Competição de plantas daninhas na cultura do fumo (Nicotiana tabacum L.)

Abstract

The use of no-tillage in tobacco cultivation is still restricted to isolated sites and to some farmers, who seek to preserve the soil and increase productivity. Productivity can be affected by competition between weeds and cropping in agricultural environments. A plant that has a well developed root system in length and length has superior competitive ability due to the greater potential of water and nutrient absorption. Competition may occur because of other factors such as light, carbon dioxide and space. However, competition will only occur when the depletion zone of the crop and weed roots overlaps. The objective of the work is to determine the critical period of prevention of interference to the culture of smoking. The experiment was carried out in São Jorge-PR, in the area of a rural producer, from August to December 2016. The experimental design was a randomized block design, with two treatments, with ten plots each and three replications for each plot, That is, two-factor 2x10 scheme with 3 replicates. Varying according to the days after the transplant (DAT), where the weeds were made, starting in the dirty and finishing in the clean, of 0-12 | 0-24 | 0-36 | 0-48 | 0-60 | 0-72 | 0-84 | 0-96 | 0-108 | 0-120 days, and days before harvest (DAC), with 12-0 weeds | 24-0 | 36-0 | 48-0 | 60-0 | 72-0 | 84-0 | 96-0 | 108-0 and 120-0 days. Smoke lines were set at a distance of 1.15 m and 0.45 to 0.5 m between plants. At the end of the crop cycle, stature (E), leaf area (FA), dry matter (DM), number of leaves (NF) and distance between nodes of the tobacco plants were determined. The critical period of interference prevention (PCPI) of the smoking culture ranges from 14 to 108 days after transplantation. The data of AF, MS, E, EM and NF, did not differ statistically between the periods of cohabitation and without cohabitation with weeds.