The Reasons and Solutions for the Yellowing of Full Bloom Star Leaves
As a popular ornamental plant among gardening enthusiasts, the yellowing of Full Bloom Star leaves often troubles growers. This article systematically sorts out the three core causes: light regulation, water management, and the use of chemical equipment, accompanied by high-definition real-shot illustrations to help you quickly identify problems and implement precise treatments.
1.1 Mechanism of Sunburn Injury
When the intensity of UV radiation exceeds 2000μW/cm² at noon in summer, continuous direct exposure for over 3 hours leads to a photoinhibition reaction in the leaves, damaging the chloroplast structure and presenting scorching yellow spots. Observations show that when the ambient temperature is greater than 35°C, the rate of yellowing accelerates by a multiple.
1.2 Scientific Shading Scheme
Adopt a three-tiered progressive protection: ① Set up a 50% shade net ② Place a reflective screen 1 meter away from the plant ③ Use a layer of perlite as an insulating layer at the bottom of the pot. After pruning yellow leaves, spray a 0.1% ferrous sulfate solution to promote the regeneration of new leaves.
Two, Yellowing Due to Water Imbalance
2.1 Key Points of Dry-Wet Cycle
Monitor the soil moisture with a moisture meter to maintain the substrate moisture content between 40-60%. Use the "dry-see-dry-wet" method: water thoroughly when the top 2cm of soil is dry, avoiding waterlogging. Experimental data shows that scientific watering can reduce the yellow leaf rate by 78%.
2.2 Techniques for Root Revival
Rotten roots should be pruned to healthy white roots and soaked in ABT root powder at 200ppm for 30 minutes. During transplantation, prepare new soil with the ratio of peat: vermiculite: perlite = 5:3:2, and maintain an air humidity of over 70% during the recovery period.
Three, Standard Treatment for Pesticide Contamination
3.1 Cross-contamination of Equipment
A residual glyphosate concentration >0.1ppm in spraying equipment can cause phytotoxicity. It is recommended to equip with dedicated application devices and thoroughly clean with a 5% sodium hydroxide solution three times before and after use.
3.2 Systemic Detoxification Scheme
Immediately spray a mixture of brassinolide (0.01mg/L) + gibberellin (50mg/L) after detecting phytotoxicity, treating once every 3 days for 3 times to repair 90% of the damaged cells. In severe cases, replace all the growing substrates.
Four, Key Points of Supporting Maintenance
Apply a slow-release fertilizer with an N-P-K ratio of 20-10-20 monthly, maintain a day-night temperature difference of 8-10°C, and regularly prevent diseases with a 800x solution of carbendazim. Comprehensive management can extend the ornamental period of Full Bloom Star to 200 days.
Mastering the three core elements of environmental control, precise watering, and standardized medication, combined with diagrammatic diagnosis and step-by-step treatment, can systematically solve the yellowing problem of Full Bloom Star leaves. It is recommended to establish a maintenance log to record temperature and humidity and operational data, gradually forming a personalized maintenance plan.