Diagrs., illus., tables. Includes bibliographies. Summaries (En, Es, Fr). Title page: Proceedings of a Symposium on Sorghum and Millets for Human Food;

The results are presented separately under the following headings: morphological, physical and chemical characteristics; leaching of nitrate under grain sorghum in a tropical monsoonal climate; and grain sorghum fertilizer requirements under dryland conditions. Representative soils of 3 widely occurring red earth families - Tindall, Blain and Emu - were sudied under the auspices of the National Soil Fertility Project. Grain sorghum (Sorghum bicolor Dekalb E57) was used as the test plant.

Fifteen sorghum (Sorghum bicolor (L.) Moench) lines, representing diverse germplasm currently used in crop breeding programs in the United States, were grown on the seven soils, used in part I of this study, to produce Fe, Zn, and Cu stresses or Al and Mn toxicities in soybeans. All 15 sorghum lines developed Fe and Zn deficiencies with symptoms ranging from some interveinal chlorosis to necrotic and twisted leaf tips. The sorghum lines responded differentially to Cu stress. When Cu was added to the soil, yields increased and P, Fe, and Zn concentration significantly decreased in the plant material. The sorghum lines responded differentially to Al in Bladen soil. Five lines grew poorly and developed a chlorosis with some purple pigmentation; five lines were green and made good growth; and five lines were intermediate in their response. The chlorotic lines contained significantly less Fe and P than the green sorghum. On Richland soil (high Mn), yields were relatively good and the sorghum plants did not develop any persistent toxicity symptoms. Care should be taken to select the sorghum line best adapted to Fe, Zn, or Cu stresses and to Al toxicity so that the plant and the soil may be compatible.

Double-cropping systems involving no-till planting are becoming popular in the southeastern USA, but adequate management practices have not been developed. Therefore, this study was conducted to determine the effects of the following tillage systems. Corn [Zea mays (L.)] and grain sorghum [Sorghum bicolor (L.)] were planted without tillage following winter wheat [Triticum aestirum (L.)] or barley [Hordeum vulgate (L.)] and with conventional tillage following previous summer crop at two locations in Georgia for 4 years with and without irrigation. Corn and grain sorghum yields did not differ significantly for conventional tillage and no-till plantings made on the same date. No-till corn and grain sorghum produced higher yields when early planted (after small grain for forage) than when late planted (after small grain for grain). Irrigation increased conventionally tilled corn yields by 31% (at Experiment) and grain sorghum yields by more than 20%. The smaller increases observed for irrigated early-planted no-till corn and grain sorghum were attributed to a higher soil water content on nonirrigated no-till. Irrigation did not increase yields of late planted no-till corn and grain sorghum due to interfering biological factors.

The effect of soy and cottonseed fortification on the nutritional characteristics, storage stability, flavor and color of sorghum was determined. Protein efficiency ratios were significantly higher in blends of sorghum meal with up to 25% defatted, toasted soy than in blends of sorghum meal with liquid cyclone process cottonseed flour. Lysine was nutritionally limiting in blends containing 15% soy or cottonseed flour. Combinations of sorghum grits, meal and flour with 15% soy grits and flour and cottonseed were stored at 49.degree. C for 2 mo., 37.degree. C for 6 mo. and 25.degree. C for 12 mo. All combinations displayed adequate stability as measured by changes in available lysine, fat acidity and flavor. Flavor comparisons were made between all-sorghum meal and blends containing up to 50% soy or cottonseed flour. The flavor of all blends was acceptable. There were no preferences between all-sorghum meal and blends containing up to 20% soy or 50% cottonseed flour. Color changes were more apparent with additions of cottonseed than soy.