The Course Of Fluorescent Green Spot Disease Of Tea Plant And It's Physiological Characteristic

The fluorescent green spot disease is a physiological disease of tea mature leaves that happens widely in all over the country. There are many green spots on the lower epidermis of diseased leaves, and the yellow-greenish fluorescence can be observed from the green spots when it was excited by the light. The tea plants suffering this disease are in poor growth and their output will reduce.In order to investigate the cause of this disease and physiological characteristic of diseased tea plants and aim to provide theoretic basis of measure to prevent the disease occurrence, the following researchs were conducted by the author:1 The content of thirteen elements, including N, P, K, Na, Ca, Mg, Fe, Mn, Cu, Zn, Al, S and B, were analyzed in the tea leaves from different area, tea cultivars and various degree of disease. The results indicated the cause of this disease is relative to the excess of Ca, Mn and Al or the deficiency of B and Cu.2 In order to induce the disease tea plants, one-year-old clonal tea trees ( named Fu-ding-da-bai ) were cultivated by sandy hydroponics and treated with the excessive content of Ca, Mn and Al or the deficiency of B and Cu, respectively. The results showed that the excess of Ca, Mn, Al as well as B( but only in the hydroponics ) resulted in the occurrence of fluorescent green spot disease. Moreover, the disease tea plant can be more easily induced by treated with the nutrient infusion of excessive B plus with the excess of Ca, Mn or Al, respectively.3 The diseased tea plants induced by sandy hydroponics were detected and observed the following items: photosynthesis, shoot growing status ( the number and length of new shoots, length of interval leaves, leaf area, index of leaf shape), root activity and root growing status ( dry weight, total length, diameter, total surface area ).Compared to the normal tea plants, the diseased tea plants showed that the rate of net photosynthesis declined , intercellular CO2 concentration increased; the number of new shoots increased but the length of interval leaves and total shoots became shorter, the number of leaves on the shoots reduced, leaf area and index of leaf shape had small difference, root activity declined obviously and the numerical value of root growing status reduced. All above results indicated that the physiological characteristics of diseased tea plants had changed evidently.4 The thirteen elements in roots and leaves of tea plants, which cultivated by sandy hydroponics and treated with excess of Ca, Mn, Al and B, were analyzed. The results showed: it could increase the content of Ca, Mn or B respectively in the root and leave of tea plants when it was treated with excess of Ca, Mn, or B, meanwhile, it could not increase the content of Al in tea plants when it was treated with excess of Al, but increased the content of Ca and Mn obviously, these treatments have also remarkable influence on the content of other elements such as: reducing the content of Zn to deficiency and inactive Fe in the root and leaves, declining the content of N, P and K in leaves and Cu in root, but increasing the content of S, Mg and Na in tea plants and the content of P in root only treated by excess of Ca or Al...