Forage and Tuber Yields and Digestibility of Selected Wild and Cultivated Genotypes of Jerusalem Artichoke

Abstract

AbstractJerusalem artichoke (Helianthus tuberosus L.), a perennial forb, has the potential to be utilized as a silage or tuber crop, but little is known about the variability for forage and tuber yields of wild and cultivated genotypes. Four wild and six cultivated genotypes were evaluated for forage and tuber yields, biomass allocation, and in vitro digestible dry matter (IVDDM) concentrations of stems, leaves, tubers, and whole plants (all above‐ground biomass) at different stages of plant development and compared to an annual commercial oilseed sunflower (H. annuus L.) ‘Hybrid 894’. The perennial genotypes were maintained as pure stands while the annual Hybrid 894 was replanted each year. The cultivated Jerusalem artichoke ‘Sunchoke’ had the highest forage yield (6.3 Mg ha−2) which is comparable to some common forage species. The cultivated genotypes also had the highest mean tuber yield (7.19 Mg ha−1). At maturity, the allocation of biomass for Jerusalem artichoke was 68, 23, and 9% for stems, leaves, and heads, respectively. At flowering, the whole‐plant concentration of IVDDM was above the accepted level (598 g kg−1) for adequate animal nutrition for all genotypes except wild ‘Iowa’, wild ‘Texas’, and cultivated Sunchoke. The sunflower Hybrid 894 had higher IVDDM concentrations than the Jerusalem artichoke genotypes. The significant negative correlation between forage yield and IVDDM concentration indicates that these characteristics cannot be simultaneously improved in a breeding program. There appeared to be enough variability to select for increased forage or tuber yields in Jerusalem artichoke.