SOWING DEPTH AND N-FERTILIZING IN RELATION TO YIELD AND UNIFORMITY IN ONION CROPS (ALLIUM CEPA L.)

The optimal sowing depth for onion seed (Allium cepa) was found to vary with soil type.
On a sandy loam and a deep humus soil 25 mm and 25– 35 mm sowing depth respectively, gave the highest percentage of emergence and the greatest uniformity of emergence.
Sowing at a depth of 15 mm resulted, on both soil types, in a more predictable emergence and plant establishment.

Increasing application of N-fertilisers at rates up to 150 kg N per ha of calcium nitrate reduced emergence and gave a 10–20% reduction in the plant population, but this did not affect bulb yield.
Delaying the supply of N fertiliser until after emergence prevented any reduction of the plant population.

No relationship between variation in times of emergence of individual seedlings and variation in individual bulb weight at harvest was found.

Symposium on the Timing of Field vegetable Production

K. Henriksen

https://doi.org/10.17660/ActaHortic.1978.72.7