大豆不同栽培模式与天敌协同对大豆蚜控制作用研究

2008—2010年,在辽宁东部岫岩县进行了大豆不同栽培模式(清种、大豆与玉米8∶2和8∶8间作)与天敌协同对大豆蚜控制作用研究。结果表明,不同栽培模式大豆蚜及天敌种群数量变动趋势有一定差异,但百株蚜量与天敌单位相关均达到极显著或显著水平,天敌跟随紧密,对蚜虫具有明显的控制作用。大豆蚜和天敌一般在7月11日—21日出现第1次高峰(主要危害期),7月26日—8月6日出现第2次高峰,个别年份延后或不明显。各年度间大豆蚜的发生程度不同,3种栽培模式的控蚜作用也有差异。轻发生年(2008、2009年)第1次高峰期3种栽培模式平均百株蚜量较低(0.4万头~1.3万头,清种间作),天敌单位数量较高(51~226个),天敌控蚜作用均比较明显;第2次高峰期平均百株蚜量上升(0.9万头~2.7万头,间作清种),但因天敌、蚜霉菌、植株抗性及小型蚜比例高(70%)等因子综合影响,蚜虫种群迅速下降,大豆均未明显受害。重发生年(2010年)第1次高峰期清种模式平均百株蚜量高达4.6万头,分别是8∶2模式的3.8倍和8∶8模式的2.6倍,天敌不足以控制蚜虫的增长,酿成危害;而间作模式蚜虫增长缓慢,蚜量低(1.2万头,1.8万头),天敌效能高,表明间作模式与天敌协同控蚜效果明显。

Coordinated effects of different cultivation patterns and natural enemies on soybean aphid,Aphis glycines

The coordinated effects of different cultivation patterns （soybean monoculture,soybean/maize 8 ∶ 2 and 8 ∶8） and natural enemies on soybean aphid,Aphis glycines were studied during 2008 to 2010 in Xiuyan country,eastern Liaoning Province,China.The result showed that population dynamics tendencies of soybean aphids and natural enemies observed from different cultivation patterns were different,however,significant correlations were found between the aphid population per 100 plants and the unit of natural enemies; the population dynamics of natural enemies fluctuated closely with soybean aphids,suggesting that the former had a significant controlling effect on the latter.The first population peaks of soybean aphids （the main damage period） and natural enemies were generally appeared from 11 to 21 in July; the second population peaks appeared from 26 July to 6 August,and might delay or do not obvious in some years.Soybean aphids occurred in a varying degree each year,and the control effects of three kinds of cultivation patterns on soybean aphids were also varied.In light occurrence years （2008 and 2009）,average aphid population per 100 plants （4 to 14 thousand individuals,monoculture＞intercropping） was lower than outbreak year,while the unit of natural enemies was high （51 to 226 individuals）,hence,natural enemies had obvious control effects on aphids.In light occurrence years,average aphid population per 100 plants increased at the second population peak （9 to 27 thousand individuals,intercropping＞monoculture）,however,aphid population dropped rapidly and soybean has not been damaged obviously because of the comprehensive influence factors such as natural enemies,aphid mycete,plant resistance,and a high proportion of minitype aphids （70 ％）.In serious occurrence years （2010）,average aphid population per 100 plants was up to 46 thousand individuals in monoculture pattern,which was 3.8 times to soybean/maize 8 ∶ 2 pattern and 2.6 times to soybean/maize 8 ∶ 8 pattern.Natural