Corn silage harvest is upon us in many places, though hay crops are competing for farmers' attention. The latest GDD numbers are in for Sept 8th (see section 2), and they suggest that while most of the early-silking crops are past their prime, crops that silked during the latter half of July are at or very near peak quality in most places. Here is the link to our recent webinar on things to keep in mind in advance of this year's silage harvest: 2021 Central NY Corn Silage Pre-Harvest webinar

There was a second alfalfa field in the Hudson Valley that experienced high fall armyworm populations, so keep your eyes peeled. My traps have been empty for two weeks running and I have found very few in the alfalfa fields I've been sweeping, but that doesn't mean they aren't still a threat for another few weeks.

Other than some pea aphids and the odd alfalfa caterpillar larva, alfalfa crops in our region are generally quite clean heading into fall.

Take note of problem areas in your soybean fields and let me know if you would like me to sample your field for soybean cyst nematode. This pest is widespread in NY, and I'm afraid that this year's wet conditions may have allowed them to spread more easily through infested fields. Sampling and analysis are free via grant funding from the NY Corn and Soybean Growers Association, though I am limited in the number of samples I can submit. So let me know.

2. Growing Degree Days (GDD) for planting date and silking date (Climate Smart Farming Growing Degree Day Calculator)

For corn silage, we are using base 50/86, as corn development starts at 50F and ceases above 86F. Silage corn needs 750-800 GDD (depending on hybrid maturity) after silking to reach a whole plant DM of 32%. Remember that we can expect to accumulate 20-25 GDD per day, or even up to 30, so this is not a large window. Under typical late season dry down conditions we can expect the crop to reach 35% DM four to seven days later. Check your crop to see how close you may be to harvest:

Not everyone planted their corn on one of the planting dates or in one of the locations I have listed, so this chart shows the estimated GDD for each location on each potential planting date in between (based on the actual GDD on those four dates). The locations are ordered top-to-bottom from lowest elevation to highest (the number after the location name is the elevation in feet above sea level). So if your farm is near one of the locations on this list but there's a location here that more closely matches your elevation, try that instead. You can find GDDs for your own specific location and planting date using the Climate Smart Farming CSF Growing Degree Day Calculator, but for those who might have more difficulty using that tool, maybe this chart can help.

As we get closer to silage harvest, remember that silage corn needs 750-800 GDD after silking to reach a whole plant DM of 32% (depending on hybrid maturity). Under typical late season dry down conditions we can expect the crop to reach 35% DM four to seven days later. When using this chart, remember that actual GDD were calculated for July 14, 18, 22, and 26 silking dates. Dates in-between those four dates are estimates. As always, remember that GDD estimates are good for getting you in the ballpark, but are no substitute for actual conditions in the field.