Spring Safflower Performance under Growth Stage Based Irrigation in the Southern High Plains

Abstract

Water stress is the most important environmental factor limiting crop yield in the southern High Plains. Drought tolerant crops along with deficit irrigation strategies may be promising for sustainable agriculture in the region. The objective of this study was to assess water relations, photosynthesis, yield‐forming components, and yield of spring safflower (Carthamus tinctorius L.) cultivars under growth stage based irrigation management. A blocked split plot design was used with irrigation treatments (fully irrigated [FI], stress at vegetative stage [VS], stress at reproductive stage [RS], and dryland [DL]) as the main plot and cultivars (PI8311, 99OL and Nutrisaff) as subplot in four replications. Measurements of water potential (Ψl) indicated that irrigation treatments imposed water stress on safflower. Safflower responded to stress by regulating stomata and osmotic adjustment. Water stress significantly reduced photosynthesis (Pn), leaf area index (LAI) and light interception in all stress treatments, resulting in decreased biomass accumulation. Seed yield of safflower was strongly related to biomass production (R2 = 0.61). Among yield‐forming traits, heads per plant were more influential in yield formation than seeds per head and 1000‐seed weight. Compared to the FI treatment, RS treatment reduced seed yield by 19 and 20% in 2013 and 2014, respectively; while the same reduction in VS treatment was 25 and 22%, respectively. However, seed yield differences between RS and VS treatments were not statistically significant.

Growth‐Stage‐Based Irrigation Management on Biomass, Yield, and Yield Attributes of Spring Canola in the Southern Great Plains

“…Height of RS plants was not statistically different from that of in in FI plants, whereas the height of VS plants was similar to that of DL plants. Similar observations on plant height in response to water availability have been made in other crops like black bean (Phaseolus vulgaris L.; Nielsen and Nelson, 1998), potato (Solanum tuberosum L.; Yuan et al, 2003), and safflower (Carthamus tinctorius L.; Singh et al, 2016b). In general, plants were taller in 2015 due to greater seasonal rainfall and better growing condition than in 2016.…”

“…All treatment combinations were replicated four times. The ANOVA was performed using the general linear model (GLM) procedure of SAS software (SAS Institute, 2008) with irrigation treatment and cultivar as fixed effects (Singh et al, 2016a(Singh et al, , 2016b. Year and replicate were considered as random effects.…”

“…The objective of this study was to assess biomass partitioning and yield of spring canola (Brassica napus L.) under deficit irrigation. Therefore, understanding the critical growth stage of alternative crop for irrigation will help in developing proper irrigation strategies to maximize return per unit of water (Singh et al, 2016b). Seed yield of VS was similar to FI in both years but was greater by 93 and 200% in 2015 and by 120 and 263% in 2016 than RS and DL, respectively.…”

“…In addition, if more economically important traditional crops require irrigation at any time during the season, irrigation to alternative crops will be skipped. Therefore, understanding the critical growth stage of alternative crop for irrigation will help in developing proper irrigation strategies to maximize return per unit of water (Singh et al, 2016b). Canola refers to the cultivars of Brassica napus L. and Brassica rapa L. (O'Donovan, 1994).…”

Physiological response and productivity of safflower lines under water deficit and rehydration

“…Stress tolerant plants are able to maintain turgor during stress, or survive turgor reduction, or recover turgor completely after rehydration (Gazanchian et al 2007). The maintenance of turgor under low water availability could be due to the osmotic adjustment and could be a drought tolerance mechanism (Singh et al 2016c).…”