2021 has generally been a good year for growing corn, except in more poorly fields. Corn maturity looks to be average to early around the county. Of course the weather the rest of the summer will have a lot to say about that. We are monitoring a few fields around the county to help gauge when corn might be ready to harvest.
Forecasting silage harvest dates after tasseling using GDD is a great way to help plan your harvest and be successful.
It takes out half of the risk by forecasting silage harvest after the corn has tasseled. Through research done by Bill Cox at the Musgrave Research Farm, corn with a RM of 96-99 needs about 750GDD after tasseling to get it near silage maturity. Corn with a RM of 100-115 needs about 800GDD. This method predicts getting the corn to about 32%DM. By the time the corn is ready to chop at the 35% or higher DM, the GDD accumulation might end up being almost 900 from the date of tassel. By using the Climate Smart Farming website to track GDD by field location and utilizing the GDD needed after tassel, Table 1 shows the predicted date range of silage harvest based on the locations being scouted. Table 1 will also compares the dry matter percentage at different GDD after tasseling.
Remember that all things depend on the weather and this is only a guide to work out when corn silage might be ready. We will be offering several corn dry down days as we approach harvest time. We will continue to monitor corn maturity and publish updates as the season moves forward.
| Town | Planting Date | RM | Location | Tassel Date | GDD From Tassel to Silage Harvest | Estimated Harvest Date |
| Roxbury | 5/20 | 96 | Upland | 7/26 | 750 | 9/21 (9/9-9/29) |
| Middletown | 5/20 | 92 | Valley Floor | 7/28 | 750 | 9/24 (9/12-10/6) |
| Delhi | 5/23 | 98/94 | River Flat | 8/1 | 750 | 9/29 (9/16-10/19) |
| Davenport | 5/10 | 110 | Valley floor | 7/22 | 800 | 9/22 (9/9-10/5) |
| Davenport | 4/27 | 110 | Valley Floor | 7/19 | 800 | 9/17 (9/7-9/26) |
To use the GDD tool with your own information go to climatesmartfarming.org/tools/csf-growing-degree-day-calculator. Use the tools in the upper left of the page to select your farm from a the map, enter your planting date, and select GDD Base as 50F (86/50). This will display a chart of GDD accumulated for the season and a prediction for the rest of the season. To see the best prediction of harvest date for your field, enter the date your corn tasseled in the planting date box, click the enable target box and move the slider to 750 for hybrids 95 days or less, and 800 for longer season hybrids. The green target zone will display the range of predicted dates corn will be ready for chopping.
There are several helpful videos on this page that will help you use the tool as well.