I refuse to let my husband spray chemicals along our fence lines to kill weeds and keep the grass down. Instead, I do allow him to use organic herbicide - a mixture of 20% vinegar and orange oil. It does the trick without contaminating the soil.
For small, quick applications the small sprayer works fine. For the actual fence line, the backpack sprayer works best. Although larger models exist that hold more spray and need to pulled behind a tractor, the backpack allows easy access to any area that needs to be reached.
Besides, the backpack model is one more to get great exercise, fresh air, and a good look at your animals and their environment.
For other organic control of insects in your garden, check out Ohio Earth Food, Inc - all their products are organic.
Food, Inc will change how you look at the food you buy at your local grocery store - a must see!!