Yield, Protein, and Remobilization of Water Soluble Carbohydrate and Nitrogen of Three Spring Wheat Cultivars as Influenced by Nitrogen Input

Abstract

Plant breeders have attempted to use extended green leaf duration (EGLD) traits for spring wheat (Triticum aestivum L.) yield improvement in Montana. The objective of this study was to investigate the yield, protein, harvest index (HI), remobilization of water‐soluble carbohydrate (WSCRM) and nitrogen (NRM), N uptake, nitrogen harvest index (NHI) and nitrogen recovery in grains (NRG) of two spring wheat cultivars with EGLD (Vida and Reeder) and one without the traits (Outlook) as influenced by N input rates at dryland and irrigated environments. Vida, selected from a cross between Reeder and Scholar, exhibited a greater grain yield but lower protein content compared with Reeder and Outlook; this yield advantage likely resulted from higher HI, as well as greater postanthesis biomass (PABM) accumulation of Vida under irrigation. The yield advantage was greater at the irrigated site (23%) than at dryland (7–12%). The average contribution of WSCRM to grain yield (WSCCGY) was 8 and 12%, and NRM to grain N (NRCGN) was 67 and 60% at the dryland and irrigated site, respectively. No evidence showed Reeder and Vida had a greater WSCCGY or NRCGN than Outlook. The WSCRM and NRM were influenced by N input rates. Lower grain protein contents in Vida than in Reeder and Outlook was attributed to higher N contents in the straw and greater biomass yields of Vida even though Vida took up more N from soil. High N application rates reduced the NHI and NRG for all cultivars at both dryland and irrigated environments.

A Split Application Approach to Nitrogen and Growth Regulator Management for Perennial Ryegrass Seed Production

“…The positive yield response as a result of the single standard NAM in Exp. Biomass production generally increases and HI generally decreases with greater N availability in perennial ryegrass as was observed in our study and is often observed in small grain crops (Table 3 and 5) (Chen et al, 2011;Cookson et al, 2000). Thousand seed weight (TSW) as affected by the interaction between growth regulator program (GRP) and N application method (NAM).…”

“…2 2009 and 2010 final RCI readings, respectively) suggesting that early harvest season N availability was less critical for obtaining a seed yield response and that split N applications may be more appropriate when a fall N application has been made. Biomass production generally increases and HI generally decreases with greater N availability in perennial ryegrass as was observed in our study and is often observed in small grain crops (Table 3 and 5) (Chen et al, 2011;Cookson et al, 2000). The effect of NAM on biomass and HI in our study may have been caused by differences in N availability during periods of vigorous vegetative growth however the effects were drastically different in each year, probably due to weather, plant growth patterns, and timing of N application.…”

Photosynthesis and Leaf Senescence as Determinants of Plant Productivity

“…Chen et al 2011;Chen et al 2010;Spano et al 2003; and review by Gregersen et al 2013). In some cases, this is accompanied by reductions in nitrogen remobilisation efficiency (Chen et al 2010(Chen et al , 2011Spano et al 2003) and low harvest index (Gong et al 2005). These findings illustrate some of the constraints imposed by the growth environment that can limit the productivity of a crop, making it difficult in practice to exploit any potential benefits offered by delayed senescence.…”

“…There is however an increasing number of reports demonstrating that cultivars with delayed senescence ('staygreen' phenotypes) characteristics, particularly in wheat, are functional stay-green plants having increased yields (e.g. Chen et al 2011;Chen et al 2010;Spano et al 2003; and review by Gregersen et al 2013). In some cases, this is accompanied by reductions in nitrogen remobilisation efficiency (Chen et al 2010(Chen et al , 2011Spano et al 2003) and low harvest index (Gong et al 2005).…”

“…As discussed above, it is possible to delay senescence in stay-green phenotypes and to increase yield accordingly. However, delaying senescence is often achieved at the expense of nitrogen remobilisation and hence stay-green cultivars can exhibit relatively low grain protein contents (Chen et al 2011). The functionality of the photosynthetic apparatus must stay high even during the phase of dismantling and degradation of the different chloroplast components as illustrated in Fig.…”