Yield response of Pima S7 and Phytogen 57 were improved during 1999 and 2000 with pre-plant applications of N-phuric 15-49-0 and Phosphoric 7-26-0-7. The economic yield response was improved because of the improved timing, placement, and increased nutrient availability due to the acidified root zone during early season stand establishment and fruit set. The pre-plant applications improved the calcium and phosphorus availability by lowering pH in the root zone. No negative affect was seen on impending nitrate conversion and nitrogen availability from the NH ³ sidedress.