Using Mineral Clay to Manage Pests and Increase Fruit Quality and Yield in Blackberries

December 19, 2019
University of Arkansas

SEARCY, Arkansas -- Primocane blackberries, which can extend the fruiting season by months over traditional plant varieties, are changing the way farmers are growing berries. But they don’t come without their pest and production challenges, which University of Arkansas researchers are trying to solve with a naturally occurring soil mineral.

In a Research and Education Grant, researchers are studying how well kaolin clay manages blackberry insect pests, as well as helps lower the leaf temperatures during the summer when heat can damage fruit production and quality. Kaolin clay is a naturally occurring mineral that is touted for its pest repellant features and its ability to reduce sunburn on crops. Products, such as Surround®, are applied as a whitewash to the plants during the growing season.

University of Arkansas entomologist Donn Johnson said that they are still collecting field data and assessing the effectiveness of the kaolin clay whitewash on pest control. But, so far, researchers found that the leaf temperatures “do not change a whole lot with the whitewash application.” At each farm location, temperatures in the plant canopy were 1.2 degrees Fahrenheit cooler than ambient air temperatures.

In the research project, experiments at all three farm sites included randomized complete blocks with four replications of each of the following treatments: 1) Surround WP® applied weekly during July-September; 2) Surround WP® applied weekly plus conventional integrated pest management practices; 3) No Surround WP® but used conventional integrated pest management practices, and 4) No Surround WP® and no disease or insect control. Leaf temperatures were monitored in all plots throughout the season. In addition, plots were monitored for spotted wing Drosophila, broad mites, spider mites and stink bugs, and weekly inspections and severity ratings were made for anthracnose, cane blight, rosette, or other diseases.

Published by the Southern Region of the Sustainable Agriculture Research and Education (SARE) program. Funded by the USDA National Institute of Food and Agriculture (NIFA), Southern SARE operates under cooperative agreements with the University of Georgia, Fort Valley State University, and the Kerr Center for Sustainable Agriculture to offer competitive grants to advance sustainable agriculture in America's Southern region. This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, through Southern Sustainable Agriculture Research and Education, under sub-award number: LS16-274. USDA is an equal opportunity employer and service provider. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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Topics: Berries (Brambles), Botanical Pesticides, Fruit, Pest Management
Related Locations: Arkansas, South