Abstract

Nitrogen fertilisation and plant spacing hold potential for the integrated management of rice insect pests. Field experiments were conducted in Kilombero, Tanzania to evaluate the effects of plant spacing and nitrogenous fertiliser on incidences and density of spotted and African pink stem borers. A 3 × 4 × 4 factorial experiment was used in a randomized complete block design with three replications. Treatments included application of urea fertiliser at four levels (0, 40, 80, and 160 kg N ha⁻¹) and spacing at four levels (10 cm × 10 cm, 15 cm × 15 cm, 20 cm × 20 cm, and 25 cm × 25 cm). Nitrogen significantly increased dead hearts by 4.8%, white heads by 2.8% and stem borer larvae density from 0 to 5.6 larvae/m². Decreasing the planting density significantly increased dead hearts by 4.7%, white heads by 2.7% and stem borer larvae density from 0 to 5.4 larvae/m². The interaction of nitrogen fertiliser rates and plant spacing did not affect stem borer incidences nor larvae density, but did influence the rice yield.

摘要

施氮肥和株距在水稻害虫综合治理方面具有潜力。在坦桑尼亚的基隆贝罗进行了田间试验，以评估株距和氮肥对斑点和非洲粉螟的发病率和密度的影响。3 × 4 × 4 析因实验用于随机完整区组设计，重复三次。处理包括四个水平（0、40、80 和 160 kg N ha ^-1）和四个水平（10 cm × 10 cm、15 cm × 15 cm、20 cm × 20 cm 和 25厘米 × 25 厘米）。氮使死心显着增加 4.8%，白头增加 2.8%，螟幼虫密度从 0 增加到 5.6 个幼虫/m ². 降低种植密度使死心显着增加了 4.7%，白头显着增加了 2.7%，螟幼虫密度从 0 增加到 5.4 个幼虫/m ²。氮肥施用量和株距的相互作用不影响螟虫发生率和幼虫密度，但确实影响水稻产量。