EFFECTS OF MINERAL FERTILIZER DOSE ON GROWTH, YEILD AND MATERIAL QUALITY OF TEA FIELDS PICKED BY MACHINES.

Abstract

         The study “The Effecs of fertilizer dose on the growth, productivity and quality of raw tea harvested by tea plucking machine” in Thai Nguyen province shows that: increasing the amount of NPK by 20-80% compared with the current process (applying for tea crop plucked by hand) has shortened the duration from cutting to the first harvest by machine by 2-8 days; 1-4.5 days between two times of harvest by machine; has increased the productivity of tea from 20 to 44.8%; and the productivity of tea has highly increased when increasing the amount of fertilizer by 20-40% used for tea crop compared with the control. If we continue to raise the amount of fertilizer from 60 to 80%, the productivity of tea will still raise but slowly. The accounting for economic efficiency suggests that we can achieve the highest profit if increasing by 40% the amount of fertilizer in comparison with the control.