Weed disinfestation in soils for seedling production using a solar collector

Abstract

The health of the substrate used for seedling production in nurseries is a primary and decisive factor for the final quality of the product to be obtained, with emphasis on the production of coffee seedlings. Therefore, two experiments were carried out with the objective of evaluating the efficiency of a solar collector in the disinfestation of substrates used in plant nurseries in terms of controlling weeds (Urochloa brizantha, Digitaria insularis, Euphorbia heterophylla and Ipomea grandifolia), as well as their effects in the development of lettuce plants (bioindicator). In the first experiment, weed seeds were added to the experimental soil which, after mixing, was distributed into eight treatments, namely: solar collector (four and six days), oven with forced air circulation at 70°C (two and three days), transparent PET bottle (six days), 4 L-plastic pot sealed with plastic film (four and six days) and check plots without thermal treatment. In the second experiment, the soil heat treatment procedure was repeated, but without the addition of weed seeds and without treatment with sealed pots. In this case, after heat treatment, lettuce seedlings were grown in the soil, used as a bioindicator. In summary, the best weed control was obtained with the use of a solar collector for 4 and 6 days. In general, all heat treatments provided better results than the check plots in terms of the development of lettuce seedlings.