EVALUATION OF SOFT X-RAY IRRADIATED POLLEN AND CPPU FOR DIPLOID SEEDLESS WATERMELON PRODUCTION

There is much interest in seedless watermelons in the consumer market.
Soft X-ray irradiated pollen and CPPU hormone were evaluated to produce diploid seedless watermelon.
Pollen was irradiated with soft X-ray at 800 Gy before pollination.
Three concentrations of CPPU were applied as 50 ppm sprayed on ovary, 100 ppm rubbed on female flower pedicel and 1000 ppm applied on both sides of the shoot near female flower attachment.
Seedlessness was almost similar in all CPPU treatments (95%). TSS and rind thickness was slightly higher in CPPU treated fruits than in the control.
Similarly X-ray irradiated pollen also depicted higher TSS (12.0 Bx) than the control (10.8) but yielded similar fruit weight.
However, higher concentration of CPPU showed cracks in fruits (95%). In a second set of experiments CPPU (50 ppm), soft X-ray irradiated pollen (800 Gy) and a combined application of X-ray (800 Gy) pollen and CPPU (50 ppm) were compared.
The combined application yielded more fruit set (90%), seedlessness (95%), TSS (11.8 Bx) and marketable fruits (90%). CPPU (50 ppm) showed higher rind thickness (13.7 mm), harvest time (50 days after anthesis) and large aborted seeds than the X-ray treatment.
This also indicated high sink strength up to 15 days post anthesis but over all fruit weight was at par.

International Symposium on Greenhouses, Environmental Controls and In-house Mechanization for Crop Production in the Tropics and Sub-Tropics

S.W. Kwon, M.J. Jaskani, B.R. Ko, Y.G. Choi

Citrullus lanatus, parthenocarpy, growth regulator, X-ray, sugar, fruit growth

https://doi.org/10.17660/ActaHortic.2006.710.30