Efecto de la epoca de transplante, densidad y control de malezas, en la produccion de radicchio rosso di chioggia (Chichorium intibus L.V. foliosum Bischoff) cv. Cesare.

In order to know the effects of the transplanting season, density and weed control over the production of radicchio rosso di Chioggia crop (Cichorium intybus L. var. foliosum Bischoff) in Chile, two trials were made during the 1991 season. The Cesare cultivar was utilized in both trials. Trial-1 evaluated three transplanting dates (May 24, June 26 and July 26), three crop densities (10, 8.75 and 7.5 plants/m2) and three weed control systems (Pronamide herbicide before and after transplanting and hand weeding). The effect of the different treatments on radicchio growth was evaluated measuring average plant weight, width and height, yield, leaf color and plant opening degree. The results showed a greater radicchio plant growth at the first and second transplanting date in relation to average plant height and weight parameters, but a lower percent of good quality market plants was obtained, with the first transplanting date which is presenting a greater percent of close plants and with intense red color, which is required for their marketing. Densities of 8,75 and 7,5 plants/m2 allowed to obtain radicchio plants statistically superior in growth expressed in average plant weight and width, with the 10 and 8,75 plants/m2 densities showing a greater yield than the 7.5 plants/m2 density. For this reason it proved more suitable to use 8,75 plants/m2 density at the transplanting dates to achieve more good quality market plants. Pronamide applications before and after transplanting were made at 1.75 kg a.i./ha rates and were compared with hand weeding control at each transplanting date; no phytotoxicity symptoms were observed in the plants. It was observed that Pronamide applications before and after transplanting at the second and third transplanting date achieved a radicchio plant development (average plant width) equal to that shown by hand weeding. But when applications were made before the first transplanting date, the number of radicchio plants was statistically inferior to that shown by hand weeding. This response resulted mainly form the density of Compositae weeds, which were not controlled by the herbicide. In Trial-2, transplanted on June 21, a 40 day Critical Interference Period of weed growth starting at transplanting was determined for this crop under the conditions outlined above.