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The endophytic and stimulating effect of four strains of Trichoderma asperellumSamuels, Lieckfeldt & Nirenberg (Ta. 13, Ta. 78, Ta. 85, and Ta. 90) on Phaseolus vulgaris (Cv.BAT-304) was evaluated under semi-controlled conditions. The number of leaves and roots, plantheight, root length, fresh foliar and root mass, dry foliar and root mass, endophytic capacity in roots,foliar content of N, P, K and the induction of peroxidase enzymes (POD), polyphenoloxidases (PPO),and phenylalanine ammonium lyases (PAL) were determined. The evaluations were carried out in 15-day old plants sown at two times:1) plant sowing and soil inoculation with Trichoderma at the sametime, 2) planting seven days after soil inoculation with the fungus). The strain Ta. 85 produced the greatest stimulation in terms of number of leaves, plant height and root length with the first time ofsowing. All the strains were endophytic for the bean cultivar studied. Ta. 90 and Ta.85 increased theleaf content of N with the first sowing time, whereas Ta. 78, Ta. 85, and Ta. 90 did it with the secondsowing time. Only Ta. 78 increased the leaf K with respect to the control with the second sowing time.The plants treated with Ta. 78 showed higher POD, PPO and PAL enzymatic activities with respect tothe control plants. Ta. 13 increased POD and PPO activities, whereas Ta. 85 and Ta. 90 only the PPOactivity. The results suggest that strain Ta. 85 inoculated at bean planting is efficient in stimulatinggrowth, whereas Ta. 78 stood out in nutrition and induction of possible resistance in this crop |
