Objective:

To determine the response of commercial spring wheat varieties to insecticide and fungicide inputs. 

Results:

Stripe rust and the Orange Wheat Blossom Midge (OWBM) are two pests in spring wheat which have a negative impact on grain yield and quality. This study was conducted to evaluate the level of plant resistance present in common spring wheat varieties, and to determine the agronomic response of these materials when treated for the control of both pests. Sixteen varieties were planted as a split plot, randomized complete block design. The main-plot was pesticide treatment and the sub-plot was variety. Headline was applied on June 20th at flag leaf for the control of stripe rust, and Lorsban Advanced was applied on June 30th at heading, for control of the OWBM.

Orange Wheat Blossom Midge pressure was uncommonly low this year. The average number of larvae per spike, regardless of treatment, was 0.4 this year compared to 9.0 in 2013. Similarly, stripe rust pressure also was low this year. Stripe rust infection only averaged 5.7% in the non-treated check varieties compared to 31.7% infection in 2013. Despite the low level of stripe rust infection, significant differences where observed among varieties. Duclair, Oneal and Hank were most susceptible, having infection levels above 15 percent. The effect of fungicide input treatment was significant for Hank and Oneal, but had no impact on Duclair. Pesticide inputs impacted thousand kernel weights. On average, TKW’s were 38.8 and 40.1 for non-treated and treated varieties, with Hank and Corbin showing the greatest benefit.

The lack of pest pressure resulted in excellent yields and grain quality. Yields averaged 109.2 bu/A with Cabernet, Duclair, Vida and Volt producing yields in excess of 114 bu/A. Protein averaged 14.7 percent, with Egan having the highest protein at 16.2 percent and Volt the lowest at 13.8 percent. There were no differences among varieties for test weight, which averaged 59.9 lb/bu. Falling number averaged 308.6 seconds, and ranged from a low of 216.7 for Vida to a high of 398.1 for McNeal.

Overall, low pest pressure prevented an assessment of varietal differences to stripe rust and OWBM and negated any benefit associated with either insecticide or fungicide treatment.

Table 1. Materials and Methods.

Seeding Date: 4/30/2014 Harvest Date: 9/8/2014
Julian Date: 120 Julian Date: 251
Seeding Rate: 80 lb/A Soil Type: Creston SiL
Previous Crop: Alfalfa Soil Test: 163-14-138
Tillage: Conventional Fertilizer: 200-30-100
Irrigation: None Herbicide: Huskie 11 floz/A + Axial XL 16.4 floz/A

Table 2. Agronomic response of spring wheat varieties to fungicide and insecticide inputs, Kalispell, 2014.

       Heading (Julian)            Height (in)            Lodging (%) Stripe Rust (%) July 23
Cultivar Check Treated Avg. Check Treated Avg. Check Treated Avg. Check Treated Avg.
Brennan 177 177 177 33.3 32.3 32.8 0.0 0.0 0.0 1.3 0.0 0.7
Buck Pronto 176 175 176 34.7 36.0 35.3 0.0 0.0 0.0 6.0 6.7 6.3
Cabernet 178 178 178 31.0 29.0 30.0 0.0 0.7 0.3 4.7 3.3 4.0
Choteau 179 178 179 35.0 35.0 35.0 0.0 0.0 0.0 6.0 6.7 6.3
Corbin 178 178 178 36.3 35.3 35.8 5.0 0.0 2.5 3.3 4.3 3.8
Duclair 177 177 177 38.3 35.7 37.0 3.3 0.0 1.7 16.3 13.7 15.0
Egan 183 182 183 36.3 36.0 36.2 0.0 0.0 0.0 2.0 1.3 1.7
Hank 177 176 177 35.7 30.7 33.2 0.0 1.3 0.7 15.7 4.3 10.0
McNeal 182 183 183 35.0 38.0 36.5 0.0 0.7 0.3 3.0 1.0 2.0
Mott 184 183 183 40.0 42.0 41.0 0.0 1.3 0.7 8.3 1.7 5.0
Oneal 182 181 182 37.0 35.7 36.3 3.3 0.0 1.7 18.0 7.7 12.8
Reeder 178 180 179 37.0 38.7 37.8 0.0 0.0 0.0 2.7 1.3 2.0
Solano 180 178 179 33.0 30.3 31.7 0.0 1.0 0.5 2.7 2.3 2.5
SY Tyra 178 179 179 34.0 33.0 33.5 0.0 0.0 0.0 0.0 0.7 0.3
Vida 182 180 181 35.7 36.7 36.2 0.0 0.0 0.0 0.0 3.0 1.5
Volt 184 184 184 34.7 35.3 35.0 0.0 0.0 0.0 1.7 4.0 2.8
Mean 180 179 179 35.4 35.0 35.2 0.7 0.3 0.5 5.7 3.9 4.8
LSD           ns 1.1            ns 3.0            ns ns           4.6 3.3
Pr>F        0.0945 0.0001       0.5350 0.0001        0.4262 0.7363        0.0007 0.0001

