Fertilization and nutrient management trials in peanut

Peanut response to fertilization with manganese, boron, and calcium, was evaluated in 2016 as a continuation of research from past years. Various sources of calcium were evaluated alone or as supplemental treatments. Manganese studies included control, Ag-Mn (Mn sulfate, 30% Mn, 15% S) at 0.25 and 0.5 lb Mn/a, and Mn+Micro Mix (Mn chelate, 10% Mn, 1.65% B, and <1 % Co, Fe, Mo, Zn) at 0.05, 0.25, 0.50 lb Mn/a. Lack of differences among treatments in yield, grade, and leaf Mn, as well as lack of visual Mn deficiency symptoms suggests that the peanuts were not limited by Mn under any treatment. It is likely that the soil (pH 6 to 6.5) provides adequate Mn for peanuts. Boron studies included control, Borosol-10 (boric acid), Solubor (sodium borate), and Boron Xtra (Custom Ag Formulations, Fresno, CA). Borosol-10 was applied at 1, and 2 times the recommended rate (X) at early bloom, as well as split applications of IX and 2X at early bloom and mid-bloom. Yield and grade did not respond to B applications, but leaf and seed B did. Overall, Solubor 2x and Borosol-10 2x (split or single application) were able to supply the most B to the plant. Calcium studies included control, gypsum (1000 lb/a), lime (1000 lb/a), Black Gypsum ( 1000 lb/a; The Andersons, Inc., Maumee, OH) and Full Measure Cal (3 gal/a; Full Measure LLC, Bristol, RI). No differences in yield and grade were observed among the products. However, Black gypsum provided significantly more Ca to the seed ( 540 mg Ca/kg) than the control ( 440 mg Ca/kg) indicating that this treatment has value for providing Ca to the nut. Full measure was comparable to the control.