Organic polyculture of passion fruit, pineapple, corn and cassava: the influence of green manure and distance between espaliers
The organic fruit crop should incorporate the principles of sustainable agriculture, with a guarantee of productivity coupled with ecological diversity, using techniques of policultive with regional species. The aim of the study was to evaluate the effect of the green manure crops [Canavalia ensiformis (jack beans), Crotalaria spectabilis (sunn hemp), Pueraria phaseoloides (tropical kudzu), Arachis pintoi (peanut forage) and spontaneous plants] and distance between espaliers on the yields of Passiflora edulis f. flavicarpa (passion fruit), Ananas comosus (pineapple), Zea mays (maize), Manihot esculenta (cassava) and biomass in organic polyculture in the state of Acre, Brazil. The randomized block design experiment comprised plots encompassing the space between the rows of passion fruits (espaliers located 3 m or 4 m apart), and subplots that contained the green manure crops. Green biomass yield by jack beans, sunn hemp and tropical kudzu was greater than that provided by peanut forage and spontaneous plants. The polyculture of passion fruit, pineapple, maize and cassava presented a high overall yield (44462 kg ha-1). The land-use efficiency of the polyculture system was between 2.45 (with sunn hemp) and 2.77 (with tropical kudzu) times greater than that achieved by individual monocultures. The yields of passion fruit (with tropical kudzu as cover crop) and pineapple (with spontaneous plants as green manure) were enhanced by some 72 and 34%, respectively, when cultivated in plots comprising 3 m-spaced espaliers in comparison with plots containing 4 m-spaced espaliers.