One-third (35–40%) of the overall yield improvement could be attributed to the G component and two-thirds to interaction between the M factor by the environment (E) component (Duvick, 1999; Unger and Baumhardt, 1999; Assefa and Staggenborg, 2010). Similar yield gains were also documented by Miller and Kebede (1984). (2008) documented a slower rate of yield improvement in sorghum relative to maize (Zea mays L.). Yield and yield components of grain sorghum as influenced by row width and stand density. Overall, sorghum yield improvement seemed to be primarily achieved by gains under environmental stress and low yielding environments rather than by modifications or improvements on maximum yield potential (Assefa and Staggenborg, 2010). doi: 10.2134/agronj1973.00021962006500050009x Cross Ref Full Text | Google Scholar Stickler, F.
Moench) improvement has been related to targeted modifications in genotype (G component) and management practices (M component), such as (a) fertilization rates, (b) irrigation, and (c) tillage practices (Eghball and Power, 1995; Duvick, 1999; Assefa and Staggenborg, 2010).
A long-term study conducted in Texas (1939–1997) documented yield improvements were mainly related to the introduction of new sorghum hybrids, water conditions at planting, better weed (herbicide) control and conservation practices such as zero tillage (Unger and Baumhardt, 1999). doi: 10.2134/agronj1965.00021962005700060015x Cross Ref Full Text | Google Scholar Stone, L.
The E factor (e.g., water and temperature) exerts a large influence; thus, endpoint sorghum productivity may be considered the outcome of a complex G × E × M interaction. Utilization of previously accumulated and concurrently absorbed nitrogen during reproductive growth in maize.
From a plant nutrition perspective, nitrogen (N) is the main nutrient influencing plant growth, aboveground biomass, and yield (Roy and Wright, 1973; Kamoshita et al., 1998; Borrell and Hammer, 2000; Wortmann et al., 2007; van Oosterom et al., 2010; Kaizzi et al., 2012; Mahama et al., 2014).
The main objective of this original research paper is to document and understand sorghum NUE and physiological mechanisms related to grain N dynamics.
The study of different grain N sources, herein defined as the reproductive-stage shoot N remobilization (Remobilized N), reproductive-stage whole-plant N content (Reproductive N), and vegetative-stage whole-plant N content (Vegetative N), was pursued with the goal of synthesizing scientific literature for sorghum [Sorghum bicolor (L.) Moench] crop. For modern sorghum hybrids, N application improved yields via modification of aboveground biomass, seed number, and grain HI (Mahama et al., 2014). Improvement of NUE (yield to available N ratio) can be understood via dissecting NUE into two components: N recovery efficiency (NRE, plant N uptake to soil N supply) and (NIE, yield to plant N uptake ratio) (Ciampitti and Vyn, 2012). Sorghum, one of the world's top five cereal crops is an important food and nutrition source as climate changes.Sorghum is one of the single most efficient crops in water use and solar energy conversion.For more details, read the article in Hudson Alpha Institute for Biotechnology website or download the open access paper in BMC Genomics.Unraveling the complexity underpinning nitrogen (N) use efficiency (NUE) can be physiologically approached via examining grain N sources and N internal efficiency (NIE) (yield to plant N content ratio). The research paper published in BMC Genomics notes that changes in sugar transport mechanisms could reveal the genetic pathways that lead to sugar remaining in the stalk of sweet sorghum, rather than moving to the seed.In the world's changing climate, important food crops are key to securing nutrition. Understanding the mechanisms that help this plant store sugar in its stalk will help develop more productive varieties.For the main stem, leaf area increases until full expansion of the flag leaf occurs; a waxy bloom often covered leaf sheath and stem organs. Changes in area, yield gains, and yield stability of sorghum in major sorghum-producing countries, 1970 to 2009. Grains are developed in the head organ (in the uppermost section of the plant) after flowering time.