Effects of Spraying Boron and Phosphorus on Physiological Characteristics of Tobacco

In order to study the influence of boro n( B) and phosphoru s( P) on enzyme activity during the growth and development of flue-cured tobacco, B and/or P fertilizer were sprayed in flue-cured tobacco growth period. The important enzymes activities such as peroxidase( POD), superoxide dismut ase( SOD), catalase( CAT), phenylalanine ammonia lyas e( PAL), converting enzym e( INV),nitrate reductase( NR) and amylase( WL) at different growth stages were tested. The results showed that the B and P fertilizer spraying didn' t change trend of the tobacco activity changing during the growth period of tobacco plant. Spraying P fertilizer increased superoxide dismutase, catalase, phenylalanine ammonia lyase activity at tobacco maturity stages; spraying the B fertilizer improved the catalase,invertase and amylase activity at the early growth stage; and spraying the P and B fertilizer together reduced superoxide dismutase and nitrate reductase activity and improved the peroxidase activity at the late growth stage. In conclusion, spraying the B and P fertilizer together could keep tobacco enzyme activity at a proper level which was conducive to the growth and maturity of tobacco plant.