Determinism of some phytohormones and potassium nitrate on the vegetative growth of Tangelo (Citrus x tangelo) in the Sudano-Sahelian area of Mali

In Mali, citrus fruits contribute significantly to the nutritional balance of the population due to their high content of vitamin C, carotenoids and polyphenols. The citrus sector in Mali is rich in several species, but the current trend in citrus production is towards the production of Tangelo (or Citrus×tangelo). The objective of this study was to determine the effects of phytohormones 2,4,5-T, AG3 and potassium nitrate (KNO3) on vegetative growth of Tangelo. The trial was conducted in Koulikoro district, especially on the experimental plot of the IPR/IFRA of Katibougou. The plant material used is Tangelo orlando with white pulp. The experimental design was a Fisher block with three replications. The three products and water (check) were applied by spraying the leaves of the young plants at 110 days after planting. Observations were made on the following growth parameters: graft diameter, graft length and number of vegetative branches at 90th, 180th and 270th days after the application. The results of the analysis of variance of the different treatments revealed significant (p<1% and p<5%) and non-significant differences. The phytohormone 2,4,5-T followed by AG3, showed the best growth in height, diameter and number of vegetative branches at all measurement periods. Weak to very weak effects of KNO3, and water were found on all studied parameters. The application of 2,4,5-T on Tangelo at the plant’s seedling stage improved vegetative growth which may result in early flowering and could improve yield and fruit quality in Sudano-Sahelian area of Mali.