Seasonal Nitrogen Fixation and Dry Matter Accumulation by Peanuts1

Abstract

AbstractYield improvement of peanut (Arachis hypogaea L.) is partially dependent on N nutrition. The differential ability of peanut cultivars to fix N symbiotically and best utilize this N supply are traits that may be useful in plant breeding. Four peanut cultivars representing Spanish and Virginia subspecies var. vulgaris and var. hypogaea, respectively, were grown for 1 year on a sandy soil to determine seasonal patterns of nodulation, acetylene reduction, and N accumulation in pods, leaves, and stems. The two Virginia cultivars ‘Florunner’ and ‘Florigiant’ accumulated more N in vegetative organs than the Spanish cultivars ‘Tamnut 74’ and ‘Starr’. The Virginia cultivar also maintained a higher percentage N in the leaves throughout the season than did the Spanish cultivars. The Virginia cultivar tended to accumulate N in fruit at a faster rate than the Spanish cultivars. Nodule mass on the Virginia cultivars was more than 50% greater than on the Spanish cultivars at midseason. Acetylene reduction was also substantially higher for the Virginia cultivars at midseason. Conclusions are restricted because severe insect damage to plants terminated the experiment approximately 3 weeks before the normal harvest date. The result suggest that the Virginia cultivars have greater N fixing capability than Spanish cultivars.