engleski

Effect of kaolin clay application on photosynthetic efficiancy and yield of pear cultivars

Each plant has certain environmental requirements for its growth and development. Unfavourable environmental conditions can produce a stress on plants resulting in lower yields. The photochemical activity is also affected by environmental stresses. Environmental stresses such as a high midday temperature and high irradiance result in a midday depression of photosynthesis in pear. Kaolin, white clay, protects plants from extreme heat and ultraviolet radiation by increasing leaf reflectance. During heat stress kaolin reduces the temperature of leaves and increases photosynthetic efficiency. Kaolin is used to mitigate the negative effects of those stresses on plant. The objectives of this experiment were to evaluate the effects of kaolin on photosynthesis, fruit yield and quality in two pear cultivars (Abbe Fetel and Conferance). Experiment were performed in the experimental orchards Tovljač, Agricultural institute Osijek. The effect of foliar applications of kaolin clay (Cutisan) on pear leaves by measuring chlorophyll a fluorescence (Fv/Fm), were studied during summer 2015. We used the chlorophyll a fluorescence to evaluate the benefit of this application against stressful conditions, caused by high temperature and high irradiance. The results by the OJIP test showed that a kaolin on the pear leaves could protect leaves against high irradiance, because pear leaves sprayed with kaolin showed a higher photosynthetic efficiency at mid-day compared to trees non-treated with kaolin. The total fruit weight (yield) from the kaolin sprayed pear trees, in both cultivars, was higher than in untreated trees. The results indicate that the application of kaolin should be considered as useful technological measure and effective tool for reducing stress of pear trees, which can effect on increasing of yield and its quality.

kaolin; pear; stress; chlorophyll fluorescence; OJIP test

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