25-i.com is a free, informational site about agricultural chemicals: how herbicides, insecticides and fungicides are chosen and rotated, how to calibrate a sprayer, how to store and handle products safely, and what the words on a pesticide label mean. We do not sell any products.
Plain-language explanations for growers, students and new applicators. Always use them alongside the product label.
Matching herbicide chemistry and timing to the weed spectrum in row crops, and rotating modes of action. Read the guide.
Why insect populations become resistant and how thresholds, rotation and non-chemical controls slow it down. Read the guide.
Segregation, temperature, inventory and spill readiness for crop protection products. Read the guide.
Measuring nozzle output, speed and pressure to apply the labeled rate accurately. Read the guide.
Signal words, PPE, REI and PHI, drift, spills and disposal in one checklist. Open the checklist.
Definitions of label and agronomy terms, from adjuvant to wettable powder. Browse the glossary.
Simple browser-based arithmetic helpers. Calibrate first and always check results against the label.
The product label is the legal document for rates, crops, PPE and intervals. Our guides explain the concepts; the label gives the rules.
Registration and use restrictions differ by country and state. Your state lead agency or extension office can confirm what applies to you.
Use the calculators as a cross-check, not as a substitute for calibrating your own equipment and checking by hand.
For field-specific decisions, talk to a certified crop adviser, licensed applicator or extension specialist.
Spotted an error or want a topic covered? Send us a note. We cannot give site-specific spray recommendations.
For a pesticide exposure emergency call poison control (1-800-222-1222 in the U.S.) or your local emergency number.
Educational articles on crop protection practice.
Matching chemistry to weeds, timing and crop, and rotating modes of action.
Read GuideStrategies for lasting pest control through rotation, thresholds and IPM.
Read GuideStep-by-step calibration so you apply exactly the labeled rate.
Read Guide