Regrowth of leaf tissue after mowing is necessary to form photosynthetic leaf area required for CO2 assimilation and plant growth and development. Leaf tissue regrowth often is dependent on levels of reserve carbohydrates stored in leaf sheaths and leaf bases. The objective of this study was to quantify mowing injury by measuring levels of fructan, sucrose, glucose, and fructose and efficiency of photosystem II (PSII) in not-cut, rolled, single-cut, and double-cut creeping bentgrass (Agrostis stolonifera L.) grown in a greenhouse. Efficiency of PSII was reduced in double-cut grasses by as much as 9% compared with not-cut grasses. Fructan levels were reduced in single- and double-cut grasses compared with not-cut grasses by 52% and 45%, respectively, 36 h after mowing. Glucose levels were 31% lower in double-cut grasses compared with not-cut grasses. No differences were observed in sucrose and fructose levels among not-cut, rolled, single-cut, and double-cut grasses. Mowing transiently reduced fructan and glucose levels in mowed grasses. Duration of reduction of fructan levels, magnitude of reduction in glucose levels, and efficiency of PSII were greatest in double-cut grasses, suggesting that multiple cuttings may be more damaging to plant vigor than single cutting.

Phytophthora root and stem rot is a devastating disease of soybean [Glycine max (L.) [Merr.] that occurs annually in North America. Plant death and severe yield loss can This article is protected by copyright. All rights reserved. transpire when conditions are favorable for pathogen development. The first objective was to determine the efficacy of oxathiapiprolin as a soybean seed treatment using laboratory inoculum layer assays with different races of Phytophthora sojae. The second objective was to evaluate oxathiapiprolin seed treatments in wide area agronomic field testing using unmanned aerial vehicle (UAV) image-to-data analysis to quantify emergence, vigor, and greenness traits. The final objective was to examine the yield potential of seed treatments with oxathiapiprolin. Using inoculum layer efficacy testing in a growth chamber with P. sojae races 4, 7, or 31, seed treated with oxathiapiprolin had significantly higher visual root growth scores compared to non-treated seed. Across 115 field locations from 2018-2020, UAV remote sensing image analysis at the V2 growth stage indicated oxathiapiprolin in combination with other fungicides had significantly better emergence, more vigor, and more intense greenness compared to non-treated controls. Entries treated with oxathiapiprolin in combination with other fungicides had an average +161 kg/ha yield difference compared to non-treated entries from 2018 to 2020. Oxathiapiprolin as a seed treatment is an effective management tool for soybean producers, providing efficacy against P. sojae, and improving emergence, vigor, greenness, and final yield.

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