Jamieson Brothers Double Strength Blight Guard for the prevention of foliar blight in tomatoes and potatoes - 500ml concentrate

JBA Blight Guard Concentrate Plus

A powerful, natural formula designed to help prevent foliar blight in tomatoes and potato blight.

This new and improved version of JBA Blight Guard is twice as strong as the original and now includes added colloidal silver, known for its antibacterial, antifungal, and antiviral properties.

Made from 100% natural ingredients, this product contains no harmful chemicals and is safe for use in your garden. It offers effective blight prevention and is a natural alternative to chemical fungicide treatments.

Directions for Use:

SHAKE WELL BEFORE USE.

Mix 40ml of concentrate with 20 litres of water for full-strength protection (use 20ml to replicate the original Blight Guard formula). The built-in measuring chamber holds approximately 40ml.

Apply using a sprayer or watering can—ensure thorough coverage on both the upper and lower leaf surfaces. Spraying is the most effective method, especially when protecting against early blight, late blight, and Wet Weather Blight.

For smaller batches, mix 10ml concentrate with 5 litres of water.

Apply every 7 days from June to September, or more frequently during a Smith Period (see below), particularly when a blight risk forecast is high.

Use any mixed solution within 48 hours.

Allow 24 hours after application before consuming treated crops.

Avoid direct spraying onto tomatoes to prevent possible scorch marks.

Please note: This product helps reduce the risk of blight but cannot guarantee full protection in all circumstances. It is a preventative solution and not a cure. JBA Blight Guard helps support plant resistance to Phytophthora infestans, Pythium ultimum, Pythium aphanidermatum, Ascochyta Blight, and Ascochyta gossypii.

What is a Smith Period?

A Smith Period refers to weather conditions that encourage blight infections: a 48-hour period where the minimum temperature is 10°C or more and the relative humidity exceeds 90% for at least 11 hours on both days. These conditions are used to trigger warnings in blightspy, blight watch, and blightwatch systems. For best results, monitor local data and forecasts such as Blightcast or The Hutton Criteria.