Assessing the Pattern of Seed Development and Maturation in Yard Long Bean [Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt]

Abstract

Background: Seed maturation is genetically controlled process involves a sequence of morphological and physiological changes extending from fertilization to total independence from the mother plant. Yard long bean (Vigna unguiculata subsp. sesquipedalis (L) verdcourt) is an important leguminous vegetable crop which meets greater demand of the vegetable especially in South India and some parts of North India. However, information on optimum harvest time of yard long bean seeds are still limited. Hence, this study was carried out to determine the physiological maturity of yard long bean to obtain good quality of seeds for better planting value. Methods: The laboratory experiment was carried out at Department of Seed Science and Technology, Tamil Nadu Agricultural University, Coimbatore, India to determine the appropriate time of harvesting yard long bean cv. Arka Mangala seeds. The crop was raised as bulk in the field during kharif season of 2019 and the pods were harvested at three days interval from 3 days after anthesis (DAA) to 30 DAA and subjected for determinations of pod and seed characteristics. Result: The results revealed that pod length, pod fresh weight and pod dry weight increased rapidly during 3 DAA to 12 DAA and showed maximum pod length (67.7 cm), pod fresh weight (28.56 g/pod) at 12 DAA. The seeds attained physiological maturity at about 24 DAA with 22 per cent moisture content concurred with maximum dry weight (18.80 g/100 seeds), protein content (18.6%) and maximum physiological parameters viz., speed of germination (7.1), germination per cent (94%), root length (23.5 cm), shoot length (20.5 cm), dry matter production (0.949 g/10 seedlings), vigour index I (4136) and vigour index II (89).