SEX EXPRESSION AND LEVEL OF PHYTOHORMONES IN MONOECIOUS CUCUMBER AS AFFECTED BY PLANT GROWTH REGULATORS

The hormone levels of auxin and gibberellin were studied in monoecious cucumber plants treated with growth regulators e.g. 2-chloroethylphosphonic acid (ethrel), gibberellic acid (GA3) and maleic hydrazide (MH). The studies were conducted at Vegetable Crops Research Programme, National Agricultural Research Centre Islamabad, Pakistan during 2003 and 2004. The greatest increase in female flower production, lowest male to female sex ratio, highest number offruits/plant and yield were recorded with the application ofMH at 450 yM/l as compared to control. Ethrel also significantly lowered the male to female sex ratio in cucumber. The treated plants had an increased level ofauxin hormone. Hormone GA level had a positive correlation with the number ofpistillateflower/plant, fruit set percentage and IAA level had a negative correlation with sex ratio.