What is the yellowing of geranium leaves?
As a household green plant, geraniums are responsible for the beauty of their leaves, and the problem of yellowing has worried countless flower friends. This article will deeply analyze the three major yellowing factors, use scientific maintenance methods to rejuvenate the plant, and help you become a geranium maintenance master. 1. Analysis of the causes of high temperature burns on yellow leaves caused by temperature imbalance When the environmental temperature continues to exceed 32 ° C, geraniums will activate self-protection mechanisms and reduce metabolic consumption by reducing chlorophyll synthesis. At this time, the edges of the old leaves first appear browned, while the new leaves appear wilted. The high-temperature yellow leaf rescue guidelines recommend the use of a "stepped cooling method": first move the plants to a 28℃ environment for 3 days, and then gradually reduce the temperature to 25℃. Combined with foliar spray every morning (pay attention to avoid the high temperature period at noon), using softened water with pH 6.0 has a better effect. 2. Early warning signals of improper water management, water accumulation and rotten roots, the watering amount needs to be adjusted in conjunction with the material of the basin. The pottery basin evaporates quickly and can be poured thoroughly in 3 days, and the plastic basin should be extended to 5 days. If yellow leaves are accompanied by blackening at the base and soil is stuck into clumps, it is a typical symptom of waterlogging. The scientific soil blending improvement plan recommends a gold ratio of perlite: peat soil: vermiculite =4:3:3. Reserve 1/3 of the heart soil when changing pots. After cutting off the rotten roots, soak them in 800 times carbendazim solution for 20 minutes before planting. 3. Disease invasion and control key points for identification of fungal diseases Leaf spot disease is initially manifested as needle-like yellow spots, while downy mildew produces a grayish-white mold layer from the back of the leaves. These two diseases spread at times faster when humidity>70%. The new idea for biological control alternately uses Bacillus subtilis (1:1000) and Trichoderma harzianum (1:800), sprayed on the back of leaves every week. In case of severe infection, systematic treatment can be carried out with the systemic drug difenoconazole.
By accurately regulating temperature and humidity, establishing a scientific watering cycle, and implementing a three-level disease prevention system, more than 90% of yellow leaf problems can be effectively controlled. It is recommended to conduct leaf microscopic examination every month and use an EC value detector to monitor soil conditions so that geraniums remain oily green all year round.