Effects of water stress on total biomass, tuber yield, harvest index and water use efficiency in Jerusalem artichoke

Abstract

The objectives of this study were to determine the effects of drought on tuber yield, total biomass, harvest index, water use efficiency of tuber yield (WUEt) and water use efficiency of biomass (WUEb), and to evaluate the differential responses of Jerusalem artichoke ( JA) varieties under drought stress. The 3 × 5 factorial combinations of three water regimes (Field capacity (FC), 50% available soil water (50%AW) and 25%AW), and five JA varieties ( JA 60, JA 125, JA 5, JA 89 and HEL 65) were arranged in a pot experiment in a randomized complete block design with four replications for two years. Data were recorded for tuber dry weight, total biomass, harvest index, WUEt and WUEb at harvest. Drought reduced tuber dry weight, total biomass, harvest index, WUEt and WUEb, and reductions were more severe under the severe drought stress of 25%AW. Varieties were significantly different for all traits under drought and well-watered conditions. The JA varieties were classified into three groups. The first category was comprised of the JA 5 variety with high tuber yield potential and low drought tolerance, the second category consisted of JA 60 and JA 125 varieties with low tuber yield potential and high drought tolerance, and the third group included JA 89 and HEL 65 varieties with low tuber yield potential and low drought tolerance. The multiple regression analysis showed that tuber yield, total biomass and harvest index at 50%AW and 25%AW depended largely on the reductions of tuber yield, total biomass and harvest index under drought. Therefore, the results of this study recommend that the selection of JA genotypes with low reduction in yield under drought stress could be a criterion in drought resistance breeding programs for development of JA varieties with high tuber yield under drought stress. JA with drought tolerance in this study means high tuber yield under drought conditions. JA 5 had high yield and WUEt across water regimes and could be used as parental source for drought tolerance breeding programs in further research. The objectives of this study were to determine the effects of drought on tuber yield, total biomass, harvest index, water use efficiency of tuber yield (WUEt) and water use efficiency of biomass (WUEb), and to evaluate the differential responses of Jerusalem artichoke (JA) varieties under drought stress. The 3 × 5 factorial combinations of three water regimes (Field capacity (FC), 50% available soil water (50%AW) and 25%AW), and five JA varieties (JA 60, JA 125, JA 5, JA 89 and HEL 65) were arranged in a pot experiment in a randomized complete block design with four replications for two years. Data were recorded for tuber dry weight, total biomass, harvest index, WUEt and WUEb at harvest. Drought reduced tuber dry weight, total biomass, harvest index, WUEt and WUEb, and reductions were more severe under the severe drought stress of 25%AW. Varieties were significantly different for all traits under drought and well-watered conditions. The JA varieties were classified into three groups....

Root responses of Jerusalem artichoke genotypes to different water regimes

“…The experimental unit consisted of 5 pots requiring a total of 300 pots for each experiment. The varieties JA 60 and JA 125 had low tuber yield, JA 5 had intermediate tuber yield and JA 89 and HEL 65 had high tuber dry weight under drought stress conditions [11].…”

“…Drought reduces productivity of agricultural crops including Jerusalem artichoke [5e10]. Yield loss of 20% under mild water stress has been reported [5,6] and yield loss higher than 90% has been reported under severe drought stress [11]. Although drought problems can be alleviated by irrigation, management of irrigation systems is sometimes difficult in those geographical areas of the world where water resource are not either readily available or too expensive to maintain.…”

“…The selection of Jerusalem artichoke for drought tolerance has primary been based on biomass production and tuber dry weight under drought stress conditions. In tropical regions of the world, JA 5 was reported as a drought tolerant variety with high tuber yield under drought stress conditions [11]. The progress in breeding for drought tolerance varieties has been slow because yield and related traits vary greatly, depending on ecological environmental conditions.…”

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

“…The correlation coefficients between inulin yield and tuber yield (Ruttanaprasert et al, 2016) were positive and significant for all water regimes in 2012 and 2013, ns, ** = nonsignificant and significant at P ≤ 0.001 probability levels, respectively. W1 = 100% AW (FC), W2 = 50% AW, W3 = 25% AW.…”

Incorporating field wind data to improve crop evapotranspiration parameterization in heterogeneous regions

“…We validated this assumption by checking to see if there were any trends in apparent K c during the study and by comparing the ET observations with plant canopy height. While a formal literature value of K c has not been published for Jerusalem artichoke, multiple researchers (Monti et al 2005;Ruttanaprasert et al 2016) have used measured sunflower (Helianthus annuus) K c to parameterize ET due to similar plant morphology between sunflower and Jerusalem artichoke; thus, we use midperiod K cb (K cb = 1.00) to estimate K c (Lamm et al 2010). The STLS tanks are elevated and are surrounded by nonvegetated gravel and concrete, and thus are exposed to the "clothesline" effect, resulting in high ET and K c (Skaggs et al 2006); therefore, we multiplied the literature sunflower K c value by 1.33 following the ratio of observed to the literature alfalfa K c for the STLS observed in early summer (Skaggs et al 2006).…”