Yield of Indeterminate, Small-vine Cowpea Cultivars Unaffected by Uniformity of Within-row Spacing

Abstract

Cowpea [Vigna unguiculata (L.) Walp.] planters can produce variable within-row seed spacing. We determined whether precision planting of cowpea would produce a yield advantage over more random planting at the same rate. Studies were conducted from May 1992 to Feb. 1993 at three locations: Uvalde, Texas; Bixby, Okla.; and Fort Pierce, Fla. Seeds of the indeterminate, small-vine cowpea cultivars Mississippi Silver and Pinkeye Purplehull BVR were hand-planted at 42 per 3.15 m of row. Seeds within rows were either spaced uniformly at 7.5 cm [control, with sd = 0] or in one of two random sequences (sd = 4.8). At harvest, in Oklahoma and Florida, mean within-row spacings were similar, but sd values of random-sequence plots remained greater than those of control plots. Control plots averaged four more plants at harvest than random-sequence plots in Texas. However, seed yield (seed dry weight per hectare) and harvest index were unaffected by uniformity of within-row spacing at all three locations. Thus, precision seeding of indeterminate, small-vine cowpea cultivars seems unlikely to produce a yield advantage over more random planting at the same rate.