Various Turf Covers for Kentucky bluegrass Growth and Spring Green-up

Abstract

ABSTRACT. Winter turfgrass injury is one of the critical problems of many golf courses in Korea. Turfgrass loss from freezing injury due to low temperature leads to many types of damages including weed invasion, increased herbicide cost, increased soil erosion, and expensive re-establishment. Although Kentucky bluegrass (Poa pratensis L.) which is the most widely used among cool-season grasses in Korea is well known as cold tolerance species, freezing injuries to Kentucky bluegrass during winter are often found. Protecting the turfgrass crown is necessary to recover from low temperature stress in winter because shoots and roots can be recovered from the crown. Turf covers may protect the crowns from direct low temperatures and desiccation. Six different turf covers were installed to cover Kentucky bluegrass during a period of low temperatures. Turf covers had positive effects for spring green-up of Kentucky bluegrass based on the study. Applying any type of turf covers on Kentucky bluegrass resulted in an increase average and minimum temperature compared to the uncovered plot. Among turf covers, clear PVC film without holes produced the longest root length and the highest turfgrass quality.

Late Fall Nitrogen Application and Turf Cover for Zoysiagrass (Zoysia japonica) Spring Green-up

“…Non-covered turf had greater turfgrass color than covered turf from May 28 when maximum air temperature reached 30.2 o C (Table 6). Lee (2013) reported similar results with turf cover study. He found non-covered turf had greater -------------------------------------------------Turf quality ------------------------------------------------- ----------------------------------------------- Turf cover was applied at December 7, 2013 immediately after the N treatment.…”

“…The air temperature of 30.2 o C measured in the study is the range of optimal temperature for zoysiagrass, but the temperature under cover could be higher than air temperature. Lee (2013) also reported that the temperature difference between air and under cover was 3.1 to 8.7 o C with various types of turf covers. Therefore, the temperature under the cover could be 38.9 o C which is higher than optimal temperature for shoot growth of warm-season grasses.…”

“…Differences between covered and non-covered turf for root length were found after May 16 when maximum temperature reached the optimum range for root growth of warm-season grasses. In contrast, the maximum air temperature was out of optimum range for cool-season grasses before root length of Kentucky bluegrass was measured (Lee, 2013). Compare to root length, leaf length are influenced by turf cover main effects from May 12 to June 17.…”

“…Tapp et al (1988) used straw, polypropylene or polyester covers as sources of TC on bermudagrass and found TCs enhanced turfgrass quality and spring green-up for bermudagrass compared without TCs. Lee (2013) investigated the effects of various turf covers on Kentucky bluegrass and found that any type of turf covers on Kentucky bluegrass resulted in an increase of average and minimum temperature compared to the uncovered plot and among turf covers, clear PVC film without holes produced the longest root length and the highest turfgrass quality. Although data from the previous researches have been reported for the positive effects of TCs on turfgrass, it is still not clear for both cool-and warm-season grasses and negative effects may exist.…”

“…There was no difference between turf cover treatments for root length until May 16. When turf cover with clear poly-vinyl chloride (PVC) film used for Kentucky bluegrass, no differences were found between covered and non-covered turf for root length (Lee, 2013). However, covered zoysiagrass had longer root length with greater turfgrass color and quality than non-covered zoysiagrass when maximum air temperature is 29.5 o C. Covered turf had longer leaf length than non-covered turf from May 12 to June 17.…”