Plant Population and Irrigation Effects on Spanish Peanuts (Arachis hypogaea L.)1

Abstract Both irrigated and nonirrigated conditions were imposed on various populations for three years using the peanut (Arachis hypogaea L.) cultivar Argentine. Row spacings were 0.25, 0.5, 0.75 and 1 m. Within-row plant spacings ranged between 2 and 27 plants/m. The dependent variables of yield (kg/ha and g/plant), other kernels (%) and net return ($/ha) were fitted with a surface response equation Y = β1 + β2X1 + β3X12+ β4X2 + β5X22+ β6X1X2, with X1 spacing between rows and X2 spacing between plants within the row. This model fitted all dependent variables very well for both irrigated and nonirrigated conditions. Resulting interpolation of the data using the above equation indicated that the 0.25 m row spacing gave the highest yield of unshelled peanuts for both irrigated and nonirrigated conditions. Approximately 15 plants/m was the optimal plant spacing (in all row spacings) for maximum yield and quality. Integrating yield and quality in terms of net returns, the 0.25 m row spacing was optimal for p...