Responses of growth, physiological traits and tuber yield in Helianthus tuberosus to seasonal variations under tropical area

•Seasonal variation was the main effect on growth, physiological traits and tuber yield.•Tuber yield and tuber growth rate was the highest in the post-rainy season.•Biomass and crop growth rate was the highest in the early-rainy season.•Low temperature and short photoperiod was a favorable condition for tuber development.•High temperature and long photoperiod induced vegetative growth but decreased tuber initiation.

Seasonal variations affect growth and yield of a crop, primarily by changing its phenological developmental processes. The objective of the present study was to evaluate seasonal variation effects on growth and development of Jerusalem artichoke. The experiment was conducted during the early-rainy seasons in June-September 2011 and the post-rainy seasons in September-December in 2011, and two seasons were repeated in 2012 at the Field Crop Research Station of Khon Kaen University. A randomize complete block design (RCBD) with 5 replications was used. Four Jerusalem genotypes including JA 89, HEL 65, CN 52867 and KT 50-4 were used. Results indicated similar phenological development between the early and post rainy-seasons. However, high temperature combined with long photoperiod during the early-rainy seasons delayed tuber initiation and extended maturity. Low temperature and short photoperiod was a favorable condition for tuber development but reduced vegetative and reproductive development. On average, tuber dry weights and tuber growth rate were higher in the post-rainy season compared to the early-rainy season. On the other hand, biomass and crop growth rates were higher in the early-rainy seasons compared to the post-rainy seasons. The knowledge obtained in this study is important for Jerusalem artichoke production and selection of Jerusalem artichoke genotypes in the tropical climate.