Limited transpiration under high vapor pressure deficits of creeping bentgrass by application of Daconil-Action®

Abstract

First observation that chemical spray can induce limited-transpiration rate under high vapor pressure deficit. It appears that acibenzolar may be key in inducing this water conservation trait. Irrigation and water use have become major issues in management of turfgrasses. Plant health products that have been introduced into the turfgrass market have been observed to improve plant performance in water stress conditions. In this study, we evaluated whether a selection of common plant health products alter the ability of creeping bentgrass (Agrostis stolonifera L.) to control transpiration under high vapor pressure deficit (VPD). The plant health treatments--Daconil Action, Insignia, and Signature--were applied to plots on golf course putting greens located in Raleigh NC and in Scottsdale, AZ. Using intact cores removed from the putting greens, transpiration rates were measured over a range of VPDs in controlled conditions. In all cases stretching over a 3-year period, bentgrass cores from field plots treated with Daconil-Action limited transpiration under high VPD conditions, while check treatments with water, and others treated with Insignia or Signature did not. Transpiration control became engaged when VPDs reached values ranging from 1.39 to 2.50 kPa, and was not strongly influenced by the field temperature at which the bentgrass was growing. Because all plots in NC had been treated with chlorothalonil-the key ingredient in Daconil Action to control diseases-it was concluded that the likely chemical ingredient in Daconil Action triggering the transpiration control response was acibenzolar. This is the first evidence that the limited-transpiration trait can be induced by a chemical application, and it implies significant potential for ameliorating drought vulnerability in cool-season turfgrasses, and likely other plant species.

Coordination between vapor pressure deficit and CO2 on the regulation of photosynthesis and productivity in greenhouse tomato production

“…Our research has shown that controlling VPD can benefit protected cultivation systems 20,25–27 , similar to other findings 28,29 . However, most such studies focus on VPD levels below 4 kPa and few consider VPD up to or even beyond 5–6 kPa 30 , yet this represents the climate characteristics of most arid and semi-arid areas, such as northwest China. The highest VPD in a summer greenhouse in this region can be up to 6 kPa, but a suitable VPD for tomato growth is less than 2 kPa 31 .…”

Metabolic Effects of Acibenzolar-S-Methyl for Improving Heat or Drought Stress in Creeping Bentgrass

“…A number of metabolic pathways induced by ASM during pathogen attack, including anti-oxidant metabolism, have also been demonstrated to be activated during abiotic stress (Soylu et al, 2003). Several recent studies under field conditions have demonstrated that ASM improved heat and drought tolerance in creeping bentgrass (Shekoofa et al, 2015; Jespersen and Huang, 2016), and the improved drought performance of creeping bentgrass was associated with ASM-reduction of transpirational water loss (Shekoofa et al, 2015). The mode of action for ASM regulation of abiotic stress tolerance is still unclear and how it alters metabolic pathways to improve stress tolerance is not well understood.…”

Understanding and Exploiting Transpiration Response to Vapor Pressure Deficit for Water Limited Environments

“…However, VPD breakpoints for other species are also typically lower than what we observed in our study. For example, transpiration control occurred between 1.39 and 2.50 kPa in Agrostis stolonifera ( Shekoofa et al, 2016a ) in a study that demonstrated limited transpiration responses in high VPD environments can also be induced chemically. This could be partially due to the lower VPD environments that many plant species grow, and are therefore, tested in.…”