University of Nebraska-Lincoln
|
University of Nebraska-Lincoln |
| Hybrid: | Experiment 1: Pioneer 33G26 Experiment 2: N58-D1 |
| Row Spacing: | 30 inches |
| Planting Date | 26 April 2000 |
| Planter: | Kinze model 2100, 4 row cone |
| Planting Depth: | 2 inches |
| Application Equipment: | Granular Insecticides Planting: Planter mounted cone-belt system |
| Field Preparation: | Spring 2000 - disked and harrowed |
| Herbicides Applied: | 4 May 2000: Bicep II Magnum, 2.1 qt./A, pre-emerge |
| Fertilizer Applied: | 150 lb. N/A applied as NH3 on 4 April 2000 |
| Previous Crop: | Continuous corn (trap crop) |
| Soil Information: | |
| Type: |
Silty clay loam |
| Ph: |
6.4 |
| CEC: |
29.4 |
| % organic matter: |
2.8 |
| % clay: |
29.05 |
| % silt: |
66.67 |
| % sand: |
4.28 |
| Plant Population: | Overall mean number of plants/33.5' ± SEM Experiment 1: 46.9 ± 0.6 Experiment 2: 45.5 ± 0.8 |
| Phytotoxicity: | There were no significant differences (P > 0.05) among treatment stand count means or among number of abnormal plants/treatment at V2-3 growth stage (Hanway 1997). |
| Insecticide History: | Insecticide free: 1991, 1993, 1994, 1997-1999 Multiclass soil insecticide trials: 1990, 1992, 1995-1996 |
| Species Present: | Northern corn rootworm, Diabrotica barberi Smith and Lawrence, and western corn rootworm, D. virgifera virgifera LeConte. Initial rootworm egg hatch detected 24 May 2000 (predominantly western corn rootworm) |
| Root Evaluation: | A 1 - 6 root rating scale (Hills and Peters, 1971) and 0 - 3 root rating scale (Oleson and Tollefson, unpublished) were used to evaluate larval corn rootworm damage in each treatment. Five roots were evaluated in each treatment per replication. (See Nebguide G92-1108-A for the 1 - 6 rating scale description, and the Iowa State University Corn Rootworm Home Page for the 0 - 3 rating scale description.) |
| Root Evaluation Date: | 13 July 2000 |
| Design: | Randomized complete block design Replicated four times Single row treatments |
| Row Length: | 33.5 feet |
| Statistical Analysis: | Root Ratings: Standard ANOVA procedures, LSD test was used for mean separation where statistical differences (P less than or equal to 0.05) occurred. |
| Air Temperature: | 17oC |
| Wind speed: | 10-15 mph at 5 ft. height |
| Wind direction: | SE |
| Soil temperature 2" depth: | 15oC |
| Soil temperature surface: | 18oC |
| Soil moisture, 0-3" depth: | 18.6% water (gravimetric method) |
| % cloud cover: | 100% |
| % relative humidity: | not recorded |
| Residue on surface: | 40% of soil surface covered with crop residue; soil very moist |
| April | 10 | 0.45 inch | |
| 15 | 0.55 inch | ||
| 27 | 0.45 inch | ||
| 30 | 0.20 inch | ||
| Total | 1.65 inches | ||
| May | 08 | 0.75 inch | |
| 18 | 0.40 inch | ||
| 20 | 0.20 inch | ||
| 26 | 0.90 inch | ||
| 30 | 0.25 inch | ||
| Total | 2.50 inches | ||
| June | 10 | 0.70 inch | |
| 12 | 0.30 inch | ||
| 13 | 0.45 | ||
| 15 | 0.20 inch | ||
| 20 | 0.80 inch | ||
| 24 | 1.80 inches | ||
| 25 | 2.20 inches | ||
| Total | 6.45 inches | ||
| July | 02 | 0.20 inch | |
| 04 | 0.50 inch | ||
| 12 | 0.50 inch | ||
| 16 | 0.25 inch | ||
| 18 | 0.80 inch | ||
| 20 | 0.20 inch | ||
| 28 | 0.60 inch | ||
| 29 | 0.30 inch | ||
| Total | 3.35 inches |
| Insecticide | Rate/Placement1 | Mean Root Damage Rating2 | |
| (1-6 scale) | (0-3 scale) | ||
| Aztec 2.1G | TB | 2.40a | 0.23 a |
| Force 3.0G | TB | 2.95a | 0.46 a |
| Gaucho 00MW018 A4 | 0.60 mg/k ST | 3.85 b | 1.30 b |
| Gaucho 00MW018 A2 | 1.35 mg/k ST | 4.15 b | 1.69 b |
| Gaucho 00MW018 A3 | 1.00 mg/k ST | 4.20 b | 1.58 b |
| Untreated | 5.30 c | 2.55 c | |
| Insecticide | Rate/Placement1 oz ai/1000 ft. |
Mean Root Damage Rating2 | |
| (1-6 scale) | (0-3 scale) | ||
| Counter 20 CR | 1.2 TB | 2.25 a | 0.21 a |
| Force 3G | 0.12 TB | 2.45 a | 0.20 a |
| Lorsban 15G | 1.2 TB | 2.50 a | 0.21 a |
| ProShield Force ST | ST | 3.20 b | 0.71 b |
| Untreated | 4.15 c | 1.48 c | |
