GAMETOCIDAL EFFECTS OF GIBBERELLIC ACID (GA3, GA4+7) ON COMMON ONION (ALLIUM CEPA L.)
The treatments were 10 and 15 respectively in 1978 and 1979; the 1 plant-unit was repeated 4 times in experiment 1 and 10 times in experiment 2.
Per each plant 3 umbels were maintained: 1 bagged to control the selfing rate in presence of blowflies, the second one bagged without blowflies, the third umbel free to open pollination. The data recorded for each umbel were: total number of flowers, number of seeded flowers, number of perfect seeds, weight and germination of perfect seeds. In the 1979 experiment, the pollen germination of the 'open' umbels was also tested.
The most efficient concentrations resulted to be 2 000 ppm for GA3 and 5 000 ppm for GA4+7 sprayed 10 times at 2–3 day intervals starting from the bolting stage.