COMPARATIVE INFLUENCE OF MYCORRHIZA AND PHOSPHORUS ON THE GROWTH OF BOMBAX COSTATUM PELLEGR & VUILLET FROM DIFFERENT PROVENANCES

Abstract

Arbuscular mycorrhiza has a potential to colonize plant roots towards increasing plant uptake of phosphorous and other nutrients for plant growth. This study investigated comparative influence of Mycorrhiza and Phosphorus on the growth of Bombax costatum seeds from different provenances with a view to improving the growth of the species was investigated. B. costatum seeds were collected from four provenances (Aponmu, Oluwa, Ibadan and Oyo). Seeds from each provenance were sown and at the two-leaf stage after germination, seedlings from each source were transplanted into polythene pots containing mycorrhiza inoculum soil. The inoculation was done at rate of 20 g of mycorrhiza to 2 kg of potting soil. The single super phosphate fertilizer was applied at 0 mg/l (control), 25 mg/l, 50 mg/l, 75 mg/l and 100 mg/l. Seedling height (cm), collar diameter (cm), number of leaves and leaf area (cm2) were assessed fortnightly for 12 weeks. The experimental design was 2 x 4 x 5 factorial arranged in Completely Randomized Design and replicated four times. Data were subjected to analysis of variance (ANOVA). Results show that there were significant differences (p<0.05) among mycorrhiza inoculum, phosphate fertilizer and provenances on the growth of B. costatum. The treatment with 75 mg/l phosphorus fertilizer had the highest height and leaf area of 20.0 cm and 110.7 cm2 while the lowest values 14.4 cm and 88.8 cm2 were observed for the treatment with 0 mg/l. Growth of B. costatum was enhanced by mycorrhiza inoculum and application of phosphate fertilizer.