陇东旱塬区复种马铃薯田蛴螬及金针虫防治药剂筛选试验

陇东旱塬区种植冬油菜和冬小麦后，土地闲置期可复种马铃薯，但蛴螬、金针虫等地下害虫对马铃薯为害严重，科学合理防治蛴螬、金针虫对保证马铃薯产量非常重要。为筛选出陇东旱塬区复种马铃薯田防治蛴螬、金针虫危害的低毒高效的适宜药剂，以马铃薯品种陇薯7号为指示品种，蛴螬、金针虫为防治对象，选用3种高效低毒杀虫剂对各药剂的拌种或喷沟处理进行田间防效试验，调查各处理蛴螬、金针虫虫口基数，出苗期的出苗率、受害率、安全性和成熟期的受害率、安全性。结果表明，35%噻虫嗪种衣剂、60%帮巧时种衣剂防效均达85%以上，且拌种处理和喷沟处理无显著差异。60%帮巧时悬浮种衣剂拌种和喷沟防效均好，分别为88.44%、90.36%；折合产量高，分别为16 407.41、17 066.14 kg/hm2，较空白对照分别增产16.71%、21.40%，较常规药剂对照分别增产12.07%、16.57%；保产效果好，分别为95.39%、96.20%。见于此，60%帮巧时悬浮种衣剂可作为陇东旱塬区复种马铃薯田蛴螬、金针虫防治的候选杀虫剂；并建议用48.00 mL的药量稀释10倍液后拌种薯100 kg，将525.00 mL的药量稀释250倍液，按225 L/hm2喷沟。

Screening of Insecticides to Control Grubs and Wireworms in Potato Field of Multiple Cropping on the Loess Plateau of Eastern Gansu

After harvesting winter rapeseed and winter wheat in the dryland area of Longdong, potatoes can be resowed during the idle period of the land, where underground pests such as grubs and wireworms pose serious harm to potatoes. Scientific prevention and control of grubs and wireworms is important for potato yield. In order to screen suitable insecticides with low toxicity and high efficiency for controlling the grubs and wireworms in the mutiple sowing potato fields in the dryland area of Longdong, selecting potato variety Longshu 7 as the indicator variety, three high-efficiency and low toxicity insecticides were selected to conduct field control experiments through the seed dressing or ditch spraying treatment of each pesticide. The population density of grubs and wireworms in each treatment was investigated, and the emergence rate, damage rate, safety during the emergence period, damage rate and safety at mature stage were also investigated. The results indicated control effect was over 85% using the seed coating agent of 35% thiamethoxam and 60% Bangqiaoshi, which was not significant between seed dressing treatment and ditch spraying treatment. The 60% Bangqiaoshi suspension seed coating agent had the best effect whether it was seed coating or trench spraying, that was 88.44% and 90.36%, respectively. The equivalently average yield of two above treatments was 16 407.41 and 17 066.14 kg/ha, comparing with the blank control and the conventional pesticide, which added 16.71%, 21.40% and 12.07%, 16.57%, respectively. Furthermore, the ratio of maintaining yield of 60% Bangqiaoshi reached to 95.39% and 96.20%, respectively, for these two treatments. Therefore, 60% Bangqiaoshi suspension seed coating agent could be regarded as a candidate insecticide to control grubs and wireworms in multiple cropped potato field of the Longdong dryland. It is recommended that a dosage of 48.00 mL of 60% Bangqiaoshi was diluted to 10 times to deal with 100 kg potato tuberor and 525.00 mL was diluted to 250 times to spray ditch with a dosage of 225 L/ha.