Cropping Systems


The Team:
Daniel I. Leskovar, Vegetable Physiology, AgriLife Research –Uvalde
Tom Cothren, Crop Physiology, Soils and Crops Department-TAMU
Xuejun Dong, Crop Ecophysiology, AgriLife Research-Uvalde
Nithya Rajan, Crop Physiology, Soils and Crops Department-TAMU
Kevin Crosby, Vegetable Breeder, Department Horticultural Sciences-TAMU
Thomas Marek, Irrigation Engineer, AgriLife Research-Amarillo
Wenwei Xu, Corn Breeder, AgriLife Research-Lubbock
Qingwu Xue, Crop Stress Physiology, Texas A&M AgriLife Research-Amarillo

Impacts

Water savings

  • Studies with new drought tolerant corn hybrids at 3 irrigation levels (100%, 75% and 50% ET) in the north Texas High Plains indicated that it is possible to maintain 200 bu/ac of yield at irrigation level of 75% ET requirement with some new hybrids. This irrigation level can allow irrigation water savings over 20% or 5 inches.
  • In the north Texas Panhandle, saving 1 inch/ac/year of irrigation for the regional corn acreage would result in a total water savings of nearly 40,000 ac-ft or 13 billion gallons. The overall economic return will be easily multiplied adding the savings in pumping and other production costs.
  • Deficit irrigation applied in the Wintergarden conditions can save 37% irrigation water in melons with a moderate reduction in yield, but not in fruit quality.
  • Water use efficiency was improved by 13% under deficit irrigation in specialty melons.
  • Water savings in leafy greens grown in hydroponic production system was >90% as compared to overhead (LEPA) and subsurface drip irrigation.

Farmer benefits – Crop strategies

  • Hormonal (ABA) application during early development in pepper and melons improves drought tolerance, quality and marketability of vegetable transplants, benefiting growers and commercial nurseries.
  • Application of white plastic mulch reduced drought and heat stress on all the pepper genotypes and resulted in superior quality fruits compared to bare soil or black plastic mulch.
  • The test on 15 winter wheat varieties showed that the top popular ‘Fannin’ tended to have low yield in dryland conditions in the Uvalde area, compared with ‘Cedar’ and ‘TAM 112’.
  • Applying a mixture of beneficial soil bacteria amendment (Ag1000) can improve leaf water use efficiency and root growth in corn under pivot irrigation.
  • High biomass sorghum could be an attractive crop in the Texas High Plains since it can achieve high yields (up to 8 t/ac) under limited irrigation and up to 6 t/ac under dryland conditions with about 8-in seasonal rainfall.
  • New low-stature TAMU corn is currently replacing 2% of the 26,348 acres of irrigated yellow corn (gross value $22.7 million at 150 bu/acre and $5.75/bu) grown in the District 10 alone (Wintergarden region).

TAMU genetics – Crop performance

  • New TAMU experimental hybrid green chile increased yields by 80-120% compared to commercial open-pollinated cultivars at Amarillo and Uvalde.
  • Using the mini-rhizotron measurement system, we observed that the compact low-stature corn hybrid developed at AgriLife Lubbock by the plant breeder Wenwei Xu grew larger roots compared with two other hybrids of taller stature. Also in this year’s test, smut infection almost always occurred on a tall statured corn hybrid. This has important implications for future water savings in corn growing areas.
  • Developing drought tolerant and water use efficiency (WUE) wheat in the US Southern Great Plains will help growers maximize their yields under water-limited conditions. The research is providing breeders and geneticists selection tools to manage and improve crop performance.
  • The newer cultivars TAM 111 and TAM 112 used soil water more efficiently than a relative older cultivar, TAM 105. A complementary greenhouse study provided a better understanding of the differences in physiological mechanisms to respond to drought between TAM 111 and TAM 112.

Morphological and physiological trait responses under water deficit

  • Studying the rhizosphere microbial community structure and related root traits can provide significant insights for underlying mechanisms of improved water use efficiency.
  • Leaf area, leaf number and leaf-level photosynthetic rates were identified as important traits for screening melon germplasm in water deficit conditions.
  • The greenhouse root trait study with 22 pepper genotypes showed that cultivar NM 6-4 had the highest root length, surface area and root volume.
  • Photosynthesis and gas exchange of cultivars JAL USAP 0825 and Serrano Alcon were significantly higher than other cultivars. A 37% reduction in stomatal conductance and 18% reduction in photosynthesis were found in the 50% ET treatment.
  • Strong linear relationships between canopy temperature (IRT measurements) and photosynthetic activity as well as canopy temperature and final yield across years were found in cotton, especially for plots subjected to some water availability limitation during the season (dryland conditions).
  • For cotton, canopy temperature seems to be a better predictor of photosynthetic activity and yield when the crop is under some drought stress.
  • Field phenotyping evaluations in the High Plains showed that cooler canopies contributed to higher yield in new drought tolerant cultivars, and that spectral reflectance data can be used to characterize genotypic variation in wheat genotypes.

Disclosures, Patent Applications, and Licensing Agreements:

  • Released new heat tolerant, virus resistant tomato- ‘TAM Hot-Ty’
  • Disclosure of new virus-resistant processing tomato for south Texas canning industry

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