Strawberry Disease Control: Fungicide Update, 2000

Strawberry Disease Control: Fungicide Update, 2000 Dan Legard GCREC- Dover University of Florida

Important diseases in Florida • Gray Mold • (Botrytis cinerea) • Anthracnose fruit rot • (Colletotrichum acutatum) • Powdery Mildew • (Sphaerotheca macularis)

wide host range grows & produces spores on dead plant material spores are wind and splash dispersed likes cool and wet weather infects flower first then fruit Botrytis cinerea Botrytis fruit rot (gray mold)

Then produces air- borne condia Botrytis colonizes senescent foliage Botrytis invades the fruit as it matures That infect flower parts (stamen and petals)

Botrytis fruit rot control: 1999-2000

Colletotrichum diseases (anthracnose) • Two species involved: • C. gloeosporioides (crown rot) • C. acutatum (fruit rot) • C. acutatum are resistant to Benlate® • Favored by warm & wet weather • Spores are splash dispersed

Mature lesion with orange spore masses Young lesions Colletotrichum fruit rotC. acutatum

Anthracnose fruit rot control: 1999-2000

Favored by humid cool weather, but not rain Strawberry only host Survives on live plants or forms resting stage (cleistothecia) Spores are wind dispersed Infected transplants main source of disease Powdery mildew

Cultivar Sweet Charlie Cultivar Sweet Charlie Cultivar Camarosa Powdery mildew

Powdery Mildew Control:1999-2000

Recommendation • Botrytis fruit rot: Captan / Thiram weekly & Elevate weekly during the second peak bloom period • Anthracnose fruit rot: Captan weekly and Quadris every 14 days starting in mid-January • Powdery mildew: Rotate Nova, Benlate, or sulfur on a 7 day schedule

Strawberry Disease Control: Fungicide Update, 2000