Evaluation of action thresholds for chronic rice insect pests in the Philippines. I. Less frequently occurring pests and overall assessment
Evaluation of action thresholds for chronic rice insect pests in the Philippines. I. Less frequently occurring pests and overall assessment
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DOI：
10.1080/09670870400028284
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发表时间：
2005-01-01
影响因子：
1.5
通讯作者：
Batay-An, EH
中科院分区：
文献类型：
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作者：
Litsinger, JA;Bandong, JP;Batay-An, EH
制定了行动阈值，作为杀虫剂应用的决策工具，并在菲律宾的四个地点针对水稻的主要虫害进行了为期13年的测试。行动阈值处理进行了比较，农民的做法，预防性杀虫剂的使用，和未经处理的检查。使用杀虫剂检查方法的产量损失数据在相同的试验田中将产量损失划分为三个作物生长阶段。79%的农田中超过行动阈值的慢性害虫是轮生蛆Hydrelia philippina Ferino（双翅目：蜉蝣科）、食叶害虫Naranga aenescens摩尔和Rivula atimeta（Swinhoe）（鳞翅目：夜蛾科）、持叶害虫稻纵卷叶螟Cnaphalocrocis medinalis（Guenee）和Marasmia patnalis布拉德利（鳞翅目：螟蛾科）以及蛀干害虫Scirpophaga incertulas（步行者）和S.无斑螟蛾（步行者）（鳞翅目：螟蛾科）。轻微的慢性害虫仅在一个地点达到阈值水平：稻蝽Leptocorisa oratorius（F.）（科罗纳达尔）、白背飞虱白背飞虱（Sogatella furcifera）（Horvath）（萨拉戈萨）和绿色叶蝉（Nephotettix virescens）（Distant）（Guimba）;褐飞虱（Nilaparvata lugens）（Stal）在任何田间均未超过阈值。蛀干害虫是造成产量损失的主要害虫。尽管杀虫剂检查方法低估了损失，但测得的平均作物损失为0.62吨/公顷，这表明有足够的纠正行动余地。但损失在作物生长阶段均匀分布（0.15-0.24吨/公顷），减少了杀虫剂的影响。行动阈值处理的总体产量超过了未处理的对照，在害虫密度最高的两个地点尤其如此。阈值的好处是减少杀虫剂的使用，从而节省费用。然而，所有的做法都显示出经济效益差，包括农民的做法。农民的做法是使用低剂量的杀虫剂，时间与虫害不一致，但产量往往与阈值处理相似。农民使用杀虫剂似乎更多是为了规避风险，而不是为了盈利。当根据产生的害虫密度和产量损失标准进行评估时，最佳阈值特征显示准确度> 90%正确决策。今后的工作需要改进杀虫剂应对措施，而不是监测工具。农民往往认为作物管理不理想，因此需要将种植业纳入改进的作物管理中，以利用现代高分蘖品种的高耐受性。提高产量潜力的作物管理措施，如选择成熟期较长的品种和氮肥，可能是比杀虫剂更有效的害虫管理策略。
Action thresholds as decision tools for insecticide application were developed and tested against the major insect pests of rice at four sites in the Philippines over a 13-year period. Action threshold treatments were compared to the farmers' practice, prophylactic insecticide usage, and an untreated check. Yield loss data using the insecticide check method partitioned yield losses over three crop growth stages in the same test fields. Chronic pests that exceeded action thresholds in 79% of fields were whorl maggot Hydrellia philippina Ferino (Diptera: Ephydridae), defoliators Naranga aenescens Moore and Rivula atimeta (Swinhoe) (Lepidoptera: Noctuidae), leaffolders Cnaphalocrocis medinalis (Guenee) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), and stemborers Scirpophaga incertulas (Walker) and S. innotata (Walker) ( Lepidoptera: Pyralidae). Minor chronic pests reached threshold levels in only one site each: rice bug Leptocorisa oratorius (F.) (Koronadal), whitebacked planthopper Sogatella furcifera (Horvath) (Zaragoza) and green leafhopper Nephotettix virescens (Distant) (Guimba); brown planthopper Nilaparvata lugens (Stal) did not exceed a threshold in any field. Stemborers were the most important pest group in terms of yield loss. Despite the insecticide check method underestimating losses, a mean crop loss of 0.62 t/ha was measured which showed ample scope for corrective action. But loss was evenly distributed across crop growth stages (0.15-0.24 t/ha) reducing the impact of insecticides. Action threshold treatments overall outyielded the untreated check, more so in the two sites with highest pest density. The benefit of thresholds was to reduce insecticide usage, as a cost saving. However all the practices showed poor economic returns including the farmers' practice. Farmers' practice employed low insecticide dosages and timing was not consistent with pest damage, but yields were often similar to threshold treatments. Farmers appear to use insecticide more for risk aversion than for profit. The best threshold characters when evaluated against resulting pest density and yield loss criteria showed accuracies > 90% correct decisions. Future work is needed to improve the insecticide response rather than monitoring tools. Thresholds need to be incorporated into improved crop management, which was often found suboptimal by farmers, to take advantage of the high levels of tolerance in modern high tillering cultivars. Crop husbandry practices which improve yield potential such as selection of longer maturing varieties and nitrogen fertilizer may be a more effective pest management strategy than insecticides.