Texas High Plains Research Articles

Three Women Artists: Expanding Abstract Expressionism in the American West by Amy Von Lintel and Bonnie Roos

Reviewed by: Three Women Artists: Expanding Abstract Expressionism in the American West by Amy Von Lintel and Bonnie Roos Randolph K. Tibbits Three Women Artists: Expanding Abstract Expressionism in the American West. By Amy Von Lintel and Bonnie Roos. (College Station: Texas A&M University Press, 2022. Pp. 341. Illustrations, appendix, notes, bibliography, index.) From the late 1950s onward, Abstract Expressionism (Ab-Ex), which reigned supreme in the New York art world at mid-century but had begun to fade there, found renewed life and a new home in a seemingly unlikely location: the Texas Panhandle and surrounding areas. This development occurred thanks to a symbiotic partnership between a "closeted gay man" (2) and a number of New York City-based Ab-Ex artists, mostly women, who were underappreciated in the big city. That is one of the bold propositions advanced by the authors of this interesting and beautiful new book. [End Page 599] The Three Women Artists of the title, painter Elaine de Kooning, mosaic artist Jeanne Reynal, and sculptor Louise Nevelson, were not unknown in their lifetimes, but they have become the subjects of increased interest and regard in recent years as scholars and the viewing public have taken a closer look at the art and careers of women artists throughout history. Amarillo gallerist, teacher, and art promoter Dord Fitz, the closeted gay man, is little known, even to those who have an active interest in the art history of Texas. One of the valuable contributions of the book is its deft presentation of a rich and provocative story of "decentered" modernism, as the authors call it (2), in which important contemporary American art was as vital on the High Plains of Texas as in the sometimes myopic New York art world, with both places giving as well as taking as far the art itself was concerned. Fitz, an Oklahoman who had to reinvent himself after being fired from a plum academic job at the University of Kentucky following a 1951 arrest on morals charges, returned with his wife and children to Bannister Ranch in the western part of the state. He applied his experience in art and education to teaching art classes in northwest Oklahoma and surrounding areas of Kansas and Texas, fostering a patron base on which he could build when he opened his art gallery in Amarillo, and began showing and promoting avant-garde New York art. Through annual trips to New York, he established relationships with the artists he wished to show. He found De Kooning, Reynal, and Nevelson particularly responsive because he offered them the prospect of an appreciative public, and additional income from art sales and teaching, on a more gender-level playing field than they faced in New York, where male artists received significantly more attention. The authors assert that Fitz and the women artists who became his gallery stars meshed in part because of their shared experiences navigating gender and sexuality hurdles as they operated in male- and hetero-dominated environments. This is another of the refreshingly exciting threads of the story the book tells, one only recently being addressed in either Texas history or art history. Clearly Fitz thrived based on his connections to the New Yorkers, but the artists, and their art, profited too. All three spent time in Amarillo, where Fitz made sure they had the Texas experience. But in addition to entertaining visits, all three, especially De Kooning, who is quoted as saying, "I love Texas" (21), sold art, found new influences for their work, and developed mutually beneficial relationships with local patrons and students. This in a place that stereotypes often cast as indifferent, even hostile, to such things as abstract art. Von Lintel has already done a masterful job of showing how the Texas experience helped shape the art of the preeminent American Modernist, Georgia O'Keeffe. With this new volume, she and co-author Roos have made an equally important contribution to broadening our understanding [End Page 600] of Texas as both receptive home and active contributor to American art of this later era. Randolph K. Tibbits Houston Earlier Texas Art Group Copyright © 2022 The Texas State Historical Association

Evaluation of growth-stage-based variable deficit irrigation strategies for cotton production in the Texas High Plains

Evaluation of growth-stage-based variable deficit irrigation strategies for cotton production in the Texas High Plains

Impact Of Remote Pulmonary Artery Pressure Monitoring Program In A Rural Texas High Plains Region Population: A Nursing Perspective

Impact Of Remote Pulmonary Artery Pressure Monitoring Program In A Rural Texas High Plains Region Population: A Nursing Perspective

