During an agricultural aerial application flight near hilly terrain, the pilot pulled up at the end of an application run in order to execute his reversal turn. During the pull-up/turn sequence, the airplane encountered a localized wind shear, which resulted in the airplane's nose dropping down and to the right. Although the pilot attempted a recovery, he did not have enough altitude to do so, and therefore the airplane impacted the terrain. The pilot reported that there was no indication of problems with the flight controls or the engine. The impact sequence resulted in substantial damage to both the fuselage and the wings.