Peanut or Groundnut (Arachis hypogaea L) is among the major leguminous crops grown in the world. Its maturity period varies in the maximum percentage of mature fruits at harvest (Young and Mason, 1972). However, the subterranean nature of fruiting and its indeterminate growth habit makes it difficult to determine when to harvest to ensure optimum yield (Jordan et al., 2005; Jordan, 2006a). Thus, most farmers link change in morphological features of the plant: yellowing of foliage, dropping of older leaves, hard pods, visible net venation, seed color etc. to determine maturity of pods. However, both biotic and abiotic factors could result in change in morphological features of a plant without necessarily being an indication of maturity. This book contains an in-depth field and pot experiments conducted over two growing seasons on three classes of groundnut varieties (runner, semi-runner and bunch). The explicit literature review, research methodology, statistical result, discussions and recommendations in this book would be of great help to researchers, teachers, farmers, students and those with interest in Agriculture and farmer based organizations (FBO).