Objective:

Evaluate fungicides for crop tolerance and stripe rust control in spring wheat. 

Materials and Methods:

Buck Pronto spring wheat was planted on May 3 in a field previously cropped to barley. A tankmix of Axial (16.4 oz/A) and Huskie (11 oz/A) was applied on June 5 to control weeds. Fungicides were applied were applied on June 19, 2017 using a CO2 backpack sprayer equipped with TeeJet XR11002 nozzles in a volume of 20 GPA. The crop was 13 inches tall and was in the boot stage. Stripe rust infection at application was about 10 percent. The study was treated with Curtail at 2 pt/A on June 19 for the control of Canada thistle.

Results:

All treatments afforded excellent crop tolerance. Similarly, all treatments initially provided excellent control of stripe rust. That being said, hot, dry conditions prevent the disease from developing into a serious outbreak. There was essentially no infection present when the study was evaluated at 25 days after applications or at harvest. Concurrently, there were no treatment differences detected for yield, protein or test weight.

Summary:

The drought and heat stress prevented the initial stripe rust infection from increasing, which in turn, prevented an assessment of the fungicide treatments. 

Effect of Absolute Maxx and Prosaro on strie rust control in spring wheat, Kalispell, MT - 2017.

Treatment Rate 6/26 CI % 6/26 SR % 7/14 SR % 8/16 SR % 8/16 YLD bu/A 8/16 PRO % 8/16 TWT lb/bu
Untreated 0 20.7 3.7 0 67.7 14.2 60.3
Absolute Maxx
Induce 90 SL		 4 floz/A
0.125% v/v		 0 1 0 0 60.5 14.2 60.4
Absolute Maxx
Induce 90 SL		 5 floz/A
0.125% v/v		 0 1.3 0 0 65.3 14.3 60.4
Prosaro
Induce 90 SL		 5 floz/A
0.125% v/v		 0 0.3 0 0 65.5 14.3 60.5
Tebuzol 3.6F
Induce 90 SL		 4 floz/A
0.125% v/v		 0 0.7 0 0 63.4 14.4 60.2
Mean 0.0 4.8 0.7 0.0 64.5 14.3 60.4
LSD P = 0.05 ns ns 1.9 ns ns ns ns
CV 0.0 240.7 140.8 0.0 8.1 1.2 0.5
Pr>F 1.000 0.2278 0.0080 1.000 0.5602 0.8106 0.7086

CI: crop injury; SR: stripe rust; YLD: yield; PRO: protein; TWT: test weight; ns: non-significant