Effect of harvest date on agronomic and chemical characteristics of Ontario peanuts

A field experiment was conducted in 1980 and 1981, on Fox loamy sand, to study the influence of five successive harvest dates on the agronomic and chemical characteristics of peanuts (Arachis hypogaea L.) grown in Ontario. A spanish type (cv. Comet) and a valencia type (cv. McRan) were examined. Delaying harvest increased yield, sound mature kernels, seed-hull ratio, oil content and the economic return. Crude protein tended to be higher in the immature peanuts but the iodine number and oil stability showed larger differences between cultivars than among harvest dates. Cultivar differences were also apparent for the fatty acids, and more mature peanuts tended to be higher in oleic acid and lower in palmitic, behenic and lignoceric acids.Key words: Peanuts, valencia, spanish, harvest dates, yield, maturity, quality