Organic potatoes and late blighjt

Potatoes can be susceptible to a nasty fungus called "Late Blight".
This is especially serious for the organic farmer who cannot use the strong chemicals available on the market. There is only one item approved for organic farming that makes a difference and that is made up of copper in a form we can mix with water called "Copper Hydroxide". Our soils are low in this mineral as well so the addition of copper is a benefit to its mineral balance.



We like to start our spraying when the plants reach 4-6 inches in height. The leaves are coated with the copper which forms a protection from spores when they land on the leaves.

In this photo I am driving through our first potato field that is ready for spraying with the sprayer behind me. You can see the potatoes are at the required height.






Here, you can see the booms extended with the sprayer in operation. We are using a pressure of about 250 psi, traveling at 5 miles per hour and this will apply 2 kg of copper per 10 acres.










My view of the booms in the mirror. They must be kept level and at the right height above the plants for best coverage.











From now on until harvest we will continue to spray every 5-10 days depending on weather conditions. The more rain the more often we need to spray. As the new leaves are forming they are vulnerable to the blight spores and must be covered before any land. Copper spraying is my 1st priority on the farm.

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