Oakes Irrigation Research
Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Voice: (701) 742-2189, FAX: (701)
742-2700, email: rgreenla@ndsuext.nodak.edu
PHOENIX AND COBRA FOR WHITE MOLD CONTROL IN EDIBLE BEAN, 2001
Pat Gross and Luis del Rio, NDSU Plant Pathology Department
See “WHITE MOLD CONTROL IN EDIBLE BEAN, 2001 STUDIES” for description of general materials and methods. Phoenix and Cobra were applied on June 29 at pre-bloom. Topsin M 70WP fungicide was applied on July 9 at 100% bloom. Phytotoxicity was evaluated on July 2 and 9. Evaluation was done using a scale 1-5: 1= no phytotoxicity, 2= 1 to10%, 3= 11 to 25%, 4=26 to 50% and 5=>55% phytotoxicity. Canopy reduction was evaluated on July 30. The evaluation was based on the canopy of the untreated checks and the standard treatment (Topsin). White mold incidence was evaluated on July 29 and Aug 6.
Table 51. Phoenix and Cobra effect on white mold incidence and severity, and edible bean yield
Table 50. Phytotoxicity of lactofen on dry beans at Oakes, ND 2001
Treatment |
% Phytotoxicity1 |
Canopy2 reduction July 30 |
Yield (lbs/acre) |
||
Chemical |
Rate/acre |
July 2 |
July 9 |
||
Untreated check |
|
0 |
0 |
0 |
1794 |
Phoenix |
2.0 oz |
13.8 |
11.3 |
17.5 |
1677 |
Phoenix |
3.0 oz |
18.8 |
15.0 |
16.3 |
1777 |
Phoenix |
4.0 oz |
21.3 |
17.5 |
21.3 |
1771 |
Cobra |
2.0 oz |
17.5 |
13.8 |
21.3 |
1673 |
Cobra |
3.0 oz |
20.0 |
16.3 |
21.3 |
1837 |
Topsin |
1.5 lb |
0 |
0 |
0 |
2033 |
LSD (0.05) |
|
4.7 |
5.1 |
5.6 |
243 |
1Percent phytotoxicity based on nonsprayed plots 1=0%, 2=1-10%, 3=11-25%, 4=26-50%, 5>55%.
2Percent canopy reduction based on unsprayed plots.
Table 51. Phoenix and Cobra effect on white mold incidence and severity at Oakes, ND 2001.
Treatment |
% incidence1 |
% severity2 |
Yield (lbs/acre) |
|||
Chemical |
Rate/acre |
July 26 |
Aug 6 |
July 26 |
Aug 6 |
|
Untreated check |
--- |
81.3 |
87.5 |
22.2 |
46.6 |
1794 |
Phoenix |
2.0 oz |
22.5 |
17.5 |
2.4 |
2.5 |
1677 |
Phoenix |
3.0 oz |
20.0 |
22.5 |
3.5 |
7.4 |
1777 |
Phoenix |
4.0 oz |
18.8 |
23.8 |
2.6 |
4.3 |
1771 |
Cobra |
2.0 oz |
21.3 |
23.8 |
2.7 |
7.3 |
1673 |
Cobra |
3.0 oz |
17.5 |
17.5 |
1.6 |
3.3 |
1837 |
Topsin |
1.5 lb |
45.0 |
45.0 |
9.5 |
18.5 |
2033 |
LSD (0.05) |
|
12.4 |
12.3 |
7.7 |
11.9 |
243 |
1Incidence based on number of infected plants per plots divided by total number of observations.
2Severity based on scale: 0-5: (0 =0%), (1 = 5%), (2 = 15%), (3 = 40%), (4 = 65%), (5 = 85%) infection.
Rainfall was below average for the growing season. Frequent irrigation throughout the summer provided good soil moisture. Temperatures were warmer then the five-year average starting around June 8. These warm temperatures provided favorable plant growth. Plants began to flower around July 1. Row closure was around 50% at the time of the first spray application on July 5. Plants continued to flower uniformly for most of the summer. White mold was not observed from natural infection so a suspension of white mold spores was sprayed on the middle two rows of each plot on July 9 to insure white mold infection. White mold was observed in the field around seven days later. White mold was uniform across the field. Temperatures were warm at the time of spray application which may have contributed to more plant damage. Plants that had lactofen applied had less canopy which may have contributed to less white mold infection.
Go to Oakes Irrigation Research Site 2001 annual report
Go to Oakes Irrigation Research Site disease studies