Table 2. (continued)

            Septoria (%)           Yield (bu/A)            Protein (%)    Test weight (lb/bu)
Cultivar Check Treated Avg. Check Treated Avg. Check Treated Avg. Check Treated Avg.
Brennan 33.3 28.3 30.8 98.4 100.6 99.5 15.1 15.3 15.2 59.9 60.1 60.0
Buck Pronto 55.0 26.7 40.8 103.9 96.0 100.0 15.2 15.1 15.2 59.2 60.4 59.8
Cabernet 61.7 36.7 49.2 114.3 116.4 115.3 14.2 14.3 14.3 58.9 59.6 59.3
Choteau 56.7 28.3 42.5 106.5 110.0 108.2 14.9 14.7 14.8 59.6 60.4 30.0
Corbin 35.0 6.7 20.8 105.9 104.7 105.3 14.6 14.6 14.6 60.2 60.8 60.5
Duclair 51.7 17.7 34.7 117.9 110.4 114.1 14.7 14.7 14.7 59.0 59.2 59.1
Egan 40.0 36.7 38.3 111.8 106.9 109.3 16.1 16.4 16.2 60.1 60.4 60.3
Hank 40.0 15.0 27.5 103.8 115.8 109.8 14.1 14.4 14.2 58.3 59.6 59.0
McNeal 25.0 21.7 23.3 103.0 110.8 106.9 14.9 14.9 14.9 60.1 61.0 60.6
Mott 33.3 25.0 29.2 105.0 116.7 110.9 14.1 14.6 14.3 59.5 60.1 59.8
Oneal 28.3 6.0 17.2 96.1 108.6 102.3 14.4 14.9 14.7 59.8 60.5 60.1
Reeder 16.7 3.3 10.0 114.1 110.6 112.3 14.7 15.0 14.9 60.6 60.9 60.7
Solano 40.0 11.7 25.8 106.1 100.2 103.1 15.2 15.0 15.1 59.4 59.9 59.6
SY Tyra 38.3 11.7 25.0 104.9 108.9 106.9 14.3 14.3 14.3 59.6 60.7 60.2
Vida 21.7 7.7 14.7 124.5 117.6 121.0 14.9 14.6 14.7 59.1 60.2 59.6
Volt 27.7 11.3 19.5 119.3 124.3 121.8 13.8 13.7 13.8 61.2 58.8 60.0
Mean 37.8 18.4 28.1 108.5 109.9 109.2 14.7 14.8 14.7 59.7 60.2 59.9
LSD            ns 17.4            ns 8.5            ns 0.4            ns ns
Pr>F        0.7787 0.0009       0.1707 0.0001       0.5975 0.0001       0.4857 0.1978

Table 2. (continued)

               TKW (g)   Falling Number (sec)      OWBM (no/spike)
Cultivar Check Treated Avg. Check Treated Avg. Check Treated Avg.
Brennan 35.8 37.7 36.8 258.7 258.4 258.5 0.3 0.0 0.2
Buck Pronto 43.2 45.2 44.2 345.1 364.9 355.0 0.1 0.2 0.2
Cabernet 41.5 39.9 40.7 326.8 329.9 328.3 0.0 0.1 0.1
Choteau 36.7 38.4 37.6 287.7 331.5 309.6 0.4 0.1 0.3
Corbin 42.7 47.9 45.3 288.7 344.4 316.6 0.0 0.1 0.1
Duclair 38.0 38.8 38.4 230.5 279.1 254.8 0.1 0.0 0.1
Egan 36.0 37.2 36.6 377.5 371.2 374.4 0.2 0.0 0.1
Hank 42.1 47.5 44.8 289.6 314.1 301.8 0.3 0.3 0.3
McNeal 39.4 40.5 40.0 370.3 426.0 398.1 2.8 0.0 1.4
Mott 33.8 35.0 34.4 295.9 290.4 293.2 1.6 0.3 0.9
Oneal 35.4 38.4 36.9 344.9 372.2 358.6 1.4 0.4 0.9
Reeder 41.8 39.0 40.4 306.1 343.1 324.6 0.0 0.0 0.0
Solano 43.3 41.7 42.5 239.0 280.3 259.7 2.1 0.0 1.1
SY Tyra 36.2 39.0 37.6 210.2 228.2 219.2 0.8 0.0 0.4
Vida 37.8 38.9 38.3 176.6 256.7 216.7 0.4 0..0 0.2
Volt 36.7 36.8 36.8 350.2 387.0 368.6 0.3 0.4 0.4
Mean 38.8 40.1 39.4 293.6 323.6 308.6 0.7 0.1 0.4
LSD           3.1 2.2            ns 27.4            ns ns
Pr>F       0.0276 0.0001        0.0971 0.0001        0.4628 0.4333

TKW: thousand kernel weight; OWBM: orange wheat blossom midge (number per spike); ns: non-significant