This article aims at verifying the possible allelopathic effects of Raphanus raphanistrum L. on the germination of lettuce and tomato seeds. For that, we prepare aqueous extracts of nabiça leaves and roots. After the leaves and roots were triturated in industrial blender, we diluted the raw extract in distilled water, until the concentrations of five and ten percent (m/v). The germination tests were accomplished by putting twenty-five lettuce and tomato seeds in Petri plates, which were humidified with the obtained extracts, accomplishing four repetitions in each treatment. The control treatment was only watered with distilled water. The seeds were kept in germination camera at twenty-five degrees Celsius for five days. After that period, we observed that all the concentrations of nabiça extract reduced the percentage, speed, index of germination speed and radicular length of lettuce seeds, being larger the effect in the treatments with leaves. In tomato seeds, only the ten-percent extract of leaves reduced the germination percentage, radicular and epicotyl length. However, ten-percent extracts of leaves and roots caused delay in the germination process and number of plantules germinated a day, being the ten-percent extract of leaves more active.
allelopathy; nabiça; lettuce; tomato
