Effects of water regimes on inulin content and inulin yield of Jerusalem artichoke genotypes with different levels of drought tolerance

Abstract

Drought is a recurring problem of Jerusalem artichoke (Helianthus tuberosus L.) production under rainfed conditions. A better understanding of the responses of Jerusalem artichoke genotypes to drought can lead to the improvement of inulin content and inulin yield in Jerusalem artichoke and its production planning. The objective of this study was to compare the responses of five Jerusalem artichoke genotypes (JA60, JA125, JA5, JA89, and HEL65) to three water regimes (100% available water (AW; field capacity), 50% AW, and 25% AW) for inulin content and inulin yield. The experimental results showed that water regimes and Jerusalem artichoke genotypes were significantly different for inulin content and inulin yield. The interactions between Jerusalem artichoke genotypes and water regimes were also significant for inulin content and inulin yield. Under field capacity level, the results from the experimental years (2012 and 2013) showed that JA125, JA5, JA60, and HEL65 had the highest inulin content. Under 50% and 25% AW, JA5 and HEL65 had high inulin content, while JA5 had the highest inulin yield. The results indicated that if irrigation is available, JA5 should be planted because of its high inulin content under well-irrigated conditions. However, JA5, JA125, and JA60 are highly recommended under rainfed conditions because of their high inulin content under drought conditions. The results were limited to a pot experiment, and further field experiments are still required.