Abstract
Due to the continuous differentiation of inflorescences throughout the growing season, the day-neutral strawberry cultivars are likely to produce an insufficient number of runners. For the improvement of the runner production, the effects of GA3 at 50 ppm, BA at 50 ppm, combination of GA3 at 50 ppm and BA at 50 ppm, and 15N-15P-15K fertilizer levels on runner production, flowering, and growth parameters were evaluated in three cultivars of dayneutral strawberry (Fragaria×ananassa Duch.‘Summer Berry’, ‘Miyoshi’, and‘Enrai’) .
Application of GA3, BA, and GA3+BA resulted in a 2-3 fold increase of the number of runners in‘Miyoshi’, whereas GA3 and GA3+BA led to an increase of about 8 and 4 times in‘Enrai’and‘Summer Berry’, respectively.
GA3 significantly increased the petiole length in‘Miyoshi’and‘Enrai’, and all the growth regulators increased the petiole length in‘Summer Berry’. GA3 increased the number of leaves only in‘Miyoshi’, whereas in‘Summer Berry’BA increased the number of leaves. The number of inflorescences and the leaf area in all the cultivars were not affected by the treatments with growth regulators.
The application of slow release fertilizer NPK (N, P2O5, K2O, 15-15-15) at the rate of 100 mg/pot induced a higher inflorescence production and enhanced the other growth parameters compared with the application at 0 and 50 mg/pot. The runner production was promoted by NPK at 100 mg/pot only in‘Enrai’.
It was suggested that the growth regulator treatments and fertilizer level improved runner production, but the responses varied with cultivars. These data may contribute to the improvement of vegetative propagation of strawberry in the tropics.
