Minufiya J. Agric Rres., 29(2004): 1339-1346

EFFECT OF BULB SIZE AND PLANT DENSITY ON ONION

SEED PRODUCTION UNDER RAINFED CONDITIONS.

Atif Y. Mahadeen

Dept. Plant Production, Fac. Agric., Mu’tah Univ. ,Karak, Jordan.

ABSTRACT:

A field experiment was conducted to explore the best

combination of bulb size and plant density for onion seed production

under rainfed conditions in Rabba Agricultural Research Station. Three

mother bulb sizes; i.e, small (3.0-5.0 cm), medium (5.1-7.0 cm) and large

(7.1-9.0 cm) diameter were used. Mother bulbs were planted at three plant

densities (inter- and intra- spacing were 0.15X0.60 m, 0.30X0.60 m and

0.45X0.60 m). The highest seed yield per plant was produced by planting

large mother bulbs at low plant density compared with other

combinations. Planting small mother bulbs at all plant densities and

medium bulbs at high plant density produced the lowest seed yield per

plant. Seed yield of small mother bulb size was not affected by plant

density. Each increase in bulb size and planting density resulted in a

significant increase in seed yield and number of umbels per unit area.

Therefore, though higher plant density and large mother bulbs produces

more seed yield per ha, planting medium size bulbs at medium or low

plant density are more practical and preferred for seed production.