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Response of Onions to P Placement 1
Author(s) -
Mulkey J. R.,
Albach E. L.,
Dainello F. J.
Publication year - 1979
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1979.00021962007100060034x
Subject(s) - sowing , seedling , yield (engineering) , allium , agronomy , horticulture , bolting , biology , mathematics , materials science , metallurgy
Considerable variation in seedling size, vigor, and plant development occurs in onions ( Allium cepa L.) where phosphate fertilizers are surface‐applied and incorporated prior to planting. Our objective was to determine the influence of P rates and placement techniques on the growth and development of fall‐seeded onions. During the fall of 1975 and 1977, two rates of P (21.8 and 43.6 kg/ha) were banded at planting at 0, 2.5, 5, 7.5, 10, and 15 cm directly below the seed and at 0, 2, 4, 6, and 8 cm laterally from the seed at a constant depth of 5 cm. The soil was a Aridic calciustoll, fine, mixed hyperthermic. Seedling growth and P uptake by onions were enhanced when P was applied in a band directly below the seed at a depth of 2.5 cm. Maximum yield was obtained when P was applied directly below the seed row at a depth of 2.5 to 7.5 cm. Yield was influenced more by P placement than rate of application. Maturity was effected by both depth and lateral placement of P. This experiment has shown that precise vertical and lateral placement of P must be achieved for optimum growth and development of onions.