Efeito do "ethephon", das giberlinas, do chlormequat e do tiba, na expressão do sexo e na produção de pepino (Cucumis sativus L.)

Resumo

Two experiments were performed under both green house and field conditions to study the effects of ethephon, gibberrellins, chlormequat and TIBA on sex expression and production of the monoecious cucumber "Aoday" (Cucumis sativus L.).

The application of ethephon (250 ppm) alone or in combination with gibberellins (2.000 ppm), chlormequat (2.000 ppm) or TIBA (20 ppm) caused a significant increase in the number of pistillate (female) flowers and the earlier formation of these flowers at lower nodes. The same treatments caused a significant decrease in the number of staminate (male) flowers and the delayed formation of these flowers at higher nodes.

The application of gibberellins, chlormequat, TIBA and their combinations did not significantly affect the number of male and female flowers or the number of days to the anthesis of the first male flower in relation to the control plants.

The formation of female flowers was completely inhibited by treatments with gibberellins or gibberellins + chlormequat.

Under field conditions the application of ethephon alone or in combination with chlormequat or TIBA increased significantly the early yield of marketable cucumbers (47 days after planting) without affecting the final marketable yield or the average fruit weight.