Weed Control Materials for Tree Nuts
Posted: October 17, 2012
Dr. Bernard Zandstra, Weed Specialist at Michigan State University, recently put out a table listing herbicides that are labeled for nut trees. As he indicated, large acreage of most nut trees are grown in areas that have decidedly different climatic and soil conditions from here in the eastern U.S. Most of the almonds are grown in California while pecans are grown primarily in the southern states and west through Oklahoma and Texas; filberts/hazelnuts are primarily grown in Oregon. You may have a few nut trees under which you would like to control weed growth. In all cases the herbicides are common ones used in deciduous tree fruit production.
Dr. Zandstra developed the table by looking at herbicide labels from the CDMS labels web site (http://www.cdms.net/LabelsMsds/LMDefault.aspx ). His table represents Michigan conditions for rates and timing, weather conditions and weed controlled. In all instances if you apply one of the materials to your nut trees be sure you read the label for any limitations or precautions.
| Table 1. Weed control in tree nuts – 2013. Compiled by Bernard Zandstra, MSU. | ||||
|---|---|---|---|---|
| Crop | Application timing | Chemical Common Name Trade Name | Pounds active ingredient and amount of product per acre | Remarks, target weeds, preharvest interval (PHI) |
| Almonds Filberts Pecans Pistachios Walnuts | Preemergence | Indaziflam (Alion 1.675C) | 0.065-0.085 lb ai 5.0-6.5 fl oz | Controls most broadleaves and grasses. Apply to nut trees that have been established for one year or more. Apply to pecans and pistachios that have been established for three or more years. Do not use on soils with more than 20 percent gravel. Fourteen-day PHI. |
| All tree nuts | Preemergence | Flumioxazin (Chateau SW 51WDG) | 0.191-0.383 lb ai 6-12 oz | Controls most broadleaves and grasses. Fall application is most effective. Apply to trees established at least one year. Weak on horseweed. Apply before bud swell. Moisture is necessary to activate herbicide. Sixty-day PHI. |
| Almonds Filberts Pecans | Preemergence | Napropamide (Devrinol 50DF) | 4 lb ai 8 lb | Controls annual broadleaf weeds and grasses for four to five weeks. Apply to weed free soil surface. May be applied to newly planted trees. Thirty-five-day PHI. |
| Almonds Beechnuts Brazil nuts Butternuts Chestnuts Chinquapin Macadamia Pecans Pistachios | Preemergence | Oxyfluorfen (Goal 2XL) | 1.25-1.5 lb ai 5-6 pt | Controls most annual broadleaves and grasses. Apply before bud swell in the spring. |
| Pecans | Preemergence | Diuron (Karmex 80DF) | 1.6-3.2 lb ai 2-4 lb | Controls annual broadleaves and grasses for six to eight weeks. Do not use on sand, loamy sand, gravelly soils, or on soil with less than 1 percent organic matter. Apply in the spring before weeds emerge. |
| All tree nuts | Preemergence | Rimsulfuron (Matrix 25 DF) | 0.063 lb ai 4 oz | Apply to trees that have been established for one year or more. Controls grasses and broadleaves. Fourteen-day PHI. |
| Macadamia Filberts Pecans Walnuts | Preemergence | Simazine (Princep 4L) | 2-4 lb ai 2-4 qt. | Controls broadleaves and grasses for four to six weeks. Apply before weeds emerge in the spring. Twenty-one-day PHI. |
| All tree nuts | Preemergence | Pendimethalin (Prowl H2O 3.8CS) | 1.9-5.99 lb ai 2-6.3 qt | Controls annual grasses and some broadleaves. Apply before bud swell. Do not apply to newly transplanted trees until ground has settled and no cracks are present. Sixty-day PHI. |
| Filberts Walnuts Almonds | Preemergence | Norflurazon (Solicam 80 DF) | 2-4 lb ai 2.5-5 lb | Controls annual grasses, some broadleaves, and yellow nutsedge. Apply in spring or fall. Sixty-day PHI. |
