Black Cutworms Continue to Arrive

Cutworm moths continue to fly into our region this week. Traps in Castile and Spencerport caught 50 and 55 moths. The storm on Monday was a million-dollar rain for many but came up from the south, bringing unwanted cutworms with it. I’m sure we will also start to see more potato leafhoppers too. All the larvae from BCW’s that have arrived up to May 17 are big enough to be cutting plants. I found one of the early arrivers yesterday that was close to pupating. Larvae from the big flight on May 23 will all be big enough to cut plants by this weekend. I know there have been a lot of corn acres scouted so far and some fields exceeded that 3-5% and have been sprayed. Unfortunately, many of those acres might have to be scouted again until they reach the critical V6 growth stage.

Later planted corn will have a high potential of injury from these continuing overlapping cutworm flights over the last 4 weeks. Be prepared as early post herbicide applications near in case you need to add an insecticide to the mix.

Soybean Aphid Scouting

I saw a resurgence of soybean aphids (SBA) last year after they have been fairly quiet for a couple seasons. I saw them flying from buckthorn to young soybeans last week but I did not get into any soybeans since. I seem to find the first soybean colonies in mid-June. The winged females will lay live young (all females) and will bounce from plant to plant seeding potential new colonies. We are still early enough that those soybeans treated with an insecticide on the seed should control these early aphids. These first SBA infestations are hard to locate so here’s a tip. Look for the ants! The ants search out these aphids to get their waste products; honeydew. If you see ants on a soybean plant, I guarantee the aphids will be there. Here is a video on scouting for SBA by looking for the ants, https://www.youtube.com/watch?v=wwWEQSnD0LM. Threshold is 250 aphids per plant but could be lower if on small plants particularly if plants are stressed.

Winter Wheat Update

All of the wheat should be pollinated now. I believe we had an excellent period for pollination. I know some areas were droughty and I hope the rain on Monday wasn’t too late and yield potential was not lost. Cereal leaf beetle larvae are still out there feeding and getting larger. Keep an eye out for flag leaves turning white from feeding injury. I have not seen or heard of any armyworm infestations in wheat. Keep watching for the blackbirds! We are in the fourth quarter of getting our wheat to harvest. Keep scouting!

Alfalfa Pest Update 

Potato leafhoppers were found in very low numbers last week, but I expect numbers in the sweep nets to increase now. As mentioned earlier, I’m sure they came riding up with Monday’s rainstorm. I had one land on me when I was in a corn field yesterday. See the piece with thresholds in last week’s Crop Alert. Alfalfa weevil has been torturing some second cut alfalfa fields. Some of the first larvae should be done and pupating but there are smaller ones still feeding. I took this picture on Monday of a field that had to be sprayed last week. Some of these fields will be cut very soon. Third cut will really have to be watched for some weevil feeding and now leafhoppers could become a major player.

• Plant cutting around 300 Degree Days
• Degree Day data from Network for Environment and Weather Applications, NEWA

4 Timely Tips for Nutrient Management

This year, you have all taken the time to formulate a strategic plan for your crop rotations. From acres of corn and soybeans planted to seed treatment, fertilizer, and integrated pest management programs. This week, after what seemed like a prolonged dry spell, we finally got some rain. While it is impossible to eliminate all plant stresses, there are several management techniques that can help mitigate them.

1. Vigilant Scouting

Crop scouting allows you to stay on top of your field conditions, detect and diagnose problems in a timely manner, and take corrective action before significant crop losses occur.

2. In Season Soil Sampling

With many farms implementing site-specific management, there is a rising need to asses the heterogeneity in nutrient needs across the field. Fields divided into smaller management zones based on similar characteristics, can result in more targeted and effective resource use. Determine the nutrient levels in these zones across your fields by collecting soil samples in accordance with their location.

3. Pre-sidedress Nitrate Test (PSNT)

The Pre-sidedress Nitrate Test (PSNT) is an in-season soil nitrate test that can be used to determine whether maize requires additional nitrogen (N) fertilizer. This test should be performed on soil samples collected just prior to sidedressing (just prior to the corn’s peak N demand). Fields with a history of manure and/or sod incorporation can undergo the test.

The PSNT is designed to: (1) estimate the soil’s nitrate-supplying potential and (2) determine whether there’s sufficient N to meet crop requirements.

Cornell Agronomy Factsheet # 3: http://nmsp.cals.cornell.edu/publications/factsheets/factsheet3.pdf

4. Tissue Testing

Mid-season tissue testing on corn, soybeans, and other crops is common for evaluating whether the crop has an adequate nutritional supply. Though tissue testing gives historical information, I feel it can assist us in identifying a “hidden hunger”. Tissue testing is also beneficial for determining the sufficiency of nitrogen, sulfur, and the majority of micronutrients, such as iron, zinc, manganese, boron, and copper, for which soil test interpretations are not as dependable.

Instructions for Taking Samples for Plant Analysis by Penn State. https://agsci.psu.edu/aasl/plant-analysis/plant-tissue-total-analysis/instructions-for-taking-samples-for-plant-analysis

Next report will be June 21.