Abstract Most peanut (Arachis hypogaea L.) fields of the Southern Coastal Plain are treated with either vernolate (S-propyl dipropylthiocarbamate) or benefin (N-butyl-N-ethyl-a,a,a-trifluoro-2, 6-dinitro-p-toluidine) or a combination of these two herbicides to control certain weeds. The nematicide DBCP (1,2-dibromo-3-chloropropane) is also used in some fields. Field and greenhouse experiments were conducted to determine the effect of vernolate, benefin, DBCP, and Rhizobium sp. on nodulation, yield, quality, and chemical composition of ‘Starr’ peanuts. The application of herbicides, nematicide, and inoculant had no significant effect on yield, sound mature kernels, or ether extract of ‘Starr’ peanuts. The N content of the leaf and seed and the number of nodules were not affected by the treatments. Nematode infestation was low and did not affect yield. In the greenhouse studies, the application of lime, herbicides, or fertilizer did not affect certain morphological characteristics of the plant or N content of the peanut leaves. Nitrogen fertilization increased the weight of the peanut foliage.

AbstractThe differential response of peanut (Arachis hypogaea L.) cultivars to soil applications of Ca has been established for many years. Recent research reports, however, have indicated that peanut cultivars respond similarly to Ca application. This may result in part from new peanut cultivars differing in their response to Ca. Experiments were therefore conducted on a low Ca soil to measure responses of three commonly grown peanut cultivars to soil‐applied Ca.Gypsum was applied at 0 and 1,121 kg/ha in a split‐plot design using ‘Florunner,’ ‘Florigiant,’ and ‘NC‐Fla 14’ peanut cultivars. Other nutrients were applied uniformly. Yield, sound mature kernels (SMK), extra large kernels (ELK), and % N and oil in the seed were measured.Results from this experiment show that gypsum had no effect on yield or sound mature kernels of Florunner peanuts. Florunner peanuts produced higher yields and grades than Florigiant or NC‐Fla 14, regardless of treatments. Gypsum application to Florigiant and NC‐Fla 14 peanuts increased yields, sound mature kernels, and extra large kernels. In general, gypsum increased the % oil in all cultivars. Florigiant contained less oil than the other cultivars. Nitrogen content of the seed of all cultivars was reduced by gypsum application. These data indicate that on low Ca soils Florunner peanuts can produce higher yields and quality with or without gypsum, while Florigiant and NC‐Fla 14 need gypsum fertilization to increase yield and improve quality.

Abstract Due to conflicting results of previous studies, experiments were conducted to study the effect of rate and time of application of N on the yield of fruit and on seed grade, percent N and oil content of Spanish peanuts (Arachis hypogaea L.). Rates and times of application of N had no significant effect on yield, grade or percent N in seed of Starr peanuts grown on three different soil types. Application of 134.4 kg of N/ha to Fuquay soil 6 weeks after planting decreased oil content in the seed. When the same rate of N was split into two applications (1/2 at planting and 1/2 at 6 weeks), the oil content was significantly higher than when all the N was applied 6 weeks after planting. On Tifton soil, split applications of N (1/2 at 6 weeks and 1/2 at 12 weeks) tend to reduce the oil content of seeds as the N rates increased. The 134.4 kg/ha rate of N applied by this method produced a significantly lower oil content than where all the N was applied at planting or 6 weeks after planting.