Exploring the Impact of Winter Storm Uri on Power Outage, Air Quality, and Water Systems in Texas, USA

Texas was hit by a record-setting cold snap from the 14–17 February 2021 after three decades that resulted in power outages, disruption of the public water systems, and other cascading effects. This study investigates the unprecedented impact of winter storm Uri on power outages, air quality, and water systems in Texas, USA. Analysis of the Parameter Regression of Independent Slopes Model (PRISM) gridded climate data showed that the average daily freezing temperature range was 0–−19 °C on 14 February 2021, with severe levels (−17–−19 °C) occurring in the Texas High Plains. Our results showed that the extreme freezing temperature persisted from 14–17 February 2021, significantly affecting power operation and reliability, and creating power outages across Texas. Uri impacted the public water systems and air quality on time scales ranging from a few minutes to several days, resulting in 322 boiling notices. The air quality index level exceeded the standard limit by 51.7%, 61.7%, 50.8%, and 60% in Dallas–Fort Worth, Houston–Galveston, Austin, and Lubbock regions. The level of the pollutants exceeded the EPA NAAQS standard allowable limits during winter storm Uri. In general, this study gives information on the government’s future preparedness, policies, communication, and response to storm impacts on vulnerable regions and communities.

Root distribution, soil water depletion, and water productivity of sweet corn under deficit irrigation and biochar application

Root modifications can play a vital role in crop adjustments to soil water deficit. It is important to understand root growth and soil water depletion patterns to develop effective cropping systems, especially in semi-arid regions like Texas High Plains (THP). This study evaluated root growth, soil water depletion, and water productivity (WP) of sweet corn under three deficit irrigation treatments [100 %, 70 % and 40 % crop evapotranspiration (ETc)] and biochar application (hardwood and softwood). The experimental units were replicated 4 times in a split-plot design. The results revealed no interaction between irrigation and biochar treatments for almost all measured parameters. The 70 % ETc treatment increased the root length density (RLD) over 100 % ETc during 2019, while no differences were observed among irrigation treatments in 2020. Both deficit irrigations (70 % and 40 % ETc) increased soil water depletion compared to 100 % ETc, the highest being in 40 % ETc. The 70 % ETc maintained a similar yield and increased WP by 21 % compared to 100 % ETc across two years. However, 40 % ETc resulted in significant decline in yield and WP in 2020. The hardwood biochar increased RLD over no biochar treatment without affecting the soil water status and WP. Long-term studies are needed to investigate biochar effects beyond two years of application. In case of limited water availability, 70 % ETc can be recommended as an alternative to 100 % ETc in the THP of the US.

Soil Potassium Effects on Cotton Lint Yield and Fiber Quality on the Texas High Plains

When comparing soil potassium (K) levels common in West Texas to the current Mehlich III-K critical levels for cotton (Gossypium hirsutum L.), fertilizer K applications are seldom recommended. However, when soil K is applied, positive responses in cotton yield have been reported. Studies were conducted in Lamesa and New Deal, TX to: 1) determine K effects on leaf K concentrations; 2) evaluate whether K application increases crop growth, yield, and fiber quality in sufficient K soils; and 3) evaluate whether K application under water deficit conditions also increases growth, yield, and fiber quality. In Lamesa, muriate of potash (KCl) was applied using two methods, knife-injected (0-0-15) and broadcast (0-0-60); and at New Deal, KCl was applied using knife injection. Potassium application rates included 0, 45, 90, 135, and 180 kg ha-1 with both high (90% ET) and low (30% ET) irrigation levels. At Lamesa in 2016 at 90% ET irrigation, lint yield was greater when 90 kg K ha-1 was broadcast (2,153 kg ha-1 lint) compared to the 180 kg K ha-1 treatment, and all K treatments with 30% ET irrigation. There were no lint yield differences in 2017 at Lamesa. At New Deal, lint yield was similar amongst all K application rates in both years. Although K application increased yield with the 90% ET irrigation level with broadcast application, no differences were observed in water-deficit cotton suggesting further research is needed to better understand the dynamics of K on lint yield in semiarid cotton production systems.

