Compost tea as a sustainable alternative to promote plant growth and resistance against Rhizoctonia solani in potato plants

Compost teas (CTs) are organic extracts originated by mixing mature compost with tap water under controlled conditions. The application of these extracts could constitute a biostimulant and eco-friendly alternative for sustainable agriculture. Thus, this study was proposed to verify the contribution of different doses and Trichoderma-fortified green waste based-CT in plant susceptibility against Rhizoctonia solani infection, as well as in plant growth and tuber quality in two potato cultivars (Agria and Hermes) grown under greenhouse and field conditions. The results showed that CT-treated plants displayed a higher resistance to Rhizoctonia solani, being Hermes the most susceptible cultivar. Moreover, CT-treated plants showed an enhancement in yield, shoot number, tuber weight and tuber size, as well as an advance in potato sprouting, especially in those plants treated with the highest CT dose. A similar trend was observed in both cultivars. Furthermore, to confirm the effect of CT on sprouting, an additional study in the laboratory was carried out with Agria cultivar, in which it was observed that the advance in the crop cycle is induced by CT supply. Subsequently, the fried-quality parameters of tubers coming from potato plants grown under the different treatments in field conditions were studied. The addition of CT to potato plants reduced fried defects, total soluble solids in tubers, while increasing moisture content. However, both cultivars displayed several differences under control conditions, since Agria displayed high fried defects, as well as a reduction in total soluble solids and in the slice puncture test. Therefore, the application of CT is a dose-dependent effective approach to decrease R. solani attack, advance potato cycle and promote plant growth, as well as to obtain a better fried-quality tuber that is highly valued by the agri-food industries.