Alfalfa

Field Observations Thru May 12

Throughout the growing season I will post information on different pests or issues I am seeing in our fields in Knox County.  This week Mother Nature is finally cooperating, a little, and we are starting to make some planting progress.  Below are a some to observations to keep an eye on.

Alfalfa

Continue to scout fields for Alfalfa Weevil.

Click here for Alfalfa Weevil Scouting Guide

 

 

Corn

Finally, we are planting!  While conditions are not perfect, we are able to get some seeds in the ground!

Most of our early planted corn has sprouted, some has finally begun to emerge.  As you evaluate your plant stand, do not be too concerned, yet – it is still early!

Click here to read the following post from OSU Agronomists Osler Ortez, Laura Lindsey, Alexander Lindsey

Soybeans

Same story as corn.  Early planted soybeans are beginning to emerge. As you evaluate your plant stand, do not be too concerned, yet – it is still early!

Click here to read the following post from OSU Agronomists Osler Ortez, Laura Lindsey, Alexander Lindsey

Wheat

Trapped heads in Wheat.  While rare, I have seen this before. It looks like the heads are trapped in the boot.  This is usually a weather related issue.

Under warm conditions, the heads are pushed out of the leaf sheath quickly, but when it’s cold/cool, the process is slower, causing the heads to get trapped.  This is particularly problematic on awned varieties.  This issue could cause some constriction and affect grain full at the tips of the head, but usually not a major cause for concern.  

Click here for more information

Field Observations Thru May 5

Throughout the growing season I will post information on different pests or issues I am seeing in our fields in Knox County.  This week, not much happening in our fields due to the cold, wet weather. Below are a some to observations to keep an eye on.

Alfalfa Weevil

 Even with the chilly weather we have experienced the last 2 weeks,  we have accumulated enough growing degree days for alfalfa weevils to be active. These cold temperatures may have slowed feeding but the temperatures haven’t been cold enough to kill the weevil larvae.  We are concerned that as soon as it warms they will speed up their feeding again with a vengeance.  Scout your fields now, not when excessive feeding grabs your attention.  Keep in mind that at a certain point, early harvest is preferable to treatment.

Click here for Alfalfa Weevil Scouting Guide

Here is a video about scouting weevils in alfalfa:  https://forages.osu.edu/video

Alfalfa Weevil Update  – C.O.R.N. Newsletter

Wheat 

Even with chilly temps wheat is growing at a good pace.  Most of our week is passing through Feekes 7 and is in (or soon will be ) in Feekes 8.  As our wheat approaches Feekes 9 it is time to scout your fields and evaluate your stand/yield potential and determine if fungicide applications are warranted.  2023 Wheat Fungicide Ratings can be found in this post from earlier this week.

Updated Tri-State Fertilizer Recommendations Now Available

After 25 years, the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa has been comprehensively updated and is now available. The full version can be downloaded as a free pdf, or a printed copy can be purchased: https://extensionpubs.osu.edu/search.php?search_query=974&section=product

A summarized version of findings can be found here: go.osu.edu/fert-recs

The recommendations are based on more than a decade of field trials evaluating N, P, K, S and micronutrients, including over 300 on-farm trials across 41 Ohio counties. This work confirms that the original Tri-State recommendations provided sound guidelines for nutrient management. However, some changes in the recommendations have been made to keep pace with contemporary practices in Ohio’s field crops. This new guide provides an objective framework for farmers to manage nutrients as judiciously and profitably as possible.

Red counties reflect the Ohio counties where fertilizer trials were conducted (2014 – 2018).

Leafhoppers, Grasshoppers, and Beetles, Oh My!

Source: Kelley Tilmon, Andy Michel, OSU

As the summer progresses we are receiving reports of insect problems often encouraged by hot, dry weather.  Last week we reported on spider mites and especially if you are in an area of continued dry weather we recommend scouting your soybeans and corn  https://agcrops.osu.edu/newsletter/corn-newsletter/2020-22/watch-spider-mites-dry-areas .

Some areas are also reporting increases in young grasshoppers in soybeans, another insect favored by dry weather.  Grasshoppers of often start on field edges so early scouting may allow for an edge treatment.  Japanese beetles are another common defoliator of soybean that are starting to appear.  Both of these pests fall into a general defoliation measurement, and we recommend treatment if defoliation is approaching 20% on the majority of plants in post-flowering beans.  Download our guide to estimating defoliation in soybean at https://aginsects.osu.edu/sites/aginsects/files/imce/Leaf%20Defoliators%20PDF_0.pdf

A weird problem being reported not just in Ohio but in parts of the Midwest as far-flung as Minnesota is the red headed flea beetle, which is being found in corn and soybean.  This is a small, narrow, shiny black beetle with a red head which springs like a flea when disturbed.  Feeding in soybean creates small round holes and in corn longer narrow strips of damage.  This feeding is seldom economic.  In soybean follow the general defoliation threshold of 20%.  Leaf feeding in corn is almost never economic, but be on the watch for silk-clipping, which is rare but possible.  There are no thresholds in corn, but our Minnesota colleague Bruce Potter suggest this guideline: “flea beetles are very numerous (it is likely more than 5-10/plant), pollination is less than 50% complete, and numerous plants have silks clipped to within 1/2 inch, you might consider an insecticide.”

Finally, earlier in the season we reported higher than usual numbers of potato leafhopper in alfalfa and encouraged stepping up scouting.  In some fields third-cut alfalfa is being heavily impacted by this insect.  You can review our scouting advice for this insect at https://agcrops.osu.edu/newsletter/corn-newsletter/2020-17/time-start-scouting-potato-leafhoppers-alfalfa

Alfalfa Weevil – It’s Closer Than You Think

Green alfalfa weevil larvae (the main feeding stage) at various growth stages, and brown adults. Photo by Julie Peterson, University of Nebraska.

Though it seems like spring has been slow to come this year, we have actually accumulated enough degree days to see potential outbreaks of alfalfa weevil in some locations.  Ohio experienced its 5th warmest winter on record (1895-2020) and March temperatures averaged 2-8°F above average. Overwintered adults begin laying eggs when temperatures exceed 48°F.  Peak larval activity and feeding damage occurs between 325 and 575 heat units (based on accumulation of heat units from January 1 with a base of 48°F).  Current (Jan. 1 – Apr. 11, 2020) heating units range from near 100 in far northeastern Ohio, 100-200 across much of northern Ohio, and 200-300 units across much of central, southwest, and southeast Ohio. South central Ohio has currently eclipsed 300 units as evident at OSU South Centers in Piketon.

In short, now is the time to start scouting.  Alfalfa fields should be scouted weekly for weevils until at least the first harvest.  Don’t let your guard down with the recent turn to cooler weather! We’ve seen significant weevil infestations in past years when early warm weather pushed weevil development earlier than normal, followed by cooler weather later that slowed alfalfa growth. Continue reading Alfalfa Weevil – It’s Closer Than You Think →