DOI: 10.36347/sjavs.2023.v10i08.001

Pages: 99-113

With the objective of developing biological management options for coffee rust, through the characterization and evaluation of native isolates of Lecanicillium spp. The inoculum was obtained from hyperparasitized rust pustules and purified in potato dextrose agar culture medium. Lecanicillium spp. isolates were studied by microscopic, macroscopic, and physiological characterization, as well as In Vitro tests to determine the parasitism of each isolate on uredospores and rust pustules, and the potential for mass production of conidia on organic substrates: soybean, sorghum and rice. Six native isolates of the genus Lecanicillium spp. were obtained from 20 samples, with conidia ranging in size from 2.5 to 7.5 µ in length and from 1.5 to 2 µ in width, in groups or solitary, hyaline in color and cylindrical or ellipsoidal in shape. The size of the phialides ranged from 20 to 28 µ with a base width of 2.5 µ. Phialides were found solitary or in whorls originating from straight conidiophores, the conidia generally in groups of two to six, sometimes solitary. The average radial growth of Lecanicillium spp. 20 days after inoculation was 18 mm in PDA, 15 mm in EMA and 16 mm in SDA. The Majada isolate presented the highest percentage of viability with 99.7% at 22 hours. The isolate La Gotera on the soybean-based organic substrate showed the highest conidial yield of 1.08E+09 per gram of substrate compared to the other substrates and the other isolates. The Jinotega isolate presented the highest parasitism of uredospores in Petri dishes 16.6%. The highest percentage of parasitism on pustules was presented by the isolate La Gotera with 88.3%.