Cereal Leaf Beetle Eggs have Hatched
Found the first CLB larvae in wheat on Tuesday. Larvae are shiny and black and almost look slug-like. They cover themselves in their own excrement and are pale orange when clean (after a rain). They feed on the green epidermis of the leaf and their damage results in a windowpane appearance as the leaves have strips of white. They are not causing much injury now, but they will as they get bigger. I also saw adults still paired up and laying eggs. Threshold is three eggs and larvae per plant or one larva per flag leaf. Oats are small but CLB adults may move into the them as they get bigger and should to be monitored.
Winter Wheat Heads Starting to Emerge
Some of the early planted winter wheat started to head this week with awns pushing out of the boot. Most of the fields still had the head an inch or two down in the boot. It is time to get ready to apply a fungicide as full head emergence is not far away and flowering will begin in some fields next week. Fungicide applications at flowering of Miravis-Ace, Prosaro, Prosaro-Pro and Sphaerex will be crucial in suppressing Fusarium head blight (FHB). These fungicides also protect upper leaves against fungal leaf blotches, powdery mildew, and rusts. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB and mycotoxin suppression can be expected. Check the Fusarium Risk Assessment Tool as we get closer (http://www.wheatscab.psu.edu/ ) as your winter wheat crop approaches heading and flowering. Right now, it looks like the 6-day risk forecast for the NWNY region is at medium to high risk for FHB infection. Let’s hope that gets better when most of our wheat is flowering.
No armyworm larvae have been found yet in fields. The larvae would still be very small and would be hard to detect. I’m sure there are a couple fields out there that will have a problem so keep watching for chewed and missing lower leaves.
Check Your Alfalfa for Weevil Injury
I have been getting lots of reports of alfalfa fields that are over threshold for weevil injury (40% of the stems with feeding damage). I checked one field on Monday and could easily see feeding and could find the small larvae (first and second instar) hiding in the unfurled leaves at the top. Some fields have been over threshold and were sprayed because they were more than 10 days from being harvested. The problem I see with sprayed first cutting alfalfa is that it kills all the natural enemies. Pea aphids which are normally held in check rebound and then become an issue. So, if you sprayed, be aware of pea aphids. If your alfalfa is within 10 days of harvest, cutting early is a good method of minimizing weevil damage. Eighty percent of feeding occurs in the fourth instar. This is when yield and quality losses occur.
Pheromone Trap Update
Black cutworms (BCW) continue to arrive and significant flights were caught again at four of the six locations. The site in Wayne County had its first significant flight this week and was the highest trap catch. We are halfway to 300-degree day point across the whole region. This is when the BCW will be big enough to cut corn plants. Eggs will continue to hatch and larvae will feed on corn leaves until that time. Look for holes in the leaves and cut leaves on the ground. Remember, an insecticide treatment is warranted if 5% of more of the plants are injured or missing.
Common armyworms (CAW) continue to be active and arrive in Yates and Wyoming Counties. Wayne also had its first significant CAW flight of the spring. Winter grain and grass fields will be the places we will need to watch. Larvae are small and will be feeding down at the base of plants on the lower leaves. A sweep net is a great tool to use on grass hay fields to detect their presence.
- Egg hatch around 90 Degree Days
- Plant cutting around 300 Degree Days
- Degree Day data from Network for Environment and Weather Applications, NEWA
Summary of Alfalfa Height and Prediction of % NDF- May 13, 2024
1st Cutting Forage Quality Update
This is the first week of monitoring 1st cutting for quality this year. Our procedure consists of using alfalfa height to predict Neutral Detergent Fiber (NDF) for alfalfa, alfalfa/grass mixed, and grass stands. Alfalfa height has proven to be a reliable indicator of NDF values in the field.
Height indicators alfalfa and grass for NDF content are below:
- In general, we say 100% grass stands should be cut when nearby alfalfa is 14 inches tall to achieve the desired 50% NDF.
- Begin cutting 50/50 mixed alfalfa and grass stands when nearby alfalfa is 22 inches tall for the desired 44% NDF.
- Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall for desired 40% NDF.
Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of 0.8% points and alfalfa of 0.5% point. NDF usually increases about 0.8 to 1.2/day for grasses expecting the lower end of that range in cooler weather and the higher end in warmer. Alfalfa NDF increases about 0.4 to 0.7/ day again depending on temperatures. Predictions are adjusted for the coming week’s weather and right now assuming normal growth.
In the attached spreadsheet locations around the region are listed where we have measured alfalfa height. You can use the location and elevation as a guide to conditions that may be like your farm.
As of today, May 13th, 2024, alfalfa heights averaged 18 inches across all locations. An average growth of 4 inches. Grass stands are starting to head out and should be harvested. If you have not harvested, you should be thinking about which fields are going to be taken for quality forage or tonnage. Mixed stands are ready to harvest this week May 15th and pure alfalfa will be ready to harvest around Memorial weekend beginning of June.
It is important that you get first cutting off in a timely manner for quality purposes, so please communicate in advance with your team on how you are going to plant corn and successfully harvest 1st cutting.
CLICK CHART TO ENLARGE
Next report will be May 22.
