Nitrogen fertilization on ornamental ginger under fertigation in protected cultivation

Adubação nitrogenada na produção do gengibre ornamental fertirrigado em cultivo protegido

ABSTRACT

Tropical floriculture has increased significantly in the last decade due to a growing worldwide market trend of consuming exotic, colorful, beautiful and durable flowers. Among the tropical floriculture products, ornamental gingers, species belonging to the families Zingiberaceae and Costaceae, have high potential for ornamental use, both for landscaping, for cut and potted flower and foliage. However, little information can be found in literature when it comes to crop fertilization, mainly concerning nitrogen fertilization, quite important to tropical soils which are poor in organic matter resource. Thus, this study aimed to evaluate application of nitrogen doses, using fertigation for growing ornamental ginger under protected cultivation. The experiment was carried out from 2012 to 2016, using seedlings produced in vitro multiplication. Plantlets remained for a period of acclimatization in a nursery and, then were planted in pits spaced 1x1 m in a greenhouse. The agronomic parameters and recommendation of nitrogen using SPAD were evaluated from the beginning 2013 until 2016. The experimental arrangement was in randomized blocks with five nitrogen doses (0, 100, 200, 300 and 400 kg ha^-1) and 4 replicates. The increase of nitrogen doses, up to 400 kg ha^-1 via fertigation, produces 77 100-cm-height commercial flowers/tussock/year, favoring the commercial production and standardization of ornamental ginger.

Keywords:
Zingiber spectabile; SPAD index; tropical floriculture