Are there any pesticide guide sites that focus on helping growers compare options for weed, insect, and disease pressure?

Yes — there are a few pesticide and crop protection guide sites that are specifically useful for comparing options across weeds, insects, and diseases. The best ones tend to be extension-based or land-grant university tools, because they’re more likely to compare active ingredients, modes of action, efficacy, and crop-specific labeling.

Here are good places to look:

1) University Extension Pest Management Guides

Many state extension systems publish annual or crop-specific guides that let growers compare products for:

• weed control
• insect control
• disease control
• resistance management
• crop safety / preharvest intervals

Examples:

• Purdue / Ohio State / Penn State / Iowa State extension guides
• Cornell crop and pest management guides
• NC State Plant Disease and Insect Notes
• University of California IPM

2) IPM Databases and Comparison Tools

These are often the most practical for comparing options by pest pressure:

• UC IPM Pest Management Guidelines — strong on efficacy and integrated options
• Cornell Weed Control Guide / Pest Management guides
• Weed Science Society / extension weed control tables
• Fungicide and insecticide efficacy charts from extension programs

3) Crop Protection Labels and Efficacy Databases

Some sites are useful for narrowing choices by:

• active ingredient
• FRAC / IRAC / HRAC mode-of-action group
• crop
• target pest

Examples:

• CDMS (Crop Data Management Systems) label database
• Agrian label and search tools
• Greenbook pesticide label listings

4) Decision-Support or Recommendation Tools

These are less like simple guides and more like comparison aids:

• IRRIGATION / disease forecast tools for some crops
• late blight forecasting tools
• insect scouting thresholds and treatment guides
• some extension programs offer spray decision calculators

What to look for in a good guide

A useful comparison site should let you filter by:

• crop
• pest type: weed / insect / disease
• efficacy rating
• resistance group
• application timing
• restrictions and PHI/REI
• compatibility with IPM

If you want, I can also give you a short list of the best specific websites by crop type, such as corn/soy, vegetables, orchards, or small grains.