Dicamba effects on fruiting in sensitive cotton

Abstract Since the release of dicamba-tolerant cotton in 2016, preplant and POST applications of dicamba to control glyphosate-resistant Palmer amaranth have increased. With the increase in area treated with dicamba, the risk of off-target movement to nontarget crops has increased. A field study was conducted at the Texas Tech University New Deal Research Farm equipped with subsurface drip irrigation in 2017 and 2018 to evaluate non-dicamba tolerant cotton response to dicamba when applied at four crop growth stages [first square (FS) + 2 wk, first bloom (FB), FB + 2 wk, and FB + 5 wk]. Dicamba at 0.56 (1×), 0.056 (1/10×), 0.0112 (1/50×), 0.0056 (1/100×), and 0.00112 (1/500×) kg ae ha−1 was applied to ‘FM 1830GLT’ cotton. When applications were made at FS + 2 wk, a shift in boll nodal position was apparent following dicamba at the 1/50× rate in 2017 and at 1/10× in 2018 compared to the nontreated control (NTC). A shift in boll distribution from the 1/50× rate of dicamba was apparent at FB in 2017, but not in 2018. Dicamba applied at the 1× rate at FB + 2 wk resulted in reduced boll numbers. No change in boll number or boll position was apparent following any dicamba rate when applied at FB + 5 wk in both years. Dicamba applied at 1/500×, 1/100×, and 1/50× rates at all timings did not affect yield relative to the NTC. When dicamba was applied at the 1/10× rate, the greatest yield loss was observed at FS + 2 wk followed by FB and FB + 2 wk. Micronaire increased following dicamba applied at 1/10× at FS + 2 wk, FB, and FB + 2 wk in 2017. In 2018, micronaire decreased following dicamba applied at 1/10× at FB + 5 wk.

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Polymer and deficit irrigation influence on water use efficiency and yield of muskmelon under surface and subsurface drip irrigation

Soil and Water Research ◽

10.17221/94/2020-swr ◽

2021 ◽

Author(s):

Faisal Zeineldin ◽

Yousef Al-Molhim

Keyword(s):

Water Use Efficiency ◽

Open Field ◽

Water Use ◽

Drip Irrigation ◽

Deficit Irrigation ◽

Subsurface Drip Irrigation ◽

Growth Stages ◽

Polymer Addition ◽

Use Efficiency ◽

Subsurface Drip

Water scarcity is a major constraint facing vegetable production sustainability in open field farming of arid regions like the Kingdom of Saudi Arabia. This study was carried out in an open field of the Research and Training Station of King Faisal University in the eastern region of the Kingdom. The objective was to assess the influences of the polymer addition (PA), deficit irrigation regime (DIR), and their combination on the production and water use efficiency (WUE) of muskmelons. PA treatments of 0.0, 0.2 and 0.4% and the irrigation treatments of 100, 75 and 50% of reference evapotranspiration (ETo), were imposed throughout the growth stages of muskmelons under surface drip irrigation (DI) and subsurface drip irrigation (SDI). The polymer addition of 0.4% enhanced the field water holding capacity of the medium sandy soil within the locality of the emitters by 43.6%. The soil water content of the surface layer within the vicinity of the polymer amended soil layer increased in a range of 72.4 to 99.4% to the combined influences of the 0.4% PA with the DI and SDI, but were marked more under the SDI. The combination of the 100% ETo DIR with polymer additions significantly (P < 0.05) enhanced the muskmelon fruit yield (MFY) under the SDI compared to DI. The PA of 0.4% improved WUE and MFY by 67.7, 70.4% under the SDI, and 58.6, 24.2% under the DI, respectively. Without the polymer addition (0.0% PA), the MFY significantly (P < 0.05) decreased with the increase of the DIRs under both DI and SDI.

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Subsurface Drip Irrigation and Fertigation of Broccoli

Soil Science Society of America Journal ◽

10.2136/sssaj2002.0178 ◽

2002 ◽

Vol 66 (1) ◽

pp. 178 ◽

Cited By ~ 4

Author(s):

Thomas L. Thompson ◽

Thomas A. Doerge ◽

Ronald E. Godin

Keyword(s):

Drip Irrigation ◽

Subsurface Drip Irrigation ◽

Subsurface Drip

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Behaviour of the fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation

Water Science & Technology ◽

10.2166/wst.2000.0294 ◽

2000 ◽

Vol 42 (1-2) ◽

pp. 75-79 ◽

Cited By ~ 7

Author(s):

C. Campos ◽

G. Oron ◽

M. Salgot ◽

L. Gillerman

Keyword(s):

Organic Matter ◽

Drip Irrigation ◽

Organic Matter Content ◽

Fecal Pollution ◽

Fecal Coliforms ◽

Subsurface Drip Irrigation ◽

Treated Wastewater ◽

Reclaimed Wastewater ◽

Pollution Indicators ◽

Subsurface Drip

A critical objective for any wastewater reuse programme is to minimise health and environmental hazard. When applying wastewater to soil–plant systems, it is to be noted that the passage of water through the soil considerably reduces the number of microorganisms carried by the reclaimed wastewater. Factors that affect survival include number and type of microorganisms, soil organic matter content, temperature, moisture, pH, rainfall, sunlight, protection provided by foliage and antagonism by soil microflora. The purpose of this work was to examine the behaviour of fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation. The experiment was conducted in a vineyard located at a commercial farm near the City of Arad (Israel). Wastewater and soil samples were monitored during the irrigation period and examined for fecal coliforms, somatic and F+ coliphages and helminth eggs. Physico-chemical parameters were controlled in order to determine their relationship with removal of microorganisms. The results showed high reduction of the concentration of microorganisms when wastewater moves through the soil; and a good correlation between the reduction of fecal pollution indicators and moisture content, organic matter concentration and pH. The application of secondary treated domestic wastewater in this specific soil and under these irrigation systems affect the survival of microorganisms, thus reducing the health and environmental risk.

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