黄露桃冻害的发生及防止对策

黄露桃果大、味美，鲜食加工皆宜，是罐装珍品，畅销国内外。江苏洪泽县自１９８６年引入，由于冬季严寒，花芽易遭冻害。特别是１９９１年冬，最低气温曾达１７．１℃，花芽受冻较重，产量受损极大。我们通过５年的田间普查研究，掌握了花芽冻害规律，并总结出一套高产栽培技术，使６６７ｍ２产量由８年前的１４３０ｋｇ提高到２３３０ｋｇ，增产６２．９％，现将冻害症状和防止措施阐述如下：一、冻害症状１．１冻害症状，主要表现在花芽、枝干、叶芽均可受冻。受冻花芽，从包含鳞片开始，由外向里干枯，导致花原始体死亡。据镜检等项观…     

白粉虱发生及防治对策

白粉虱属同翅目、粉虱科,是限定性有害生物和检疫对象。该虫可为害多种蔬菜、棉花及花卉等。以温室番茄、茄子、辣椒、黄瓜、鲜切花受害严重。2003年白粉虱在邳州地区普遍发生,2004年发生较重,近几年来为害多种农作物和花卉．     

蛴螬的发生及防治对策

蛴螬又名白土蚕 ,是鞘翅目、金龟子科幼虫的总称。其种类多 ,分布遍及全县各乡镇 ,食性杂 ,除为害玉米、小麦、马铃薯、蔬菜等农作物外 ,还为害烤烟、中药材、苗圃、果园等经济作物。为害时常咬断幼苗根部或咬伤嫩茎 ,造成缺窝断行。近年来 ,蛴螬发生发展有逐年加重趋势 ,特别在地势低洼、土壤保水性能好、空气充足且有机质丰富的地块发生严重。赫章县植保植检站于 2 0 0 0～ 2 0 0 2年在朱明乡玉米地进行定点调查 ,平均每 6 6 7ｍ2 分别有蛴螬 10 6 7.2头、2 334.5头、3135 .7头 ,作物受害株率分别为8.4 % ,12 .7% ,17.3%。连续 3年的调查…     

小麦纹枯病发生及防治对策

小麦纹枯病是近几年来在小麦生产上发生的一种真菌性病害,已逐步上升为小麦上的主要病害,其为害同水稻纹枯病一样,具有发病快,为害重的特点,严重时中心病团出现死穗。从１９９６年开始,小麦纹枯病在我县小麦生产中逐步蔓延,１９９７年调查２５块田,平均病株率为３...     

四川省棉铃虫的发生及防治对策

四川省棉铃虫的发生及防治对策刘牛（四川省植保站，６１００４１）棉铃虫是四川省棉花上重要害虫之一，每年都有发生。在过去的２０多年中，１９７２和１９８１年曾两度大发生，其发生面积分别占棉田种植面积的６７．３％和３９．２％。近几年来，棉铃虫的发生又趋严重，...     

矢尖蚧的发生规律及防治对策

正矢尖蚧(unaspis yanonesis kuwana)属同翅目,盾蚧科,又名矢根介売虫、箭头介壳虫。矢尖蚧虫害在国内柑橘产区普遍发生,贵州省内分布亦很普遍,主要为害柑橘类植物,成虫、若虫均栖于嫩枝、叶片及果实上为害,受害严重的树梢可能全枯死;叶片受害有退绿的斑点并卷缩萎焉,易黄化脱落;被害果的果皮上出现黄绿色斑点。据剑河县柳川镇关口、廉刀弯、巫会溪等橘园调查,被害株率一般为74.5%,最高达96.8%。矢尖蚧对柑     

桃蛀螟的发生规律及防治对策

通过10年黑光灯及田间观察,初步明确了桃蛀螟在郧西的发生规律,通过试验提出了农业、物理、化学防治方法。     

忍冬白粉病发生规律及防治对策

通过对忍冬白粉病的危害程度和发生规律的调查,提出相应的防治措施,以期提高忍冬(金银花)产量和品质.     

