EFFECTS OF SOURCE, LEVEL AND TIME OF NITROGEN APPLICATION ON YIELD OF ONION IN THE SUDAN GEZIRA

Experiments on onions were made at the Gezira Research Station in Wad-Medani (14°23’N) during 1970–73. The treatments included three sources of nitrogen: sulphate of ammonia, urea and ammonium nitrate; three levels of nitrogen (0, 95, 190 kg N/ha); and three times of fertilizer application: before sowing, two weeks after sowing and split application at two and 4 weeks after sowing.

These were arranged in a factorial design replicated 4 times.
Onions were direct seeded on ridges 60 cm apart and in-row spacing of 10 cm.

There was no differential response to the source of nitrogen in the three seasons.
However addition of all the nitrogen fertilizers gave significant increases in total yield, average bulb weight, large bulbs and doubles.
Compared to pre-sowing applications, post-sowing applications of nitrogen increased the yields, averege bulb size and large bulbs.

IV Africa Symposium on Horticultural Crops

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https://doi.org/10.17660/ActaHortic.1977.53.6