Nitrogen fertility studies on the buffalo gourd (Cucurbita foetidissima) grown as an annual root crop

Abstract

A fertility study was initiated at the Maricopa Agricultural Center in 1984 to determine how nitrogen levels influenced growth, development, and root yield of the potential domesticate, buffalo gourd (Cucurbita foetidissima). Nitrogen had little or no effect upon the following parameters: seedling emergence, early growth rates, specific leaf weights, individual root weights, consumptive water use, canopy organic N content, and nitrate and ash content of all organs. Percent root dry matter and total carbohydrate content dropped linearly as N was increased, whereas canopy dry matter production, root organic N content, petiole nitrate concentration, and leaf area indices exhibited a positive linear response. A quadratic response curve best fitted fresh weight root yields, total root dry matter and carbohydrate production, water use efficiencies, and final plant populations. A modest amount of N (84 kg ha⁻¹) provided maximum yield response in this feral species grown at 405,000 plants ha⁻¹.