Fungicides – How the Benefits Outweigh the Cost

Well folks, it may only be the middle of February, but it’s time to start thinking about your 2019 crop protection programs. I’m sure many of you saw some disease pressure in your fields in 2018. Whether it be watching your corn fall at the end of the season, or seeing lesions on your soybeans, the hot and humid July we saw in 2018 created a breeding ground for many disease pathogens across the state of New York. Luckily, there are some management strategies that can be done to help reduce disease pressure for 2019.

What are some of the diseases you saw in your fields this past season? Here are some of the more widespread diseases we saw and how fungicides can help in 2019 –

Northern Corn Leaf Blight
Northern Corn Leaf Blight is a disease we typically see every year in New York State, and it is favored by wet, humid, and cooler weather. If lesions begin early in the season, typically before silking, it can cause some significant yield loss come harvest. Lesions are long, slender, and taper at the ends.

Gray Leaf Spot
Like Northern Corn Leaf Blight, Gray Leaf Spot also favors wet, humid conditions. Gray Leaf Spot also favors reduced tillage or continuous corn fields. Symptoms of Gray Leaf Spot include lesions that begin as small yellow halos. They are first noticed in the lower leaves and will elongate to pale brown lesions with blunt ends – often termed “matchsticks.”

Anthracnose
Anthracnose is typically seen widespread across New York State each year. Anthracnose Leaf Blight and Anthracnose Stalk Rot are both caused by the same fungus and can be identified by the water-soaked lesions either found on the stalk, or you guessed it, on the leaves. Anthracnose Leaf Blight is typically seen earlier in the season, while Anthracnose Stalk Rot is seen later in the season.

Eyespot
Eyespot is favored by cool, wet weather and can be identified by oval or circular spots on the leaves. They appear water soaked an eventually form brownish purple margins with a yellow halo. This fungus spreads through wind or locally on crop debris.

Common Rust
Rust symptoms will typically appear after silking as small, round brown pustules on both leaf surfaces. Rust is favored by cool, moist weather and are blown north during our growing season. If severe enough, early leaf death is possible.

Making sure you correctly identify the disease is essential to choosing the correct management strategy. Give your local CaroVail a call if you’re seeing disease lesions in your fields for help diagnosing and to discuss possible management options. Look here for some information from Cornell on these diseases.

The Benefits of Fungicides
When you’re deciding on a management strategy, it’s important to take into consideration the different factors that play into how severe a disease outbreak may be. What is the disease history of the field? Is it a no – till field or a field with significant crop residue? Is it continuous corn – on – corn? Did you plant a resistant variety? Are the weather patterns favoring heavy disease pressure?

Fungicides may be curative or preventative, or both. What are your options?

1. 1x Early Curative or Preventative at Stage V5 – V8
   1. Prevent Disease Pressure
2. 2x Early and Late Curative & Preventative Spray
   1. Application at V5 – V8
   2. Application at VT – R1
   3. Late & Mid – Season Foliar and Stalk Health
3. 1x Late Season Curative & Preventative Spray
   1. Application at VT – R1
   2. Late Season Foliar & Stalk Health