Spore Release byBotryosphaeria dothideain Pistachio Orchards and Disease Control by Altering the Trajectory Angle of Sprinklers

To design a disease-control management approach, release of pycnidiospores of Botryosphaeria dothidea from infected pistachio was studied in both laboratory and field. In laboratory studies, more cirrhi developed from pycnidia in pistachio rachises infected by B. dothidea that were dry in the field than in rachises washed several times during previous sprinkler irrigations. Pycnidia in older rachises produced fewer cirrhi than did younger rachises. Dry rachises released maximum numbers of pycnidiospores (up to 1,000 per milliliter of water) within 2-3 h of irrigation, and only three to four pycnidiospores were recovered after 10 h of sprinkling []