Most guy's do not have trouble with lower pecs. They tend to get over developed compared to the upper chest. But for those who do not:
One of the prime movements that do hit the lower portion are wide dips (as suggested by BigAlski). But going too deep may cause a problem with the shoulder joints for some people, when extra weight is used. Can also do the wide grip dip with the knuckles facing forward, giving a whole different feel and stretch to the exercise. A similar muscle press-up, on a chinning bar, can be consider also. Middle/close grip dips are very powerful position when handling heavier added weight. A 100lbs+ for workout reps is not out of the question after awhile. If anyone can train on a "V" bar, than any position, from extra wide to extremely close gripping is possible. Anyone could easily make a "V" dipping device with 2X4's and a solid base. We did at out gym. Any dipping movement will also hit the anterior delts and triceps. Holding the body more upright, with elbows glued to the side, is an excellent tricep mass builder.
I know that the decline press will build lower pec's (most any movement, where pressing down and/or along the body, affects the lower range of the pec's) but to me it's just too awkward. Where as, to my mind, any form of dipping gives better results. The pec deck and bent arm pullovers are other considerations for lower pecs. Good Luck.
Medford: Those A- cup's need a lot of lower pec work for some of the less gifted females. A lot of guy's find that out on blind dates.
