Rosa is one of the world's famous ornamental plants, breeding rose often encounter the situation of yellow rose leaves, today's small editor and everyone to analyze the causes of yellow rose leaves and the corresponding treatment.
Cause analysis and treatment of yellow rose leaves: 1. Too little or too much water
The rose likes moistening, but is afraid of dampness and avoids waterlogging. It can be watered 3-4 times according to the weather conditions from the germination of early spring to the flowering period to keep the soil moist. If drought occurs at this time, the number of flowers will be greatly reduced, and it is necessary to water 2-3 times in summer. Drainage and waterlogging prevention should be paid attention to in rainy season. Because the rose afraid of waterlogging, waterlogging easily rotten roots. In autumn, water should be poured twice or three times as appropriate. Pay attention not to make the root of the plant seeper when watering all year round.
2. Improper fertilization
The newly planted roses need to be fertilized in the soil in autumn. Before that, a small amount of chemical fertilizer solution can be sprayed on the leaves, such as 0.2% solution of urea potassium dihydrogen phosphate. If the fertilizer is applied too early, it is easy to burn the root system and cause plant death.
The main damage to leaves, petioles and young shoots. At the beginning of the disease, purple brown to brown spots appeared on the front of the leaves, and the enlarged spots were mostly round or amorphous black brown. It can be sprayed with carbendazim, thiophanate methyl and dakonin.
4. Powdery mildew
After 3-5 days of the emergence of the white powder layer, the leaves became water stained and gradually lost their green and yellow color. When the serious injury occurred, the leaves fell off. At the onset stage, carbendazim and Triadimefon can be sprayed, but Guoguang Yinna has the best effect.
5. Rose rust
Rust is a common disease of rose. Both the leaves and the new branches may be infected. If the disease is serious, it will cause a large area of leaves to fall off, causing flowers to lose ornamental value and even die. If the disease is found to be dealt with promptly, 800 times liquid three azolone spray can be used once a week for 3-4 consecutive days.
Rose growth habit: Rose likes sunshine. The growth temperature of pink flowers is between 25 and 35. When the temperature is high, the flowers will bloom more, and they can endure half shade and cold. In most areas of northern China, they can overwinter in the open air. However, it can grow better in deep, loose, fertile and moist soil with smooth drainage, and can also grow normally on sticky soil. Not resistant to water and humidity, avoid water. The mature organic fertilizer should be applied to the new plant. In the first 12 years after frost planting, furrows can be opened every year in late autumn to apply base fertilizer to facilitate growth and flowering. It has strong sprouting ability, resistant to cutting and pollution. Generally, the flowering period is from May to September every year, which can be as long as half a year. However, due to the global warming caused by the greenhouse effect, roses in some places began to bloom in April or even March earlier.
The above is the rose leaf yellowing reason analysis and the corresponding treatment method. Plants in the process of cultivation will also have some other different problems, you can pay attention to other articles about roses by plant house.