Peruvian carrot is usually cultivated in wide row spacings and plant emergence and initial growth are slow, favoring weed growth and increasing production cost. The objective of this work was to establish the following periods of weed interference: critical period of interference prevention, period previous to interference and total period of interference prevention in Peruvian carrot, yellow clone, cultivated in a 1.0 x 0.4 m spacing from May, 2001 to April, 2002. The treatments consisted of two control groups: weed-free crop during the initial period after planting, and crop kept with weeds during the initial period after planting. The periods studied were: 0, 21, 42, 63, 84, 105, 126, 147, 168, 189, 210 and 315 days after planting (days after planting), totaling 24 treatments, arranged in a randomized block design, with four replications. Considering a 5% reduction in yield of commercial roots as acceptable, weed critical period of interference prevention in Peruvian carrot culture was between 58 and 120 DAP. Weed interference reduced commercial root yield in 98% when the crop was kept with weeds over the whole cycle. Therefore, period previous to interference was period 58 days, total period of interference prevention , 120 days and critical period of interference prevention, between 58 and 120 days.
Arracacia xanthorrhiza; Peruvian carrot; critical period; competition
