The growth of cherry production in Chile has been consistent with an increase in export volume year after year. However, it is increasingly common to see orchards affected by wood diseases, especially Cytospora Leucostoma. Therefore, disease control alternatives that can remain present in the orchard competing and controlling inocula of the pathogenic fungus are necessary. This is why the application of Tifi Powder® (Trichoderma atroviride MUCL 45632) on the control of Cytospora leucostoma was studied.
Materials and methods
New cherry var. Santina plants were used on Maxma 14 rootstock, where Tifi Polvo® was applied at a dose of 1.5 kg/ha during the winter break.
For the test, a pruning cut was made on the main axes and after 24 hours, Tifi powder was applied with a motor pump. Then, after another 24 hours, a suspension of conidia of the pathogen Cytospora leucostoma was inoculated on the wound at a concentration of 1×10^5 CFU/ml. In the evaluations, the percentage of inhibition of necrotic lesions was analyzed through the formula:
Results of progression of necrotic lesion inside the trunk
Eight months after inoculation and application of Tifi Polvo®, the necrotic lesion inside the trunk, under the bark, was evaluated. Tifi Polvo® inhibited the progression of the necrotic lesion by 37.5%, indicating that the progression and development of the disease was stopped (Image 1).
Cytospora reisolation results. Regarding the reisolation of Cytospora leucostoma, it was possible to rescue the pathogen Cytospora leucostoma from the area of the advance, confirming that the lesion was caused by the inoculated pathogen.
Conclusions:
The application of TIFI POWDER at a dose of 250 g/Hl (1.5 Kg/Ha) in winter recess, post pruning, managed to reduce the damage caused by the fungus Cytospora leucostoma by 37.5%, in Santina variety cherry trees.
The application of TIFI POWDER at low temperatures did not reduce its effectiveness, managing to control and reduce the progression of the necrotic lesion generated by Cytospora leucostoma.
The rainfall that occurred during the month of application of TIFI POWDER (August) did not wash away the product, its trichodermas managed to establish themselves correctly in the plant tissue.
