Sorghum

Abstract: Worldwide, nitrogen use efficiency (NUE) for cereal production (wheat, Triticum aestivum L.; corn, Zea mays L.; rice, Oryza sativa L. and O. glaberrima Steud.; barley, Hordeum vulgare L.; sorghum, Sorghum bicolor (L.) Moench; millet, Pennisetum glaucum (L.) R. Br.; oat, Avena sativa L.; and rye, Secale cereale L.) is approximately 33%. The unaccounted 67% represents a $15.9 billion annual loss of N fertilizer (assuming fertilizer-soil equilibrium). Loss of fertilizer N results from gaseous plant emission, soil denitrification, surface runoff, volatilization, and leaching. Increased cereal NUE is unlikely, unless a systems approach is implemented that uses varieties with high harvest index, incorporated NH₄-N fertilizer, application of prescribed rates consistent with in-field variability using sensor-based systems within production fields, low N rates applied at flowering, and forage production systems. Furthermore, increased cereal NUE must accompany increased yields needed to feed a growing world population that has yet to benefit from the promise of N₂-fixing cereal crops. The Consultative Group on International Agricultural Research (CGIAR) linked with advanced research programs at universities and research institutes is uniquely positioned to refine fertilizer N use in the world via the extension of improved NUE hybrids and cultivars and management practices in both the developed and developing world. Contribution from the Okla. Agric. Exp. Stn.

Abstract: The phylogenetic relationships of the genus Sorghum and related genera were studied by sequencing the nuclear ribosomal DNA (rDNA) internal transcribed spacer region (ITS). DNA was extracted from 15 Sorghum accessions, including one accession from each of the sections Chaetosorghum and Heterosorghum, four accessions from Parasorghum, two accessions from Stiposorghum, and seven representatives from three species of the section Sorghum (one accession from each of S. propinquum and S. halepense, and five races of S. bicolor). The maize (Zea mays) line, H95, and an accession from Cleistachne sorghoides were also included in the study. Variable nucleotides were used to construct a strict consensus phylogenetic tree. The analyses indicate that S. propinquum, S. halepense and S. bicolor subsp. arundinaceum race aethiopicum may be the closest wild relatives of cultivated sorghum; Sorghum nitidum may be the closest 2n=10 relative to S. bicolor, the sections Chaetosorghum and Heterosorghum appear closely related to each other and more closely related to the section Sorghum than Parasorghum; and the section Parasorghum is not monophyletic. The results also indicate that the genus Sorghum is a very ancient and diverse group.

Abstract: Climate change is a serious threat to crop productivity in regions that are already food insecure. We assessed the projected impacts of climate change on the yield of eight major crops in Africa and South Asia using a systematic review and meta-analysis of data in 52 original publications from an initial screen of 1144 studies. Here we show that the projected mean change in yield of all crops is 8% by the 2050s in both regions. Across Africa, mean yield changes of 17% (wheat), 5% (maize), 15% (sorghum) and 10% (millet) and across South Asia of 16% (maize) and 11% (sorghum) were estimated. No mean change in yield was detected for rice. The limited number of studies identified for cassava, sugarcane and yams precluded any opportunity to conduct a meta-analysis for these crops. Variation about the projected mean yield change for all crops was smaller in studies that used an ensemble of >3 climate (GCM) models. Conversely, complex simulation studies that used biophysical crop models showed the greatest variation in mean yield changes. Evidence of crop yield impact in Africa and South Asia is robust for wheat, maize, sorghum and millet, and either inconclusive, absent or contradictory for rice, cassava and sugarcane.

Abstract: Preface. Contributors. ORIGIN AND HISTORY. Origins of Domesticated Sorghum and Its Early Diffusion to India and China (C. Kimber). Classification and Characterization of Sorghum (J. Dahlberg). Development of Some Agricultural Industries in Several African and Asian Countries (L. House, et al.). History of Cultivar Development in the United States: From "Memoirs of A. B. Maunder--Sorghum Breeder" (C. Smith & R. Frederiksen). THE SORGHUM PLANT. Physiology and Genetics of Maturity and Height (P. Morgan & S. Finlayson). Genetics and Cytogenetics (W. Rooney). Collection, Conversion, and Utilization of Sorghum (D. Rosenow & J. Dahlberg). Techniques in Developing New Cultivars (W. Rooney & C. Smith). New Horizons in Biotechnology (P. Subudhi & H. Nguyen). PRODUCTION AND PRODUCTION HAZARDS. Sorghum Production Statistics (C. Smith). Integrated Crop Management for Sorghum (J. Cothren, et al.). Insect Pests of Sorghum (G. Teetes & B. Pendleton). Diseases and Disease Management in Sorghum (R. Frederiksen). Weeds and Their Control in Grain Sorghum (P. Stahlman & G. Wicks). Marketing (T. Lust, et al.). PROCESSING AND PRODUCTS. Structure and Chemistry of the Sorghum Caryopsis (R. Waniska & L. Rooney). Sorghum Food and Industrial Utilization (L. Rooney & R. Waniska). Value of Sorghum and Sorghum Coproducts in Diets for Livestock (J. Hancock). Fermentated Products: Beverages and Porridges (J. Taylor & J. Dewar). Forages and Fodder (J. Pedersen & J. Fritz). Index.