Management of Fusarium fruit rot of Luffa cylindrical, a new occurred disease at North Egypt caused by Fusarium incarnatum and Fusarium chlamydosporum

Abstract Fusarium rot of Luffa cylindrical was detected at Kafr-El-Dawar province, Beheira governorate, North Egypt during the growing season 2021. Surveyed disease incidence at Beheira, Kafr El-Shekh and Sharkia governorate showed fruit rot incidence recorded as 18.33%, 16.12%, and 12.42%, respectively. Two fungal isolates of Fusarium spp. were tested for their pathogenic ability to induce Fusarium rot disease and proved typical disease symptoms. Online BLAST program was used for rapid identification and confirmation of identity performance of ITS and DNA sequencing, then compared with sequences available in GenBank. The two fungal isolates were identified as Fusarium incarnatum and Fusarium chlamydosporum and registered under accession number MN480497 and MN480498, respectively. Under laboratory conditions, the tested organic acids, essential oils and organic salts had significant inhibitory effect against the linear growth of the two fungal isolates. Complete fungal growth (100%) was recorded at 0.75 g/l of Topsin-M70 (Thiophanate-methyl) and 0.5% of salicylic acid. Meanwhile, moderate effect was observed at benzoic acid, coumarine, and cinnamon, thyme oil and garlic oil treatments. Under field conditions for two successive seasons, similar trend was also observed. Foliar spray with the fungicide Topsin-M70 had superior effect on disease expression followed by all applied fungicide alternative treatments. The highest fruit rot disease reduction was recorded at salicylic acid and coumarin treatments followed by thyme oil, benzoic acid and potassium carbonate, garlic oil, boric acid and sodium bicarbonate, respectively. It may be concluded that the applied treatments are considered applicable, safe and cost-effective method for controlling such pre-harvest fruit diseases under field conditions.