In the eyes of gardening enthusiasts, roses are flowers full of romantic aura. When white spots appear on the leaves of roses, it undoubtedly casts a shadow over the beautiful flowers. This article will reveal the secrets of white spots on rose leaves and provide effective prevention and control methods.
Reasons for white spots on rose leaves1. Rose powdery mildew
Rose powdery mildew is one of the common causes of white spots on rose leaves. This disease mainly occurs during the vigorous growth period of roses, and is manifested as white powdery substances on leaves, young branches, and buds. The pathogen of powdery mildew will rapidly reproduce under suitable temperature and humidity conditions, causing poor growth of rose plants.
2. Rose gray mold
Rose gray mold is also a common disease, with symptoms similar to powdery mildew. However, powdery mildew shows white powdery substance, while gray mold shows gray mold layer. Gray mold mainly occurs during the flowering period of roses, and can cause flower rot in severe cases.
3. Rose leaf spot disease
Rose leaf spot disease is a disease caused by fungi, which is manifested as round or irregular black-brown spots on the leaves. In severe cases, it can lead to leaf withering and falling off.
4. Rose pest damage
In addition to diseases, white spots on rose leaves may also be caused by pests, such as spider mites and scale insects, which will absorb the sap of rose plants, causing white spots on the leaves.
Prevention and control methods for white spots on rose leaves1. Daily management
(1) Maintain ventilation and light: Reasonably arrange rose plants, maintain ventilation and light, and reduce the incidence of diseases.
(2) Reasonable fertilization: Apply organic fertilizers to improve the disease resistance of rose plants.
(3) Timely pruning: Prune diseased branches and leaves in time to reduce the spread of pathogens.
2. Chemical control
(1) Powdery mildew: You can choose to spray 70% methylthiophanate wettable powder 800 times liquid or 25% flutolanate emulsion 1500 times liquid.
(2) Gray mold: You can choose to spray 50% carbendazim wettable powder 1000 times liquid or 50% difenoconazole wettable powder 1500 times liquid.
(3) Leaf spot disease: You can choose to spray 50% carbendazim wettable powder 1000 times liquid or 50% difenoconazole wettable powder 1500 times liquid.
(4) Pest damage: You can choose to spray 10% imidacloprid wettable powder 2000 times liquid or 40% chlorpyrifos emulsion 1000 times liquid.
White spots on rose leaves are common diseases and pest damage in rose plants. Understanding their causes and prevention and control methods can help gardening enthusiasts better care for rose plants. In practice, appropriate prevention and control methods should be selected according to specific conditions to ensure the healthy growth of rose plants.
References:
[1] Zhang Lili, Li Xiaofang, Wang Lijun. Occurrence and control of rose powdery mildew[J]. Plant Protection, 2018, 44(2): 1-3.
[2] Liu Xiaohong, Zhang Xiaohui, Wang Fang. Research on the control of rose gray mold[J]. Plant Protection, 2019, 45(1): 1-3.
[3] Wang Lijun, Zhang Lili, Li Xiaofang. Research on the control of rose leaf spot disease[J]. Plant Protection, 2017, 43(3): 1-3.