LEVANTAMENTO FITOSSOCIOLÓGICO DE PLANTAS DANINHAS NA SUCESSÃO ENTRE A CULTURA DA BRAQUIÁRIA E FEIJÇÃO CAUPI

Abstract

Cowpea (Vigna unguiculata) is a crop that has been gaining visibility within the national agricultural scene. Despite the good productive attributes, one of the factors that can most negatively affect this crop is direct contact with weeds. Carrying out management strategies, which include phytosociological surveys to quantify, identify and understand the dynamics of weeds, becomes a fundamental tool within the production system. Thus, the objective of this work was to provide a phytosociological survey of weeds present in the area of succession between brachiaria grass and cowpea. The experiment was carried out on the farm of the Instituto Federal Goiano Campus Posse. Initially, he collected weeds in the brachiaria area, prior to the cultivation of beans. In the cowpea cultivation area, collections took place at 14, 21, 28, 35, 42, 49, 56 and 63 days after cowpea emergence. To collect the plants, a hollow square measuring 0.5mx0.5m was used. The evaluations with the launch of the square with the cowpea cultivar BRS Marataoã installed in an experimental area, where it was repeated in four blocks being represented as area 01, 02, 03 and 04. For identification, the plants were removed from the field and in laboratory identified as to family, genus and species, according to the literature for classification. After identification, the descriptive analyzes of the study were determined, which were carried out using phytosociological parameters, which are represented, namely: absolute density, relative density, absolute frequency, relative frequency, absolute dominance, relative dominance, value of coverage and importance index of each weed found in the cowpea cultivation area. Under the conditions of the present study, the most representative weed families were Poaceae, Fabaceae and Malvaceae. Among the areas sampled, areas 01 and 02 had the highest numbers of individuals compared to areas 03 and 04, which may possibly be related to inadequate management conditions within the area, which may favor the flow of weeds in a given area. The most relevant species were Brachiaria brizantha, Malvastrum coromidelium, Portulaca oleraceae and Poa annua, which obtained high importance index values in the present work. There is evidence that proves that there is no correlation between the study area and the time of weed infestation in relation to the development of cowpea. All collection times were the same for the occurrence of weeds. Finally, through the analyzes carried out, knowledge about the weed community in an agricultural production system highlights the phytosociological survey as an essential part in the management of weeds in bean crops, assisting in decision-making, preventive planning and reduction of costs to the producer.