Postharvest New Fungicid And Hot Treatment For The Research Of Black Spot Disease In Chinese Ya Pears

Propionic acid as a kind of natural fungicide, with its good security, non-toxic, no residue, advantages of natural environmental protection in the aspect of postharvest fruits caused more attention. However, little is known about the effect of Propionic acid-hot treatment for control of fungal Pathogens causing Postharvest diseases of the fresh fruits.Black spot disease caused by Alternaria alternata (Fr.) is one of the main postharvest diseases of Chinese Ya pears and causes serious economic loss during storage.The fungitoxicity of postharvest propionic acid and hot treatment at different temperatures and times was investigated in vitro and directly on Chinese Ya pears.Propionic acid hot water treatment can effectively inhibit Alternaria alternata (Fr.). The Incidence of Chinese Ya pear with the increase of concentration of propionic acid were reduced. The results showed that the combined treatment of hot water and propanoic acid had no evident influence on fruit firmness, total acidity and total soluble sugars, but reduced respiration rate; Moreover, the combined treatment significantly inhibited pear black spot incidence of postharvest Chinese Ya pear, and the residue level of propionic acid in fruit was much lower than the maximum residual limit set by the national standard.7000mg/L propionic acid-45℃hot water treatment for30min, not only to the black spot disease inhibition to have certain effect, and is no adverse effect on fruit quality, avoid the use of chemical pesticides bring food safety problems.By measuring the results of postharvest Chinese Ya pear black spot incidence, respiration rate, total acidity, total soluble sugars and the residue level of propionic acid after hot air treatment with different concentrations of propionic acid.Established the level of hot air treatment with propionic acid for black spot disease technology, determined the technical index of25℃-2%propionic acid for30min and45℃hot air treatment for270min. Laboratory experimental results show that the technology can completely kill black spot diseaes of Chinease Ya pear, is no adverse effect on fruit quality, and the residue level of propionic acid in fruit was much lower than the maximum residual limit set by the national standard. It can be used as export fruits were candidates for the postharvest fruits technology.