Blackberry anthracnose, caused by Colletotrichum spp., is an important disease of cultivated blackberry in the world. In Colombia, it is the number one limiting factor for commercial production. This study was conducted to determine the species of Colletotrichum infecting blackberry plants as well as the organ distribution, pathogenicity and response to benomyl of the isolated strains. Sixty isolates from stems (n = 20), thorns (n = 20) and inflorescences (n = 20) were identified as Colletotrichum acutatum and Colletotrichum gloeosporioides by a species‐specific polymerase chain reaction (PCR). Both Colletotrichum species were found in the same plant but on different organs. Colletotrichum gloeosporioides species predominated in thorn lesions (n = 16) and C. acutatum in stems (n = 15) and inflorescence (n = 15). Pathogenicity assays on detached blackberry organs demonstrated differences between the two species with an average period of lesion development of 8.7 days for C. gloeosporioides and 10.3 days for C. acutatum. Wound inoculated organs had 90% disease development compared to 17.5% in non‐wounded. All C. acutatum isolates (n = 34) were benomyl tolerant, whereas C. gloeosporioides isolates (n = 26) were 30.7% sensitive and 69.2% moderately tolerant. Phylogenetic analysis with ITS sequences of a subset of 18 strains showed that strains classified as C. gloeosporioides had 100% identity to Colletotrichum kahawae, which belongs to the C. gloeosporioides species complex, whereas C. acutatum strains clustered into two different groups, with high similarity to the A2 and the A4 molecular groups. These data demonstrate for the first time the differential distribution of both species complexes in blackberry plant organs and further clarifies the taxonomy of the strains.

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In order to control the main diseases that affect blackberries (Rubus glaucus Benth.), a research in which 12 treatments to San Antonio ecotype plants originated in vitro was conducted. These treatments were: 1: Trichoderma harzianum+richoderma koningii (Tropical Fungus), 2: Trichoderma sp. (Bioprotection), 3: Trichoderma koningiopsis (Th003 Trichoderma), 4: Trichoderma asperellum (Th034 Trichoderma), 5: Trichoderma asperellum (T-30 Trichoderma), 6: Trichoderma asperellum (T-98 Trichoderma), 7:Burkholderia cepacia (Botrycid), 8: extract of Swinglea glutinosa (Ecoswin), 9: traditional farming treatments (Mancozeb, Propamocarb), 10: chemical products applications (Mancozeb, Mandipropamida, Carbendazim, Propamocar and Metalaxil+Mancozeb) alternated according to the impact of the disease, 11: chemical products applications alternated with organic products according to the suppliers recommendations and presence of the diseases, 12: absolute control, no treatment was applied to the plants. The applications were carried out every 15 days, each plant was an experimental unit and each treatment was made of five experimental units. 12 treatments were made through a RCBD (randomized complete block design) with three repetitions for a total of 15 experimental units per treatment. The assessments were performed every 8 days, and the variables were: number of healthy and sick fruits/treatment, costs/treatment and gross profit. A variance analysis and a Tukey test 5% were made. The best treatments were T11 (rotation of chemicals with biological products), T10 (rotation of chemical products according to the impact of the disease) and T3 (T. koningiopsis); considering the obtained performance/treatment, treatment cost and profit.

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