<p> The emergence of this disease in walnut has caused serious damage. In Spain it was detected in Extremadura, in 1977 and immediately in other production areas. Results in premature fruit drop and nutty and moist and Blackened walnut is observed. Necrosis at the end of the fruit is previously observed. At first it was confused by symptom of bacterial because Xanthonomas pv.juglandis arboreal. Subsequent observations, allowed to establish that the pathology was different to bacterial, detecting the presence of different species of the fungus Fusarium, Alternaria and Colletotrichum. It is considered that some varieties are more susceptible to disease. Hatley, Chandler, Serr and Vina </p>
<p> It is difficult to fight this disease. Three to four copper treatments are recommended, starting in pre-sprouting, which will add mancozeb. The use of tebuconazole in phases bloom and post-bloom, seems to give interesting results. The conditions of plant stress due to lack of watering or fertilizers, excessive humidity, etc. have been cited as factors that increase the risk </p>
<p>Experimentation continues in progress to determine more precisely the cause and to establish strategies to fight it</p>