– The fungus flourishes when the weather is cool, sunlight is low, and humidity is high. If you live in this type of climate or had a very wet/gray season, avoid watering your plants late in the day, and especially avoid watering the leaves if they won’t have a chance to dry out before evening.
– Use drip irrigation to water only the root zone of your plants and minimize water drifts or splashes.
– Grow your garlic and onions in the sunniest spot possible, and allow enough space between plants for air to circulate among the foliage.
– Fertilize adequately, but not excessively. Over-application of nitrogen (which results in lush foliage growth) has been found to make allium plants more susceptible to rust infections.
– Rotate your crops and do not grow garlic, onions, leeks, and other alliums in the same area where rust appeared in the previous three years on any allium crop.