Single superphosphate depresses molybdenum uptake and limits yield response to phosphorus in groundnut (Arachis hypogaea L.) grown on an acid sandy soil in Niger,West Africa

The effect of phosphorus (P) fertilization on dry matter production and nitrogen (N) uptake of groundnut (Arachis hypogaea L.) was studied during the growing seasons of 1989, 1990 and 1991 under rainfed conditions on an acid sandy soil in Niger, West Africa. Annual application of 16 kg P ha^–1 as single superphosphate (SSP) failed to increase the total dry matter production significantly in all three years.Fertilization with SSP increased the concentrations of P and sulfur (S) in shoots from deficiency to sufficiency levels. It decreased the already very low concentrations of molybdenum (Mo), especially in the nodules, and also the N concentration in the shoot dry matter.With SSP application, total N uptake declined over three years. Foliar application of P and soil application of triple superphosphate (TSP) enhanced dry matter production, N and Mo uptake.Although these acid sandy soils are known to be deficient in P and S, care must be taken in using SSP in groundnuts as it may induce Mo deficiency, unless supplementary Mo is applied.ICRISAT Journal Article No. 1230     

A novel compound, 12,13,17-trihydroxy-9(Z)-Octadecenoic acid,from linoleic acid by a new microbial isolateClavibacter sp. ALA2

A novel compound, 12,13,17-trihydroxy-9(Z)-octadecenoic acid (THOA), was produced from linoleic acid by microbial transformation at 25% yield. The newly isolated microbial strain that catalyzed this transformation was identified asClavibacter sp. ALA2. The product was purified by high-pressure liquid chromatography, and its structure was determined by¹H and¹³C nuclear magnetic resonance, Fourier transform infrared, and mass spectroscopy. Maximum production of THOA was reached after 85 h of reaction. THOA was not further metabolized by strain ALA2. This is the first report on 12,13,17-trihydroxy unsaturated fatty acid and its production by microbial transformation.