Soil desiccation and fumigation for armillaria root rot in citrus

Numerous Unsuccessful attempts have been made to replant sites in citrus groves where trees have been infected with Armillaria mellea. The original rootstock, sweet orange, is susceptible. Some sour orange rootstocks are resistant to the disease, but cannot be recommended because of susceptibility to tristeza (quick decline). Troyer citrange and trifoliate orange are most commonly replanted now, but both are extremely susceptible to Armillaria mellea. An Ichang hybrid has shown resistance in greenhouse tests and is now being field tested.