Selection of the Most Appropriate Coating Particle Film for Improving Photosynthesis in Mango
Incremental irradiation, especially during summer, decreases net photosynthesis. Sunburn causes damage to leaves and fruit and consequently decreases the fruit yield and quality. Trials have reported success in using particle film technology for coating fruit tree leaves to remedy these adverse effects of strong summer irradiation. The objectives of this experiment were to compare the suspension properties, precipitation and light transmission of four coating materials?kaolin, bentonite, calcium carbonate and dolomite?and to study the leaf coating properties by measuring photosynthesis after the application of materials. The results showed that 60 g.L-1 kaolin had good suspension in water and was the slowest to precipitate. Kaolin was the most effective leaf coating material to reduce transmission through a glass plate by 70.14%. The average percentage of photosynthetic photon flux through a glass plate for bentonite, calcium carbonate and dolomite was 93.50, 92.28 and 86.78%, respectively. Mango leaves sprayed with kaolin had higher average net photosynthesis (Pn), stomatal conductance (gs) and transpiration rate (E) than in bentonite and untreated leaves which had significantly different average values for Pn, gs and E. Therefore, kaolin was suitable for use as a coating material on mango leaves.