Orchard Fumigation

Trident Agricultural Products, Inc.
Serving Your Fumigation Needs

Orchard Establishment
FUMIGATION GUIDELINES

I. TIMING. Delayed soil prep until the last minute is the mistake most often made by growers. Whether replacing an old orchard or establishing a new orchard site, clearing should be completed as soon as possible. If the proposed orchard is planted with grass or some annual crop, these need to be turned under 30 to 60 days in advance of fumigation. Disc or rotavate the site following the initial ground breaking. The objective in all cases is to give plant residues time to break down. Plant residues absorb fumigants, reducing fumigation effectiveness.

II. TILTH. Improper soil preparation is the major reason for fumigation failures. Once plant residues have broken down, rip the soil to the depth desirable for fumigant penetration. It is advantageous to rip the soil in two directions (I.e. X) at a depth of 24 inches. Compacted soils limit the amount of diffusion and penetration of fumigants. Disc or rotavate the surface to break up plant debris and clods. Removing debris (tree roots, pipe and large rocks) will aid in achieving the proper surface seal necessary to prevent gas escape.

III. SOIL MOISTURE. 50% - 75% field capacity of moisture. Fumigants perform poorly in wet fields. Excessive soil moisture blocks fumigant movement. The best results are obtained when surface soil moisture is in seed bed condition and subsurface levels are dry. If a compromise is to be made, fumigate more on the dry side.

IV. TEMPERATURE. do not fumigate if soil temperatures are below 40%F. Generally soil temperatures between 45% and 75% at the depth of injection are best for fumigant volatilization.

V. DOSAGE. Material rates and fumigant combinations applied depend on soil type and the degree of pest infestation. Taking a soil sample will aid in making the decision. Consult with you Trident representative for recommendations.

VI. EXPOSURE. Immediately following the application, seal the soil surface. Use a disc and packer or a cult packer to remove shank marks and pack the surface soil. Failure to seal the soil surface may reduce fumigation effectiveness and / or expose non-target areas to the fumigant.

VII. FERTILIZATION. Fumigation may temporarily cause micronutrients to be unavailable. Fumigate soils before applying manure, sawdust or other organic matter.

VIII. PLANTING. Because of the nature of soil fumigants and soil conditions as influenced by the weather, it is ideal to fumigate in the fall after harvest. This will allow for the necessary exposure period along with adequate time for fumigant dissipation before planting. Spring applications may delay planting. It is far better to plant later in the spring to allow for fumigant dissipation. Skipping fumigation because it sets back a planting date is a poor choice. A May-planted tree planted in fumigated soil will usually outperform a March-planted tree suffering from even a mild case of replant disease. Long-term productivity should be the main concern, not date of planting.

Many factors affect soil fumigation and its effectiveness for pest control. The pest and its habits will affect fumigant selection, application rate, time of application, fumigant placement, and necessary length of exposure. Soil factors also play a key role in fumigation. Soil texture, soil conditions, debris, soil moisture, and soil temperature may affect the volatility, movement, and availability of the fumigant once applied. Fumigant dosage is both pest and soil dependent. Because these factors are beyond our control, Trident can neither give nor imply a guarantee of results.

TRIDENT SERVING THE NORTHWEST

WENATCHEE, WA
Adrian Roozen
509-961-5027

YAKIMA, WA
Robert Rauert
509-961-1495

HOOD RIVER, OR.
Jeff Fowler
360-921-3635

WOODLAND, WA.
Mike Conway
360-921-1486

P.O. Box 1909 Woodland WA. 98674
Office (360) - 225 - 3588
Fax - (360) 225 - 1126
EMail - tridentag@aol.com