Effects of Sowing Dates and Seed Rates on Sets Yield and Quality of the Red Onion (Allium cepa) cv. ‘Saggai Improved’

الملخص

An experiment was conducted at Shambat Research Station,
Khartoum North for two growing seasons (2003/4 and 2004/5) to
investigate the effects of three sowing dates (15 Dec., 15 Jan. and 15 Feb.)
and five seed rates (90, 100, 110, 120 and 130 kg ha -1 ) on the yield and
quality of the sets of red onion cultivar “Saggai Improved” .The first
season gave the best vegetative growth, high total number and weight of
sets ha -1 as well as improved set quality. High levels of seed rates
increased the total number of sets ha -1 in the first season, while they had
no effect on growth attributes and size grades per m-2 . However average
set weight decreased when high levels of seed rates were used. Early
planting date (15 Dec.) resulted in better plant growth as reflected in
increased leaf number plant-1 , fresh and dry weight of sets and total fresh
and dry weight. Significant increases in the total number and weight of
sets ha -1 , improved set quality and set weight due to early planting were
also realized