Nativa, Sinop, v. 10, n. 1, p. 01-04, 2022. Pesquisas Agrárias e Ambientais DOI: https://doi.org/10.31413/nativa.v10i1.11824 ISSN: 2318-7670 Adequate use of nitrogen associated with molybdenum in crambe crop Tiago Roque Benetoli da SILVA 1* , Andressa Gomes BRANDÃO 1 , Deonir SECCO 2 , Reginaldo Ferreira SANTOS 2 , Charline Zaratin ALVES 3 , Araceli Ciotti MARINS 4 1 Department of Agronomic Sciences, State University of Maringá, Umuarama, PR, Brazil. 2 State University of Western Paraná, Cascavel, PR, Brazil. 3 Federal University of Mato Grosso do Sul, Chapadão do Sul, MS, Brazil. 4 Federal Technological University of Paraná, Toledo, PR, Brazil. *E-mail: trbsilva@uem.br (ORCID: 0000-0002-2015-2103; 0000-0002-2550-3857; 0000-0002-3042-159X; 0000-0002-7745-9173; 0000-0001-6228-078X; 0000-0001-8932-7015) Recebido em 11/02/2021; Aceito em 07/09/2021; Publicado em 14/03/2022. ABSTRACT: Crambe is serving as alternative oilseed for biodiesel production, however, there are still impediments to commercial expansion because need more information about adequate fertilization. The study aimed evaluating adequate nitrogen rate applied in topdressing, associated with leaf molybdenum in crambe crop under field conditions. Treatments were four nitrogen rates (0, 40, 80 and 120 kg N ha -1 ) and two rates of leaf molybdenum (0, 80 g ha -1 ) in a 4 x 2 factorial under randomized complete block design experiment with four replications. Parameters evaluated were shoot dry matter, thousand grains weight, grain yield and oil content in the seed. There was no significant influence of treatments on thousand grains mass. Nitrogen rates linearly increased dry matter shoots and oil content. Grain yield growth as nitrogen increased. When molybdenum was used, grain yield increased significantly when compared to the absence of nutrient application. Keywords: Nitrogen fertilizer; leaf molybdenum; oilseed. Uso adequado do nitrogênio associado ao molibdênio no cultivo de crambe RESUMO: O Crambe é uma oleaginosa que serve como alternativa para a produção de biodiesel, porém, ainda existem impedimentos à expansão comercial, pois são necessárias mais informações sobre a fertilização adequada. O estudo teve como objetivo avaliar a dose adequada de nitrogênio aplicada em cobertura, associada ao molibdênio foliar na cultura do crambe em condições de campo. Os tratamentos foram quatro doses de nitrogênio (0, 40, 80 e 120 kg N ha -1 ) e duas doses de molibdênio foliar (0, 80 g ha -1 ) em esquema fatorial 4 x 2 em delineamento de blocos ao acaso com quatro repetições. Os parâmetros avaliados foram matéria seca da parte aérea, massa de mil grãos, rendimento de grãos e teor de óleo na semente. Não houve influência significativa dos tratamentos na massa de mil grãos. As doses de nitrogênio aumentaram linearmente a matéria seca da parte aérea e o teor de óleo. Houve incremento da produtividade de grãos com o aumento do nitrogênio. Quando o molibdênio foi utilizado, a produtividade de grãos aumentou significativamente em relação à ausência de aplicação desse nutriente. Palavras-chave: Adubação nitrogenada; molibdênio via foliar; oleaginosa. 1. INTRODUCTION Crambe (Crambe abyssinica) is important crop and its oil has high erucic acid content which can be used as an industrial lubricant and corrosion inhibitor (LARA- FIOREZE et al., 2013). This plant species is cultivated in winter, with high oil content in grains, serving as raw material to make biodiesel (SILVA et al., 2012), biofuel production from vegetable oils is a global reality (LARA-FIOREZE et al., 2013). It is interesting to expand and search for alternative raw materials, to evaluate the attributes such as oil content, grain yield, production system and crop cycle, as well as grains that are not used as food source, ensuring the system sustainability. Therefore, the species in question becomes alternative because it is a winter crop (SILVA et al., 2012), however, there are still impediments to its commercial expansion in the country, since information such as evaluation appropriate sowing season in different States, fertilization, density and the loss of crop yields, as well as market structuring are not well understood (PITOL et al., 2010; LARA-FIOREZE et al., 2013). To most cultivated species, fertilizers are the costliest inputs, and their efficient use is key to optimal ensuring grain yield. However, studies regarding the response to crambe fertilization are still scarce. It is known that the plant absorbs high amount of nitrogen (N), which is due to the need of grain, to its high protein content (SOUZA et al., 2009), however, we did not observe in the literature, recommendations of nitrogen fertilization to crambe. To increase nitrogen application efficiency, molybdenum use becomes important. Among molybdenum functions is the nitrate reductase enzyme constitution (DECHEN et al., 2018). This enzyme has three prosthetic groups, one of which is molybdenum cofactor, which associated with pterine, originates the molybdopterin complex (SOUZA;