E.G. CANUDAS1, K.H. QUESENBERRY2, L.E. SOLLENBERGER2 and G.M. PRINE2
1Colegio de Postgraduados, Centro de Ganaderia, CRECIDATH, Apto. Postal. 421, Veracruz, Ver. 91700 Mexico
2University of Florida, Department of Agronomy, IFAS-0681, Gainesville, FL 32611 USA
Rhizoma peanut (Arachis glabrata) is a warm-season perennial forage legume adapted to well-drained soils in the subtropics and tropics. Because little seed is, produced, it is propagated by rhizomes, but information on establishment is limited. An experiment was conducted to determine the effect of herbicide application, peanut cultivar and planting rate on establishment of peanut. Herbicide treatments were, no postemergence herbicide application (Ho), application for control of broadleaf weeds only (Hb), and application for control of broadleaf and grass weeds (Hbg). Cultivars were Arbrook and Florigraze, and planting rates were 0.35, 0.7, 1.4, 2.4, and 3.8 t/ha of rhizomes.
At the end of the establishment year (1983), peanut ground cover and dry matter (DM) harvested were approximately 2 times higher for Hbg than for Ho or Hb. DM yield of broadleaf weed was less than 0.25 t/ha in Hb and Hbg but 2.8 t/ha in Ho. Grass weed yield was 3.3, 1.5, and less than 0.1 t/ha in Hb, Ho, and Hbg plots. Grass stands were probably reduced in Ho due to competition from tall-growing broadleaf weeds. Arbrook ground cover and DM harvested were higher than for Florigraze. DM harvested increased linearly for both cultivars over the range of planting rates used.
In the second year, broadleaf weeds were chemically controlled on all plots, but no herbicides were used for grass control. Peanut DM yield of Hb and Hbg treatments was not different in the second year, but peanut yields in Hbg were greater than for Ho. As in 1983, peanut cover and DM harvested were higher for Arbrook than for Florigraze in 1984 at all herbicide treatments and planting rates. Peanut DM response to planting rate was quadratic in 1984 with 90% of maximum yield obtained at the 2.5 t/ha rate.