Citrus tristeza is one of the most destructive diseases of citrus and its causing agent CTV was introduced from Japan to northern Iran in the late 1960s. After about three decades of restriction to originally infected Satsuma trees, natural spread of CTV has being undertaken and melon aphid (Aphis gossypii Glov.) was confirmed as a potent vector in these areas. Regarding the specificity of aphi...

Professor Hume was right: rootstocks are critical and much is still to be learned. Rootstocks and scions are the foundation of many tree fruit industries of the world. Together, those components establish profitability, but it can be argued that the rootstock is the critical component; otherwise, scions would be grown on their own roots everywhere. There is no precedent for the failure of a cit...