Field Crop Update September 24, 2026

We're narrowing down our target date for our knapweed field walk at the Stone Quarry Art Park in Cazenovia. We're looking at possibly Oct 14th, but we still need to confirm - so pencil that in until further notice. We will walk through and inspect our trial plots (looking at fertility and cutting frequency only - no herbicides in these trials) and discuss data from those plots and others in the region. It will probably run from late morning through lunch (included) and it will be free. So even if hayfield/pasture weeds aren't an issue on your farm, come on out for some good conversation and a lunch to go with it - perhaps especially if weeds aren't an issue for you, so you can share some insight and tips with others in the farming community!

Tar spot of corn is in the Susquehanna valley - and as you inspect your fields or begin harvest, please get in touch if you suspect you have this disease so we can document the spread!

Foliar sprays between tasseling and the milk stage are an option for those able to do so. Rotation out of corn for 1-2 years can help break down residue and reduce the initial inoculum in the field, and rotating out of corn for 3 years is ideal to break the cycle.

Lots of decent weather coming up for crop maturity and hay making. We may have a few locations that experience a risk of potential frost tonight, but then we should remain reliably above freezing for at least the next 7-10 days or so. But as you can see in the first slide coming up, most of our region (except Oneonta?) is anywhere from a few days to two weeks behind schedule for GDD. Here's the weather update from Jessica Spaccio, Northeast Regional Climate Center at Cornell:

(See: Climate Smart Farming Growing Degree Day Calculator)

Growing degree days (GDD) are calculated by taking the average daily temperature and subtracting the base temperature for development of a given organism ((High + Low)/2 – base temp = GDD).

For corn, we use base 50/86, as corn development starts at 50 degrees F and ceases above 86F. Check your location and planting date for grain GDD.

For silage, we track GDD from silking. Silking in our region began mid-July and is continuing through the first half of August. Your crop may have tasseled on or more closely to one of these dates. So while our GDD tables can get you in the ballpark, check your own whole-plant DM to make sure you’re ready, and not ahead/behind schedule!

Remember: Silage corn needs 750-800 GDD (depending on hybrid maturity) after silking to reach a whole plant DM of 32%. Under typical late season dry down conditions we can expect the crop to reach 35% DM four to seven days later. We can expect to accumulate 15-25 GDD per day, or even up to 30, so peak maturity can creep up on us quickly. But no matter what the numbers say, always check your crop to see how close you may be to harvest. For more details, see this article. 

Silking date / silage forecast GDD color key (BALLPARK ONLY - these are based on corn development from silking at GDD (which is the best sight-unseen forecasting method we have, but still has limitations):

Blue: Time to make plans (32-35% DM anywhere between 5 – 11 days from now, depending on maturity).

Green: Gas up the harvester and the trucks (32-35% DM in 2 – 8 days, depending on maturity).

Yellow: See you in the field soon (32-35% DM imminently).

Red: It’s either already in the bunk or it’s eventually going for high-moisture corn or grain (DM likely closer to 40%).