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ARS Home » Plains Area » Mandan, North Dakota » Northern Great Plains Research Laboratory » Research » Publications at this Location » Publication #398835
Research Project: Sustainable Agricultural Systems for the Northern Great Plains

Location: Northern Great Plains Research Laboratory

Title: Impact of fire and drought on axillary bud numbers in Kentucky bluegrass (Poa pratensis L.)

Author
item Hendrickson, John
item BINSTOCK, LEVI - North Dakota State University
item DEKEYSER, EDWARD - North Dakota State University
item Toledo, David
item KOBIELA, BRIANNA - North Dakota State University
item Clemensen, Andrea
item Carrlson, Andrew
item Kobilansky, Chantel

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/12/2023
Publication Date: 2/12/2023
Citation: Hendrickson, J.R., Binstock, L., Dekeyser, E.S., Toledo, D.N., Kobiela, B., Clemensen, A.K., Carrlson, A.J., Kobilansky, C.L. 2023. Impact of fire and drought on axillary bud numbers in Kentucky bluegrass (Poa pratensis L.). Meeting Abstract. 1.

Interpretive Summary:

Technical Abstract: Kentucky bluegrass, a perennial, cool-season, non-native grass, has rapidly increased on rangelands in the northern Great Plains but the underlying mechanism for this increase is unknown. Two potential mechanisms are reduction in burning and increased precipitation. A project was initiated at the Northern Great Plains Research Laboratory (USDA-ARS) near Mandan, North Dakota, USA using rain intercept shelters and fall fire to evaluate drought and burning effects on Kentucky bluegrass axillary bud numbers. Rain intercept shelters (3 x 3 m) were used to intercept 0, 30, or 60% of ambient precipitation during the growing season. Half of each plot under the shelter was burned in the fall of 2017, 2019, and 2020. Treatments were replicated 3 times in 3 separate blocks. In May and October of 2020 and 2021, a 4.78 cm id diameter core was taken out of the burned and unburned portions of each plot. After collection, soil was rinsed from the cores using a 1 mm screen, and loose thatch and root mass were removed. The remaining material was soaked for 24 hours in a 0.1% w/v tetrazolium chloride solution which turns active axillary buds red. Crown material was examined using a dissecting microscope and the number of active buds was recorded. There were significant interactions for drought by burning (P=0.0642) and time by burning (P=0.0020). Under moderate (30%) drought stress, burned plots produced half of the amount of Kentucky bluegrass axillary buds as unburned plots. In October 2020, burned plots produced about 46% of the Kentucky bluegrass axillary buds as unburned plots. A strong regional drought starting in 2020 and continuing through 2021, may have impacted the effects of drought treatments. This study highlights the importance of understanding interactions when determining the best management strategies.