Sex expression in cucumber plants as affected by mechanical stress

Sex expression in cucumber plants, as affected by mechanical stress, was examined using 4 cultivars with different genetic backgrounds for sex expression. Mechanical stress given to the plant greatly reduced growth and increased the number of pistillate (female) flowers in the monoecious type, but it had no effect on the sex expression of the gynoecious type. The effect of mechanical stress on the growth and sex expression of the monoecious type was nullified by the foliar application of gibberellin A4+7. Silver nitrate also was effective in nullifying the effect of mechanical stress on sex expression, but not the effect of growth retardation. Pistillate flowers in a gynoecious strain were reduced by silver nitrate.