I would like to spray my new apple trees with Imidian to prevent fungus and pests. Does anyone know what an alternate name for this pesticide is, since Google returns no results for it?
It's name is spelled as Imidan, it is available only in some countries and it doesn't protect against fungus because it is an insecticide. Although it can be used against pests, it is highly toxic to bees, so unless you can artificially pollinate your apples, you run the risk of killing those beneficial insects.
Alternate names include Appa, Decemthion, Imidan, Kemolate, Fesdan, Prolate, PMC and Safidon.
From what I've read, primary use of this product is to control codling moth - you can do that with a couple of pheremone traps, followed by (if necessary) a treatment spray far less toxic than a product based on organophosphates, or a nematode based spray treatment. As it's a contact and not a systemic insecticide, using it before there's a problem is pointless, in other words, its not a preventative treatment. Further information on nematodes and pheremone traps here https://www.rhs.org.uk/advice/profile?PID=489
Dormant oils are your best bet and safest. Killing bees is almost worse than killing humans. We lose our bees and humans will go bye bye.
Prevention is best done by pruning, cleaning up the debris as soon as possible and to not worry about a few insects. They will always be there. Otherwise, spraying insecticide means it is also poisonous to bees, birds, dogs, cats and kids and adults.
Dormant oils are what fruit tree growers swear by. Suffocates or prevents insects from laying eggs or hibernating over winter. I'd get a professional apple tree pruner (a laborer from an apple farm or a Cooperative Extension Service recommended tree pruner that knows fruit trees). Then clean up all the debris. Have an arborist (who also might know how to prune fruit trees correctly) check the health of your trees.
Insecticides are never for prevention. They are bandaids for problems that could have been prevented by proper management. Fungicides on the other hand are preventative as they are akin to a rain coat on plants. Once you've got fungus, you will not be able to 'cure' it, only mitigate any damage.
Look into dormant oils. There is not one other product you should even consider for prevention. There are also summer oils but they require far more expertise so that one doesn't have their plants frying in the heat and sun.
First get an arborist or fruit tree expert recommended by your Cooperative Extension service of your closest University. Let them find out whether or not you even need to spray 'horticultural oils' at all. These oils will also kill beneficial insects. Between beneficial insects and healthy tree and cleaning up debris...you shouldn't have to spray a thing.
Since your trees are young, forget about spraying them with anything. Keep weeds and grass and soil and mulch away from the base of your trees. Again a good pruner would be able to 'start' your trees now to limit their height and prevent too many branches, too much fruit that will cause disease, attract insects and reduce decent sized fruit. They will also be able to coach you for maintenance pruning. Tell you about the proper tools (by pass and tree saws only, no anvil) and how to use alcohol to clean your tools so that you do not infect your trees inadvertently. Make sure your trees are not planted too low allowing soil or mulch to touch the bark.
Please don't use insect sprays. A tree full of insects one year is not worth the killing of bees. ONE bee gets insecticide/pesticide on their little feet or packets of pollen takes it back to the hive and can kill the entire hive. That winter will be a great time to use dormant oil. If all our bees decline to a certain point, well, in two to three months us humans will know starvation. We can forget ever seeing a flower again. Truly bees are so vital that heck with a few problems on your trees! Apple trees provide for hosts of insects, birds, animals as well as humans...all of which will be sickened or killed and what fruit you might get will be inedible. Without bees, no fruit. horticultural oils