Gregg Munshaw

Nitrogen and Sprigging Rate Effects on ‘Latitude 36’ Hybrid Bermudagrass Establishment

Hybrid bermudagrass [Cynodon dactylon · Cynodon transvaalensis] is frequently used throughout the southern and transitional climatic zones of the United States. These grasses can only be vegetatively propagated, such as by sprigging. Turfmanagers will often apply high rates of sprigs and nitrogen (N) in an attempt to minimize the time to establishment. However, little is known about how planting and N rates affect establishment. The objective of this study was to determine optimum sprigging andN rates during the establishment of ‘Latitude 36’ hybrid bermudagrass to minimize time to full surface cover. The study was conducted in four locations across the southern United States during Summer 2015. Sprigging rates consisted of 200, 400, 600, and 800 U.S. bushels/acre (9.3 gal/bushel), andN rates were 0, 11, 22, and 44 lb/acreN per week. Results showed that as the N rate increased, percent cover generally increased but only slightly [7% difference between high and low rates 5 weeks after planting (WAP)]. The effect of sprig rate on percent cover indicated that as rate increased, cover also increased. Differences in establishment due to sprig rate were present until 6 WAP at which time all plots achieved 100% cover. The greatest difference betweenN and sprig rate was that sprig rate showed differences in percent cover immediately, whereas N rate differences were not apparent until 2 WAP. Increasing sprig rather than N rate should be considered to speed up establishment.

Optimum Seasonal Mowing Heights for Smooth Crabgrass Reduction in Tall Fescue Lawns

Cultural control methods for pest management are desirable as they can reduce pesticide use resulting in reduced costs and environmental impact. Previous research has shown increased mowing heights can reduce crabgrass (Digitaria sp.) populations. However, seasonal mowing height adjustments may further decrease crabgrass populations as lower heights of cut can increase turf density during optimal growing conditions. An experiment was conducted to determine ideal mowing height combinations during summer vs. fall/spring for crabgrass reductions in a tall fescue (Festuca arundinacea) sward. A half rate of prodiamine was included as a split-plot treatment to determine if mowing height combinations could reduce the amount of pesticide required to control crabgrass. Four fall/ springmowing heights (1, 2, 3, and 4 inches) were combinedwith the same summer mowing heights such that all heights were represented in both seasons. Results indicate that seasonal mowing height variations did not provide any better reduction in crabgrass populations over only using higher heights of cut consistently throughout the year. Also, the half rate of prodiamine successfully controlled crabgrass in all mowing heights except the lowest mowing height during summer months.