|January 27, 2004
"Does this wheat have a chance of making grain" is the question I am answering most at this time. For 80 percent of the wheat acreage, plant stand is erratic at best. The likelihood of this wheat crop making enough grain to justify harvesting is poor. My justification for such a statement is:
I think you can tell by the reasons given that the likelihood of this crop being harvested for grain is low. A producer would probably be trading dollars by the time the harvest was complete. It will cost about seven to nine bushels of grain to pay for the harvest cost and hauling. I'm not sure that most of our late emerging acreage will produce 10 bushels.
- Late maturity: Late emerged wheat will mature later subjecting the wheat to higher temperatures and drought stress during grain fill. Disease organisms will usually be present at higher levels during the latter part of the growing season, causing more risk to the maturing crop from wheat leaf rust and/or stem rust.
- Poor Root System Development: Seedlings which emerge in December and January have a weak, shallow root system. The root system will not have the potential for moisture and nutrient uptake that wheat planted in the optimum time frame would. Hot, dry conditions at flowering and during grain fill would result in a significant yield reduction.
- Tiller numbers: Wheat grows very slowly at low temperatures and is essentially dormant below 40 degrees. Late emergence dates subjects the wheat to cooler temperatures which results in very few tillers being produced prior to winter dormancy. Higher seeding rates are commonly used to offset this reduction in tillering, but the lack of rain hampered emergence and resulted in low number of tillers surviving until spring.
- Phosphorus inefficiency: Phosphorus availability is low in cold soils. P moves by diffusion from the soil solution to the root surface, and diffusion rates are inversely related to soil temperature. Root system expansion is slower in cold soils which results in lower phosphorus uptake by the plant. Phosphorus is an important nutrient in the development of the root system and ultimately a healthy plant.
- Vernalization: Winter wheat undergoes two important physiological changes in the fall. The processes that bring about these changes are known as vernalization and cold acclimation. Vernalization is required before heading will take place the next spring. If seeding takes place after the optimum date, vernalization will be affected and maturity delayed. Cold acclimation is necessary before plants can survive the low temperatures of winter. Vernalization and cold acclimation require growth when minimum morning and maximum afternoon soil temperatures are below 45 and 50°F, respectively. Winter wheats require a number of chilling hours to stimulate the formation of reproductive growth. These chilling hours are usually considered those above freezing but below the temperature at which wheat growth goes dormant from the cold (between 40 and 32 degrees). Wheat varieties vary somewhat with respect to vernalization requirements. Late planting reduces vernalization on wheats, which may be significant, particularly in southern growing areas of District 7. Optimum planting dates for wheat grown for grain production in our area is between October 15 and November 15. Yield reductions can be expected when wheat emergence occurs after November 20, however, weather conditions will be a major influence to the extent of the reduction.
- Reduced Plant Vigor: Four to five weeks growth at temperatures higher than those required for vernalization and cold acclimation is necessary to ensure that plants have sufficient energy reserves available for a quick start in the spring. Seeding when maximum afternoon soil temperature is approximately 64°F usually allows sufficient time for this growth and development to take place. Seeding later, when temperatures were lower, resulted in delayed germination, slow plant emergence and a reduced rate of subsequent plant growth. This usually translates into a higher risk of winterkill, lower yield and delayed maturity.
Now for the remaining 20 percent of the wheat acreage. It is time to consider making an application of fertilizer. Only a small percentage of the total nitrogen used by the crop is required prior to jointing (usually around 20 to 30%). Topdress nitrogen is best utilized if applied prior to jointing. Evaluate fields as growth begins in the spring. Since tiller numbers are low, producers will want to apply the fertilizer early. The amount to apply should be based upon amount of nitrogen present in the field and yield potential. Ungrazed wheat will utilize about 1.7 pounds of nitrogen per bushel of yield. Base rates on projected yield considering: 1) the crop condition, 2) availability of moisture, 3) residual nitrogen at planting (from soil test), and 4) amount of fertilizer applied preplant. Source of nitrogen has little to do with yield response. Apply the source that can be most efficiently and economically applied. To reduce leaf burn with high rates of liquid applicator, consider using dribble nozzles.
By late-February, the wheat will reach a stage of growth where nutrient and water uptake is increasing. If producers intend to get the most from the dollars invested on fertilizer, they need to apply nutrients soon. Soil nutrient levels need to be at a high level when the formation of the head occurs. If the head can be found above the soil surface the producer has lost the opportunity to impact the number of spikelets per head and the number of seeds per spikelet.
The rains received during January may result in weed emergence in wheat. Broadleaf weed control will be an important consideration. There is a large number of herbicides available and most will do an effective job if applied to young weeds that are unstressed. For control of Wild oats you may want to read this linked publication. To improve the level of weed control producers are advised to: 1) check the weather forecast and make sure that night time temperatures will be above 40 degrees for two days prior and following the application, 2) have adequate soil moisture at the time of application, 3) read and follow the herbicide label, 4) apply at least 15 gallons of water per acre, and 5) apply herbicides to young unstressed weeds.
