RAVINDRA BABU, PJAGGA RAO, ITRAJULA2018-05-082018-05-082016http://krishikosh.egranth.ac.in/handle/1/5810044928D5298A potculture experiment was conducted in Agricultural College, Bapatla, Andhra Pradesh to study the‘Influence of organic acids in amelioration of iron (Fe) chlorosis in groundnut (Arachis hypogaea L.)" during kharif season of 2015- 16. The experimental soil was calcareous (collected from Vertisol profile), alkaline in reaction, low in organic carbon, available nitrogen, medium in available phosphorus and high in available potassium. All the micronutrients except iron were sufficient in the soil with values above their critical limits. The treatments comprised of control (T1); FeSO4.7H2O @ 0.25% (T2); citric acid @ 0.25% (T3); acetic acid @ 0.25% (T4); oxalic acid @ 0.125% (T5); ascorbic acid @ 0.25% (T6); hydroxyl amine hydrochloride (T7) were replicated thrice in completely randomized design (CRD) with three replications. Foliar application of organic acids were applied to the respective pots immediately after noticing the iron chlorosis, peg penetration and pod formation stage of the crop growth. Entire phosphorus was applied as basal dose in the form of single super phosphate, nitrogen and potassium were applied in 3 and 2 splits, respectively in the form of urea and muriate of potash as per the recommended dose of fertilizer. The influence of various treatments on iron chlorosis, soil properties and growth and yield of groundnut were determined by standard procedures at different growth stages. Among the treatments imposed organic acids treated pots resulted in significantly lower pH at different stages of the crop growth. The treatments imposed had no significant effect on EC, soil organic carbon and CEC, but slight increment was noticed in organic acids treated pots over control. Foliar application of organic acids showed non significant difference in N, P, K and significantly increased the S and Fe contents in soil. Availability of N, K nutrients was maximum in treatments treated with ascorbic acid @ 0.25%, P was higher in treatments received oxalic acid @ 0.125% and S, Fe contents in soil were higher in treatment supplied with FeSO4.7H2O @ 0.25% were found significantly superior to rest of the treatments. Foliar application of organic acids showed not significant influence on the soil enzyme activity. urease, acid, alkaline phosphatase and dehydrogenase activities were higher in organic acids received treatments than that of control. Foliar application of organic acids favoured the growth, yield and its attributes, was recorded highest in treatment that received with FeSO4.7H2O @ 0.25% besides increase in the content of N and K in plant was observed in treatment supplied with ascorbic acid @ 0.25%, but highest P content was observed in oxalic acid @ 0.125% treated pots. The results further showed that S, Fe, and chlorophyll ‘a’ & ‘b’ contents was higher in the treatment that received FeSO4.7H2O @ 0.25% and significantly superior to rest of the treatments. Uptake of N, P, K, S and Fe was found to be higher in FeSO4.7H2O @ 0.25% (T2) imposed treatment, which was at par and followed by treatment supplied with citric acid @ 0.25% (T3), significantly superior to control.en-USnullThesis