四种毒蕈对桃潜叶蛾的作用

桃潜叶蛾(Lyonetia clerkella L.)除对桃、李、杏、樱桃有较大危害外,对苹果和梨等果树也有危害.以成虫从叶背产卵于叶肉内,孵化幼虫取食叶肉成弯曲不规则虫道,造成叶片大量提早脱落,严重影响果品的产量和品质.     

鄂西北地区柑桔发生严重性冻害的原因及预防措施

鄂西北地区昼夜温差大,栽培的柑桔果实以食糖量高、酸甜适度、易化渣、外形好、色泽美而著称。大量销售北方各大城市,同时出口俄罗斯等国家,深受客户欢迎,各地政府部门也高度重视。把柑桔做为农民致富、增加收入的最主要的支柱产业大力发展。到2006年,十堰柑桔已发展到2．4万hm^2,4．3亿kg,2．5亿元。然而,由于这一带发展柑桔属于最北缘地带,发展柑桔生产每年都有轻重不同程度的冻害现象发生,具有关部门统计,     

一株高毒力刀孢蜡蚧菌最适培养条件的优化及其对桃蚜的毒力测定

刀孢蜡蚧菌Lecanicillium psalliotae是一种重要的昆虫病原真菌,在害虫生物防治中应用广泛.为明确刀孢蜡蚧菌生长和产孢的最适培养条件,本文对一株刀孢蜡蚧菌HFLP006菌株的培养条件进行优化,比较了不同培养基种类、初始接菌量、培养温度、供试碳源和氮源对该菌株产孢量的影响.结果 表明,在SDAY液体培养...     

桃中残留有机磷农药去除方法研究

本文选用洗洁精、食用碱、洗洁精加食用碱水溶液和自来水。对喷施过有机磷杀虫剂甲基对硫磷、毒死蜱的桃子进行浸渍处理。结果证明，食用碱水溶液对农药残留去除效率可达34．26％～57．23％，对毒死蜱药后7d采摘的鲜桃处理后基本可达食用标准．而甲基对硫磷仍然超标，供试洗洁精无去除作用。     

明清小冰期关中地区冻灾研究

通过对明清小冰期关中地区历史资料的搜集、整理和分析,对该时期关中地区的冻灾发生频率做了统计。结果表明:该时期冻灾的发生呈现波动变化,1451-1500A.D.(明景泰-明弘治)、1571-1730 A.D.(明隆庆-清乾隆)、1831-1910 A.D.(清道光-清宣统)这三个时期冻灾发生的频率较高,而1501-1570 A.D.(明弘治-明隆庆)、1731-1830 A.D.(清雍正-清道光)冻灾发生的频率较低。且冻灾的灾害程度与冻灾的发生频率密切相关,冻灾发生频率较高的时期,灾害的程度也较重。此外,与这一时期该地区的旱灾发生频率统计结果对比分析表明,冻灾与旱灾的发生频率基本上为同步变化。旱灾与冻灾的同步增多,对当时的社会经济发展、农业生产、社会稳定、人口数量变化等方面产生了重要影响。     

寄主植物对桃蚜羧酸酯酶和乙酰胆碱酯酶的诱导作用

在１９９５～１９９６年研究了寄主植物对桃蚜［Ｍｙｚｕｓｐｅｒｓｉｃａｅ（Ｓｕｌｚｅｒ）］羧酸酯酶（ＣａｒＥ）和乙酰胆碱酯酶（ＡＣｈＥ）的诱导作用。在试验的甘蓝、茄子和桃树３种寄主植物中，取食甘蓝的桃蚜种群ＣａｒＥ和ＡＣｈＥ活性最高，取食茄子和桃树的桃蚜种群ＣａｒＥ活性没有明显不同，而ＡＣｈＥ活性取食茄子的桃蚜种群明显高于取食桃树的种群。ＣａｒＥ与底物的亲和力是桃树＞茄子＞甘蓝，而ＡＣｈＥ与底物的亲和力则是甘蓝＞茄子＞桃树。ＡＣｈＥ与毒扁豆碱的双分子速率常数（Ｋｉ）值大小顺序为甘蓝＞桃树＞茄子     

