Seeding Practices, Cultivar Maturity, and Irrigation Effects on Simulated Grain Sorghum Yield

Abstract

Grain sorghum [Sorghum bicolor (L.) Moench] is adapted for use in dryland and irrigated cropping systems on the southern High Plains. Irrigation in this region relies on the declining Ogallala aquifer, and applications are transitioning from full to deficit evapotranspiration replacement. Our objective was to identify optimum planting date, population, row spacing, and cultivar maturity combinations to maximize grain sorghum yield using the SORKAM model and long-term weather records at Bushland, TX, for a Pullman soil (fine, mixed, superactive, thermic Torrertic Paleustoll) with reduced irrigation. Grain sorghum growth and yield was simulated under dryland and deficit-or full-irrigation conditions (rain 1 irrigation 5 2.5 or 5.0 mm d 21 ) for all combinations of planting date (15 May, 5 June, 25 June), cultivar maturity (early, 95 d; medium, 105 d; late, 120 d), population (12 and 16 plants m 22 ), and row spacing (0.38 and 0.76 m). Simulated grain yield was unaffected by planting population but increased 7% for narrow compared with wide row spacing independent of other treatment effects. Results suggest two alternative management practices to optimize yield for the southern High Plains depending on potential irrigation capacity: (i) where rain plus supplemental irrigation was ,0.2.5 mm d 21 , plant early-maturing cultivars during June and (ii) where rain plus supplemental irrigation approaches 5.0 mm d 21 , plant late-maturing cultivars on 15 May. Earlymaturity cultivars planted on 5 June were better adapted to dryland and deficit irrigation for optimum grain yield on a southern High Plains Pullman soil.

Interferência De Plantas Daninhas Em Sorgo Sacarino Em Diferentes Espaçamentos No Semiárido Mineiro

“…Além disso, a escolha do espaçamento entre linhas de semeadura e o número de plantas por área mais adequado são de extrema importância por determinarem melhor aproveitamento de fatores abióticos como água, luz e nutrientes para que a cultura possa expressar todo o seu potencial (Albuquerque et al, 2012). Para o sorgo forrageiro e o sorgo granífero, alguns autores reportaram a importância do arranjo de plantas na obtenção de maiores rendimentos (Baumhardt & Howell, 2006;Jones & Johnson, 1997 …”

Grain Sorghum Response to Water Supply and Environment

“…No-till and greater residue management can lead to considerably less evaporation which can increase profits (Klocke et al, 2009). Under simulation, grain sorghum on average produces a 7 percent greater yield when row spacing is half of that of traditional 0.76 m row spacing (Baumhardt and Howell, 2006). Simulated grain sorghum yields also showed that to maximize yield for the whole field, it is better to increase irrigation on parts of the field and have complementary dryland areas than to limit irrigate the entire field (Baumhardt et al, 2007).…”

“…Grain sorghum responds to better conditions and adequate rainfall by increasing tillers per plant thus increasing panicles per area (Baumhardt and Howell, 2006). When drought stress impacts the plant between panicle initiation and flowering time, number of seeds set could be greatly reduced, but if the stress occurred after flowering, then the seed weight could be potentially impacted (Baumhardt and Howell, 2006).…”

“…( Baumhardt and Howell, 2006). Resulting from this, a question arises on how to spread out water resources when there is a limit with how much water that can be used to irrigate with.…”

“…A simulator can be helpful in deciding the best fit for different scenarios to determine different options of mixing crops so irrigation water can be allocated (Klocke et al, 2012b) and to understand how different management practices can impact grain yields (Baumhardt and Howell, 2006). No-till and greater residue management can lead to considerably less evaporation which can increase profits (Klocke et al, 2009).…”