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Seed Size and Seeding Rate Effects upon Stand Density and Yield of Alfalfa 1
Author(s) -
Cooper C. S.,
Ditterline R. L.,
Welty L. E.
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/agronj1979.00021962007100010021x
Subject(s) - seeding , seedling , agronomy , loam , biology , competition (biology) , semis , sowing , horticulture , soil water , ecology
Legume seedlings from seed of different sizes compete with one another in pure seedings, usually to the detriment of smaller seedlings. We seeded variable rates of sized‐seed at Bozeman, Mont., to determine if less competition would permit lowering the seeding rate of alfalfa. We screened alfalfa ( Medicago sativa L.) seed to small, medium, and large sizes weighing 160, 210, and 256 mg/100 seed respectively, and also made up a composite of the three sizes. We planted seed of each size at seeding rates of 1.1, 2.2, 4.5, and 9.0 kg/ha into a Bozeman silt loam (Agric‐Pachic Cryoboroll) soil in the field and measured seedling emergence and survival and yield in the year following seeding. Number of seedlings that emerged and number of plants that survived the second year were closely related to seeding rate. Percentage of planted seeds, resulting in mature plants from two separate plantings, decreased with increased seeding rate due to more intraplant competition. More seedlings emerged from small seed, or from the seed composite of all sized‐seeds, than from medium or large seeds. Seed size did not affect yield in the year of seeding or the year following. A seeding rate as low as 1.1 kg/ha at one location and 2.2 kg/ha at a second location gave maximum yield in the year following seeding. Our data showed no advantage of sizing seed. Seedling density was as good or better with small or composited seed as with large seed at the same seeding rate.