Pecan trees are everywhere in the South, and many years they provide a bountiful crop.  I think this gives the impression that pecan trees are carefree yard trees.  Unfortunately, this is not the case.  It can be very difficult to get a good crop of pecans without spraying your trees, and this is especially true if you plant commercial cultivars which lack disease and insect resistance.

Probably the biggest mistake a home orchardist can make is to go down to the local hardware store and pick up a 'Desirable' pecan tree.  'Desirable' is a terrific cultivar, but it takes top-quality management to produce a crop, and few home growers are going to be able to provide this care.  'Desirable' is extremely susceptible to pecan scab, and in most years this disease will wipe out an unsprayed 'Desirable' tree.  'Stuart' is marginally better than 'Desirable', but not by much.  Also, make sure you are buying a grafted tree, somewhere along the stem, above the roots, you should see a graft union.  If you don't it may just be a seedling tree.  Pecans are like people, they always differ from their parents, so a seedling will have unknown nut size and quality.  Also, seedlings will take longer than grafted trees to bear fruit, often 2-3 times as long (up to 10 years). 

Below I have listed what are my favorite cultivars for yard trees, and some information on how to take care your new tree.

Kanza

Similar to Elliott but cold hardy, good choice for north Ga.

Excel

Large nut and so far immune to scab.

Auburn University has selected several cultivars specifically for use in low-input (no spray) situations.  Please see their website for further information.  We have just begun to evaluate these selections so we can not offer any information on them yet.