Photoselective Filters Impact on Turf Quality

Photoselective Filters Impact on Turf Quality

D. Petrella, M. Berger, E. Nangle, and T. Morris

Introduction:

Shade management strategies have used multiple approaches which include reductions in nitrogen rates, use of plant growth regulators, management of moisture content (Nangle et. al., 2012) and increases in mowing height as well as removal of trees and plant material surrounding area of importance that help with air movement. Research on shade however has required different approaches based on the portion of the industry that is affected. For example stadium shade or inert structure shade reduces light intensity but does not affect light quality and thus research that reports on use of shade cloth is pertinent for those situations (Russell et al., 2020). Research that focuses on plant (or tree shade) influences have shown that changes in growth habit and physiology are much greater compared to the shade cloth influence (Wherley et al., 2005, Petrella et al., 2020) and thus further work should be conducted with these materials. The reason for this difference is believed to be the reduction in the red far red ratio which occurs due to differential wavelength absorption by tree lines (Bell et al., 2005) The objective of this trial was to evaluate and compare the impact of the two types of shade materials and also investigate if a novel approach of cytokinin application could help alleviate some of the issues. Cytokinin is a plant hormone linked to enhanced cellular division as well as a promoter of branching and root growth and so this may offer a solution to aid in retention of turf quality..

Materials and methods:

This trial was established at three locations (2 in Wooster OH; 7-1-23 and 1 in Columbus; 7-6-23). Two of the surfaces consisted of newly established S-1 creeping bentgrass Agrostis stolonifera and the other surface was a mixed stand of annual bluegrass Poa annua and creeping bentgrass. Mowing heights were 0.130″ in Wooster and 0.150″ in Columbus. Surfaces were given approx approx 1.5lbs N to date in 2023 and fungicides were applied in a preventative manner. Growth regulator was applied only to the mixed annual bluegrass and creeping bentgrass stand every 14d at a rate of 12 fl oz/ acre of trinexapac ethyl. Data were collected for turf quality and normalized difference vegetation index as well as images collected using a photobox. MaxCell a synthetic cytokinin was applied on 7/12/23 at a concentration of 2.54 µmol. Data were collected for light intensity and light quality also. Light quality data indicated full sun R:FR of approx 1.2-1.3, Shade cloth R:FR was measured between 1 and 1.2 (plants respond above 1 similar to full sun) and the filters were measured at 0.2.

Results:

The impact of the filters was clearly noted on the more established plots in Wooster OH with a faster and more severe negative response to the change in light quality. The application of the cytokinin based product (not currently labelled for turf) did not provide immediate improvement and there may be a need to evaluate the product from a rate standpoint. Currently the recommendations for reducing nitrogen inputs, use of plant growth regulators, closely monitoring irrigation requirements and, selective pruning and  tree removal where possible are all approaches that should be implemented to aid with maintenance of turfgrass quality during the heavy summer paying season.

Impact of photoselective filters on turf quality and applications of MaxCell to ‘S-1’ Creeping bentgrass summer 2023, Columbus OH

†Means followed by different letters are significantly different at p<0.05

Impact of photoselective filters and applications of MaxCell on NDVI values of ‘S-1’ Creeping bentgrass summer 2023, Columbus OH

†Means followed by different letters are significantly different at p<0.05

Figure 1. Plot plan for trial evaluating Impact of photoselective filters and applications of MaxCell on NDVI values of ‘S-1’ Creeping bentgrass summer 2023, Columbus OH

References:

Bell, G.E., Danneberger, T.K. and McMahon, M.J. (2000), Spectral Irradiance Available for Turfgrass Growth in Sun and Shade. Crop Sci., 40: 189-195. https://doi.org/10.2135/cropsci2000.401189x

Nangle, E. J., Gardner, D. S., Metzger, J. D., Street, J. R., & Danneberger, T. K. (2012). Impact of Nitrogen Source and Trinexapac-ethyl Application on Creeping Bentgrass (Agrostis stolonifera L.) Physiology under Neutral Shade, Deciduous Tree Shade, and Full Sunlit Conditions. HortScience horts, 47(7), 936-942.  https://doi.org/10.21273/HORTSCI.47.7.936

Petrella DP, Breuillin-Sessoms F, Watkins E. (2022) Layering contrasting photoselective filters improves the simulation of foliar shade. Plant Methods. Feb 8;18(1):16. doi:10.1186/s13007-022-00844-8