If you want to protect your fruit tree from pests during the summer, this is almost impossible to accomplish without the use of pesticides or chemicals. This might scare some people into thinking that the actual fruits will contain traces of the chemicals. If you do things correctly, you can get rid of all the pests and not infect the actual tree. If you're going to be spraying chemicals, you most likely will be using either a handheld pump or a hose-end sprayer.
If you're using the pump sprayers, you will be able to more accurately determine the mixing of the chemicals. Unfortunately, you won't be able to spray it very far. Usually it won't reach the tops of trees. This can be achieved with the hose end sprayers, but getting the correct mix of chemicals is quite a challenge. It all depends on your water pressure to get the correct mixture of chemicals, but water pressure is not constant. One day it might be lower, in which case your chemical content would be higher. The types of materials you buy for hose application are generally in an extremely strong form. They need to be severely diluted before they are weak enough to apply.
When you are mixing the chemicals for spraying, you need to follow the directions exactly. You are dealing with dangerous chemicals, so its best to do exactly what the professionals recommend and wear the proper protective gear. When you're dealing with chemicals like this, you should always wear rubber gloves. Use the exact portions indicated on the label. Estimation won't work in this case, and you could end up killing your tree or not killing any bugs. You should usually start by putting in the proper amount of pesticide, and then top it off with all the water.
Now comes the spraying. The goal is to spray the same amount over all the areas. You still don't want to spray so much that enough builds up to drip off of the leaves. Usually you will want to get a ladder so that you can get within spraying distance of all the portions of the tree. Apply the pesticide in even, full sweeps as to hit every piece. Never go over the same part twice, because that is when you start to drip.
If you're dealing with a large and well developed tree, you should stand on a ladder under the base of the trunk. Spray all segments from the inside towards the outside. After you are done spraying the outer canopy, you're ready to get out from under there and work on the rest. Once you are done cleaning, be sure to fully and thoroughly clean off every bit of equipment you used, including your clothes. Don't include the clothes you wore while spraying in the rest of your family's laundry.
While you're spraying for pests, the main thing to keep in mind is to avoid dripping onto the ground. When this happens, the pesticides will be absorbed by the roots of the tree and be transported to the actual fruits on the trees. As long as the pesticides stay on the outside and you wash your fruit thoroughly before you eat it, you will have nothing to worry about as far as being poisoned goes.