Effect of Nitrogen Doses and Preculture of Plant Species on Watermelon Culture
Ignácio Lund Gabriel da Silva Carmo *
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Roberto Dantas de Medeiros
Brazilian Agricultural Research Corporation (EMBRAPA), Boa Vista, RR, Brazil.
Edmilson Evangelista da Silva
Brazilian Agricultural Research Corporation (EMBRAPA), Boa Vista, RR, Brazil.
Edvan Alves Chagas
Brazilian Agricultural Research Corporation (EMBRAPA), Boa Vista, RR, Brazil.
José de Anchieta Alves de Albuquerque
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Anderson Carlos de Melo Gonçalves
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Edgley Soares da Silva
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Roberto Tadashi Sakazaki
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Maria Luiza Grigio
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
Eduardo Medeiros de Oliveira
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Aims: The aim of this study was to evaluate the best crop succession strategy and nitrogen dose for irrigated watermelon cultivation in the cerrado of Roraima.
Experimental Design: The experimental design was a randomized complete block design, arranged in a split-plot scheme, with four replications.
Place and Duration of Study: Two experiments were conducted (2014/2015 and 2015/2016 growing seasons), with the ‘Crimsom Sweet’ watermelon cultivar, grown under different N doses in succession to cover crop species, at the experimental field “Água Boa”, belonging to Embrapa Roraima, located in the municipality of Boa Vista, state of Roraima, Brazil.
Methodology: The three plots consisted of cultivating watermelon in succession to: maize intercropped with pigeon pea (Cajanus cajan), Brachiaria (Urochloa ruziziensis) and control with natural vegetation. The subplots consisted of four doses of nitrogen (0, 75, 150 and 225 kg ha-1 of N) applied in the watermelon culture. The following variables were evaluated: average fruit weight, number of fruits per hectare, number of fruits per hectare with a mass between 5 and 10 kg, number of fruits per hectare with mass greater than 10 kg, productivity, soluble solids content, pH and titratable acidity.
Results: The pigeon pea provided an increase in the number of fruits per hectare with mass ≥ 10 kg and in productivity. Nitrogen doses between 118 and 124 kg ha-1 produced the highest number of fruits, number of fruits with mass ≥ 10 kg and higher soluble solids content.
Conclusion: Fruit quality was influenced by the year of cultivation, predecessor cover crop species and the N doses. Pigeon pea and U. ruziziensis favor the availability of nitrogen in the soil for the following crop in succession.
Keywords: Cerrado of roraima, Citrullus lanatus, crop succession, green manure