Assessment of Maturity over Seasons using Various Indices in Groundnut (Arachis hypogaea L.)

Background: Groundnut is a crop with puzzling nature of maturity. The ability to determine the correct data of harvest in groundnut is strongly affecting factor of the economic return from the crop. Among the different methodologies suggested for calculating the maturity index in groundnut, those which could be used at field level and with ease includes: shell out method, seed hull ratio maturity index, hull scrape method and maturity profile board (MPB) method. The present study was taken up to evaluate the efficiency of these methods in determining the maturity duration. Methods: The maturity indices were calculated in the varieties CO 7, ICGV 07222, VRI 6, VRI 8, GPBD 4, VRI 3, Chico, Gangapuri, ICGV 91114 and ICGV 93468 cultivated during 2018-19, at Tamil Nadu Agricultural University, Coimbatore. Result: In shell out and hull scrape method maturity indices ranging from 70-80% and in Seed hull ratio maturity index the range 2.9-3.6 revealed the highest number of matured pods with maximum weight. The correlation study results showed highest efficacy of hull scrape method in predicting the correct date of harvest in groundnut. The method establishes that the colour of mesocarp exactly reveals maturity status of groundnut pods. Thus, maturity index in groundnut is more reliable when calculated by hull scrape method. In case when the maturity index is below 70% the pods could be arranged on a maturity profile board (MPB) to determine the days until digging.