氨基寡糖素对桃细菌性穿孔病的防治效果及增产作用研究

为明确氨基寡糖素5%水剂对桃细菌性穿孔病的防治效果和增产作用,特进行了相关试验调查研究。结果表明,在桃树上喷施氨基寡糖素5%水剂后,对桃树主要病害桃细菌性穿孔病的防效可达63%以上,与单独使用常规化学药剂防效基本相等,具有防病、抗病、减少化学农药使用,保护环境的效果;同时可提高果实外观品质,增产率在7%左右。可在桃树生产中大面积广泛使用。     

Quantitative Models for Describing Temperature and Moisture Effects on Sporulation of Phomopsis amygdali on Peach

ABSTRACT Twigs with constriction cankers were pruned from a Prunus persica 'Jerseyglo' orchard and placed in incubators under high humidity (>95%) at constant temperatures of -6, 1, 10, 17, 24, 31, 38, and 45 degrees C. Cankers were removed for observation after 2, 6, 24, 48, 72, and 96 h incubation. Sporulation was expressed as the percentage of pycnidia producing cirri and the number of conidia per pycnidium or canker. The experiment was first performed during 1998 to 1999 and then repeated in 1999 to 2000 and 2000 to 2001. Sporulation was modeled by fitting the Richards function to each dependent variable with duration of high relative humidity as the independent variable. The asymptote and rate parameters of the Richards model were expressed as Gaussian and quadratic functions of temperature, respectively. Models created from the first two experimental repetitions were validated by statistical comparison to those created independently from the third repetition. When models were fit to the pooled data, temperature and moisture described 69 to 80% of the variation in sporulation. The models specified a temperature ranging from 0 to 37 degrees C (optimum temperatures for cirri formation and conidia production range from 19 to 20 and 22 to 23 degrees C, respectively), and the majority of sporulation occurred between 16 and 48 h from initiation of the high humidity period. These results show that the environmental criteria for sporulation coincide with those that prolong the susceptibility of infection courts during fall and spring.     

Influence of Weather Conditions on Infection of Peach Fruit by Taphrina deformans

ABSTRACT The effect of environment on the infection of peach fruit by Taphrina deformans was investigated using orchard observations under natural conditions (in 2001 to 2004) or in trees managed in such a way to exclude rainfall. These conditions were then validated using pot-grown peach plants exposed to single infection events and independent orchard observations. Leaf curl incidence was related to rainfall, length of wet periods, and the temperature during wetness and during the incubation period, as well as to the developmental stage of flowers and fruit. Weather conditions before petal fall did not influence fruit infection. After petal fall, rainfall and the duration of the wet period triggered by rainfall played a key role in infection occurrence. The minimum rainfall required for infection was 12 mm, with at least 24 h of wetness interrupted by no more than 4 h. No infection occurred when temperature was >/=17 degrees C during the wet period or >19 degrees C during incubation. Disease symptoms appeared on fruit after approximately 3 weeks of incubation, which is equivalent to 240- to 290-degree-days (base 0 degrees C). The period for fruit infection was relatively short being from petal fall until air temperature remained greater than 16 degrees C. During this period, the incidence of fruit that developed symptoms was closely related to the number of favorable events and the total wetness duration during such events.     

Influence of Environmental Conditions on Infection of Peach Shoots by Taphrina deformans

ABSTRACT The effect of weather conditions on the infection of peach shoots by Taphrina deformans was investigated both under orchard conditions and in controlled-environment experiments. Leaf curl incidence and severity were related to rainfall, length of wet periods, and temperature during wetness and during the incubation period, as well as to the development stage of shoots. Surface wetness was more important than rainfall for infection to occur. Minimum rainfall for infection was 3 mm, with a wet period of at least 12.5 h; higher amounts of rainfall did not cause infection when the wet period they triggered was shorter. Wet periods initiated by dew or fog were too short for infection to occur. Infection occurred only when air temperature was <16 degrees C during the wet period and <19 degrees C during incubation. Logistic equations relating relative disease incidence and either duration of wetness or temperature were developed under controlled-environment conditions, with asymptotes at >/=48 h of wetness and 相似文献