Architectural effect of different tea clones on the development of blister blight disease

An attempt has been made to analyze the architectural traits of six elite tea (Camellia sinensis) clones representing the three principal taxa Assam, China and Cambod with respect to the correlation of blister blight disease (Exobasidium vexans) development. In order to analyze the architecture, branching habit and flushing behavior were observed and subsequently compared with disease incidence. All the clones followed similar architectural pattern irrespective of the cultivar but varied with levels of disease severity. The number of branches was higher in China when compared to Assam and Cambod, branch length was bigger in Assam followed by Cambod and China. Branch angle of all the clones lay well within the described range of theoretical value of 45 to 90°. In general, internodal length was bigger in Assam followed by Cambod and China. These architectural characteristics determined the number of harvestable tea shoots in the bush canopy. China cultivars exhibited an erectophile type of leaf angle, which influenced effective net photosynthesis, transpiration rates and light penetration in leaves. These factors are playing important roles in a disease development strategy. This study should be useful for clonal selection for new clearings and re-planting areas. Moreover, plants breeding programmes for studying the yield and tea quality losses due to blister blight disease benefit from the findings herein.