Green Manuring with Hairy Woodrose (Merremia aegyptia L.) Mixed with Rooster Tree (Calotropis procera) in the Agronomic Production of Kale Greens (Brassica oleracea L.) in the Semi-Arid Region of Brazil

Aims: In the semi-arid region of Brazil, there are several species of spontaneous plants that develop during the rainy season, in the case of the hairy woodrose (Merremia aegyptia L.) and throughout the year, the rooster tree (Calotropis procera), these plants are being used as green manure in vegetable production. In this sense, the objective was to study the green fertilization with hairy woodrose (Merremia aegyptia L.) mixed with rooster tree on the productivity of the leafy vegetable kale greens in the semi-arid region of Brazil.

Place of Study: The experiment site was in the municipality of Mossoró, RN, Brazil, located at 5º 11' south latitude and 37º 20' west longitude and altitude of 18 m.

Study Design and Methodology: A completely randomized design was used, with treatments arranged in a 5 x 2 factorial scheme, with four replications. The first factor consisted of five amounts of green manure from the mixture of hairy woodrose (Merremia aegyptia L.) plus rooster tree (Calotropis procera) (0.0; 1.2; 2.4; 3.6 and 4.8 kg m-2 of area in green base) and the second factor by the forms of application to the soil (incorporated and cover).

Kale greens (Brassica oleracea L.) Evaluated Characteristics: At the time of harvest, the following characteristics were evaluated: plant height; number of leaves; weight of leaves; mass green of kale; Production of kale greens and dry mass.

Conclusions: The best productive performance of the leafy vegetable kale was observed in the amount of 3.6 kg m-2, with values of 17.0 leaves/plant and 1080.25 g/m2 of area. Regarding the forms of application to the soil, the method of incorporation was superior to the application of fertilizers in coverage, values of 985.8 and 788.9 g m-2 of area, respectively. Hairy woodrose (Merremia aegyptia L.) and rooster tree (Calotropis procera) are promising species to be used as green manure.