To get success it is necessary to consider the handling of harmful plants, which must be inserted in the planning of the farming as a whole, and the previous knowledge of the infestation potential (species and levels of occurrence) (OSIPE et al., 2009). As in any another culture the presence of harmful plants in the cotton plant provokes reduction in the production, for the competition that exert with the culture for water, light, nutrients, beyond making it difficult the harvest, depreciating the final product quality. The convivncia of the plants of cotton and the infestantes plants during all the cycle of the culture can cause reductions that vary of 68 95% in the productivity, without counting the inconveniences in the harvest (OSIPE et al., 2009). Some works consider first the 30/40 days as being the critical period of matocompetio for the cotton plant, others consider as critical period first the 08 weeks (OSIPE et al., 2009). The grassy ones already initiate its damage to the production if to coexist the cotton for a period of 10 the 20 days. The dicotiledneas, in turn, initiate reduction in the production after its permanence next to the culture for a period between 20 and 30 days to count of the emergency of the cotton (OSIPE et al., 2009).
The density of harmful plants is one of the factors most important, a time that, how much bigger it will be, greater will be the amount of individuals that they dispute the same resources of the way and, therefore, more intense it will be the competition suffered for the culture. In function of the difficulties found for the efficient control of the harmful plants for the mechanic-cultural methods, the use of herbicidas for cotonicultures has reached expressive indices.. More info: ClearSky Business.