Watermelon Disease Control Demonstration
Lane, Oklahoma
2009
Reports From Previous Trials
The objective of this project is to demonstrate to the use of fungicides for controlling foliar diseases in watermelon. The demonstration will include two different fungicide treatments and two different methods that can be used to decide when to apply fungicides.
Fungicides:
Application Decision Methods:
http://agweather.mesonet.ou.edu/models/watermelon/default.html
Fungicides are applied with a boom sprayer using 22.5
gallons of spray mixture per acre.

For both methods an initial fungicide application was to be made when plants began to produce male flowers. With warm conditions plants were growing fast! We made the first application when plants had fruit less than 2 inches long.
Watermelon of the cultivar Legacy was established by direct seeding on June 27 and thinned to 1 plant per 3 feet of row on July 17.
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Activity Record |
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Date |
Field Observations and Activities |
Fungicide Application |
|
|
Calendar |
Forecaster |
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|
August 14 |
Melons in Full Bloom
|
Yes |
Yes |
|
August 19 |
Mesonet output of 51 hours indicates spray not needed. |
No |
No |
| Aug. 20 |
Mesonet output of 63 hours indicates spray not needed. |
No |
No |
| Aug. 19 | Weather has been rainy and overcast. Forecaster shows 62 hours. Eighty hours are needed before spraying is recommended. |
No |
No |
| Aug. 21 | Today is the date for the calendar application to be made. Mesonet output of 76 hours indicates spray not needed. |
No |
Yes |
| Aug. 26 | Mesonet output of 107 hours indicates time to spray. We went over as 80 hours is the criterion for the decision to spray. Fungicides were applied. |
Yes |
Yes |
| Aug. ? | ? |
? |
? |
| Aug. ? | ? |
? |
? |
| Aug. ? | ? |
? |
? |
| Aug. ? | ? |
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For questions or comments contact Jim Shrefler by e-mail or by phone at 580-889-7343
This information is provided for educational purposes. When using pesticides, always read and follow label directions. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Oklahoma Cooperative Extension Service is implied.