HURRICANE Aftermath: Delayed Planting Date and Fumigation
Dear Strawberry Community.
While the weather calms down, fields are in many cases still too wet to access or even flooded. With the predicted warm and sunnier weather ahead of us, and if there is no major flooding, it still may be earliest end of this week/begin of next before you and your crew can enter to apply pre-plant fertilizer and lay the plastic.
These dynamics can delay the planting date 2 weeks or more, from begin of October to October 15 – 18 in best case scenario, depending on your region.
I had many phone calls over the course of today, all with basically the same questions: What can I do? In my discussion with N.C. Cooperative Extension Agent Brandon Parker out of Johnston County just about an hour ago, we have summarized some of the main issues:
A. Fumigation or no fumigation? The increased risk of soil-borne disease after flooding/wet soil conditions
The problem is evident. If you chose to fumigate, you will have to wait for a 20 to 21 days before transplanting and that will delay your aimed planting date. So the temptation is big not to fumigate, simply to stay on target with your planting date.
It is very well known that flooding and even heavy rain falls can facilitate the increase of diseases such as pneumonia, typhus, cholera, hepatitis A, rodent-borne diseases (Hantavirus) etc. (http://www.who.int/hac/techguidance/ems/flood_cds/en/)
But also plant diseases can be spread and facilitated through rain and floods. Especially pathogens of the class of Oomycota – such as Phytophthora species – can be spread with water.
Fumigation is the main method to control such soil-borne pest and diseases.
You should still fumigate if following points are true:
- you will be able to access your field end of this week/early next week
- your planting date will be delayed max. 1-2 weeks if you fumigate
- you or your nursery has a place to properly store the plants
B. Fumigant Choice
Fumigants have different plant back dates and they all depend on soil conditions. Usually, wet soil conditions increase the plant back date.
Most fumigant labels recommend a minimum plant back time of 14 days, if holes are punched early and there is enough time (min. 48 hours) for the soil to aerate. We highly recommend to wait longer than that.
Here a short list of plant-back intervals for the most common fumigants:
|Fumigant||min. plant back time under best possible conditions||Recommendations under current conditions||Specifics|
|Pic-Clor 60/80||14 days + 2 days for aeration||min of 18-19 (incl. 2 days for aeration days), better 20-21||7 days per 10 gal/acre|
|Metam-Sodium||14-21 days + 2 days for aeration||21 days or more||–|
|Paladin||21-42 days||min of 21 days||Highly depended on the soil temperature|
|Dazomet/Basamit||14 days in soils above 75 F||min of 21 days||–|
|Telone||–||min of 18-19 (incl. 2 days for aeration days), better 20-21||7 days per 10 gal/acre|
We recommend to fumigate and punch holes minimum 4-days before planting. You may be able to plant after 19 days instead of 21.
We don’t recommend to fumigate with a lower rate! Lower rates are not able to control pests and pathogens sufficiently!
C. Storage of plants:
If you get your delivery and you are not ready to plant, you need to store your plants properly.
Plug plants need to be frequently watered, several times a day. Don’t store the plugs directly on the ground or directly in the sun. The best storage is a screenhouse or some sort of protected, lightly shaded area with frequent watering.
Bare-roots can be stored in cold storage (not freezer!) for a week or two.
We recommend to contact your nursery and ask to hold your planting material for you just until you are ready to plant. Most nurseries will be understanding of your situation and will try to accommodate you as much as they can.
I hope that helps,