USE OF BACILLUS ARYABATHAI IN COFFEE SEEDLINGS TO MITIGATE THE EFFECTS OF WATER DEFICIT

For coffee production to be successful, the stage of choosing, preparing and managing the seedlings is essential. In the present work, the objective was to study the influence of the application of doses of Bacillus aryabhattai in arabica coffee seedlings (cultivar Araras) recently planted, submitted to accentuated water deficit. The experiment was carried out in a greenhouse in plastic pots with a capacity of 5 dm³ filled with a substrate and previously corrected to reach 70% base saturation and fertilized according to the needs of the culture. The dose used was 10-8 colony forming units (CFU) of B. aryabhattai (200 mL ha-1) inoculated directly into the pots at the time of fertilization. Water deficit treatments consisted of two levels of soil moisture maintenance: at 80% of soil field capacity (FC) and at 60% CC. The plants were submitted to the following treatments: (i) Treatment 1 – plants submitted to 80% of Soil Field Capacity, without fertilization and without inoculation; (ii) Trat 2 – plants submitted to 80% of Soil Field Capacity, without fertilization and inoculated; (iii) Trat 3 – plants submitted to 80% of Soil Field Capacity, with conventional fertilizer (MAP 11-52-00) and inoculated; (iv)Treat 4 – plants submitted to 80% of Soil Field Capacity, with slow release fertilizer (Organomineral 06-32-00) and inoculated; (v) Trat 5 – plants submitted to 80% of Soil Field Capacity, with controlled release fertilizer (Phusion 06-30-00) and inoculated; (vi) Treat 6- plants submitted to 60% of Soil Field Capacity, without fertilization and without inoculation; (vii) Trat 7 – plants submitted to 60% of Soil Field Capacity, without fertilization and inoculated; (viii) Trat 8 – plants submitted to 60% of Soil Field Capacity, with conventional fertilizer (MAP 11-52-00) and inoculated; (ix) Trat 9 – plants submitted to 60% of Soil Field Capacity, with slow release fertilizer (Organomineral 06-32-00) and inoculated; (x) Trat 10 – plants submitted to 60% of Soil Field Capacity, with controlled release fertilizer (Phusion 06-30-00) and inoculated. After transplanting, the vegetative growth of the coffee plant was measured monthly, through measurements of plant height and average crown diameter. At the end of the experiment, the number of leaves and the estimated leaf area were measured. In general, there was a difference between the treatments at 30 DAT (days after trans planting) and 60 DAT in relation to crown diameter (DCO), at 60 DAT the shoot height (APA) also differed, as well as the diameter of stem (DCA) at 75 DAT. More studies are needed to better elucidate the real effect of inoculation of B. aryabhattai.