Response of Canna indica L. to Azospirillum Bio-fertilizer, Date Palm Residues and Their Effect on Vegetative and Floral Growth

Abstract

Background: The global trend at present is to utilise organic fertilisers of various types and sources to minimise the adverse effects of chemical fertilisers as much as possible. Bio-fertilization is a biotechnology-based fertilization method that helps plants to receive even more nutrients, the method is important in enhancing the efficiency of photosynthesis by fixing nitrogen in the atmosphere and producing growth-stimulating compounds. Methods: The experiment was conducted in the lath house of the Department of Horticulture and Landscape Design, College of Agricultural Engineering Sciences, University of Baghdad-Iraq, during the 2024-2025 growing season. The soil of Canna indica L. plants were inoculated with three levels of Azospirillum bacteria (0, 50 and 100 g pot-1) and three levels of Date Palm residues (0, 4 and 8 g pot-1) to determine their effects on vegetative and floral growth. Result: The addition of Azospirillum bacteria at 100 g pot-1 resulted in a significant increase in most vegetative and floral growth characteristics and in the number of rhizomes. This treatment increased plant height, number of leaves, leaf area, main stem diameter, number of shoots, fresh weight, number of flowers, flower diameter, flowering period and number of rhizomes. The application of date palm residues at 8 g pot-1 also significantly increased most vegetative and floral growth traits and the number of rhizomes, including plant height, number of leaves, leaf area, stem diameter, number of shoots, fresh weight, number of flowers, flower diameter, flower stalk length, flowering period and number of rhizomes.