ROT OF SEED POTATO (SOLANUM TUBEROSUM L.) TUBERS AFFECTED BY STORAGE CONDITIONS AND STORAGE DURATION IN JOS, PLATEAU STATE, NIGERIA

Abstract

A study was carried out at the National Root Crops Research Institute (NRCRI), Potato Programme Kuru, Jos Plateau State, Nigeria (Longitude 08oE 47l, Latitude 09oN 441and 1,239 meters above sea level (msl)) during three seasons to investigate ‘the rot of potato (Solanum tuberosum L.) seed tubersas affected by storage conditions and storage duration.’ Five potato varieties (Nicola, Bertita, Diamant, BR63-18 and Roslin Ruaka) were stored for three durations (12, 24 and 32 weeks) in three kinds of stores (room temperature store (RTS), diffused light store (DLS) and air conditioned store (ACS). The experimental design used was completely randomized design in factorial combination of 5 potato varieties forming the main plots, three storage conditions and three storage durations constituting the split plots. There were 45 treatment combinations replicated 3 times. Weekly temperatures and relative humidity were recorded in each type of store.For percentage tuber rot, the result showed that all main effects were significant (P<0.05) except the main effect of variety and store type during season 2. All the varieties had similar percentage tuber rot except the variety Nicola which showed significantly lower tuber rot. RTS and DLS resulted in significantly higher tuber rot than the ACS. Tuber rot (%) was lowest at 24 weeks of storage in all the 3 seasons while 32 weeks of storage resulted in significantly higher rot than the other periods. All interactions were significant in the first cropping season, only the interaction of variety X storage duration was significant in the second cropping season, while inthe third cropping season, all interactions were significant except the interaction of store type X storage duration. For number of whole tubers left after storage, all the main effects and interactions were significant. Variety Nicola resulted in the highest number of whole tubers leftwhile Roslin Ruaka had the lowest tubers left in cropping seasons 1 and 2 and variety Diamant had lowest tubers left in cropping season 3. The number of tubers left decreased with storage period with the lowest number of tubers left after 32 weeks of storage. Tuber storage in ACS resulted in highest number of tubers left while RTS was lowest. The RTS and DLS characterized by higher temperature enhanced rot of tubers while the ACS with lower temperature reduced rot of tubers, it is therefore suggested that for prolong storage (8-9 months), the ACS should be used