tion (ET) limit the number of crops grown in this region. Corn (Zea mays L.), sunflower (Helianthus annuus L.), Pearl millet [Pennisetum glaucum (L.) R. Br.] is a drought-tolerant soybean [Glycine max (L.) Merr.], and proso millet crop that may serve as an alternative summer crop in Nebraska. Field (Panicum miliaceum L.) are possible crops for inclusion experiments were conducted in 2000 and 2001 near Sidney and Mead, NE, to determine the water use efficiency (WUE) and yield response in more intensive cropping systems. Grain sorghum was to water supply at critical developmental stages of pearl millet and found to be more suitable than corn, soybean, or sungrain sorghum [Sorghum bicolor (L.) Moench]. Four water regimes flower due to greater and more consistent yields. were used: (i) no irrigation, (ii) single irrigation at boot stage, (iii) Pearl millet, with its short growth cycle and drought single irrigation at mid-grain fill, and (iv) multiple irrigations. Pearl tolerance, may be a better alternative crop than grain millet grain yields were 60 to 80% that of grain sorghum. Average sorghum for western Nebraska and a possible diversifigrain yields at Mead were 5.1 Mg ha Ϫ1 for pearl millet and 6.1 Mg cation crop in eastern Nebraska cropping systems. Plett ha Ϫ1 for grain sorghum. At Sidney, average pearl millet yields were et al. (1991) indicated that pearl millet did not perform 1.9 and 3.9 Mg ha Ϫ1 in 2000 and 2001, respectively, and average grain sorghum yields were 4.1 and 5.0 Mg ha Ϫ1 in 2000 and 2001, respectively. well compared with grain sorghum and corn when grown Both crops used a similar amount of water (336 and 330 mm in 2000 in western Nebraska. However, those hybrids were exand 370 and 374 mm in 2001 for pearl millet and grain sorghum, perimental, and cool night temperatures resulted in respectively) and responded to irrigation with a linear increase in problems with seed set. Progress has been made in pearl grain yield as water use increased. Grain sorghum had greater WUE millet breeding, and hybrids less sensitive to cold night than pearl millet (12.4-13.4 kg vs. 5.1-10.4 kg grain ha Ϫ1 mm Ϫ1 ). Pearl temperatures have been developed. Pearl millet is usumillet, with lower and less stable yields, does not currently have the ally grown as a rainfed crop on sandy soil in the semiarid potential to be a substitute crop for grain sorghum in Nebraska.

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a potential crop for the Great Plains, but there are few studies on production practices. The research objective was to determine the optimal planting time for pearl millet in Nebraska relative to sorghum [Sorghum bicolor (L.) Moench]. This would optimize pearl millet yields, thus increasing the prospect for pearl millet as a crop. Studies were conducted on Sharpsburg silty clay loam (fine, smectitic, mesic, Typic Argiudoll) and Ortello sandy loam (coarse‐loamy, mixed, mesic, Udic Haplustoll) soils between 1995 and 2001. Optimal planting times were determined by relating yields with calendar date, cumulative air heat units, cumulative soil heat units, and soil temperatures. Relative yields related to air or soil heat units were effective in determining the optimal planting time. Optimum pearl millet planting times were 399 air heat units or 410 soil heat units after 1 April for the Sharpsburg soil and 406 soil heat units for the Ortello soil. The optimal sorghum planting time was 308 air heat units or 307 soil heat units after 1 April for the Sharpsburg soil and 402 air heat units after 1 April for the Ortello soil. Both crops had large planting time windows, allowing flexibility in planting time. Sorghum outyielded pearl millet for May and early‐to mid‐June planting times by 0.57 to 2.32 Mg ha−1 while pearl millet had higher yields by 0.95 to 1.20 Mg ha−1 for late June and July planting times. Sorghum produced greater yields than pearl millet for most planting times while pearl millet produced greater yields than sorghum for very late planting times.

Maize (Zea mays L.) yield component analysis is limited. Research was conducted in 2012 and 2013 at Zagreb, Croatia and Mead, Nebraska, United States with the objective to determine the influence of environment, hybrid maturity, and plant population (PP) on maize yield and yield components. Three maturity classes of maize hybrids were produced at five PP ranging from 65,000 to 105,000 plants ha -1 under rainfed conditions. Yield, ears m -2 , rows ear -1 , ear circumference, kernels ear -1 , kernels row -1 , ear length, and kernel weight were determined. Average yield was 10.7 t ha -1 , but was variable for hybrids across PP. The early maturity-hybrids had lesser ear circumference, more kernels ear -1 , greater ear length, and fewer rows ear -1 than mid-and late-maturity hybrids. Kernels ear -1 had the highest correlation with yield (r = 0.47; P < 0.01 for early-maturity hybrids; r = 0.55; P < 0.01 for the mid-and late-maturity hybrids). Path analysis indicated that ears m -2 , kernels ear -1 and kernel weight had similar direct effects on yield for early-maturity hybrids (R = 0.41 to 0.48) while kernels ear -1 had the largest direct effect (R = 0.58 versus 0.32 to 0.36) for the midand late-maturity hybrids. Rows ear -1 had an indirect effects on yield (R = 0.30 to 0.33) for all hybrids, while kernels row -1 had indirect effect (R = 0.46) on yield for mid-and latematurity hybrids. Yield component compensation was different for early-maturity hybrid than the mid-and late-maturity hybrids, likely due to the proportion of southern dent and northern flint germplasm present in these hybrids.

