Effect of nitrogen fertilization and bulb spacing on saggai red onion seed production in Berber area, River Nile State, Sudan

الملخص EN

Field experiments were conducted during the winter seasons of 2009/10 and 2010 / 11 at Dar Mali in the River Nile State, Sudan, to study the effect of different levels of nitrogen fertilizer and bulb spacing on seed production of the red onion cultivar Saggai Red.

Four in–row spacings (15, 20, 25, and 30 cm) and four fertilization levels (0, 45, 90, and 180 kg N ha-1) were used.

Nitrogen was applied in the form of urea in four equal doses (10, 30,50and 70days after planting).

The result indicated that nitrogen fertilization significantly increased the length of leaves, number of leaves, length of flowering stalk and number of flowers per umbel.

The highest records for the four growth parameters were obtained by 90 kg N fertilization.

The narrow spacing (15 cm) recorded the highest leaves length.

However, the number of leaves per plant as affected by spacing was not significant.

Bulb spacing of 25 cm resulted in the biggest number of flowers per umbel and the longest flowering stalk.

The effects of fertilization and spacing on the number of flowering stalk showed no significant difference.

Early flowering was obtained by application of 90 kg Nha-1, and 15 cm bulb spacing.

The highest 1000-seeds weight was recorded by 45 kg N ha-1 treatment and 25 cm bulb spacing.

The maximum yield of seeds ha-1was obtained by application of 90 kg Nha-1 and 20 cm bulb spacing