Row crop bits and pieces
by Emanuel County Live | June 30, 2009 12:00 am
by MARK CROSBY
As we move into the second week of June, here are a few items of possible interest for our row crop farmers.
There will be a Cotton Scout School on June 18, 2009 at the Southeast Research and Education Center near Midville. This program will offer basic information on cotton growth and development, cotton insects, and scouting procedures. The training will serve as a review for experienced scouts and producers and as an introduction to cotton insect monitoring for new scouts. For additional information call me at 237-1226.
Herbicide injury may be more common during 2009! Because of glyphosate-resistant Palmer amaranth (pigweed), many growers are using residual, at plant herbicides on many more acres than in previous years. These residual herbicides applied at planting are essential if growers are to survive this resistant pest. But this years wet, overcast planting season has provided increased herbicidal activity. As far as weed control is concerned, overall we have had great weed control but we have also had excessive cotton injury. Regardless of which residual herbicide that was applied this season, injury has been widespread and quite common.
One common complaint has been from Reflex on cotton. Significant injury could have occured when heavy rains caused soil treated with Reflex to splash on newly emerging cotton. In most situations, the cotton should recover when a favorable environment returns but growth may be slow for a short period of time. In very severe injury situations, plants where stems are “burned” and subsequently have lesions, may die from seedling disease or other environmental factors such as heavy winds.
Farmers may also see additional injury from Valor if the recommended plant-back requirements were not met, Injury will be similar to that of Reflex. It is also worth mentioning that postemergence applications of glyphosate plus metolachlor (Dual products) or Staple have also been causing injury levels greater than normal. This may be a result from “thrippy” cotton or from cloudy weather reducing leaf cuticle thickness. Regardless, avoid spraying these combinations on wet, dewy cotton and avoid adding in additional adjuvants other than what is required by the glyphosate brand selected.
Fusilade DX is now labeled for use on peanut for control of several grass species. The normal use rate for Fusilade DX is 12.0 oz/A. The maximum rate that can be applied in a single application is 24 oz/A. The maximum rate that can be applied per season is 48 oz/A. Split applications can be made 14 days apart. Either a crop oil (1.0% v/v) or non-ionic surfactant (0.25% v/v) can be used with Fusilade DX.
The pre-harvest interval (PHI) for Fusilade DX in peanut is 40 days and the rain-free period is 1 hour. Another unusual and off the wall benefit of Fusilade DX is that it also has activity on bristly starbur (i.e. Texas sandspur, goathead).
Should you apply land plaster to peanuts? Many peanut farmers are trying to decide if they need to apply land plaster to their peanuts this year? Pegging zone samples need to be taken as soon after emergence as possible in order to get the results back and get the calcium applied by the time the plants initiate blooming. Our standard UGA recommendation for calcium nutrition is to add supplemental calcium in the form of gypsum (landplaster) if the sample from the three-inch depth has less than 500 pounds per acre of calcium or if there is less than a 3:1 ratio of calcium to potassium. Many of the new cultivars we are planting now have a pod and seed size considerably larger than Georgia Green. These cultivars include Georgia-06G, Florida-07, and Tifguard. With the three large-seeded runner cultivars (Georgia-06G, Florida-07, and Tifguard) I would err on the side of caution and use 700 pounds per acre as the threshold for calcium application.
The UGA recommendation for calcium nutrition for peanut being grown for commercial, edible use is to apply 160-200 pounds per acre of elemental calcium (Ca) per acre. Most gypsum products are about 20% calcium so it would require 800 – 1,000 pounds per acre of gypsum to meet that requirement. If a field is being grown for seed production, then the rate would be doubled.
For more information on these and other topics of interest, call the Emanuel County Extension Office at 237-1226.