Response of Nitrogen and Amino Acid Sources on Development of Alternaria Alternata Causing Root Rot to Fenugreek

During a survey in Maharashtra, it was observed that fenugreek (Trigonella foenum graecum L. ) infected by Alternaria alternata (Fr. ) Keissler, were found to be dominant among the diseased samples. From these samples wild sensitive (Aa-2) and highly resistant (Aa-8) isolates were identified using carbendazim. The aim of present investigation was to evaluate nitrogen, phosphate, sulphate and micronutrients sources on disease development of fenugreek caused by Alternaria alternata. The sensitive and resistant isolates of Alternaria alternata, when grown on Czapek Dox agar medium show different response to nitrogen, and amino acid sources on development of disease on fenugreek. Different nitrogen sources like peptone, ammonium nitrate, potassium nitrate and sodium nitrate were evaluated for growth response which showed variation in results. Six amino acid sources namely, Phenylalanine, Proline, Tryptophan, Leucine, Serine and Histidine were used in this study. There was variation in the growth of the sensitive and resistant isolates on different amino acids. All these amino acids show different action on the growth of sensitive and resistant isolates. There was significant variation, in the growth of development of pathogen, Alternaria alternata, casing disease to fenugreek, either stimulant or inhibitory, when nitrogen and amino acid sources used.