Texas Agricultural Extension Service
Texas A&M University System
|January 30, 2001
What is the number one question being asked? Does this wheat have a chance of making grain? For 90 percent of the planted wheat acreage the 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.
- 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 10 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.
I have seen a lot of fields that look like they are short on Nitrogen. Wheat producers should consider making a fertilizer application as soon as soil temperatures increase. Between February 15 and March 15 the wheat will reach a stage of growth where nutrients and water uptake will increase significantly. If producers intend to get the most from the dollars invested on fertilizer they need to apply nutrients soon. Soil nutrient levels will need to be at a high level when the formation of the head occurs. It is important to have the soil nutrient level high when wheat is developing spikelets (shortly before rapid spring growth begins). 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.
For your information there will be a cotton production conference held at San Angelo on March 27, 2001. There are a number of specialists from across the state involved in this activity. This will be a training meeting for agents in cotton producing counties. The agents that are unfamiliar with cotton production will be asked to attend the introductory session which is designed to provide basic information. This will give you the opportunity of asking all those questions that you will be answering for producers in 2001.
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 2001 Result Demonstrations.
From conversations that I have had with producers several are indicating that they plan to plant cotton the end of April or the first part of May. If soil temperatures are cool (60 degrees minimum) at the time of planting then cottonseed with a cool-warm vigor index above 155 should be the only seed planted. Both Delta and Pineland Seed Company and Paymaster Seed Company conduct a cool germination test and a warm germination test on every seed lot to be sold. 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 varieties with a high vigor index (above 155) should be planted when cool soil temperatures exist at planting time.
Hopefully, most of the producers have booked their favorite cottonseed variety and have it on a pallet in the barn. Seed supplies may be tight by planting time and it is better to be ahead of the curve this year insead of trying to make cottonseed purchases just prior to planting.
The current contract on Sesame is $0.21 to $0.24 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 Fisher County Cotton Production Conference will be held on February 22, 2001. TDA license holders that attend can earn 3 CEU credits. Anyone planning to attend and/or needing additional information contact Justin Hansard at (915) 776-3259.
There will be a meeting conducted during the West Texas Farm and Ranch Show (Abilene, Texas) on February 20 & 21, 2001. For TDA license holders, the educational meeting held February 20 will be worth 3 CEUs. Two courses will be conducted on February 21 each worth 2 CEUs. For additional information contact Gary Bomar at (915) 672-6048.
- February 2, District Office Teleconference
- February 5 - 7, Bexar County, Physiology Study Group
- February 13, District Office, Administrators Meeting
- February 15, Howard County Master Gardeners
- February 16, Tom Green County, Professional Ag Workers
- February 20 & 21, Taylor County, West Texas Farm & Ranch Show
- February 20, Runnels County, Planning for Farm and Ranch Safety School
- February 22, Fisher County, Cotton Symposium
- February 23, Harris County, 4-H Foundation Meeting
- February 25 - 27, Lubbock County, Texas ASA Meeting
- March 5, District Office Conference
- March 16, Tom Green County, Professional Ag Workers
- March 20, Menard County, Forage Production Meeting
- March 27, Tom Green County, Concho Valley Cotton Conference
- March 27, Tom Green County, Southern Rolling Plains Cotton Growers
- March 30, Mason County, Hill Country Ag Day
Billy E. Warrick
Texas Agricultural Extension Service
Texas A&M University System