At low temperature, photoperiod does not effect partitioning; however, at higher temperature it significantly Peanut (Arachis hypogaea L.) is a rich source of oil, protein, increases the partitioning of photosynthate to pods unminerals, and vitamins. The chemical and physical seed quality aspects der short days. Genotypes respond to photoperiod ϫ are gaining importance because of increased use of peanut as a food temperature interactions differentially (Nigam et al., crop; however, little or no investigation has been carried out on the effect of photoperiod on these traits. The objective of this study was 1994 and 1998). to determine the effect of photoperiod on seed quality traits. The Chemical composition of seed in soybean [Glycine experiment was conducted for three seasons in a three replicate splitmax (L.) Merr.] is influenced by photoperiod. Pre-flowplot randomized complete block design with three photoperiods ering short-day treatment increases protein, oil, and (ND ϭ Normal day, 12 h; SD ϭ Short day, 8 h; LD ϭ Long day, 16 oleic fatty acid but decreases linolenic fatty acid (Hanh) as main plots and 10 genotypes as subplots. The SD and LD TianFu et al., 1995). When the short-day treatment is conditions were created artificially. Pooled analysis of variance, based imposed post-flowering, it results in higher protein and on a mixed linear model with season (S) as random and photoperiod palmitic and oleic fatty acids but oil and linolenic and (Ph) and genotype (G) as fixed effects, indicated significant S and G linolenic fatty acids are lowered (Han-TianFu et al., differences for most of the traits studied. Ph differences were signifi-1997). There is little information available in the literacant only for shelling percentage and palmitic and eicosenoic fatty acids. The interactions S ϫ Ph, S ϫ G, Ph ϫ G, and S ϫ Ph ϫ G ture on the effect of photoperiod on seed quality traits in were significant for several traits. When SD and LD treatments were peanut. The seed quality aspects are gaining importance compared with ND, shelling percentage increased under SD. Oil conbecause of increased use of peanut as a food crop in tent, oleic (O) and linolenic (L) fatty acids, and O/L ratio were notdeveloping countries. Peanut seed contains 44 to 56% affected due to variation in photoperiod. However, palmitic acid inoil and 22 to 30% protein on a dry seed basis and is a creased and eicosenoic acid decreased under SD. The SD conditions rich source of minerals (phosphorus, calcium, magnewere more interactive with seasons and genotypes for fatty acids. High sium, and potassium) and vitamins (E, K, and B group) performing and photoperiod insensitive genotypes were identified for (Savage and Keenan, 1994). Seed size, shape, color, oil Published in Crop Sci