Supported by Indiana Vegetable Growers Association and Illiana Watermelon Association, a collaborative project between Purdue University and Michigan State University that aims to help watermelon farmers improve irrigation management was recently funded. In this project, the team will conduct the scientific experiment at the Southwest Purdue Agricultural Center to test currently used irrigation management tools, and their effects in influencing watermelon yield and quality. The purpose of the trials is to develop irrigation guidelines for watermelon production in our region. The team also plans to monitor soil moisture levels in watermelon fields across the region using an real-time irrigation management technology (LOCOMOS, Low-Cost Sensor Monitoring System) developed by Dr. Younsuk Dong from the Department of Biosystems and Agricultural Engineering at the Michigan State University. The purpose of the effort is to help watermelon farmers better understand how precipitation and their current irrigation management practices affect soil moisture. The project was supported by IN SCBG IGG-277.
If you grow watermelons and are interested in participating in this project, please contact Wenjing Guan at guan40@purdue.edu.
Background about this project:
Indiana is one of the major watermelon production states in the U.S. With close to 7,000 acres of watermelons grown in Indiana, approximately half of the acreage is under supplemental irrigation through either drip irrigation or overhead irrigation. Watermelon is regarded as a relatively drought-tolerant crop. The extensive root systems are known to take up water in deep soils. Therefore, in most years, reasonable yields are achieved without supplemental irrigation. However, problems that are likely associated with water-deficient stress are often observed. In 2021, we visited watermelon fields with large percentages of misshapen fruit, and blossom end rot (Figure 1). Farmers face detrimental yield losses under such circumstances. In less severe cases, fruits are marketable, but they are in smaller sizes and yield was lower. On the other hand, over-irrigation is a concern, especially in drip-irrigated fields. We observed late-season vine decline in 2021 season, which is a problem suspected to be related to over-irrigation. Over-irrigation also leads to fertilizer leaching that causes economic loss and environmental pollution. Supplemental irrigation is valuable insurance in a dry year. But to fully justify the added cost of using supplemental irrigation, yield increases in most of the years must be achieved with proper irrigation management.
Figure 1. Blossom-end rot on watermelon.