Author
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Chen, Xianming |
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Wood, David |
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Submitted to: Fungicide and Nematocide Tests
Publication Type: Research Notes Publication Acceptance Date: 1/10/2005 Publication Date: 5/1/2005 Citation: Chen, X., Wood, D.A. Control of stripe rust of spring wheat with foliar fungicides, 2004. Fungicide and Nematocide Tests. 60:CF021. Interpretive Summary: A fungicide study was conducted in an experimental field with the Palouse silt loam soil under natural infection of stripe rust near Pullman, WA. Urea (46-0-0) was applied at the time of cultivation. Susceptible 'Lemhi' spring wheat cultivars were seeded in rows 12 in. apart with an experimental drill planter on 22 Apr 04. A mixture of Harmony Extra, Buctril, and Agridex was applied on 20 May and Hoelon 3EC was applied on 23 May when wheat plants were at tillering stage. Ammonium sulfate was broadcast at on 18 Jun when wheat plants were at early booting stage. Fungicides were applied on 19 Jun at boot stage when 'Lemhi' had 10% of stripe rust severity. A second spray of Quilt plus 1% COC was done only for the first treatment on 2 Jul at heading stage. A randomized block design was used with four replications for each treatment. Stripe rust severity (percent of infected foliage) was assessed for each plot on 21 Jun, three days after fungicide application at boot stage; 19 Jul, 30 days after fungicide application at milk stage; and on 26 Jul, 37 days after fungicide application at soft dough stage. Plots were individually measured at the time of harvesting, ranging from 103.6 to 117.0 sq ft. Yields were determined from plots harvested on 8 Sep when kernels were naturally dry. Test weight of kernels was measured for each plot. Rust, test weight, and yield data were subjected to analysis of variance and means were separated by Fishers protected LSD test. Technical Abstract: A fungicide study was conducted in an experimental field with the Palouse silt loam soil under natural infection of stripe rust near Pullman, WA. Urea (46-0-0) was applied at 60 lb/A at the time of cultivation. Susceptible 'Lemhi' spring wheat cultivars were seeded in rows of 12 in. apart at 60 lb/A with an experimental drill planter on 22 Apr 04. A mixture of 0.33 oz Harmony Extra, 0.75 pt Buctril, and 1% Agridex per A was applied on 20 May and Hoelon 3EC was applied at 2.5 pt/A on 23 May when wheat plants were at tillering stage. Ammonium sulfate (20-0-0-24) was broadcast at 30 lb/A on 18 Jun when wheat plants were at early booting stage. Fungicides were applied as fl oz of product in 16 gal water/A on 19 Jun at boot stage when 'Lemhi' had 10% stripe rust severity. Spray was done between 7:30 am and 8:45 pm when the wind was between 0.0 and 6.0 mph and temperatures between 57 C and 64 C. A 601C backpack sprayer from R & D Sprayers Inc. was used with a C3470 regulator and a 2.5 lb CO2 compress cylinder. The spray boom had four nozzles 19 in. apart, but three were used because of the width of the plots. The spray pressure was 18 psi. Six fungicide treatments and one non-treated control were used. A second spray of Quilt 14 fl oz/A plus 1% COC was done only for the first treatment with Quilt at 7 fl oz/A on 2 Jul at heading stage. A randomized block design was used with four replications for each treatment. Stripe rust severity (percent of infected foliage) was assessed for each plot on 21 Jun, three days after fungicide application at boot stage; 19 Jul, 30 days after fungicide application at milk stage; and on 26 Jul, 37 days after fungicide application at soft dough stage. Plots were individually measured at the time of harvesting, ranging from 103.6 to 117.0 sq ft. Yields were determined from plots harvested on 8 Sep when kernels were naturally dry. Test weight of kernels was measured for each plot. Rust, test weight, and yield data were subjected to analysis of variance and means were separated by Fishers protected LSD test. |