Late-Season Decline: A New Bacterial Disease of Corn Identified in the Texas Panhandle

The genus Pantoea has historically been associated with two diseases of corn, Stewart's wilt caused by P. stewartii and necrotic or white leaf spots or streaks and stalk rot caused by P. ananatis. In 2020 and 2021, a sudden and unusual decline of corn stands was observed in corn fields in two counties in the Texas High Plains region. Symptoms observed included initial light green, elongated, slightly translucent, and nonchlorotic streaked lesions with nonwavy margins that developed on leaf blades during corn vegetative growth stages, with lesions becoming necrotic at the onset of crop reproduction. Additionally, stunting of affected plants, poor ear development, and stalk rot were associated with affected stands. Diagnosis of symptomatic tissues consistently recovered bacteria. BLAST searches of the partial 16S rRNA sequences of the bacterial isolates identified them as belonging to the genus Pantoea. Investigations of the pathogenicity of two bacterial isolates, B566 and B623, under greenhouse conditions relying on Koch's postulates resulted in the development of symptoms identical to those observed on symptomatic field corn plants. The two bacteria were also successfully recovered from symptomatic leaf and stem tissues, thus satisfying Koch's postulates. Sequence analysis showed that these isolates are closely related to P. ananatis but also phylogenetically distinct. The findings from this study provide evidence for a new disease of corn caused by two Pantoea species that can result in stand decline of infected corn plants.

Drought tolerant maize hybrids have higher yields and lower water use under drought conditions at a regional scale

Drought is an enduring abiotic constraint to stable and consistent maize productivity under climate change, especially for low rainfall regions with limited irrigation. One adaptation for severe drought is using drought-tolerant (DT) hybrids. Here, we characterize differences between conventional and DT hybrids in terms of yield and water-use efficiency under drought conditions at a regional scale of the Texas High Plains (THP). Using a validated version of APSIM-Maize, we simulated yields of conventional and DT hybrids across 11 water regimes and 25 counties in THP from 1984 to 2018. When irrigation amounts were constrained to 90%, 80%, 70%, 60% and 50% of total irrigation used for the baseline scenario (BS; a simulated scenario of conventional hybrid under full irrigation), DT hybrids showed lower yield penalties under drought stress relative to conventional hybrids. This improved total production by 19%, 24%, 26%, 26%, and 21% for each of the above irrigation levels. When the yield-target was set as 90%, 80%, 70%, and 60% of BS, total regional irrigation applied to DT hybrid could be saved more than that to the conventional hybrid, and therefore reduced more 17%, 16%, 15%, and 15% of BS irrigation, respectively. We showed that DT hybrids had greater yield gain and water savings through improved water productivity under deficit irrigation, highlighting the potential of deficit irrigation for increasing yield for the adoption of DT hybrid. Our quantitative evaluation of the yield advantage and water saving potential associated with DT hybrids also highlighted the regional benefits associated with adoption of drought adaptive hybrids.

