Studies on some Garlic Diseases during Storage in Egypt

Abstract

Garlic (Allium sativum L.) is one of the more popular cultivated Alliums and many fungal pathogens causing postharvest disease under humid and warm storage conditions. Botrytis allii, Aspergillus niger and Fusarium solani were capable of causing severe rots to cloves of Balady and Chinese garlic cultivars after harvest and during storage. However, Penicillium chrysogenum, Cladosporium sp., Stemphylium botrysum, Helminthosporium allii, Alternaria tenuis and Sclerotium cepivorum were less virulent on both cultivars. Immature and mature garlic bulbs of the two cultivars greatly differed in their reactions to the three fungi. The immature bulbs of both cultivars were the most susceptible to B. allii, A. niger and F. solani, while the mature bulbs were less infected. In the same time, the percentage of dry cloves and loose bulbs were higher in immature bulbs compared with mature bulbs, either inoculated artificially or left for natural infection. In contrast, the mature bulbs showed lower percentages of depletion (waxy brake down), loose bulbs and pathological decay. Higher percentages of healthy bulbs were observed in perforated craft paper, followed by plastic nets and perforated polyethylene bags. Garlic rots were higher in immature bulbs than that in mature ones of un-inoculated bulbs of Balady and Chinese cultivars during storage for 150 days at 25°C and 10°C. Dipping the basal parts of garlic bulbs in 1000 ppm of Thiabendazole (TBZ) in soluble wax were effective in decreasing percentages of rots in bulbs artificially inoculated with each of B. allii, F. solani and A. niger or left for natural infection. Moreover, treatment with TBZ showed best protective effect against looseness in all treated bulbs.