What should I do if the dahlia leaves wither?
Dahlias are the beauty of garden flowers, and the wilting phenomenon of their leaves often makes flower friends anxious. This article will systematically analyze the four key causes of leaf wilting and provide highly operable treatment plans to help you quickly awaken plant vitality. 1. Light control strategies 1.1 Typical symptoms of light imbalance In summer, if strong light is exposed for more than 3 hours at noon, the leaves will appear burnt wilting, and the leaf margins will show burnt brown patches. The data shows that when the ambient temperature exceeds 35℃, the plant transpiration rate increases by 200%, which can easily lead to water imbalance. 1.2 The scientific sunshade plan uses a double sunshade net (shading rate of 50%-70%) to build a mobile sunshade to ensure that the plants receive soft light for 2 hours in the morning +1.5 hours in the evening every day. Monitoring found that controlling the ambient temperature below 28 ° C can shorten the blade recovery cycle by 40%. 2. Water management skills 2.1 Water accumulation warning signal After continuous rainy days, if the soil humidity of the basin continues to be>85% for 24 hours, the roots will enter an oxygen-deficient state. At this time, the leaves appear drooping wilting, and the base stems appear transparent. 2.2 The emergency drainage measure adopts the bamboo stick deep loosening basin soil method, and combines with ceramsite cushion (thickness 3- 5 cm) to build a drainage channel. Experimental data shows that this method can increase the drainage efficiency of stagnant water by 60%. It is recommended to use soft water with an EC value of <0.8mS/cm for irrigation. 3. Optimization Plan for Fertilization 3.1 Diagnosis Standards for Fertilization Damage. Symptoms such as curled leaf margins and deformed new leaves appear within 48 hours after fertilization. When white crystals precipitate from the soil surface, it indicates that the fertilizer concentration has exceeded the safety threshold (EC value of liquid fertilizer>2.5mS/cm). 3.2 The scientific topdressing process adopts the principle of "thin fertilizer and frequent application". Composed sheep manure (ratio of nitrogen, phosphorus and potassium is 3-1-2) is diluted with water at a ratio of 1:15, and combined with alginate (amount of 2ml/L) is applied every 10 days. Studies have shown that this scheme can shorten the rejuvenation time of plants to 7-10 days. 4. Pest and insect pest control system 4.1 Underground pest monitoring uses double monitoring with trap lights + yellow sticky boards every month. When ≥3 ground worms (H) or ≥5 grub larvae are caught in a single day, the prevention and control procedures need to be started immediately. 4.2 The biological control plan prioritizes the use of Beauveria bassiana (concentration of 5×10^8 spores/g) and tea cake powder (amount of 30g/m2) for soil treatment, which has a killing rate of 92% underground pests and no drug residues. Combined with foliar spray of azadirachtin (diluted 1500 times), a three-dimensional protective net can be established.
Through a four-dimensional maintenance system of light regulation, precise water control, scientific fertilization, and biological control, the problem of dahlia leaf wilting can be systematically solved. It is recommended to conduct a weekly plant health assessment, establish a maintenance log, and detect and intervene early to keep your dahlias vibrant all year round.