HPPD-resistant cotton response and weed management systems using isoxaflutole

AbstractThe southern United States produces 90% of the nation’s cotton, and the Texas High Plains is the largest contiguous cotton producing region. Since 2011, glyphosate-resistant Palmer amaranth has complicated cotton production, and alternatives to glyphosate are needed. Integrating soil residual herbicides into a weed management program is a crucial step to control glyphosate resistant weeds before emergence. The recent development of p-hydroxyphenylpyruvate dioxygenase (HPPD)-resistant cotton by BASF Corporation may allow growers to use isoxaflutole in future weed management programs. In 2019 and 2020, field experiments were conducted in New Deal, Lubbock, and Halfway, Texas, to evaluate HPPD-resistant cotton response to isoxaflutole applied preemergence (PRE) or early postemergence (EPOST) and to determine the efficacy of isoxaflutole when used as part of a season-long weed management program. At the New Deal location, cotton response was observed following the EPOST application, but it never exceeded 10%. Cotton response was greatest following the PRE application in Lubbock in 2019 but did not exceed 14%. In 2020 in Lubbock, cotton was replanted due to severe weather. There was <1% cotton response following the PRE application, and maximum cotton response observed was 9% following EPOST and mid-postemergence (MPOST) applications. Cotton lint yields were not different from those of the nontreated, weed-free control at either location. In non-crop weed control studies in Halfway, all treatments controlled Palmer amaranth ≥94% 21 d after the EPOST application. Twenty-one days after the MPOST treatment, systems with isoxaflutole applied EPOST controlled Palmer amaranth by 88% to 93%, while systems with isoxaflutole PRE controlled Palmer amaranth by 94% to 98%. End-of-season Palmer amaranth control was lowest in the system without isoxaflutole (88%) and when isoxaflutole was used EPOST (88% to 91%). These studies suggest that the use of isoxaflutole in cotton weed management systems may improve season-long control of several troublesome weeds with no adverse effects on cotton yield and quality.

Planting Date and Hybrid Affect Sugarcane Aphid Infestation, Yield, and Water Use Efficiency in Dryland Grain Sorghum

Grain sorghum (Sorghum bicolor L.) is a major dryland crop in the Texas High Plains. Currently, drought and infestation by the sugarcane aphid (SCA, Melanaphis sacchari) are the two major challenges to grain sorghum production in the area. A 2-year field study was conducted to investigate the effect of planting date (PD) and hybrid selection on yield, evapotranspiration (ET), water use efficiency (WUE), and SCA infestation. Five sorghum hybrids (86P20, SP-31A15, AG1201, AG1203, and DKS37-07) were grown on two planting dates (PD1—early May; PD2—late June) under dryland conditions. Insecticides were not used. There were significant differences in grain yield, WUE, evapotranspiration (ET), and SCA population between two PDs and among hybrids. For PD1, SCA infestation occurred after sorghum reached physiological maturity in 2017. Although SCA infestation was observed during late grain filling in 2018, SCA populations were low and did not affect yield. For PD2, SCA was present before anthesis in both years and significantly affected grain yield. Even with heavy SCA infestation in PD2, the grain yield was higher in PD2 than in PD1 due to timely precipitation. Among hybrids, AG1203, 86P20 and DK37-07 performed better with higher yield and less SCA infestation in PD2. Grain yield was more related to seeds per plant than to kernel weight and harvest index.

Soil water extractable organic matter under long‐term dryland cropping systems on the Texas High Plains

AbstractWater extractable organic matter (WEOM) is critical for soil fertility because of its role as a readily available C substrate for microbial metabolism. In the semi‐arid Texas High Plains, dryland cropping systems are common because of limited precipitation and irrigation water. Little is known about the long‐term effects of dryland cropping on soil WEOM content and composition, and how these differ from native grassland. The objective of this study was to use soils collected near Amarillo, TX, in 1977 and 2013 to examine the long‐term (72 yr total cropping length) effects of dryland cropping systems [continuous wheat and wheat–fallow rotations] and tillage methods (disk plow, stubble‐mulch tillage, and delayed stubble‐mulch tillage) on WEOM characteristics, compared with native grassland. In cropped plots, water‐extractable organic carbon (WEOC) concentrations, a measure of WEOM content, were depleted regardless of tillage or crop, with reductions up to 13% in 1977 and 60% in 2013, compared with native grassland in 2013. Other parameters of WEOM changed over time, where cropped soils from 2013 had proportionally more WEOM in aromatic, phenolic, and lignin‐like forms, attributed to recently incorporated crop residues. In contrast, WEOM in cropped soils from 1977 and native grassland (2013) contained more functional groups (e.g., aliphatic, aromatic, polysaccharide, phenol, etc.) and humic‐like substances than cropped soils in 2013. This suggests that long‐term dryland cropping led to depletion of stable, humic‐like WEOM. Enhancement of WEOM stocks and long‐term sustainability in the Texas High Plains may require more vigorous conservation systems than currently used.

