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
POTATO WEED CONTROL WITH
MATRIX
Richard Greenland and Leonard Besemann
This paper reports the results of a study conducted at the Oakes Irrigation Research Site in Oakes, ND using different rates and application timings for Matrix compared with a standard treatment of Dual plus Prowl. We looked at crop injury, weed control, and yield of potatoes.
Table 56. Herbicides and rates used.
Table 57. Weed control ratings.
Table 58. Quantity and yield of potatoes.
Materials and methods
This study was established on a Maddock sandy loam soil (2.3% soil organic matter, pH 7.6) at the Oakes Irrigation Research Site in Oakes, ND. The initial soil-P and K were high. Soil-N was medium. On 13 April 1998 we spread 140 lbs of 10-50-0, 78 lbs of 21-0-0-24, and 156 lbs of 0-0-60. Another 70 lbs of N as urea was broadcast on April 22 and incorporated with a field cultivator the next day. We spread urea (at 40 lbs N per acre) on top of the beds on June 26. We fertigated with 25 lbs N per acre as 28% N solution on July 9 and again on July 15.
We planted Russet Burbank potatoes on April 23. Plots were 17 ft long by 12 ft (four rows) wide. Admire (at 1.3 oz per 1000 ft of row) was applied in-row on top of the seed pieces as we planted them. Admire controlled Colorado potato beetle throughout the growing season. A weekly spray program with Bravo Zn, starting on July 7, kept the diseases in check. The study was overhead sprinkler irrigated throughout the season as needed.
Preemergence herbicide applications were applied in the late afternoon of May 28, 1998. Air temperature was 79F. Relative humidity was 29%. The wind was from the west at 9 mph, but was partially blocked by a wind break. We also used a wind shield so wind around the sprayer was less than 4 mph. The soil and potato foliage were dry. No weeds were present (we dragged off the potato hills on May 18 and hilled the potatoes on May 27 to control early weeds). Potatoes were 0 to 4 inches above the hill and not under stress when treated.
Post emergence herbicide applications were applied in the mid afternoon of June 16. Air temperature was 75F. Relative humidity was 53%. The wind was from the SE at 6 mph. At application time, hairy nightshade was ½ to 1 inch tall and had 2 to 3 true leaves. Redroot pigweed was ½ to ¾ inch tall and common lambsquarters was ¾ to 1 inch tall. I did not see any black nightshade or quackgrass except in plots receiving Matrix preemergence. Weeds in these plots were mostly black nightshade. Hairy nightshade was the most prevalent weed with 3 to 20 plants per square foot. Pigweed and lambsquarters had less than 1 plant per square foot. Potatoes were ½ to 1½ feet tall and vigorous. Weeds in plots treated with a preemergence application of Matrix were ½ the size and 5% as numerous as in plots not treated with Matrix preemergence. No plants were under stress when we applied the treatments.
All herbicide applications were sprayed using a CO2 backpack sprayer with 8004 flat fan nozzles. Boom pressure was 29 psi. Herbicides were applied in 45 gal of water/acre. I took crop injury and/or weed control ratings on June 26, July 10, and September 4.
On Sept. 7 we sprayed the potatoes with Diquat (1 pt/acre) to kill the vines. Eight feet of the middle two rows of each plot were harvested in early to mid October. Potatoes were graded, counted, weighed and a representative sample from each plot was checked for hollow heart.
The experimental design was a randomized complete block with four reps. I used the ANOVA procedure in SAS to analyze the data.
Results and discussion
None of the herbicide treatments injured the potatoes. All herbicide combinations controlled hairy nightshade and redroot pigweed. Dual plus Prowl controlled eastern black nightshade. Matrix controlled the hairy nightshade which allowed the black nightshade to grow better. Matrix suppressed quackgrass when applied post emergence or in combination with Lexone or Dual plus Prowl. Dual plus Prowl did not control quackgrass. None of the herbicide treatments affected the yield or quality of potatoes.
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Table 56. Herbicides and rates for the 1998 potato weed control study at the Oakes Irrigation Research Site.
| Treatment number | Herbicides | Rate (oz ai/acre) | Application timing |
|---|---|---|---|
| 1 | Matrix | 0.375 | PRE |
| 2 | Matrix + Lexone | 0.375 + 3 | PRE |
| 3 | Matrix + Activator 90 | 0.25 + 0.25% v/v | POST |
| 4 | Matrix + Activator 90 | 0.375 + 0.25% v/v | POST |
| 5 | Matrix + Lexone + Activator 90 | 0.25 + 3 +0.25% v/v | POST |
| 6 | Matrix + Lexone + Activator 90 | 0.375 + 3 +0.25% v/v | POST |
| 7 | Matrix Matrix + Activator 90 |
0.375 0.25 + 0.25% v/v |
PRE POST |
| 8 | Dual + Prowl | 24 + 10 | PRE |
| 9 | Matrix + Dual + Prowl | 0.25 + 24 + 10 | PRE |
| 10 | Untreated |
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Table 57. Weed control ratings for the 1998 potato weed control study at the Oakes Irrigation Research Site.
