明,不同授粉组合之间有花粉黏附柱头比率、单柱头平均花粉数、有萌发花粉的柱头比率和单柱头平均花粉萌发率差异显著。经不同品种授粉后,冬枣有花粉黏附柱头比率和有萌发花粉的柱头比率之间,及单柱头平均花粉数和单柱头平均花粉萌发率之间无相关性。冬枣×大叶无核枣、冬枣×无核小枣和冬枣×苹果枣三个组合的花粉萌发率高且花粉管更容易深入花柱,是较为理想的杂交组合。     

不同枣品种对NaCl胁迫的适应性研究

采用盆栽法,分别用清水(CK),100,160,200 mmol·L-1的NaCl溶液对沾化冬枣、陕抗1号枣、扁核酸枣和七月鲜枣当年生扦插苗进行了NaCl胁迫处理,测定了叶片的盐害发生率、细胞质膜透性、丙二醛(MDA)含量、可溶性蛋白质含量和游离脯氨酸含量等指标.结果表明,随着NaCl浓度升高和处理时间的延长,枣叶片受害症状逐渐加重.可溶性蛋白、MDA含量和游离脯氨酸含量随着NaCl浓度的升高而增加、细胞质膜透性增强.对各项指标综合分析结果表明,4个枣品种耐盐性排序为:七月鲜枣＞陕抗1号枣＞扁核酸枣＞沾化冬枣.     

枣缩果病的发生与防治

1症状与危害该病主要危害枣果,引起果腐和提前脱落。病菌侵入后,病程从直观上可分为:晕环、水渍状、提前着色、萎缩和脱落5个阶段。病果初在肩部或胴部出现淡黄色晕环病斑,环内略凹陷;     

鲜枣的贮藏与保鲜

一、贮前准备1.品种选择。枣的耐贮性因品种的不同而差异甚大,一般晚熟品种较早熟品种耐贮,干鲜兼用品种较鲜食品种耐贮,抗裂果品种比较耐贮,大果型品种比较耐贮。2.适时采收。用于生食的枣必须在脆熟期采收。脆熟期的标准为果面绿色减退,转为白绿色。此时果实水分多,味甜而质脆。由于枣     

枣龟蜡蚧的发生规律与防治

枣龟蜡蚧是危害枣树的主要害虫之一,通过分析论述枣龟蜡蚧的危害特点与发生规律,提出了科学有效并切实可行的防治方法.