Mr. Samuel Nomo

Potato is the fourth largest consumed crop globally; climate change effects plant phenology by reducing tuber yield and quality. Higher temperatures and long photoperiods orient the sink to source balance in favor of canopy. Gibberellin (GA) is elevated by both conditions delaying tuber initiation and growth. GA effects on potato phenology have been tested as an agricultural practice to control tuber size for intermediate planting size thus ‘Seed tubers’. Additionally the GA inhibitor Paclobutrazol (PBZ) used in agriculture reduces GA levels and tip the balance to tubers. Tuber initiation is early and growth is faster. These finding suggests PBZ as a means to regulate tuber growth in warm climates. In this study we utilize GA3 and PBZ in an agricultural field to probe the effects of GA levels in regulating tuber size and growth rate. Foliar application of GA3 increased seed tubers in previous studies and late PBZ application increases tuber size. We hypothesize that timely application of PBZ to GA3 treated plants will drive early uniform tuber filling for a shorter potato growth cycle. Additionally we aim to understand the molecular workings underlying the action of the tuber forming signal protein Solanum tuberosum SELF PRUNNING 6A (StSP6A).