Responses of Creeping Bentgrass to Trinexapac-ethyl and Biostimulants under Summer Stress

Plant growth regulators have been used to improve turfgrass quality and drought tolerance. This study was designed to investigate if foliar application of auxin (indole‐3‐butyric acid [IBA] at 2 μM) and trinexapac‐ethyl (TE, 45 g ha−1), alone or in a combination, improves creeping bentgrass (Agrostis stolonifera L.) root growth and hormone metabolism under water‐deficit conditions. The plants were subjected to well‐watered or water‐deficit stress (40–50% evapotranspiration replacement) conditions for up to 42 d in growth chambers. Water deficit reduced turf quality and net photosynthetic rate (Pn), leaf indole‐3‐acetic acid (IAA), isopentenyl adenosine (iPA) content, and root viability. Exogenous application of TE or IBA, alone or in a combination, improved turf quality, Pn, and stomatal conductance under water‐deficit conditions. Under water deficit, TE, IBA, and TE + IBA treatments also increased leaf IAA, iPA, and abscisic acid content relative to the control. The combination treatment (TE + IBA) increased root biomass relative to the control under water‐deficit and well‐watered conditions. Under water deficit, TE, IBA, TE + IBA increased root viability by 16.7, 32.2, and 56.2%, respectively, relative to the control. Under well‐watered conditions, IBA, with or without TE, also increased leaf IAA and iPA, as well as root viability. Results suggest that foliar application of auxin and TE at proper rates may promote root viability and hormonally mediated adjustments to drought, resulting in improved turf quality under water‐deficit conditions.

Section: Aba Treatmentsupporting

confidence: 94%

Section: Aba Treatmentmentioning

confidence: 88%

Section: Aba Treatmentmentioning

confidence: 88%

mentioning

confidence: 99%

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Auxin and Trinexapac‐Ethyl Impact on Root Viability and Hormone Metabolism in Creeping Bentgrass under Water Deficit

Zhang

Ervin

et al. 2017

“…These effects of TE on abiotic stress tolerance have been studied in creeping bentgrass ( Agrostis stolonifera L.), with the applications of TE improving drought tolerance by maintaining leaf hydration, leaf growth, and photosynthetic parameters (McCann and Huang, 2008), as well as increasing osmotic adjustment (Bian et al, 2009). Additionally, TE has been demonstrated to improve heat tolerance in creeping bentgrass by improving canopy and root characteristics, including canopy density, chlorophyll content, root biomass, and total root area, as well as photosynthetic rates (Xu and Huang, 2010).…”

mentioning

confidence: 99%

Effects of Trinexapac‐Ethyl and Daconil Action (Acibenzolar‐S‐Methyl and Chlorothalonil) on Heat and Drought Tolerance of Creeping Bentgrass

Jespersen

Huang

2017

Self Cite

The plant growth regulator trinexapac‐ethyl (TE) is known for its effects of suppressing shoot vertical growth. Some fungicides are claimed to promote the physiological health of plants in the absence of diseases. The objective of this study was to determine whether acibenzolar‐S‐methyl (one of the active ingredients in Daconil Action), TE alone, or the combination of the two may be most effective in promoting creeping bentgrass (Agrostis stolonifera L.) tolerance to heat and drought stress under field conditions. Daconil Action and TE were foliar applied alone or in combination to creeping bentgrass managed under fairway conditions at Rutgers University in 2014 and 2015. Stress tolerance was measured by evaluating turf quality, leaf membrane stability, relative water content, and canopy characteristics estimated by multispectral radiometry. Foliar application of either Daconil Action or TE alone improved heat and drought tolerance, and the positive effects were more pronounced and consistent during the stress periods with the combined treatment than either treatment alone. The beneficial effects of these compounds were most pronounced during periods of drought or heat when stress induced the most severe physiological damages. Foliar application of these compounds may help creeping bentgrass maintain better quality turf during hot or dry periods in warm climate conditions with limited water resources for irrigation.

Foliar application of diethyl aminoethyl hexanoate (DA‐6) alleviated summer bentgrass decline and heat damage to creeping bentgrass

Li,

Zhou,

et al. 2024

Creeping bentgrass (Agrostis stolonifera) is sensitive to supra‐optimal temperature, which makes summer bentgrass decline (SBD) a main conundrum troubling turf manager. Diethyl aminoethyl hexanoate (DA‐6) is an artificial and bioactive plant growth regulator affecting tolerance to various abiotic stresses. It is commercially available for field application due to multiple advantages such as low cost, environmentally friendly compound, and sustainable effect. However, the positive effect and mechanism of DA‐6‐mediated heat tolerance in cool‐season grass species and SBD are not yet been explored. Objectives of the study were to screen the optimal dose of DA‐6 for improvement in thermotolerance and to investigate roles of DA‐6 in regulating photosynthesis, osmotic balance, and antioxidant homeostasis in two creeping bentgrass cultivars (heat‐tolerant 13 M and heat‐sensitive Seaside II) in controlled heat condition. Summer heat tolerance induced by the DA‐6 was further evaluated for 2 years under field conditions in a subtropical zone. Results demonstrated that the optimal dose of DA‐6 was screened as 0.1 mM based on analyses of chlorophyll content, photochemical efficiency, and cell membrane stability under heat stress. Foliar application of DA‐6 significantly alleviated heat‐induced leaf senescence by improving photosynthetic performance, accumulation of sugars (sucrose, fructose, and glucose) for osmotic homeostasis, and total antioxidant capacity for reactive oxygen species scavenging in the two cultivars. A 2‐year field test was further carried out to demonstrate that turf quality of the two cultivars was significantly improved after being treated by foliar DA‐6 during hot summer months in 2020 and 2021. Current findings suggested that DA‐6‐mediated thermo‐resistant mechanism was associated with photosynthesis, osmotic adjustment, and antioxidant in cool‐season grass species. Foliar application of DA‐6 could be a cheap, effective, and environmentally friendly strategy to alleviate SBD.