Supanee Chanaweerawan and Sayan Sdoodee

pp. 9 - 14

Abstract

Total chlorophyll and nitrogen status in leaves of longkong and rambutan were evaluated by using the SPAD-502 meter. Leaves of both species were sampled from 10 year-old trees grown in an experimental plot at. Prince of Songkla University, Hat Yai campus. The relationship between SPAD-502 meter reading (SPAD) and total chlorophyll content analyzed in the laboratory was evaluated in longkong and rambutan, and they were y = -2.68+0.21x, r²= 0.77** and y = -1.11+0.18x, r²= 0.77**respectively. The data recorded by SPAD were also linearly related in a positive manner to nitrogen status in longkong (y = 1.27+0.20x, r² = 0.82**) and rambutan (y = 1.17+0.02x, , r² = 0.79**). The results show that using the SPAD-502 metet· is convenient and fast for the evaluation of total chlorophyll and nitrogen status in leaves of longkong and rambutan.