The minimum light transmittance for greenhouse crops should be determined based on the type of covering material and the crop species. Specific standards are as follows: 01 Basic Standards General Minimum Value: Most common crops (such as leafy vegetables) require a light transmittance of 70% or higher in conventional greenhouses to maintain basic growth requirements. Variations in Covering Materials: Plastic Film: New film generally has a light transmittance of 80%-90%, but in practice, due to aging, contamination, and other factors, a minimum light transmittance of 85% or higher must be maintained. Glass: The standard light transmittance requirement is 91.5% or higher. Solar Greenhouse: The light transmittance is typically 70% or higher. 02 Differences in Crop Requirements High-light Crops: Vegetables (such as tomatoes and peppers) and ornamental flowers require a light transmittance of 90% or higher. Medium-light Crops: For some leafy green vegetables or shade-tolerant crops, the light transmittance can be reduced to around 85%. Special Adjustment Scenarios: In areas or seasons with excessive sunlight, light transmittance can be adjusted to 60%-70% using tools such as sunshade nets. 03 Key Influencing Factors Material Properties: Materials with high haze (such as diffused glass) reduce light transmittance. High-transmittance, low-haze covering materials are preferred....