向日葵播种期对防治向日葵螟和黄萎病的影响

Influences of sunflower sowing dates on preventing Homoeosoma nebulellum and Verticillium dahliae

为了明确向日葵不同播期对防治向日葵螟和黄萎病的影响,于2009年5月11日至6月10日在内蒙古巴彦淖尔地区分7个时期(间隔5天)种植食葵和油葵,并系统调查向日葵螟和黄萎病的发生危害情况。结果显示,食葵和油葵的向日葵螟危害率及向日葵螟密度均以5月26日种植的最低,分别为8.00%、4.00%和0.14头/盘、0.16头/盘。随着播种期的推迟,食葵和油葵的黄萎病发病率自5月11日的98.67%和100.00%逐渐降至6月10日的24.00%和32.00%,发病级别从5月11日的2.83级和3.27级逐渐降至6月10日0.36级和0.64级,差异达到显著水平。食葵以5月31日播种的产量最高,而油葵以6月5日播种的产量最高。证明适时晚播可有效减少向日葵螟和黄萎病对向日葵的危害。

In order to illuminate the influences of sunflower sowing dates on preventing Homoeosoma nebulellum and Verticillium dahliae,confection sunflower and oil sunflower were planted in seven sowing dates,every five days from 11 May to 10 June 2009 in Bayannur,Inner Mongolia Autonomous Region.The occurrence of H.nebulellum and V.dahliae was investigated.The results indicated that the minimum infestation rate and the minimum density of H.nebulellum of confection sunflower and oil sunflower were plants sowed on 26 May,with 8.00%,4.00% and 0.14,0.16 larvae per flower respectively.With the sowing date delayed,the V.dahliae incidence of confection sunflower and oil sunflower declined from 98.67% and 100.00% on 11 May sowed plants to 24.00% and 32.00% on 10 June sowed plants.The V.dahliae disease grade declined significantly from 2.83 and 3.27 on 11 May sowed plants to 0.36 and 0.64 on 10 June sowed plants.The maximum yield of confection sunflower was sowed on 31 May,while oil sunflower on 5 June.Therefore,timely delay sowing would reduce the infestation rates of H.nebulellum and V.dahliae.