THE EFFECT OF PLANTING DATE, SET SIZE, AND SPACING ON THE YIELD OF ONION (ALLIUM CEPA) IN BOTSWANA
Experiments with planting dates and with sets of different sizes were carried out in Botswana in order to increase the yield and to reduce the seasonality of short-day onions. The mid-March planting gave the highest yield of 43.0 t/ha compared with 23.6 t/ha for the February planting and 31.2 t/ha for the April planting. The February planting produced 24% bolting plants, whereas, the March planting gave 7% and the April planting gave no bolters. Although late planting reduced bulb disorders, it also reduced bulb sizes and consequently led to low yield. In an experiment comparing three sizes of onion sets for planting, the optimum size was 0.75–1.0 in. with a yield of 45.4 t/ha. The 0.5–0.75 in. size gave 30.6 t/ha while 1.0–1.25 in. gave 37.6 t/ha. In a spacing trial with cultivars Granex 33 and Texas Grano, the treatments had no effect on yield, but influenced the bulb size.
Madisa, M.E. (1994). THE EFFECT OF PLANTING DATE, SET SIZE, AND SPACING ON THE YIELD OF ONION (ALLIUM CEPA) IN BOTSWANA. Acta Hortic. 358, 353-358