Determination of foliar uptake of water droplets on waxy leaves in controlled environmental system
Determination of foliar uptake of water droplets on waxy leaves in controlled environmental system
复制标题
受控环境系统中蜡质叶子上水滴吸收的测定
DOI：
10.13031/trans.58.11246
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发表时间：
2015
影响因子：
1.5
通讯作者：
C. R. Krause
中科院分区：
文献类型：
--
作者：
J. Gao;H. Zhu;L. Horst;C. R. Krause
为了选择合适的有效成分和喷雾助剂用量，提高农药的药效，需要建立相关的植物角质层渗透性测定技术。建立了一个相对湿度为100%的受控环境系统，在15 ° C和20°C的环境温度下，于10：30 - 13：00（中午）和16：00 - 19：00（晚上）两个昼夜时间段内，在蜡质叶片表面的不同位置直接测量叶片固着水滴的吸收速率。用单液滴发生器产生直径为340和540 µm的固着液滴。气孔密度和渗透压叶片上也分别用扫描电子显微镜（SEM）和蒸汽压渗透计测量。在环境室内100%的相对湿度下，液滴在沉积在非渗透性玻璃上后保持不变，但在沉积在叶片上后它们穿透叶片组织。叶片吸收时间随液滴大小、液滴在叶片上的沉积位置和昼夜变化而变化，但随渗透压和气孔密度变化不大。在20°C和100%相对湿度下，叶片表面上540 µm直径液滴的平均吸收速率为0.000401 ±0.000063 µL/s，是340 µm直径液滴平均吸收速率的2.1倍。结合100%相对湿度的受控环境系统和固着液滴发生器来测量水滴的叶面吸收速率，将提供一种独特的方法来阐明喷雾液滴的叶面吸收机制，以高效和有效地控制特定植物上的目标害虫。
Pertinent techniques for determination of plant cuticle permeability are needed to select proper doses of active ingredients and spray additives to improve pesticide application efficacy. A controlled environmental system with 100% relative humidity was developed for direct measurements of foliar uptake rates of sessile water droplets at various locations on waxy leaf surfaces during two diurnal periods between 10:30 and 13:00 (noon) and between 16:00 and 19:00 (evening) at ambient temperatures of 15 and 20°C. Sessile droplets of 340 and 540 µm in diameter were produced with a single-droplet generator. Stoma densities and osmotic pressures on leaves were also measured with a Scanning Electronic Microscope (SEM) and a vapor pressure osmometer, respectively. At 100% relative humidity inside the environmental chamber, droplets remained unchanged after they were deposited on a non-permeable glass but they penetrated leaf tissues after they were deposited on leaves. Foliar uptake time varied with droplet size, droplet deposition location on leaves, and diurnal period, but varied little with osmotic pressure and stoma density. An average uptake rate of 540 µm diameter droplets on a leaf surface at 20°C and 100% relative humidity was 0.000401 ±0.000063 µL/s which was 2.1 times the average absorption rate of 340-µm diameter droplets. The incorporation of the controlled environmental system with 100% relative humidity and the sessile droplet generator to measure foliar uptake rates of water droplets would provide a unique approach to elucidate the foliar uptake mechanism of spray droplets for efficient and effective control of target pests on specific plants.