The antifungal activity of some chemical salts against Fusarium oxysporum f. sp. radicis-cucumerinum causing cucumber root and stem rot disease

Cucumber root and stem rot disease caused by Fusarium oxysporum f. sp. radicis-cucumerinum (Forc) is one of the most important diseases of cucumber in Iran. In this regard, this study aimed to investigate the antifungal activity of some chemical salts against Forc in in vitro and greenhouse conditions. The experiment layout in the in vitro condition was based on a factorial experiment using a completely randomized design including three replications. Treatments included potassium sorbate (PS), mono-potassium phosphite, ammonium bicarbonate, salicylic acid (SA), di-potassium hydrogen phosphate (DPHP), and fungicide carbendazim (CAR) (Bavistin WP 60%) at 0, 0.5, 2, 4, and 5 g/l. In a greenhouse condition, the experiment was conducted using a randomized complete block design with three replications. The laboratory and greenhouse experiments showed that the treatments had a significant effect on fungal growth inhibition and disease severity. In in vitro condition, the highest control of the fungus was attributed to PS and fungicide CAR. Conversely, DPHP had the least control (8.74%) on the growth of Forc at 0.5 g/l. In a greenhouse condition, CAR prevented disease symptoms for one month. However, PS and SA controlled mycelial growth with an efficiency of 61.19 and 39.2%, respectively. Accordingly, it seems that PS and SA are fungitoxic against Forc and can control root and stem rot disease in the greenhouse by root and foliar application.