Symptoms Leaves, petioles, twigs, and pedicels can be affected, but mainly damage the leaves.
There are two types of symptoms: one is the reddish brown to purple brown spot on the surface of the early stage of the disease, and gradually enlarges into a round or amorphous dark black spot. The yellow spot is often around the lesion, and the edge is radial and sick. The spot diameter is about 3 to 15 mm. The black spots on the late lesions are scattered, that is, the conidia discs of the bacteria. In severe cases, the leaves of the lower part of the plant are yellow and early leaves, causing individual branches to die, such as black spot disease.
The other is a brown to dark brown near-circular or irregularly shaped wheel spot on which the black mold, the conidia of the pathogen, grows. In severe cases, the leaves fall early and affect growth, such as black spot disease.
The law of onset Black spot disease is the main disease on the rose, which is common and serious. The pathogens overwinter in the dead branches or soil with mycelium or conidia disks. Infection occurred in the middle and late May of the next year, and the period from July to September was the peak period. Conidia are transmitted by wind, rain or insects, and re-infected.
Rainwater is the main condition for the epidemic. In the early years of rainfall, the incidence is early and heavy. Low phlegm water, poor ventilation, insufficient light, improper fertilizer and water, etc. are conducive to the onset.
Control method
1 Use excellent disease-resistant varieties.
2 After the fall, the dead branches, fallen leaves, and burnt are removed.
3 Strengthen cultivation management, pay attention to plastic trimming, ventilation and light transmission.
4 When the new leaves are unfolded, spray 50% carbendazim WP 500-1000 times solution, or 75% chlorothalonil 500 times solution, or 80% sensitized zinc 500 times solution, 7 to 10 days once, even spray 3 to 4 times.
There are two types of symptoms: one is the reddish brown to purple brown spot on the surface of the early stage of the disease, and gradually enlarges into a round or amorphous dark black spot. The yellow spot is often around the lesion, and the edge is radial and sick. The spot diameter is about 3 to 15 mm. The black spots on the late lesions are scattered, that is, the conidia discs of the bacteria. In severe cases, the leaves of the lower part of the plant are yellow and early leaves, causing individual branches to die, such as black spot disease.
The other is a brown to dark brown near-circular or irregularly shaped wheel spot on which the black mold, the conidia of the pathogen, grows. In severe cases, the leaves fall early and affect growth, such as black spot disease.
The law of onset Black spot disease is the main disease on the rose, which is common and serious. The pathogens overwinter in the dead branches or soil with mycelium or conidia disks. Infection occurred in the middle and late May of the next year, and the period from July to September was the peak period. Conidia are transmitted by wind, rain or insects, and re-infected.
Rainwater is the main condition for the epidemic. In the early years of rainfall, the incidence is early and heavy. Low phlegm water, poor ventilation, insufficient light, improper fertilizer and water, etc. are conducive to the onset.
Control method
1 Use excellent disease-resistant varieties.
2 After the fall, the dead branches, fallen leaves, and burnt are removed.
3 Strengthen cultivation management, pay attention to plastic trimming, ventilation and light transmission.
4 When the new leaves are unfolded, spray 50% carbendazim WP 500-1000 times solution, or 75% chlorothalonil 500 times solution, or 80% sensitized zinc 500 times solution, 7 to 10 days once, even spray 3 to 4 times.
ã€Comment】 ã€Print this article】 ã€Close this page】 ã€Large, medium and small】
LVL (Laminated Veneer Lumber)
Door Core Lvl Board,Lvl Bed Slat,Lvl Scaffold Board,Laminated Veneer Lumber
Fushi Wood Co., Ltd. , http://www.sgplywood.com