Physiological ageing of potato seed tubers as affected by storage conditions and storage duration in Plateau State, Nigeria

Abstract

A study was conducted at the National Root Crops Research Institute (NRCRI), Potato Programme Kuru, Jos Plateau State, Nigeria during the 2010-2011 and 2012-2013 to investigate physiological ageing of potato (Solanum tuberosum L.) seed tubers as affected by storage conditions and storage duration in Jos, Plateau state, Nigeria. Five potato cultivars (‘Nicola’, ‘Bertita’, ‘Diamant’, ‘BR63-18’ and ‘Roslin Ruaka’) were stored for three durations (12, 24 and 32 weeks) in three kinds of store (room temperature store (RTS), diffused light store (DLS) and air conditioned store (ACS)). The experimental design was split-split plot in completely randomized design consisting of 5 potato cultivars, 3 storage conditions and 3 storage durations. Weekly temperatures and relative humidity were recorded in each type of store. The number of sprouts formed per tuber, sprout length and weight of whole tubers left after storage varied with cultivar. Storage of seed tubers in the DLS had the highest number of sprouts per tuber, while ACS had the lowest number of sprouts per tuber. Storage of seed tubers in the DLS produced the shortest sprouts. The ACS produced the heaviest whole tubers after storage while RTS and the DLS had similar tuber weight. Sprout length increased with time in storage in both seasons. The shortest sprouts occurred at 12 weeks of storage in both seasons. Tuber weight decreased with time in storage. There were significant interactions between cultivar × store type, cultivar × storage duration and storage duration × store type. Each cultivar had its critical storage temperature conditions for optimal growth and yield after planting. The RTS, characterized by higher temperature which enhanced sprouting, would be suitable for a short period of storage (3 months), while the ACS would be suitable for prolonged storage (8-9 months). DLS reduced the storage temperature appreciably, increased sprout number and suppressed sprout growth thus it could be used for seed tuber storage to control physiological ageing of tubers. The design of the diffused light store needs to be further improved by using cost saving materials.