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
CABBAGE COVER CROP STUDY, 2000
Richard G Greenland
Table 50. Cabbage response to time of killing barley cover crop.
Planting a cover crop helps reduce wind erosion and may help conserve soil organic matter and control weeds. If let grow too long it also competes with the cabbage and reduces yield and quality. In this study we investigated how tall we could let a barley cover crop grow before killing it and still not reduce cabbage yield or quality.
MATERIALS AND METHODS
| Soil: | Maddock sandy loam and Embden sandy loam; pH=6.7; 2.5% organic matter; soil-P, soil-K, and soil-S were very high. |
| Previous crops: | 1999 - onion; 1998 - pepper; 1997 - carrot. |
| Seedbed preparation: | Disked 29 October 1999. Muitiweeded (field cultivated) once on April 5 and twice on April 18 to incorporate fertilizer and herbicide treatments. |
| Planting: | Direct seeded cabbage on April 24 with a Stanhay vegetable planter modified to drill barley (1 bu/acre, 6-inch rows) between and parallel to the cabbage rows. Cabbage seeds were spaced about 7 inches apart in 16-inch rows. Plants were later thinned to 15 inches apart (about 26,000 plants/acre). Seeds were placed ¼ to ¾ inches deep into a flat, fine seedbed. |
| Plots: | Each plot was 6 ft (4 rows plus tractor tire) wide by 17 ft. long with a two foot border between each plot. The study had 4 reps. |
| Fertilizer: | On April 4, broadcast 18 lbs N/acre and 20 lbs S/acre as 21-0-0-24. Sprayed 50 lbs N/acre as 28-0-0 on April 17 and 60 lbs N/acre as 28-0-0 on May 23. Fertigated 35 lbs N/acre as 28-0-0 on June 27 and July 14. |
| Irrigation: | Overhead sprinkler irrigation as needed. |
| Pest Control: | Weeds were controlled using Treflan (1 pt/acre applied preplant incorporated on April 18), Lentagran (2 lb/acre on May 30), and by hand weeding. Sprayed Asana (8 oz/acre on Aug 18), Agree (2 lb/acre on June 22 and June 29), and Dipel (2 lb/acre on July 3 and 1 lb/acre on July 12, July 20, July 26, Aug 2, Aug 10, and Aug 28) to control cabbage looper and cabbage worm. |
| Harvest: | Ten feet of the center two rows of each plot were hand harvested on September 11. |
Cabbage yield and head size were reduced, but number of cabbage heads harvested was not reduced, when the barley living mulch was allowed to grow more than 14 inches tall before spraying it with Fusilade. When barley was allowed to grow taller, the width of the cabbage plant was reduced but cabbage height was not. This created a skinny plant that did not form a good head.
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Table 50. Time of Fusilade application to kill the barley cover crop and cabbage response in the Oakes Irrigation Research Site 2000 cabbage cover crop study.
| Application timing1 | 29 June 2000 | Heads harvested | Cabbage yield | Head size | |||
| date sprayed | barley height | cabbage height | plant width | plant height | |||
| -- inches -- | --- inches ---- | 1000s/acre | tons/acre | lbs/head | |||
| May 16 | 4 | 2 | 20.3 a | 12.0 ab | 28.2 | 46.2 a | 3.3 a |
| May 23 | 8 | 3 | 22.0 a | 11.5 b | 28.6 | 34.6 ab | 2.4 ab |
| June 8 | 14 | 7 | 17.7 b | 10.9 b | 29.9 | 38.9 ab | 2.7 a |
| June 22 | 24 | 11 | 14.5 c | 13.3 a | 27.4 | 22.4 b | 1.6 b |
| C.V. (%) | 7 | 7 | 13 | 26 | 22 | ||
| Probability | 0.0001 | 0.02 | 0.86 | 0.04 | 0.02 | ||
1Date, height of barley, and height of cabbage when plots were sprayed with Fusilade.
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Go to Oakes Irrigation Research Site Cover Crop Study page
Go to Oakes Irrigation Research Site 2000 annual report