Trends in Lesser Prairie-Chicken Habitat Extent and Distribution on the Southern High Plains

The lesser prairie-chicken (Tympanuchus pallidicinctus) is a species of prairie grouse that occupies grassland ecosystems in the Southern and Central High Plains of the Great Plains. Reduced abundance and occupied ranges have led to increased conservation efforts throughout the species’ range. Habitat loss is considered the predominant cause of these declines. In the Southern High Plains of Texas and New Mexico, lesser prairie-chicken habitat corresponds to the Sand Shinnery Oak Prairie Ecoregion, which is comprised of a mixture of sand shinnery oak (Quercus havardii)-dominated grasslands, sand sagebrush (Artemisia filifolia)-dominated grasslands, and mixed grasslands. In sand shinnery oak–grassland communities, conversion to row-crop agriculture, continuous unmanaged livestock grazing, restriction of natural fire, invasive plant species (e.g., mesquite (Prosopis spp.)), extensive use of herbicides, energy development, and a variety of other factors have also negatively affected ecosystem extent and function. We integrated historical maps and remote sensing-derived information to measure trends in the extent and geographical distribution of sand shinnery oak prairies in eastern New Mexico and northwest Texas. Potential lesser prairie-chicken habitat was reduced by 56% from a potential of 43,258 km2 to 18,908 km2 in ~115 years (since pre-settlement). Our assessment indicated both mixed grasslands and sand shinnery oak-dominated grasslands were transformed from large parcels of existing vegetation communities to urban settlements, row crops, roads, and industrial land uses by the 1970s. Currently, potential habitat is highly fragmented and restricted to isolated locations in Texas and New Mexico, with an increasing dominance in mixed grasslands, especially in the southeastern portion of the lesser prairie-chicken range. Sand shinnery oak-dominated grasslands have been declining rapidly, from 69% of its potential extent in 1985, 65% in 1995, 54% in 2005, to 42% in 2015. Mixed grasslands drastically declined to 50% of its potential distribution by 1985. Since then, it has been stable until the 2005–2015 period when it declined to 45% of its potential extent. Based on the 2015 assessment, the current potential habitat for lesser prairie-chicken is estimated at 18,908 km2 (1,890,800 ha or 4.6 million acres), where 13,126 km2 corresponds to mixed grasslands and 5782 km2 corresponds to sand shinnery oak-dominated grasslands.

Irrigation water demand and elasticities: a case study of the High Plains aquifer

The agriculture of the Texas High Plains (THP) region is primarily dependent on groundwater irrigation. Changing weather patterns along with competing demands for water resources and other anthropogenic effects have dramatically increased withdrawals from the Ogallala aquifer. In addition to on-farm changes, policy tools based on off-farm mechanisms are equally indispensable in addressing sustainable groundwater use in the THP. One such policy tool is water pricing using estimates of price elasticity of irrigation water demand. This paper estimates the elasticity of irrigation water demand in the THP and assesses the influence of water price on major inputs used in dominant irrigated crops such as corn and cotton. Using the translog profit function on an annual county-level dataset of THP crop production, spanning 23 years (1998–2020), we find that irrigation water demand is price elastic for cotton (η = – 1.58) but inelastic for corn (η = – 0.81). Our findings suggest that a non-uniform pricing policy could be a useful tool to promote the efficient use of groundwater for irrigation.

