The 1,457-hour commercial pilot lost control of the tailwheel-equipped agricultural airplane while attempting to depart from a 2,400-foot long unimproved private grass airstrip. The pilot reported that while departing on a southerly heading he was "dodging pot holes and mud holes" on the airstrip. The spray booms under the wings became entangled with tall grass resulting in a loss of directional control. The airplane exited the right side of the airstrip, the right wing collided with a fence post and the airplane "ran through a ditch." An FAA inspector interviewed the pilot, who confirmed the accident sequence. The inspector recorded structural damage. On the Airport Information block of the accident report form, the pilot categorized the runway as "dirt" and further described the condition of the runway as "holes," "rough," "soft," and "wet." At about 5 minutes after the mishap, the nearest weather reporting station, located 27-nautical miles to the south-east of the accident site, reported winds calm, visibility 5 statue miles with mist, temperature 84 degrees Fahrenheit, dew point 81 degrees Fahrenheit, and barometric pressure of 29.93 inches of Mercury. The density altitude was calculated at 1,776 feet.