ROLE OF GA-3 ON CARBON METABOLISM IN LEAVES OF QUERCUS-SERRATA, A SILKWORM HOST

Spray treatment of leaves with different concentrations of gibberellic acid (GA3) to 2-month-old plants of Quercus serrata (host of a silkwo rm) increased the levels of total chlorophyll, total sugar and crude f at but the content of crude fibre remained lower than the control. The levels of total chlorophyll and sugar were maximal at 5.0 ppm which w as the optimum conc. The crude fat level was higher at 1 and 5 ppm whi ch remained unaffected at higher doses (10 and 50 ppm). The fibre leve l with all the treatments of GA3 was always lower than that of the con trol. Over all, the GA3 treatment delayed senescence of leaves. The tr eatment of 5.0 ppm of GA3 maintained a high level of total sugar upto 60 days which seemed to be beneficial to the growth of oak tasar silkw orm.