So one more post from the Palouse in SE Washington. We have a field trial with a grower and Eric and I walked it last Wednesday. This is soft white winter wheat and it is looking good.
The heads are filling grain now, and grain protein is being made now too. Yield and protein determine payment to the grower. Outside of weather, one thing that can affect yield is insects like aphids.
And here they are. I believe these are Russian Wheat aphids. (Someone will tell me if they are not.) I just happened to get this picture that is interesting. I believe that larger brown one is what is referred to as a mummy, having been stung by a parasitic wasp that laid eggs inside. The insect world isn’t pretty. These aphids are sucking leaf juices and can cause the leaf to turn yellow. And this is the flag leaf, the energy leaf of the plant.
So there is a threshold. It is an average of 20 aphids per plant at this stage. This according to his crop scout. So this field wasn’t there. (I read where other experts say as many as 50 is threshold before damage exceeds cost of control.) But the grower was nervous about not spraying. Then there is the cost of the product (Dimethoate) and a plane. A good yield is on the line, but wheat prices aren’t the best. The field was pretty slick with aphid juice. Too bad the wasps didn’t do more. Not sure what he ended up doing. No one said farming is easy. And if they did, they are wrong.
1) Evaluate the effects of a drill application of 4 gal/A of Pro-Germinator + 2 qt/A on yield of winter wheat compared to no fertilizer applied, which is the most common treatment option. (2) Evaluate the effects of a fungicide application (Quadris) at fl ag leaf (Feekes stage 10) either alone or with foliar fertilizers. (Note: all treatments received the same topdress application: 12 gal/A High NRG-N + 16 gal/A 28%+eNhance.)
Winter wheat is usually planted right after soybean harvest here in the Upper Midwest, and is usually not fertilized at that time. Later in the growing season, foliar applications of fungicides have often shown yield increases due to suppression of fungal diseases. The application of fungicides presents an excellent opportunity for the inclusion of some crop nutrition. An experiment was conducted to evaluate the above two objectives, and this was the second year of application of these treatments.
For the foliar application, spray volume was at 20 gal/A with Turbo TeeJet nozzles (TJ-03) at a pressure of 60 psi.
Treatment yields appear in the following chart.
The application of the Pro-Germinator + Micro 500 at planting resulted in a signifi cant yield increase.
Application of Quadris, Quadris + ferti-Rain and Quadris + NResponse had a larger yield effect on the wheat that received Pro-Germinator + Micro 500 at planting. It is possible that the addition of fertilizer at planting increased yield potential. The presence of the foliar inputs was able to take advantage of wheat that was not limited by lack of nutrition in the fall, whether this was due to larger plants, or better fed.
The application of the planting-time fertilizer did not seem to have a major effect on the treatment that received no foliar application. There must have been a synergistic effect where the presence of both had a far greater effect than that of either input alone.
Treatment averages from the two years of this experiment appear in the following table.
Effect of Drill-Applied Fertilizer and Foliar Applications on Winter Wheat Yield.
North Central Research Station. 2010-2011
With Drill Fertilizer
2 yr avg.
Quadris + ferti-Rain
Quadris + NResponse
Quadris + Coron
No Drill Fertilizer
Quadris + ferti-Rain
Application rates in table:
Quadris + NResponse
Quadris: 8 fluid oz/A
Quadris + Coron
NResponse and Coron: 3 gal/A
ferti-Rain: 3 gal/A (2010); 2 gal/A (2011)
There was a 7.7 Bu/A advantage per year from the application of the planter-time fertilizer (4 gal/A Pro-Germinator + 2 qt/A Micro 500).
Addition of ferti-Rain and NResponse to the foliar application of Quadris did result in further yield increase of wheat.
To compare fertilizer program rates and sources for winter wheat.
Fall applied fertilizer programs have been researched for a number of years at the NCRS. Comparisons of a soil test program to a basic program of Pro-Germinator and Micro 500 have been tested the last 5 years to determine the importance of following a soil test. In this year’s experiment , a soil test program of 8.5 gal/A Pro-Germinator, 1 gal/A Sure-K, 2 qt/A Micro 500 and 2 gal/A access was compared to 4.25 gal/A Pro-Germinator with 2 qt/A Micro 500. These programs were also compared to a conventional fertilizer program of 10-34-0, ATS, Manganese and Zinc. Yield results appear on the chart below.
All fertilizer treatments increased wheat yield over the nitrogen only treatment.
Although the soil test program did have a higher yield than the other fertilizer programs, it was not statistically significant. Similar treatments have been evaluated in the past at the NCRS with a 2 bu average yield advantage to the soil test program. In all cases, the additional fertilizer costs were not covered by the yield increase.
The addition of access to the fertilizer program did not influence yield.
The conventional program yielded similar to the other fertilizer programs.
Long-term comparison of the methods of application on wheat yield.
Three years of testing at the NCRS has shown consistent results when it comes to method of application options for winter wheat. For comparison: preplant broadcast, drill applied, fall foliar on 2” growth and spring topdress were evaluated. Soils at the NCRS are in the mid to high levels for phosphorus, so limited inputs are required. This combined with the shortened fall growing season before dormancy provides more options for timing. Fertilizer programs and three year averages appear on the chart below.
For three years in a row, the NCRS has shown there is little difference between placement options on winter wheat.
Areas with more fall growing time and requirements of more phosphorus, it may be necessary to have nutrients on sooner to provide best yield results.