Comparison of plant regulators that can be used to control growth in wheat planting

In wheat planting, excessive growth of stems and leaves will lead to obstruction of ventilation and light transmission, resulting in high incidence of "little foot disease" and fusarium wilt, which directly affects thousand-grain weight and yield.

1. Comparison of three core parameters of growth control PGR
1. Stability test: Uniconazole has a retention rate of >85% in pH5.0-7.5 environment, and Paclobutrazol (Paclo) decomposes 40% faster when exposed to strong light

2. Yield increase effect: The critical density for Mepiquat chloride to increase yield by 12.3% is 280,000 ears/mu

3. Stress resistance data: Under high temperature (>35℃), the effect of Uniconazole decreases by 62%, while Mepiquat chloride still maintains 78% activity

2. Analysis of the characteristics of three types of mainstream PGR
1. Uniconazole (25% wettable powder)
- Duration of efficacy: 45-60 days (conventional application)
- Fertilizer enhancement effect: Promotes nitrogen absorption efficiency by 27%
- Typical case: Shandong Dezhou test field was applied at the 3-leaf stage, and the plant height was controlled within 70cm

- Taboos: Avoid mixing with copper-containing foliar fertilizers, and the risk index of use during high temperature and high humidity is >4


2. Paclobutrazol (Paclo) (15% wettable powder)
- Spatial distribution characteristics: soil residual period up to 210 days
- Light sensitivity: The drug efficacy decay rate under direct light reaches 0.8% per hour

- Economic benefits: The application cost per mu is controlled in the range of 8-12 yuan
- Applicable scenarios: Mid- and late-stage vigorous growth control (from jointing to booting stage)


3. Mepiquat chloride (20% sodium allyl sulfonate)
- Cell division inhibition mechanism: Blocking G2/M phase conversion
- Interaction: Mixing with potassium dihydrogen phosphate can increase the effective period by 15 days
- Safety interval: Stop using 21 days before harvest
- Innovative usage: The recommended dosage for drone spraying is 0.8-1.2ml/mu

III. Five-step method for precise pesticide application
1. Diagnostic criteria: Effective tillers>18/plant and plant height>1.2m

3. Mixed application ratio: uniconazole + potassium dihydrogen phosphate = 3:1 (weight ratio)

4. UAV operation parameters: flight altitude 50m, drip rate 120ml/mu

5. Early warning mechanism: when soil moisture is greater than 25%, the concentration of the liquid medicine needs to be adjusted by 30%