Control of Penicillium and Green Mold of Pomelo

The symptom characteristics are mainly harmful to the postharvest storage and transportation fruit, the symptoms of the two diseases are similar, most of them occur from the pedicel or wound, at first, the disease spot is waterlogged, the disease spot expands rapidly, the fruit becomes soft and rotten, and a layer of white mildew grows on the face. later, the white mold spot becomes green mold spot (green mold disease) or blue mold spot (penicilliosis), there is a circle of white mold belt on the outer edge of the mold spot, and the junction of the disease department is water-stained soft rot. In addition to the different pathogens (both belonging to different species), there are also many differences in symptoms, among which the most obvious difference is that the mildew spot of penicillium is blue, the white mold band on the outer edge of the mildew spot is narrow (1mm to 2mm), and the mildew spot does not paste fruit wrapping paper; green mildew spot is green, its outer edge white mold band is wider (8mm 15mm), mold spot pastes fruit wrap paper.

The pathogens and characteristics of the two diseases are different species of fungi of Penicillium subphylum. Penicillium spp. (PenicilliumitalicumWeh.) and Penicillium sp. (P.digitatumSacc.) The two bacteria are mycelium saprophytic on a variety of organic matter, they produce a large number of conidia, spread by airflow, can also be infected by contact with diseased and healthy fruit, invading from the wound to cause disease. In general, the conditions of high temperature and high humidity were favorable for the occurrence of the two diseases, but penicillium was the most common at 18-26 ℃, and green mold developed rapidly at 25-27 ℃. If the fruit is picked after rain, heavy fog or dew is not dry, the pericarp has high water content and is easy to scratch and cause disease. The fruit caused many wounds in the process of harvesting, grading, packaging, storage and transportation, as well as warm (18-27 ℃) and high humidity (95%-98% relative humidity) during storage and transportation.

Prevention and cure method

(1) spraying 50% Baogong wettable powder 1500 times solution + 2mem4murD50% 100 unit liquid at 7-15 days before harvest can reduce fruit rot during storage and transportation.

(2) pick fruit after dry dew in sunny day.

(3) be careful to prevent the fruit surface from being touched, stabbed and crushed during grading, packaging, storage and transportation.

(4) the fresh-keeping and antiseptic treatment of the fruit was carried out within 2-3 days at the latest on the day of postharvest (45% Teketo, or 25% Shibaoke, or 45% Xianan 2500O 3000 times solution mixed with 2myryl D5000 times solution for 1 minute).

(5) do a good job of warehouse disinfection (ozone disinfection or sulfur fumigation for 24 hours (10 g / m3), etc.).

(6) properly control the temperature and humidity of the warehouse (cellar) (generally 5: 9 ℃, relative humidity 85%-90%, but there are slight differences among different types), pay attention to ventilation.

(7) improve packaging (such as using "biphenyl" to treat packaging paper or film, etc.).