EFFICIENCY OF GARDEN WASTE COMPOST TEAS ON POTATO GROWTH AND ITS SUPPRESSIVENESS AGAINST RHIZOCTONIA

摘要

Compost teas are organic solutions obtained by the fermentation of compost in a liquid phase for a few days, with or without aeration. The use of these teas in agriculture is emerging for supplementing or substituting fertilizers and for their ability to suppress soil-borne pathogens. In this study physical and chemical characterization of garden waste compost tea, its application effects on potato growth and its suppressive effect against Rhizoctonia solani were analyzed. N and K content were relevant (3200 and 3848 ppm, respectively). Humic acid level was 190 mg L-1. Field trials were carried out with three fried industrial cultivars (Agria, Hermes and Lady Amarilla) in soils affected by Rhizoctonia located in Rasueros municipality (Avila, Spain) during 2017. Different dosages of compost tea (d1:1l and d2:3l per plot-7.5m2) were applied in experimental potato crops, in order to evaluate growth and production parameters (plant height, SPA units, shoots number, yield, tuber size and fried quality) and the Rhizoctonia solani control (attack severity). The application of the dosage 1 (1333,3 l ha-1), with respect to control, increased the yield (9,47%), improved the culinary quality (40 %) and reduced the Rhizoctonia incidence (12,4-23,7%). These results show that the use of garden waste compost tea can be of great interest to organic and sustainable agriculture.