Influence of Quince Rootstocks on Entomosporium Leaf Spot （Entomosporium mespili） Susceptibility in European Pear cv. Abate Fetel

Entomosporium leaf spot （ELS） is caused by the fungus Fabraea maculata （anamorph： Entomosporium mespili） and affects most pear cultivars and quince rootstocks in Brazil. The aim of this study was to characterize the effect of Adams, EMA and EMC quince rootstocks on ELS in European pear cultivar ＂Abate Fetel＂ in Southern Brazil, during the 2009/2010, 2010/2011 and 2011/2012 growing season. The incidence and severity of disease was quantified weekly in 100 randomly leaves distributed in four medium-height branches per plant with eight replications. Disease progress curves of ELS were constructed and the epidemics compared according to： （1） the beginning of symptoms appearance （BSA）; （2） the time to reach the maximum disease incidence and severity （TRMDI and TRMDS）; （3） area under the incidence and severity disease progress curve （AUIDPC and AUSDPC）. The data were analyzed by linear regression and adjusted for three empirical models： Logistic, Monomolecular and Gompertz. The Abate Fetel cultivar under all rootstocks evaluated was susceptible to E. mespili. However, there were significant differences in ELS intensity among rootstocks evaluated. The highest ELS intensities were observed in combinations with EMA and Adams quince rootstock. Abate Fetel cultivar grafted on EMC quince rootstock showed all epidemiological variables results significantly different when compared with EMA quince rootstock. EMC quince rootstock induced late resistance compared with the other considerated rootstocks. The Logistic model was the most appropriates to describe the ELS progress of Abate Fetel cultivar under all rootstocks evaluated in the edafoclimatic conditions of Southern Brazil, during the 2009/2010, 2010/2011 and 2011/2012 growing season.

香梨绵粉蚧种群消长动态及防治药剂的筛选

【目的】探明香梨绵粉蚧田间种群消长动态,为有效防治该虫提供理论依据。【方法】采用定点定时系统调查方法、开展田间及室内药剂筛选试验。【结果】香梨绵粉蚧从3月下旬即开始为害,一直持续到10月中旬。卵的3个高峰期则分别为5月上中旬、7月上旬和9月上旬;若虫全年有4个危害高峰期分别为3月下旬～4月下旬、6月、7月中旬～8月中旬以及9月底～10月中旬;成虫有3个发生高峰期,分别为4月下旬～5月上旬、6月下旬～7月上旬和8月下旬～9月上旬。使用3种有效防治药剂480 g/L毒死蜱EC、40%杀扑磷EC和20%啶虫脒SL防治效果较好,10 d的防效分别为96.68%、91.17%和86.61%。【结论】库尔勒香梨绵粉蚧1年发生3代,田间种群形成4个危害高峰,并筛选出3种有效防治药剂。

榅桲叶斑病初步研究

榅桲叶病的病原鉴定为唐棣虫形孢菌（Ｅｎｔｏｍｏｓｐｏｒｉｕｍｍｅｓｐｉｌｉ），该菌可通过伤口或表皮直接侵入；病菌只能在ＰＤＡ＋煎汁培养基上生长，且分生孢子只在榅桲煎汁中萌发．

库尔勒香梨绵粉蚧生物学特性及危害

在库尔勒地区,选择具有代表性的梨树,定点定株观察梨绵粉蚧在库尔勒香梨上的生活史和生活习性。结果表明:该虫一年发生3代,以若虫在树皮裂缝、翘皮下越冬。第1代生长发育整齐,卵高峰出现在5月中旬,1龄若虫活动高峰在6月上旬;2、3代出现世代重叠现象,第3代卵孵化盛期在9月中、下旬。成虫产卵时有卵囊,卵块15～315粒/块,初孵若虫善于爬行;以若、成虫吸取皮层汁液影响树势,附着于果实萼洼处为害,并形成贮藏害虫,降低商品果率。