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RESEARCH NEWS
Results: ʹͲʹ͵ǡ ͳʹͲΪ Ǥ Ǥ ǡ Ǥ Ǥ ǡ ǡ Table 1. The effects of PRE herbicides on crabgrass Ǥ control applied at various GDD
timings to a Kentucky bluegrass (Poa pratensis L.) stand at the Hancock Turfgrass Table 1. The effects of PRE herbicides on crabgrass control applied at various GDD timings to a Research Center, East Lansing,L.) Michigan—Summer Kentucky bluegrass (Poa pratensis stand at the Hancock 2023 Turfgrass Research Center, East Lansing, Michigan—Summer 2023
1 WALA
1 MALA 2 MALA % Crabgrass Control______________
____________________
FACTOR GDD
LEVEL 100 470 750 1270 POST
Herbicide (H)
Prodiamine Pendimethalin Dithiopyr
96.9 a 99.8 a 99.4 a 88 ab 56.2 b ** 82.8 91.4 90 NS NS
(P<0.05)
(P<0.05) GDD x H
98.2 a 99.2 a 99.1 a 83.6 ab 64.6 b ** 84 91 91.8 NS NS
98.2 a 99.5 a 99.7 a 82.2 ab 68 b ** 84.9 91.9 91.7 NS NS
Benefit Group: This research will benefit golf courses and home lawn care operators by suggesting optimal application timings for PRE-emergence herbicides for crabgrass control. It also demonstrates the effectiveness of the GDD model in predicting when to make applications.
Grad Student(s) Involved: Mike Rabe
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Table 2. The effects of PRE herbicides on crabgrass control applied at various GDD Table The of PRE herbicides on crabgrass control at GDD timings to a Table 2. 2. Theto effects of PRE herbicides on crabgrass control applied at various GDDapplied timings toat a various timings a effects Kentucky bluegrass (Poa pratensis L.) stand the Hancock Turfgrass Kentucky bluegrass (Poa pratensis L.) stand at the Hancock Research Center, East Research Center, East Kentucky bluegrass (Poa pratensis L.) standTurfgrass at the Hancock Turfgrass Research Center, East Lansing, Michigan—Summer 2024 Lansing, Michigan—Summer 2024 Lansing, Michigan—Summer 2024
1 WALA
MALA 2 MALA1 MALA 1 1WALA 2 MALA __________Control ________________________ % Crabgrass % Crabgrass Control______________
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FACTOR FACTOR GDD GDD
Herbicide Herbicide (H) (H)
LEVEL LEVEL 100 100 470 470 750 750 1270 1270 POST POST
97.8 a 98.1 a 93.1 a 95.7 a 9.7 b (P<0.05) *** (P<0.05) Prodiamine 82.5 Prodiamine Pendimethalin 79.5 Pendimethalin Dithiopyr 74.6 Dithiopyr NS (P<0.05) GDD x H (P<0.05) NS GDD x H
79.7 aa 97.8 14 89.8 aa 98.1 90.1 aa 93.1 87.2 aa 95.7 25.4 b 9.7 b *** *** 79.4 82.5 67.3 79.5 76.6 74.6 NS NS * NS
75.8 a79.7 a 84.9 a89.8 a 85.8 a90.1 a 86.6 a87.2 a 33.1 b 25.4 b ** *** 80.8 a 79.4 67 b 67.3 71.9 ab * 76.6 NS * *
75.8 a 84.9 a 85.8 a 86.6 a 33.1 b ** 80.8 a 67 b 71.9 ab * *
Image 1. ʹͲʹͶ Image1. 1. GDD model for Crabgrass Application Timing Trial in ʹͲʹͶ July 2024 at Turfgrass Research Center, East Lansing-MI. Image Hancock ǡ Ǧ Ǥ ǡ Ǧ Ǥ
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VOL 5
15
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Benefit Group: Ǧ Ǥ www.michiganturfgrass.org Ǥ 15 Grad Student(s) Involved: Ryan Bearss