Peanut Cultivar Response to Diclosulam in the Southwest Peanut Growing Region

Field experiments were conducted in the south Texas and Texas High Plains area during the 2018 through 2020 growing seasons and in southwestern Oklahoma in 2020 to evaluate runner peanut cultivars (Georgia-13M, Georgia-09B) and the Spanish cultivar (Ole´) tolerance to diclosulam at 0.026 (the manufacture’s recommended use rate) and 0.052 (twice the manufacture’s recommended use rate) kg ai/ha applied preemergence (PRE) or peanut cracking (CRACK). No diclosulam injury was noted in south Texas; however, in the Texas High Plains and Oklahoma locations significant stunting was noted with diclosulam applied PRE especially under sprinkler irrigation. In 2018 at the High Plains location, under furrow irrigation, no peanut stunting was noted. In 2019 and 2020, under sprinkler irrigation, diclosulam at 0.026 and 0.052 kg/ha applied PRE resulted in early-season stunting of 18 to 59% in both Oklahoma and the Texas High Plains. No late-season stunting was noted in Oklahoma; however, up to 20% stunting was still visible at the Texas High Plains location. No yield differences were noted in south Texas or the High Plains region in 2018 or 2020; however, in 2019 at the High Plains location, peanut yield decreased as diclosulam rate increased but application timing had no effect. At the Oklahoma location, application timing and rate effect were noted. Diclosulam applied PRE and the high rate of diclosulam reduced peanut yield. Issues still exist with diclosulam in the southwest peanut growing areas as seen previously in 2000 despite the different varieties planted. There may be opportunities to utilize diclosulam postemergence (POST) since peanut injury was 5% or less and yields were not reduced when applied CRACK.

Imagining Skyscrapers in a Wheat Field: Regionalism and Cold War Development in the Texas High Plains

Imagining Skyscrapers in a Wheat Field: Regionalism and Cold War Development in the Texas High Plains

Soil Water Dynamics and Cotton Production Following Cover Crop Use in a Semi-Arid Ecoregion

Conservation management practices such as no-tillage and cover crops can decrease soil’s susceptibility to wind erosion, but adoption of these practices has been limited on the Texas High Plains (THP) where producers are concerned with cover crop water usage. The objective of this study was to evaluate the impact of no-tillage and cover crops on cotton (Gossypium hirsutum L.) lint yield and soil water content in a deficit irrigated cropping system. Soil water was observed bi-weekly in long-term, continuous cotton systems established in 1998 that included (1) conventional tillage, winter fallow, (2) no-tillage with rye (Secale cereale L.) cover, and (3) no-tillage with mixed species cover located in Lamesa, TX, USA. Results include observations from 2018–2020 (years 21–23 of the study period). The adoption of conservation practices did not significantly reduce cotton lint yield compared to conventionally tilled, winter fallow cotton. Soil water was initially depleted with cover crops but was greater throughout the growing season following cover crop termination. Throughout the soil profile, water depletion and recharge were more dynamic with conservation practices compared to the conventionally tilled control. There were no differences in cotton water use efficiency between treatments. Results from this study indicate cover crop water usage is likely not the cause of cotton lint yield decline in this deficit irrigated semi-arid production system.

Registration of ‘CA 4014’ and ‘CA 4015’ cotton cultivars

AbstractOrganic cotton (Gossypium hirsutum L.) production in the United States is steadily growing because of increased consumer demand, market premium prices, and regulatory shifts. As organic production expands in the United States, adventitious presence of genetically engineered (GE) traits caused by either pollen‐ or seed‐mediated gene flow from nonorganically grown sources of cotton raises concerns about maintenance of purity requirements, either when marketing cotton or producing planting seed. Adapted cultivars with simply inherited, codominant leaf shape (okra‐leaf) distinct from commercial GE cotton cultivars represent an alternative strategy for maintaining purity through visual roguing, instead of expensive molecular testing. The Texas A&M AgriLife Research cotton breeding program in Lubbock, TX, developed two okra‐leaf cultivars adapted to organic production in the Texas High Plains. Cotton accession (CA) is the designation used for material developed in the Lubbock program. Cultivars ‘CA 4014’ (Reg. no. CV‐147, PI 699625) and ‘CA 4015’ (Reg. no. CV‐146, PI 699626) derived from 2014 crosses, individual plant selection followed by modified bulk selection, and 3 yr of replicated performance testing. CA 4014 and CA 4015 have similar yield and fiber quality to the cultivars currently used in Texas organic cotton production, with the advantage of a distinct and uniform morphological marker (okra‐leaf) that enables the identification and elimination, in the field, of off‐types.