| Treatment Number† | Ratings taken on June 26 | Ratings taken on September 4 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Hairy nightshade | Redroot pigweed | Lambs- quarters | E. Black nightshade | Hairy nightshade | Redroot pigweed | Lambs- quarters | E. Black nightshade | Quack- grass | |
| ------------------------------------------------- 0 to 10‡ --------------------------------------------------- | |||||||||
| 1 | 10.0 | 10.0 | 10.0 | 8.8 | 7.5 | 10.0 | 8.3 | 8.5 | 8.0 |
| 2 | 9.8 | 9.5 | 10.0 | 9.1 | 7.5 | 10.0 | 9.3 | 7.8 | 8.5 |
| 3 | 10.0 | 10.0 | 9.9 | 9.3 | 9.0 | 10.0 | 8.8 | 7.0 | 8.8 |
| 4 | 10.0 | 10.0 | 10.0 | 8.9 | 9.0 | 9.8 | 9.0 | 8.8 | 8.5 |
| 5 | 10.0 | 10.0 | 10.0 | 9.6 | 8.8 | 10.0 | 10.0 | 8.3 | 8.5 |
| 6 | 10.0 | 10.0 | 10.0 | 9.5 | 8.0 | 10.0 | 9.5 | 8.8 | 9.3 |
| 7 | 10.0 | 10.0 | 10.0 | 9.1 | 9.5 | 10.0 | 10.0 | 8.5 | 9.8 |
| 8 | 9.8 | 9.8 | 9.8 | 9.8 | 8.0 | 10.0 | 9.8 | 9.5 | 7.0 |
| 9 | 10.0 | 10.0 | 10.0 | 9.9 | 7.8 | 10.0 | 9.5 | 10.0 | 9.3 |
| 10 | 3.5 | 7.3 | 8.0 | 9.4 | 4.3 | 9.0 | 9.0 | 9.3 | 7.8 |
| LSD(0.05) | 0.9 | 0.5 | 0.3 | 0.7 | 2.4 | 0.4 | NS | 1.4 | 1.3 |
| C.V.(%) | 7 | 4 | 2 | 11 | 21 | 3 | 10 | 11 | 11 |
†See Table 56 for treatment descriptions.
‡Weed control ratings are from 0 to 10. Weed ratings are based on two things: 1) the percent of the plot free of weeds; and 2) the size, health, etc. of the weeds. A plot completely covered (zero percent of plot free from weeds) with large, vigorous weeds gets a score of "0". A plot completely free of weeds gets a score of "10".
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Table 58. Quantity and yield of potatoes in the Oakes Irrigation Research Site 1998 potato weed control study.
| Treatment Number† |
Number of potato tubers | Tuber yield | Hollow heart | Tuber size | ||||
|---|---|---|---|---|---|---|---|---|
| US #1 | US #2 | Total | US #1 | US #2 | Total | |||
| --------- 1000s of tubers/acre ---------- | ---------- cwt of tubers/acre ---------- | % | oz/tuber | |||||
| 1 | 34.3 | 67.6 | 111.8 | 235 | 197 | 460 | 43 | 6.7 |
| 2 | 38.1 | 67.2 | 118.7 | 271 | 201 | 505 | 53 | 6.8 |
| 3 | 34.5 | 59.7 | 103.0 | 252 | 183 | 457 | 63 | 7.1 |
| 4 | 39.9 | 57.4 | 109.1 | 282 | 169 | 477 | 53 | 7.1 |
| 5 | 38.8 | 62.6 | 110.7 | 258 | 195 | 471 | 53 | 6.8 |
| 6 | 37.7 | 58.5 | 106.2 | 263 | 174 | 454 | 45 | 6.9 |
| 7 | 42.7 | 65.6 | 116.4 | 302 | 200 | 516 | 53 | 7.1 |
| 8 | 34.3 | 62.4 | 108.0 | 236 | 169 | 429 | 55 | 6.4 |
| 9 | 41.7 | 54.0 | 108.9 | 281 | 162 | 469 | 45 | 6.9 |
| 10 | 34.0 | 67.8 | 109.4 | 234 | 200 | 445 | 38 | 6.5 |
| LSD(0.05) | NS | NS | NS | NS | NS | NS | NS | NS |
| C.V. (%) | 14 | 17 | 10 | 17 | 18 | 10 | 29 | 11 |
†See Table 56 for treatment descriptions.
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Go to Oakes Irrigation Research Site Weed Control Studies page
Go to Oakes Irrigation Research Site 1998 annual report