Publication Date

Summer 2018

Advisor(s) - Committee Chair

Dr. Todd Willian (Director), Dr. Becky Gilfillen, and Dr. Elmer Gray

Degree Program

Department of Agriculture

Degree Type

Master of Science


Fungal diseases pose significant challenges for grapevine producers in Kentucky due to the region’s abundant moisture and relative humidity. Methods to reduce fungicide application frequency would prove both economically and temporally valuable to producers. A field experiment was established in Bowling Green, KY in 2017 to investigate Bacillus mycoides isolate J (LifeGard) as a supplement to a fungicide program for systemic acquired resistance (SAR). Three fungicide treatment regimens were implemented consisting of a program modelled from the Midwest Fruit Pest Management Guide (2017) and an identical program supplemented with 140 g ha-1 LifeGard per application (both applied on 14 day intervals), a reduced frequency application every 28 days supplemented with 140 g ha-1 LifeGard, and an untreated control. Treatments were applied to 9-year-old French-Hybrid grapevines (cv. Chambourcin); each treatment was replicated 3 times in a randomized complete block design. All treatments were applied with a backpack sprayer delivering 150 L ha-1 at 2 Bar pressure. Canopy management, fertility, herbicide, and insect management were standardized across treatments and no supplemental irrigation was applied. Data collected included fruit yield, pH, ºBrix, and titratable acidity (TA). Data were analyzed with SAS PROC GLIMMIX; differences in means were determined at  < 0.05. Plots supplemented with B. mycoides had lower fruit pH than untreated plots but higher fruit pH than the traditional fungicide program. Treatment regime did not influence Brix, TA, or total yield; however, all treated plots yielded more high quality fruit than the untreated control.


Agriculture | Agronomy and Crop Sciences | Fruit Science | Viticulture and Oenology