ABSTRACT Vegetable cultivation in closed tunnels in the Tropics is impeded by high temperatures and poor pollination. This study compared the performance of cucurbits cultivated in open plots, in closed tunnels totally covered with small or large mesh nets (nethouse), and in open tunnels with a plastic film roof (rain shelter) in Tanzania over two seasons. Information was collected on climatic conditions, insect pest populations, vegetative development and yield. Temperatures were significantly higher under the tunnels than in the open plots during the day with few differences between the different tunnels. Insect pest populations were lower under nethouses than in open plots and under rain shelters, especially fruit flies. Higher marketable yields were obtained under nethouses with a small mesh (70.9 and 96.9 t.ha−1) and a large mesh (67.4 and 53.1 t.ha−1) than in open tunnels (12.9 and 9.1 t.ha−1) and in open plots (3.8 and 7.2 t.ha−1). Our results demonstrate that nets, especially with a small mesh size, provide versatile and efficient protection against major insect pests of cucumber, as well as a conducive environment for the development of the crop under local climatic conditions.

中文翻译：

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Nethouses 保护黄瓜植物免受虫害并提高东非的产量

摘要 热带封闭隧道中的蔬菜种植受到高温和授粉不良的阻碍。本研究比较了坦桑尼亚两个季节在开放式地块、完全覆盖有小型或大型网状网（nethouse）的封闭隧道以及带有塑料薄膜屋顶的开放式隧道（防雨棚）中栽培的葫芦的性能。收集了有关气候条件、害虫种群、营养发育和产量的信息。白天，隧道下方的温度明显高于露天地块，不同隧道之间的差异很小。网舍下的害虫种群数量低于开放式地块和避雨棚下，尤其是果蝇。在具有小网孔（70.9 和 96.9 t.ha-1）和大网孔（67.4 和 53. 1 t.ha-1) 比开放隧道（12.9 和 9.1 t.ha-1）和开放地块（3.8 和 7.2 t.ha-1）。我们的研究结果表明，网，尤其是小网眼，可以提供多种有效的保护，抵御黄瓜的主要害虫，并为当地气候条件下的作物生长提供有利的环境。