Specialists Speaking - March 2008
It’s Not Too Late To Rotate
With the high prices being contracted for corn, wheat and soybeans, producers might want to consider rotating their cotton. Although most cotton in Missouri is still grown in a monocrop system, it might be time to rotate some of those fields. The higher price for cotton has encouraged several producers to reconsider cotton.
Producers will need to consider their soil type. Although cotton does better than most crops on a sandy soil, corn is generally grown on fields with heavier textures. Silt loams would be better suited to a rotation than light sand. Irrigation is a must for corn and highly recommended for cotton.
Rotations have many benefits. First, there is generally an increase in yield. Continuous corn can cause a yield drag, but rotating corn would be beneficial to both crops. Cotton following corn would be expected to have an increased yield.
Many producers will rotate their crops to help control root-knot nematodes in cotton. This is generally a good practice, but I saw several corn fields in Dunklin County that had root-knot nematodes. Since there were juveniles present, they were reproducing on the corn. However, the populations were probably less than what they would have been following cotton.
Prices of commodities have changed dramatically since this time last year. Corn was the hot commodity in most of 2007. Cotton acreage was lost to corn due to the price differential.
However, soybeans have moved up in price to be competitive with corn, and the increase in wheat acreage due to higher prices will lead to more soybeans being grown after wheat since it fits better than either peanuts or cotton when double cropped.
Therefore, some acres of cotton will be lost to these crops this year. Cotton proved once again the reason that it has been a traditional southern crop by withstanding drought better than most crops along with peanuts during 2007 when irrigation was not available.
The Deep South was 20-25 inches below normal in rainfall, and yields were still good in many areas where stands were obtained. It is expected that cotton acreage will be down in many parts of the South by 10 percent or more.
Palmer amaranth has been the hot topic in the weed science community during winter meetings and is the focus of this issue of Cotton Farming magazine.
Glyphosate-resistant Palmer amaranth has drawn much attention; however, this weed species has several other attributes that, in conjunction with glyphosate-resistance, can make it very problematic. Palmer is a very prolific seed producer.
Published reports estimate between 200,000 and 600,000 seeds are produced from each plant. Imagine a population of 100 Palmer amaranth plants per acre, or one every 21 square feet. Imagine a herbicide that will provide 90 percent control of this weed. Ninety percent control of 100 plants per acre would leave a population of 10 plants per acre.
If these 10 plants produce an average of 400,000 seeds per plant, we have just returned 4 million seeds to the soil seedbank. I often use this analogy at producer meetings to show how quickly this weed can spread and become problematic for years to come.
Palmer amaranth also can develop a very deep root system and uses water very efficiently, helping it continue to grow, even during our hot, dry summers. Keep in mind the tools that we currently have for weed control and the tools that are being developed.
“You can pay me now, or you can pay me later.” Remember that old car care commercial? I like to think about herbicide-resistant weed development this way, especially the issue with Palmer pigweed (a.k.a. careless weed).
And it’s just not a Georgia farmer’s problem anymore. It’s everybody’s problem. And closer to home we have an issue in the Upper Gulf Coast, primarily with common water hemp.
Water hemp is also in the amaranth family and is close kin to Palmer pigweed. It is important to understand that water hemp is more difficult to control with herbicides than most other pigweeds.
And it appears that we have a tolerant/resistant population in the Upper Gulf Coast. Regardless of what you call it, the bottom line is that it is very difficult to control, and producers should take steps now to address this issue.
Start clean prior to planting, using tillage or burndown herbicides. Water hemp grows fast and can become “too large” to control by planting time.
Few herbicides will list water hemp as controlled. And if you have escapes, remove them from the field. One plant can produce more than 300,000 seeds!
Planting surveys released from the National Cotton Council indicate that cotton acres continue to be in the decline in Arkansas as well as all other states in the Mid-South. According to the report, Arkansas will reduce cotton acres another 30 percent, which will result in approximately 605,000 acres in the state.
The final cotton acreage in 2008 could still fluctuate depending on spring weather conditions and availability of soybean seed. If Arkansas has a wet spring this year, corn acreage could potentially be reduced. If this happens, and the soybean seed shortage becomes a reality, then cotton acres have a chance to increase across the state toward the 700,000 level.
Commodity prices, over all other factors, have played a major role in this acreage shift. Cotton price has been slow to increase compared to other crops. Hopefully, this will change in the near future. The big question is, “What will our cotton infrastructure look like when high cotton prices return?”
Last month we discussed how crucial early burndown can be in managing glyphosate-resistant horseweed, and reducing over wintering insect pest populations. As the saying goes, we need to “Start Clean and Stay Clean.” This is becoming more and more important as Arkansas continues to deal with weeds such as Palmer amaranth that are becoming harder to control with Roundup.
The 2007 crop year will soon be passing into history after the gins begin to wind down. High Plains producers had a great year. We are now beginning to get a good handle on the performance of many of the newer varieties, including those with the Roundup Ready Flex trait.
Our producers should seriously reflect on the past season’s situation. We were very cool and wet early and later very warm and dry. We did not really encounter much stress to reduce staple, and the overall classing results from 2007 readily show that more than 40 percent of the bales produced were a 37 staple or longer.
We also had the best micronaire in our crop since 2003. Color grades and uniformity were both excellent, and we set a record for average strength. The 2007 crop was harvested under pristine conditions. Virtually no rainfall occurred during the harvest period, and we had no inclement weather conditions.
Overall, it was the best year ever. Producers should keep in mind that the finish we obtained in 2007 is not necessarily typical for our region, and storm resistance is still important. Because of this, it is still important to compare micronaire and storm resistance over sites and years.
With the amount of data we are now getting on the newer varieties, this should be easier than when these were first introduced.
As fertilizer prices continue to rise, Georgia cotton producers continue to search for the most economical way of fertilizing this year’s crop. More producers will likely consider planting legume winter cover crops in conservation tillage systems next year to gain additional nitrogen credits.
Nematodes, however, are a real consideration and planting legume cover crops such as crimson clover and hairy vetch is not recommended in fields with known nematode problems.
Based on nitrogen (N), phosphorous (P) and potassium (K) with appropriate availability factors considered, a ton of chicken litter contains around $50 worth of fertilizer nutrients. If chicken litter is applied to land with high levels of P or K, the economic value of litter is diminished. Chicken litter is also best used as a preplant fertilizer and should be followed with an application of commercial fertilizer nitrogen as a sidedress.
All recommended P and K should be applied at planting and the use of starter fertilizers is recommended in conservation tillage.
Using the recommended rate of nitrogen with recommended split applications, some at planting and the remainder at sidedress, should greatly increase the chances of getting the most out of your fertilizer dollar.