College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, 330045, People's Republic of China.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, People's Republic of China.
Sci Rep. 2021 Sep 8;11(1):17846. doi: 10.1038/s41598-021-97061-5.
We studied the effects of leaf surface characteristics on canopy droplet behaviour using two rice cultivars with similar leaf shapes but significantly different leaf surface characteristics: Jia58 (glabrous rice; smooth leaf surface and no burrs) and Yongyou12 (hairy-leaved rice; rough leaf surface covered with burrs). The plants were subjected to spray tests with different spray pressures and nozzle apertures. The results showed that the deposition amount per unit leaf area was significantly higher in the Yongyou12 canopy than in the Jia58 canopy. The diameter, volume median diameter, number median diameter, and coverage of droplets were significantly higher in Yongyou12 than in Jia58, while the coverage density of droplets was significantly lower. The proportion of small droplets of Jia58 is higher than that of Yongyou12. Thus, a larger amount of large-sized droplets could retain on the leaf surface of hairy-leaved rice, and a larger number of small-sized droplets were retained on the leaf surface of glabrous rice. Smaller pressure and larger flow nozzle were conducive to the retention of the Jia58, while Yongyou12 required larger pressure and larger flow nozzles. Ultrastructural analyses revealed that the leaf surface of glabrous rice had no trichomes and more wax than hairy-leaved rice, and the critical surface tension was lower, resulting in the retention of mainly small droplets on its leaf surface and a lower deposition amount. Therefore, in order to increase the deposition of pesticide droplets on the leaf surface in production, glabrous rice should choose nozzles with smaller spray pressure and large flow rate.
我们研究了叶片表面特性对冠层液滴行为的影响，使用了两个具有相似叶片形状但叶片表面特性差异显著的水稻品种：Jia58（无毛稻；光滑叶片表面且无芒刺）和 Yongyou12（有毛稻；粗糙叶片表面覆盖芒刺）。对这些植物进行了不同喷雾压力和喷嘴孔径的喷雾测试。结果表明，Yongyou12 冠层的单位叶面积沉积量明显高于 Jia58 冠层。Yongyou12 的液滴直径、体积中位径、数中位径和覆盖率均明显高于 Jia58，而液滴覆盖率密度则明显较低。Jia58 的小液滴比例高于 Yongyou12。因此，更多的大尺寸液滴可以保留在有毛稻的叶片表面上，而更多的小尺寸液滴则保留在无毛稻的叶片表面上。较小的压力和较大的流量喷嘴有利于 Jia58 的保留，而 Yongyou12 需要更大的压力和更大的流量喷嘴。超微结构分析表明，无毛稻的叶片表面没有刚毛，比有毛稻有更多的蜡质，临界表面张力更低，导致其叶片表面主要保留小液滴，沉积量较低。因此，为了增加生产中农药液滴在叶片表面的沉积量，无毛稻应选择喷雾压力较小、流量较大的喷嘴。
