The effect of simultaneous application of kaolin and salicylic acid on some biochemical ‎characteristics of Nagami kumquat

Kumquat is one of the citrus fruits that has gradually become important in the world. The fruits of kumquat suffer from sunburn in intense sunlight. In order to reduce the adverse effects of solar radiation, in this experiment, treatments of kaolin (0, 3 and 5%) and salicylic acid (with concentrations of 0, 0.1 and 1 mM) were used as foliar spray on potted samples. The evaluated treatments included relative water content, gas exchange, biochemical characteristics of the leaves, antioxidant enzymes activity and concentrations of nutrients. The results showed that treatments had significant effects on the measured parameters. Kaolin increased stomatal conductance and net CO2 uptake by creating a thin coating on the plant and protecting it from environmental stresses and reducing plant temperature. Salicylic acid also had positive effects on the activities of antioxidant enzymes.The effects of treatments on the balance of plant nutrients were not very noticeable, although slight changes were observed in some cases. In general, the results of this experiment showed that the use of kaolin 5% and 1mM salicylic acid together can be considered as a cheap and effective treatment in kumquat and in order to protect the plant in high temperature and severe radiation conditions.