effect of mechanical plucking height on tea green leaf yield and its quality

tea is very important product in many countries due to huge consumption in the world and its valuable contains. the traditional harvesting method needs to be improved due to its effect on yield and quality. mechanical plucking as a substitution to conventional method is spreading quickly and is necessary to be investigated for proper adoption. one of crucial factor has been noted to be the height of harvesting in this method, hence identifying the most appropriate height was aim of this study. the research was conducted in a research station of fashalem located in the north part of iran, guilan province during last season. treatments at four plucking height level of 5, 10 and 15 cm plus control (plucking with secateurs) and their effects on tea hybrid bushes were considered. regarding quality, parameters consisted revenue of total green leaf and the leaf standard, tannin of green leaf and solid material contain in of green leaf were determined. study was performed using randomized complete block design with three replications. the results indicated that plucking height of 5 centimeter, in total green leaf and standard leaf was significantly higher than other heights. moreover 5 cm plucking height showed maximum amount of tannin and solid material compared to the other treatments. there. the effect of time was found to be significant for different parameters of quality.