| Autor: |
Scott M. Bretthauer, Richard C. Derksen, Tristan A Mueller, Loren E. Bode, Heping Zhu |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
2008 Providence, Rhode Island, June 29 - July 2, 2008. |
| DOI: |
10.13031/2013.25050 |
| Popis: |
Canopy penetration and thorough coverage are important when applying foliar fungicides to soybeans for the control of rust. The purpose of this study was to examine how spray application rate and spray droplet size affect the efficacy of soybean rust applications. Four treatments were examined: a medium droplet spectrum applied at 47 L/ha (5 GPA) and at 140 L/ha (15 GPA), and a very coarse droplet spectrum applied at 47 L/ha (5 GPA) and at 140 L/ha (15 GPA). Applications were made to soybeans planted with 91 cm (36 inch) row spacing in the R5 growth stage. Spray coverage, deposition, soybean rust severity, and yield were measured to evaluate the effectiveness of these treatments. Spray coverage was measured on Kromekote paper positioned in the upper and lower parts of the canopy. Deposition was measured using a dye and Mylar plates positioned in the upper and lower parts of the canopy. The very coarse droplet spectrum at 140 L/ha (15 GPA) had the highest coverage and deposition in both the upper and lower canopy. Overall the very coarse droplet spectrum performed better than the medium droplet spectrum. There was no difference among the treatments in soybean rust severity or yield. All the treatments had significantly lower soybean rust severity than an untreated control, and all but the very coarse droplet spectrum at 140 L/ha (15 GPA) had a significantly higher yield than the untreated control. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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