How they control weeds and insects

Hoard's Dairyman: 

How they control weeds and insects

Date: 
Mon, 03/12/2012

Four dairy producers from latest Round Table share more on cropping practices.

We have some bonus coverage from our February 25 Round Table, "Forage and tillage practices that work for them." The dairy producers discuss more on controlling weeds and insects. The four participants hail from Iowa, New York, Pennsylvania, and Wisconsin. (To read the complete Round Table, check out your February 25 issue, pages 118 to 120 or click here).

Foresight Farms (Iowa): At one time, we had some challenges with weeds in our corn ground. However, since then we have gone to using half-rate of acetochlor and nitrazine with the 40 to 80 pounds of N preplant. That is followed by Roundup application at the V-5 stage. The program has taken care of that problem. Also, we did see a nice bump in yield when we added a fungicide (half rate) with the final pass of Roundup.

We have not been very aggressive with herbicide use on our hay ground because of our cutting schedule. We do have more weed pressure than it appears and believe Roundup Ready alfalfa will work great for this application. We did try some Roundup Ready alfalfa five or six years ago before it was pulled off the market. We are diligent about spraying for leaf hoppers after each cutting, and for the first time last year, we tried some fungicide on the hay ground.

Graywood Farms (Pennsylvania): For corn, a kill-down herbicide is applied before planting. After planting, we apply a preemergence herbicide. When the corn is 12 to 24 inches tall, a postemergence spray is applied to get any late-season weeds.

Alfalfa fields are swept in early spring for weavils and again in early second-cutting growth for potato leaf hoppers. Depending on how many insects are recovered during the sweep determines whether the crop gets an insecticide or not.

Van Slyke’s Dairy (New York): We maintain an annual pest management system for weeds and insects. In alfalfa, we spray Pursuit on the new seedings after establishment and before first cutting. We watch for aphids and leaf hoppers and spray as needed, but usually a light coating of liquid manure after cutting knocks down any population of harmful insects.

In corn, we incorporate Lumax and Atrazine for season-long weed control. With the rapid shading of the narrow rows, we have had above-average success controlling weeds. However, in the last two years, we have had a few fields with a major breakthrough of late-season giant foxtail. It is a weed that has shown up after scouting ends in mid-June, and by harvest time it is as tall as the corn. Fortunately, it has been isolated to a few acres and edges of fields, but we will be making changes to our 2012 herbicide program to allow for longer residual weed control on annual grasses.

We begrudgingly grow traited corn varieties, and are quick to remind our seed salesman that we don’t appreciate not having the freedom of choice. For 2012, we are planning to plant half of our corn acres with one particular conventional hybrid, with the remaining half split between five other traited varieties. In our opinion, our industry is already seeing the negative results from overuse of traited corn such as Bt resistance and glyphosate resistance.

Woldt Farms (Wisconsin): New seedings are sprayed for weeds and usually need to be sprayed for leafhoppers. These fields are scouted weekly to see if insects get above threshold.

Traited corn is used to protect against corn borer and rootworm. A single- or two-pass herbicide program is used to control weeds, depending on the farm and amount of weed pressure.