Table 1.
Previous recommendations on irrigation termination periods for cotton based on different field experiments.
| [Reference] Location and experiment period | Climatic condition | Soil types | Irrigation system | Planting period | Results/Recommendation |
|---|---|---|---|---|---|
| 24 Texas A & M AgriLife Research, Lubbock, Texas (1996–1999) | Semi-arid | Olton clay loam | Low energy precision application | Early May to end of May | Irrigation termination suggested at cumulative daily heat units (from crop emergence) of 890 °C in high (7.6 mm d-1), and 1000 °C in low (2.5 mm d-1) and medium (5.1 mm d-1) irrigation level treatments |
| 27 28 cotton fields in states of Arkansas, Louisiana, Mississippi, Missouri, and Texas (2000–2007) | Sub-tropical | Silty loam; Sandy loam; Clay; Silty clay | Furrow irrigation | Mid-April to end of May | Optimal irrigation termination recommended at 192 GDD after physiological cutout |
| 28 San Joaquin Valley, California (1954–1968) | Semi-arid | Hesperia fine sandy loam; Panoche clay loam | Furrow irrigation | Early April (early May in 1967) | Final irrigation should be given much earlier on a high water-retaining soil (Panoche clay loam) than on a low water-retaining soil (Hesperia fine sandy loam) |
| 29 27 furrow-irrigated and 43 pivot-irrigated fields, Arkansas (2005–2012) | Sub-tropical | Heterogenous soils | Furrow and pivot irrigation | End of April to early May | Optimal irrigation termination recommended at 350 GDD after physiological cutout. Irrigation termination recommended approximately 8 days before in furrow irrigated fields as compared to pivot irrigated fields |
| 32 19 cotton fields in states of Arkansas, Louisiana, Mississippi, and Missouri (2000–2004) | Sub-tropical | Silty loam; Sandy loam; Silty clay | Furrow irrigation | Mid-April to end of May | Optimal irrigation termination recommended at 336 GDD after physiological cutout |
| 33 St. Lawrence, Texas (2003) | Semi-arid | Not reported | Sub-surface drip irrigation | Mid May | Optimal irrigation termination recommended at 300—400 Growing Degree Days (GDD) after physiological cutout |
| 34 Oklahoma State University, Oklahoma (2015–2017) | Sub-humid | Hollister silty clay loam | Open canal | Late May to early June | Increase in cotton yield reported when irrigation termination periods moved from mid- to end- August |
| 35 University of Arizona, Tucson, Arizona (2000–2002) | Arid/semi-arid | Casa Grande sandy loam; Indio clay loam | Furrow irrigation | End of March to mid-April | Significant increase in yield reported with later (late September) irrigation termination |
| 36 Southern High Plains, Texas (1984–1987) | Semi-arid | Sandy loam | Sprinkler irrigation | Mid May to early June | Terminating irrigation at first open boll limited vegetative growth and led to higher yields |
| 37 Punjab Agricultural University, India (2000–2003) | Tropical, Semi-arid | Sandy loam | Surface flooding | Early April to early May | A significant increase in cotton yield was reported with later irrigation termination |
| 38 Texas Tech University, Lubbock, Texas (2010–2011) | Semi-arid | Not reported | Sub-surface drip irrigation | Early to late May | Early irrigation termination was found desirable in a dry year for saving water for future use |
| 39 Bekaa Valley, Lebanon (2001–2002) | Mediterranean | Clay | Drip irrigation | Early to mid-May | Terminating irrigation at first open boll resulted in higher cotton yield as compared to later irrigation termination |