zz

That probably depends on a lot of factors--how soon, rain, what other sprays you are considering. Oil spray mixed with other pesticides--like spinosad--can extend their persistience. It would probably have little effect on polar or ionic chemicals like Cu fungicides.

Just a reminder--this time of yr, if you live in an area with cold winters, you should not spray citrus with oil as it can reduce cold hardiness.

zz

Oil will work on the mites, but the miners are only reduced by oil. The kelthane is moderately persistient and the oil should extend it. Oil and spinosad have been my primary defense against miners, but it is difficult to keep them under control when it rains as much as it did this summer.


I recently got a pheromone trap for the miners and it has worked better than anything I have ever tried before--there must be at least 500 miners in the trap.

Fred, actually kelthane was not needed for the control of mites on your tree. UltraFine horticultural oil alone does a very good job of controlling mites. UltraFine also provides excellent control of aphids, scale and mealy bug. Welcome to the forum. - Millet (1,180-)

Two more things to consider -- as to your first question -- oil and sulfur make an excellent defoliant -- they'll knock off every leaf on the tree. So never mix them, nor use them within several weeks of each other.

But also consider, if these are outdoor trees, oil this time of year will remarkably reduce the cold-hardiness of your trees for several months after use. That's why commercial growers never use it in the fall.

zz

It would help to know your location & if your growing in the ground or in containers.

You didn't mention anything containing elemental sulfur. But you did ask "Does it have any effect on the efficacy of subsequent sprays of other chemicals???" Sulfur would be one of the possible "other chemicals."

zz

elemental sulfur is used mainly as a miticide on citrus. On other crops, it's also excellent against powdery mildew, but we don't have the citrus-infecting form of that disease in the USA (yet).

zz

You can find plain wettable sulfur powder in small bags (couple pounds) at most any garden shop or feed and seed store.