I. Mechanism of Action of Mepiquat Chloride
Mepiquat chloride inhibits gibberellin synthesis within the peanut plant, thereby controlling the longitudinal elongation of stem and leaf cells and suppressing excessive vegetative growth. This shifts nutrients from vegetative growth to reproductive growth, promotes the penetration of peg tips into the soil, and enhances photosynthetic efficiency. Consequently, it facilitates fuller pod development, resulting in plump pods, increased yields, and improved quality.
II. Proper Application Methods
Optimal Timing: Apply for the first time between the late full-bloom stage and the early pegging stage—specifically when plant height reaches 30–35 cm and the crop canopy begins to close (inter-row closure). If rainfall is abundant and growth is vigorous, a second application may be made 15 days after the first if the plant height exceeds 45 cm.
Recommended Dosage: Use 25% Mepiquat chloride aqueous solution at a rate of 15–30 mL per mu, diluted in 30–50 kg of water for uniform spraying. Alternatively, compound formulations may be used, such as 30% Paclobutrazol·Mepiquat chloride wettable powder (30 g/mu) or 27.5% DA-6·Mepiquat chloride aqueous solution (15–20 mL/mu).
III. Key Precautions
Do not apply on plots with poor soil, drought conditions, or weak plant growth, as inhibiting growth in these cases could lead to yield loss.
Apply after 3:00 PM, focusing the spray on the apical growth points; avoid overlapping sprays. Re-apply if rainfall occurs within 6 hours of application.
Limit application to no more than twice per season to avoid excessive dosage, which could impair normal pod development.