Simulation of Spatiotemporal Variations in Cotton Lint Yield in the Texas High Plains

This study aimed to simulate the spatiotemporal variation in cotton (Gossypium hirsutum L.) growth and lint yield using a remote sensing-integrated crop model (RSCM) for cotton. The developed modeling scheme incorporated proximal sensing data and satellite imagery. We formulated this model and evaluated its accuracy using field datasets obtained in Lamesa in 1999, Halfway in 2002 and 2004, and Lubbock in 2003–2005 in the Texas High Plains in the USA. We found that RSCM cotton could reproduce the cotton leaf area index and lint yield across different locations and irrigation systems with a statistically significant degree of accuracy. RSCM cotton was also used to simulate cotton lint yield for the field circles in Halfway. The RSCM system could accurately reproduce the spatiotemporal variations in cotton lint yield when integrated with satellite images. From the results of this study, we predict that the proposed crop-modeling approach will be applicable for the practical monitoring of cotton growth and productivity by farmers. Furthermore, a user can operate the modeling system with minimal input data, owing to the integration of proximal and remote sensing information.

Response of maize hybrids under limited irrigation capacities: Yield and yield components

AbstractGrain yield of maize (Zea mays L.) in the semiarid Texas High Plains (THP) is greatly reduced when irrigation cannot meet peak water requirements. Drought‐tolerant hybrids may mitigate yield losses resulting from water deficits. We examined the effect of irrigation capacity (8.47 and 4.23 mm d–1) and planting rates (74,000 and 95,000 seeds ha–1) during three growing seasons (2016–2018) on grain yield and yield components of three maize hybrids, two of which were considered drought tolerant. Crop water deficits at the low irrigation level usually extended temporally from seventh leaf collar to dough stage. Mean grain yields varied from 5.2 Mg ha–1 under the low irrigation level to 19.9 Mg ha–1 at the high irrigation level. Hybrid did not influence grain yield and aboveground biomass in all 3 yr. Although kernel number and kernel mass were significantly influenced by hybrid across all years, this did not result in grain yield differences because greater kernel mass compensated for reduced kernel number. Harvest index did not significantly differ between conventional and drought‐tolerant hybrids. In 2016, grain yield was significantly influenced by plant density only at the low irrigation level, with 44% greater yields at the low plant density. For the patterns and level of water stress observed during these three growing seasons, the three hybrids performed similarly. Besides using hybrids well adapted to the region, mitigation of yield reductions under limited irrigation capacities in the THP can be achieved by concentrating irrigation on less land area and optimizing planting rates.

Response of maize hybrids under limited irrigation capacities: Crop water use

AbstractMaize (Zea mays L.) production in the semiarid Texas High Plains (THP) often suffers exceptional yield reductions when irrigation cannot meet seasonal and peak water requirements. Drought‐tolerant hybrids may reduce yield losses resulting from water stress by altering seasonal soil water use patterns to permit greater uptake during yield‐sensitive growth stages. We examined the effect of irrigation capacity (8.47 and 4.23 mm d−1) and planting rates (74,000 and 95,000 seeds ha−1) during three growing seasons (2016–2018) on water use of three maize hybrids, two of which were considered drought tolerant. Changes in stored soil water were examined for the entire profile and for segregated depth increments (0–0.4, 0.4–0.8, and 0.8–1.4 m). Seasonal crop evapotranspiration averaged 754 and 592 mm across years for the high and low irrigation capacities, respectively. Irrigation level significantly affected seasonal change in stored soil water in 1 yr (2018) with greater depletion at harvest under the low irrigation capacity. Soil water use at 0.8–1.4 m comprised <4% of seasonal water use. Hybrids did not differ with respect to growing season crop water use. Stored soil water throughout the growing season within the examined depth increments were similar among hybrids and plant densities, with significant differences occurring infrequently and being inconsistent across years. Drought‐tolerant traits may have a diminished effect on transpiration in this study because of the dense soil‐limiting root proliferation or the high atmospheric demand at the study location.