Effects of plant growth regulators on the growth and lipid accumulation in the solid endosperm of Ta Xanh coconut (Cocos nucifera L.)

Abstract

The growth of Ta Xanh coconut fruit is divided into four stages: slow growth, rapid growth, mature and ripening. In the mature and ripening stages, lipid accumulation increased at the strongest level in the endosperm. This study was conducted with the purpose of studying the effects of plant growth regulators on the growth and lipid accumulation in copra (solid endosperm) from the mature to ripening stage in Ta Xanh coconut fruit. Fresh weight, dry weight and lipid content in solid endosperm after treatments with 1 mg/L NAA, 10 mg/L BA and 20 mg/L GA3 individually or in combination with ethrel were determined. Results showed that the treatment of 20 mg/L GA3 on the 8-month-old fruits increased the copra fresh weight and dry weight. Treatments of 1 mg/L NAA, 20 mg/l GA3 or 200-250 mg/L ethrel on the 10-month-old fruits increased the ratio of lipid in the copra of each fruit. Treatment of 200 mg/L ethrel had a positive effect on increasing of the fresh weight, dry weight and lipid concent in the solid endosperm of the 10-month-old Ta Xanh coconut after 1 or 2 weeks of combinated treatment of 1 mg/L NAA, 10 mg/L BA and 20 mg/L GA3.