For your information there will be a Small Grain Production Conference held at Abilene on August 19, 2004. There are a number of specialists from across the state involved in this activity. This will be a training opportunity for agents in wheat and oat producing counties. The agents that are unfamiliar with wheat production need to contact me and let me know if your interested in a training session covering basic information. This will give you the opportunity of asking all those questions that you will be answering for producers in 2004.
For the counties that have Hessian Fly, you may want to let producers know of cultural practices they can use to reduce the population of the insect pest. 1) Don't spread the problem--be sure that harvesters are clean before they leave the field. 2) Turn the residue under (9 or more inches is needed). 3) Select resistant varieties to plant next season. 4) Plant late; for our area planting before November 1 would allow for multiple generations of the Hessian Fly to develop. For more information go to http://ianrpubs.unl.edu/Insects/g46.htm. NOTE: The heat of a controlled burn is not hot enough to kill the insect at or below the soil surface. Burning wheat stubble would only get rid of the organic mater--not the insect.
Due to practices used by several of the larger cottonseed companies, the way we design and conduct tests have changed. I still attempt to include the varieties that the producer wants and varieties that preform well in the county. However, there are 10 to 20 new varieties being introduced each year. Our main thrust is to eliminate varieties that don't preform before they make it into large scale production. To do this we have to put varieties into a wide range of tests. We are serving our producers well if we can identify what genetically superior lines are available and what their growth and development traits are. Contact me soon and let's design your 2004 Result Demonstrations.
The cotton producers that like to plant in marginal soil temperatures should plant cottonseed with a cool-warm vigor index above 155. Two of the large seed companies are conducting the cool germination test and the warm germination test on every seed lot that they have. Producers can request a copy of that information and by combining the numbers obtained from both tests, determine the cool-warm vigor index for the seed lot. Only those seed lots with a high vigor index should be planted when cool soil temperatures exist at planting time.
The rains received during January may result in weed emergence in acreage where seedbeds have already been prepared. An application of 2,4-D will control a broad spectrum of broadleaf weeds, however, the replant window can be up to 90 days. Read and follow the herbicide label.
Grain and Forage Sorghum
It is time to request Corn, Grain Sorghum and Forage Sorghum seed for 2004 result demonstrations. If you need additional information about the varieties and hybrids available, I have compiled a list of company web sites and the URL is: http://sanangelo.tamu.edu/agronomy/newsltr/company.htm. Companies need to be contacted in the near future to acquire the seed you need for testing.
The current contract on Sesame is $0.24 to $0.25 per pound. Contracts will be offered to previous growers first and then opened up to other growers if additional acreage is needed. For information about sesame production refer to the following URL. http://sanangelo.tamu.edu/agronomy/factshet/sesame.htm.
Pesticide Recertification Training
Don't forget that your TDA pesticide applicators license will expire the end of February. If you have not gotten your paperwork for renewal you may want to contact the TDA.
The Rolling Plains Cotton Conference will be held on February 9, 2004. TDA license holders that attend can earn 5 CEU credits. Anyone planning to attend and/or needing additional information contact Todd Vineyard at (325) 823-2432 or Brandon Anderson at (940) 864-2658.
On Monday February 9, there will be a training conducted at Abilene for producers needing to obtain a Private Applicators License. For more details and to register for the meeting call Gary Bomar at (325) 672-6048.
There will be a meeting conducted February 10, 8:30 a.m. at the Cross Plains Community Center. The educational meeting will be worth 5 CEUs (1 IPM, 1 Laws/Reg, 3 General) for TDA license holders that complete the paperwork. For additional information contact Robert Pritz at (325) 854-1518.
There will be a meeting conducted February 12, starting at 1:00 p.m. at the Texas A&M Agricultural Research and Extension Center north of San Angelo, Texas. The educational meeting will be worth 5 CEUs for TDA license holders that complete the program and paperwork. For additional information contact John Begnaud at (325) 659-6522.
There will be a meeting conducted during the Texas Farm & Ranch Expo (Abilene, Texas) on February 17 & 18, 2004. For TDA license holders, the educational meeting held February 17 will be worth 3 CEUs. Two courses will be conducted on February 18 each worth 3 CEUs. For additional information contact Gary Bomar at (325) 672-6048.
- February 2, District Office, Office Conference
- February 9, Jones County, Multi-County Cotton Conference
- February 10, Callahan County, Forage Production Meeting
- February 12, Tom Green County, CEU Course
- February 17 & 18, Taylor County, Texas Farm & Ranch Expo
- February 17, Traveling, Mobile Phone (325) 650-1486
- February 20, Tom Green County, Professional Ag Workers
- February 23 & 24, Erath County, Texas ASA Meeting
- March 1, District Office, Office Conference
- March 4, Midland County, Multi-County Crops Programming Meeting
- March 4, Midland County, Small Pasture Management Meeting
- March 11, Taylor County, Soil and Soil Fertility Meeting
- March 16, Brown County, County Ag Day
- March 19, Tom Green County, Professional Ag Workers
- March 25 & 26, Annual Leave
- March 31, Nolan County, Multi-County Cotton Conference
Billy E. Warrick
Texas Cooperative Extension
Texas A&M University System