nutrient-poor soil and low rainfall conditions, yet it is capable of rapid and vigorous growth under favorable Pearl millet [Pennisetum glaucum (L.) R. Br.] is a staple grain conditions (Maiti and Bidinger, 1981). Pearl millet is a crop in the arid and semiarid regions of Africa and India, and a new potential alternative grain crop for areas of the Great grain crop in the USA. A 2-year field experiment was conducted near Mead, NE, in 1995 and 1996 on a Sharpsburg silty clay loam (fine, Plains with sandy soil, low rainfall, and a short growing smectitic, mesic Typic Argiudoll) soil with approximately 29 g kg Ϫ1 season since dwarf hybrids with good yield potential organic matter, 35 kg ha Ϫ1 NO 3 -N, and pH of 6.0. The objective was have been developed. A better understanding of pearl to determine the influence of hybrid and N on grain yield, dry matter millet growth and its N concentration and accumulation accumulation and partitioning, and growth rates throughout the growis necessary to improve pearl millet grain yield and ing season. Nitrogen concentrations, uptake, and use efficiency were promote its adoption by farmers in the Great Plains. also determined. Treatments were a factorial combination of the pearl Growth rate is a physiological trait associated with millet dwarf hybrids (59022A ϫ 89-0083, 1011A ϫ 086R, and 1361M ϫ increased grain yield in cereal crops. Growth is generally 6Rm) and N levels (0 and 78 kg ha Ϫ1 ) in a randomized complete a function of environmental factors (such as temperablock design. Two plants per plot were sampled at 2-wk intervals ture and solar radiation) and mineral nutrition, along and partitioned into plant parts, dried, weighed, and analyzed for N concentration. Applied N increased grain yield by 0.4 to 0.5 Mg ha Ϫ1 , with genotype and production practices. General asbut had only a small effect on dry matter accumulation and partipects of growth and development of pearl millet plants tioning. Hybrid differences were small for grain yield. Pearl millet dry were reported by Maiti and Bidinger (1981) and Bramelmatter accumulation increased cubically in both years, with maximum Cox et al. (1984). Dry matter accumulation by pearl crop growth rates among hybrids ranging from 0.48 to 0.57 g m Ϫ2 permillet under different management conditions have growing degree day (GDD) in 1995 and ranging from 1.9 to 3.1 g m Ϫ2 been reported in Africa (Azam-Ali et al., 1984), Austra-GDD Ϫ1 maximum in 1996. The relative growth rate among hybrids lia (Coaldrake and Pearson, 1985), and India (Craufurd declined from 0.012 to 0.020 g Ϫ1 m Ϫ2 GDD Ϫ1 in both years to near and Bidinger, 1989; Carberry et al., 1985). zero at physiological maturity. Nitrogen concentrations were higherMineral nutrition is one of the most important factors during the vegetative stages and decreased with plant age. Applied affecting plant productivity (Clark, 1990), and N is the N decreased N use efficiency for aboveground biomass (NUE 1 ) by 18 to 25 g DM g Ϫ1 N, and N use efficiency for grain (NUE 2 ) by 7 to major nutrient...

Soybean [Glycine max (L.) Merr.] rotation enhances grain sorghum [Sorghum bicolor (L.) Moench] yield, but infl uence on grain quality has not been measured. The objective was to determine the effect of cropping sequence (CS) and soil amendment (SA) on grain yield and quality. Sorghum grain yield and quality, soil NO 3-N and water were measured in a rotation study in 2003 and 2004 on a Sharpsburg silty clay loam (fi ne, smectitic, mesic Typic Argiudoll). Cropping sequences were continuous sorghum, and sorghum rotated with non-nodulating and nodulating soybean. Soil amendments consisted of no amendment, manure (17-26 Mg dry matter ha −1 yr −1), and N (84 kg ha −1 yr −1). CS × SA interaction effects were found for most parameters. Rotation with non-nodulating soybean without SA increased yield by 2.6 to 2.8 Mg ha −1 over continuous sorghum without SA. Rotation without SA with nodulating soybean further increased yield by 1.7 to 1.8 Mg ha −1 over rotation with non-nodulating soybean. Grain N increased by 0.5 to 1.0, 2.5 to 5.0, and 3.3 to 4.9 g kg −1 for N application to continuous sorghum and sorghum rotated with non-nodulating and nodulating soybean, respectively. Tangential abrasive dehulling device (TADD) removal indicated that continuous sorghum without SA produced the softest grain with 43 to 44% TADD removal, and sorghum rotated with nodulating soybean with manure produced the hardest grain with 22 to 27% TADD removal. As food end-use opportunities for sorghum grain evolve, use of crop rotation and SA application will be important to produce grain with desirable quality attributes.