Effectiveness of Plant Growth-Promoting Rhizobacteria (PGPR) in Inhibiting Fusarium Wilt Disease in Tomato Plants (Solanum lycopersicum)

Fusarium wilt is major soil born disease of tomato caused by fungus Fusarium oxysporum f. sp. Lycopersici limiting production of tomato in all over the word. This study was conducted to assess the incidence of Fusarium wilt in important tomato growing areas of Khyber Pakhtunkhwa (KPK), Pakistan and to appraise the bio-control prospective of indigenous Plant Growth Promoting Rhizobacteria (PGPR) against the Fusarium oxysporum f. sp. Lycopersici. An organized field survey of district Haripur, Abbottabad, and Mansehra of Khyber Pakhtunkhwa (KPK) was conducted to evaluate the disease occurrence, with incidence ranging from 18% to 94%. The highest disease incidence of 94% was recorded from Dewal Manal (Abbottabad) followed by 90% in Kachi village of Haripur District highlighting them as potential hotspots of the disease. Lowest disease incidence of 18% was recorded from Hamsherian village of district Mansehra and Bal Dheri village of District Abbottabad. Isolation and pathogenicity testing rooted F. oxysporum f. sp. lycopersici as the causal organism. Five PGPR isolates (Pseudomonas and Bacillus spp.) formerly isolated and characterized from tomato growing areas were evaluated for antagonism against the causal organism using in-vitro dual culture technique. Greenhouse experiment was performed with 31 PGPR treatments, including single bacteria and their different combinations arranged in a Randomized Complete Block Design (RCBD). Results showed notable disease control and growth promotion by PGPR treatments (p < 0.05). The combination of RBT2, RBT4 and RBT5 isolates minimize the disease severity by 71% and promote the plant growth parameters as compared to single and pairwise treatments. This study emphasise the potential of indigenous PGPR isolates as an eco-friendly technique for controlling Fusarium wilt disease in tomato. To encourage the use of these formulations in sustainable agriculture, field testing in a variety of agro-climatic settings is advised.