American Society for Horticultural Science
Inbred onions, Allium cepa L, were grown with different levels of fertilizer and soil. moisture to determine treatment influence on seed yield. Nitrogen (253 kg/ha) alone or in combination with P (162 kg/ha> reduced plant survival, umbels per plant, pollination index, and seed yield where soil moisture was low but the reduction was nil. or not as severe where soil moisture was high.
Shasha'a, N. S., W. F. Campbell, and W. P. Nye. 1976. Effect of Fertilizer and Moisture on Seed Yield of Onion. Hortscience 11(4):425-426.