April 8, 2014
2014 Cropping System Update
Tony Vyn, cropping systems specialist, stressed his concerns related to tillage on wet soils and the potential for compaction, and stressed patience regarding the first tillage trip in the spring. Some fall strip till fields experienced berm deterioration and may need a spring strip till operation prior to planting. If tillage is planned, minimum tillage should be implemented. No reason to get alarmed at this date on the calendar. In some cases, high speed vertical tillage may help dry out top soil. Residue accumulation around ponds will be an issue. Heavy residue concentrations will need addressed prior to planting.
Travis Legleiter, weed science program specialist, discussed termination of cover crops and controlling winter annual weeds. In most cases, Glyphosate & a Sharpen product along with 2,4-D will be the best herbicide option. However, the green vegetation to be controlled must be actively growing to increase the opportunity for successful control. As a rule of thumb, night time temperatures must be 45 degrees and above for 3 nights in a row in order for target weeds and crops to be considered actively growing. In some cases, wheat fields may need to be abandoned and planted to corn or soybeans. One qt. of generic glyphosate should take care of the wheat, but before spraying scout the field to see if broad-leaved weeds are present, which might require additional herbicides such as the above mentioned Sharpen products and 2,4-D.
Bill Johnson, weed specialist, stressed that if the no-till field is to go to soybeans include residual products in the tank mix. Some of the more common residual soybean herbicide products for controlling marestail include: Sencor, Valor, and Authority. If marestail is a problem producers should consider an early and late spring burndown herbicide application. At a minimum use a residual with the late application. However, another option is to split the residual and add a residue to the tank mix for both the early and late spring application. This will reduce the chance of any spring germinating marestail getting established if weather conditions turn wet after the first application. It is important to get marestail weeds sprayed before they bolt. They really need to be controlled before they reach 6” height. Most winter annual weeds, cover crops, and winter grain crops can be tough to kill. Use the right products, the right rate, and treat only when the green vegetation is actively growing. Also try to get the treatment accomplished when the green vegetation is at the appropriate growth stage. Finally, be sure to respect any planting restrictions that may be associated with some of the herbicide products.
John Obermeyer, integrated pest management specialist, warned us that slugs could become an issue, especially in weedy fields or fields with cover crops if damp, wet conditions continue. Heavy, wet residue is an ideal environment for slug development. Unfortunately, slugs are not easy to control. Baits are on option, but are expensive ($15 to $20/acre) and control is not guaranteed. In worse case scenarios tillage might be necessary. Row cleaners could help by removing the residue from the row. John also announced that the first Black Cutworm moth captures took place in Randolph County and alfalfa weevil hatch is occurring in southern Indiana.
Keith Johnson, forage specialist, discussed the impact of the cool wet spring on forage production. Although spring alfalfa and legume seeding season is here, soil conditions will probably not allow many producers to reach the spring target date of mid-April. Seeding into early May can be successful but additional management will be needed to control potato leafhopper and spring germinating weeds. Potato leafhopper can be lethal on young succulent alfalfa seedlings. Also, producers who will abandon winter wheat fields might consider harvesting the winter wheat for forage if not worthy of grain. However, be sure to check with your crop insurance agent before harvesting the field for forage. Some heaving of alfalfa is still being reported. Finally, livestock producers should be careful not to turn animals out on spring pastures too early. As a rule of thumb, the pasture growth needs to be in the 4” plus range.
Jim Camberato, soil fertility & plant nutrition specialist, feels that fall N applications are still probably ok, but as soils start to warm up, losses will begin. He still anticipates a lot of concerns regarding spring NH3 applications and corn seedling damage. Anhydrous application needs to be a minimum of 7” deep to help reduce the chances for corn seedling damage. Results of an anhydrous ammonia research study showed that injections of 150 lb. actual N, were safe at 5 to 6” from the seed, while the distance increased to 7 to 8” for injections of 200 lb. of actual NH3.
On sandy soils, wheat fields may have already lost some of their top dressed nitrogen. If winter wheat fields have not yet been top dressed or if nitrogen losses have occurred there is still time to make a nitrogen application. Research trials show that winter wheat can still respond to nitrogen applications at jointing. If fields showing nitrogen deficiency do not respond to a nitrogen application, sulfur deficiency is likely. The only way to know for sure is to tissue test.
Bob Nielsen, corn management specialist, stressed patience this planting season. Also, over the last few years there have been a lot of farmers switching to pop up fertilizer. Seedling injury from pop-up fertilizer is common. As a rule of thumb, on heavy soils 5 lbs. of N and K is the upper limit, while the rate for sandy soils is 3 lbs. of N and K. This year growers might want to visit with their seed supplier to get the cold germination test for each of their corn varieties. Warm germination tests are on the seed tag, but cold germination are not. Cold germinations must be 85% or higher. Plant the varieties with the best cold germination tests first. Bob reminded anyone working on on-farm research projects to be making final contact with their growers if they have not already done so.