First Report of Diaporthe gulyae Causing Phomopsis Stem Canker of Sunflower (Helianthus annuus) in Argentina
Between 2014 and 2017, elongated, brown lesions were observed on the stem and heads of sunflower (Helianthus annuus L.) plants in the Argentine Southern Sunflower Region (ASSR). A total of 66 diseased plants (40 stems and 26 heads) were sampled from the three production fields: Balcarce (37°52′36.6″S; 58°15′29.4″W; 19 samples), Orense (38°41′36.3″S; 59°47′01.9″W; 36 samples), and Pieres (38°23′31.2″S; 58°40′22.8″W; 11 samples). Fungal isolations were made from the lesion margins of the stem and head by cutting, surface disinfesting, and plating tissue pieces on potato dextrose agar (PDA) amended with 0.02% lactic acid (pH 4.5). The PDA plates were incubated at 25°C for 7 to 10 days under a 12-h photoperiod, and hyphal tips of white to gray colonies were transferred to fresh PDA plates.
DOI of Published Version
Mancebo, M. F.; Bazzalo, M. E.; Reid, R. J.; Kontz, B.; and Mathew, F. M., "First Report of Diaporthe gulyae Causing Phomopsis Stem Canker of Sunflower (Helianthus annuus) in Argentina" (2019). Agronomy, Horticulture and Plant Science Faculty Publications. 290.