Saturday, January 15, 2011

Dormant spray recommendations.

Always read and follow label instructions!
For the products we sell, mix together in each gallon of spray:
2 oz LiquiCop (= 4 Tbsp)
2.5 – 3.5 oz spray oil
(= 5 – 7 Tbsp, or 1/8 to <1/4 cup)

You can use a hose-end sprayer** if you use the lower amount of oil (you will barely add any water to the concentrated mixture). Otherwise, use a tank sprayer.
Spray the tree thoroughly, to the point of runoff.
It will probably take about two gallons of spray to cover a medium-size tree with conventional training and pruning; one gallon of spray to cover a summer-pruned backyard orchard tree.
Spray peaches and nectarines while they are still dormant.
You can spray other fruit trees such as apricots. plums, and cherries with the same mixture.
Many fruit species such as figs, persimmons, and pomegranates need no spraying. Citrus are sprayed only as needed for specific pest and disease problems.
Dormant and bloom sprays don’t control the worms that get into apples and pears, or the new fruit-fly larvae that are attacking cherries. For those we use growing-season sprays.

The diseases we are concerned about are:
• peach leaf curl, which only affects peaches and nectarines. Sprays are only effective before the buds break. If they show color (green or pink) it is too late.
• brown rot, which primarily affects apricot (and almond) blossoms. See note*. Sprays are only effective when the trees are in bud and bloom. Plums and cherries, as well as peaches and nectarines, can also get brown rot, but it is much less common.
• This spray mixture also helps control shothole fungus, and the oil helps to reduce over-wintering insects.

MicroCop (copper sulfate) and Polysul (lime sulfur) are no longer available, so we are now recommending the liquid copper spray. It is less effective for leaf curl, unfortunately, but easier to apply. The problem is that the final spray solution, following label rates, is lower concentration than you were applying before. We cannot recommend that you exceed the label rates.

** You cannot apply both products at the same time in a Dial-A-Pro hose-end sprayer. Apply each at the label rate, 24 hours apart.
* Copper is not effective for brown rot on apricots, and there is no organic or low-toxicity alternative available to homeowners. Chlorothalonil is available, but is very toxic; read and follow label instructions carefully if you choose to use it. Note non-chemical suggestions for control measures at
Prompt removal and destruction of fruit mummies and diseased plant parts prevents the buildup of brown rot inoculum and helps keep rot below damaging levels. Prune trees to allow good ventilation. Furrow irrigate or use low-angle sprinklers to avoid wetting blossoms, foliage, and fruit. Plant varieties that are least susceptible.

Product information:


Spray Oil

draft Jan 14 2011

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