| All tree nuts | Preemergence | Oryzalin (Surflan 4 AS) | 2-6 lb ai 2-6 qt. | Controls annual grasses and some broadleaves for four to six weeks. Apply in spring before weeds emerge. Needs rainfall to activate. |
| All tree nuts | Preemergence | Isoxaben (Trellis 75 DF) | 0.5-1 lb ai 0.66-1.33 lb | Controls broadleaves for four to six weeks. Apply to established bearing and non-bearing trees. Needs rainfall of 0.5 inch to activate. Sixty-day PHI. |
| Filberts | Preemergence | Dichlobenil (Casoron 1.4 CS) | 1.96-3.92 lb ai 1.4-2.8 gal | Controls most annual and perennial weeds for eight to 10 weeks. Apply to trees established at least 1 year. Use high rate for perennial weed control. |
| Almonds Blk walnuts Eng walnuts Pecan Pistachios | Preemergence | Penoxsulam and oxyfluorfen (Pindar 4.013 GT) | 0.75-1.5 lb ai 1.5-3.0 pt | Controls most annual weeds and some perennials. Apply to almond trees that have been established at least 15 months. Apply to other tree nut crops that have been established at least nine months. Apply only to crops in good health and vigor. |
| All tree nuts | Preemergence Postemergence | Halosulfuron (Sandea 75DF) | 0.031-0.063 lb ai 2/3-1 1/3 oz. | Controls nutsedge and broadleaf weeds. Apply to nut trees that have been established one year or more. One-day PHI. |
| Almonds Pistachios Walnuts | Postemergence | Saflufenacil (Treevex 70 WG) | 0.044 lb ai 1.0 oz | Controls horseweed and other broadleaves. Apply as a postemergence-directed spray to the base of the trees. Seven-day PHI. |
| All tree nuts | Postemergence | Glyphosate (Touchdown 5.4, Roundup 5.4) | 0.5-2 lb ai 0.7-3.6 qt | Apply with a preemergence herbicide in spring for control of emerged annual and perennial weeds. Reapply during the season as needed. Avoid contact with crop foliage or green bark. Three-day PHI. |
| All tree nuts | Postemergence | Carfentrazone (Aim 2 EC) | 0.031 lb ai 2 fl oz | Controls small broadleaf weeds. Include NIS in tank mix. Three-day PHI. |
| Pecans Macadamia | Postemergence | Fluazifop-P (Fusilade DX 2E) | 0.094-0.188 lb ai 6-12 fl oz | Controls annual and perennial grasses. Maximum of 48 fl oz/acre per season on macadamia nuts and 72 fl oz/acre on pecans. Include NIS. Thirty-day PHI for pecans, one-day PHI for macadamia nuts. |
| All tree nuts | Postemergence | Paraquat (Gramoxone SL 2) | 0.375-1 lb ai 1.5-4.0 pt. | Desiccates green foliage. Make applications prior to shaking for harvest. Include NIS. Maximum of five applications per year. |
| All tree nuts | Postemergence | Sethoxydim (Poast 1.5L) | 0.188-0.469 lb ai 1-2.5 pt | Kills grasses. Use high rate for perennial grasses. Maximum of 10 pt/acre per year. Include NIS. Fifteen-day PHI. |
| Almonds Filberts Hickory Macadamia Pecans Pistachios Walnuts | Postemergence | Glufosinate (Rely 280 2.34L) | 0.75-1.28 lb ai 48-82 fl oz. | Desiccates green foliage of annual and perennial weeds. If weeds are less than 3 inches high, apply 48 fl oz/acre. If weeds are less than 6 inches high, apply 56 fl oz/acre. If weeds are more than 6 inches in height, apply 56-82 fl oz/acre. Include NIS. |
| Almond Filbert Pecan Pistachio Walnut | Postemergence | Clethodium (Select Max 0.97E) | 0.068-0.12 lb ai 9-16 fl oz | Kills annual and perennial grasses. Use high rate for annual bluegrass control. Use a minimum of 15 gal/acre of spray mix. Include NIS in the tank-mix. Use on non-bearing trees only. |
| All tree nuts | Postemergence | Pyraflufen (Venue 0.117 SC) | 0.0014-0.0019 lb ai 1-4 fl oz | Use with other postemergence herbicides to improve broadleaf weed desiccation. Include NIS. Zero-day PHI. |
| All tree nuts | Postemergence | 2, 4-D (Weedar 64 3.8L) | 1.5 lb ai 3 pt | Controls most annual and perennial broadleaf weeds. For filberts, apply a maximum of 2.1 pt of product per acre. Allow at least 30 days between applications. 60-day PHI. |
Contact Information
- Professor of Tree Fruit
