A synergistic application strategy combining Mepiquat chloride with suitable foliar fertilizers can achieve multiple benefits: controlling excessive vegetative growth, supplementing nutrients, and preventing premature senescence. Below are the standard operational guidelines:
I. Core Principles for Mepiquat Chloride Tank-Mixing
**Compatibility Requirements:** Mepiquat chloride is compatible only with acidic or neutral foliar fertilizers; mixing with strongly alkaline substances is strictly prohibited. A small-scale compatibility test must be conducted prior to mixing; large-scale application should proceed only if no precipitation or discoloration occurs.
**Operational Procedures:** Strictly adhere to the "secondary dilution" method: fully dissolve the foliar fertilizer first, dilute the Mepiquat chloride separately, and finally mix the two stock solutions thoroughly. Prepare the mixture immediately before use; do not store it for extended periods.
II. Common Safe and Synergistic Combinations
**Mepiquat chloride + Potassium Dihydrogen Phosphate (MKP)**
**Synergistic Advantages:** Both aqueous solutions have a pH of approximately 5.5–6.5, ensuring good stability. Mepiquat chloride controls excessive vegetative growth, while MKP supplements phosphorus and potassium, promoting nutrient translocation to fruits or pods and preventing late-stage premature senescence. It also enhances crop resistance to lodging and "dry-hot wind" stress.
**Applicable Crops:** Suitable for the vast majority of crops, including wheat, peanuts, cotton, and vegetables; this is the most versatile combination.
**Mepiquat chloride + Amino Acid Water-Soluble Fertilizer**
**Synergistic Advantages:** Controls growth while supplementing small-molecule active nutrients and promoting robust root development, thereby avoiding the growth decline that can result from growth control alone. It performs exceptionally well on leguminous crops such as soybeans.
**Mepiquat chloride + Brassinosteroid + Potassium Dihydrogen Phosphate (MKP)**
**Synergistic Advantages:** Combines growth control, nutrient supplementation, and enhanced stress resistance. Application during the wheat flowering stage significantly improves resistance to dry-hot winds and increases the thousand-kernel weight.
III. Crop-Specific Application Plans for Mepiquat Chloride
**Wheat:** During the jointing stage, apply 10 ml of 25% Mepiquat chloride and 40–50 g of Potassium Dihydrogen Phosphate per mu (approx. 667 m²), diluted in 15 kg of water for spraying. This controls the elongation of basal internodes, preventing lodging and premature senescence. Peanuts: During the early flowering stage, apply a mixture of 0.1% Mepiquat chloride and 0.3% potassium dihydrogen phosphate as a uniform foliar spray; this controls excessive vegetative growth, promotes the penetration of fruiting pegs into the soil, and increases the rate of well-filled pods.
Cotton: During the early flowering stage, apply 1.5–3 g of Mepiquat chloride and 50 g of potassium dihydrogen phosphate per mu (diluted in 15–20 kg of water) to control excessive growth and prevent the shedding of buds and bolls; supplement with boron fertilizer in the later stages to prevent premature senescence.
Solanaceous vegetables (e.g., tomatoes, eggplants, peppers): During the flowering and fruiting stages, apply a mixture of 25 ml of 25% Mepiquat chloride and 80 g of potassium dihydrogen phosphate (diluted in 15 kg of water) as a foliar spray; this controls excessive growth and promotes fruit setting, preventing premature senescence caused by leggy, uncontrolled vegetative growth.
