Thewotit can be attacked by insects (dipteran larvae, aphids ...), fungi and bacteria. Thewalnut diseasesfungal and bacterial are more likely during humid and rainy spring years. On this page we will see howcure the walnuteliminating and trying to prevent the most common diseases.
Among the fungal diseases that affect walnuts is theanthracnose. This disease is caused by Marssonina juglandis and is very common. Symptoms include damaged leaves, shoots and husks, with the appearance of greyish spots that can be more or less large. This fungal disease sees the subsequent death of the affected tissues. If the disease is a lotrooted, you could see the loss of leaves with consequent repercussions on vegetative activity and with a low production ofnuts.
To eliminate this fungal disease of the walnut it is possible to resort to the chemical fight based on copper preparations (Bordeaux mixture, tribasic sulphate and oxychloride at the doses indicated on the label) with a treatment to be carried out when the leaves fall and a couple of interventions to be done during spring, when the first gray spots appear. Forcure the walnutand prevent this fungal disease it is advisable to perform all appropriatepruning.
Through thepruningby thinning the crown of the walnut, the penetration of light and the circulation of air will be favored, factors that reduce the risk of fungal infections.
Another walnut disease that needs treatment with copper-based preparations is the bacterial disease caused by Xanthomonas campestris yglandis, commonly called "black spots on the walnut". This disease manifests itself at the vegetative restart with the appearance of small oily spots of angular shape which then cause necrosis of the affected tissues up to the appearance of elongated notches that reach the shoots causing them to dry out. This bacterium also affects young fruits, also in this case black spots appear but this time they are localized on the apical area of thenuts (the area opposite the peduncle). The black spots on thenutsthey are a consequence of the appearance of this disease during flowering. It is through the residue of the stigmas (which is located right in the apical area of thenuts) that the infection reaches the kernel causing it to rot.
Forcure the walnutfrom this disease it is important to intervene in autumn, when the leaves fall and the buds open. With plants that have gone into production, it is also important to intervene when the floral stigmas appear.
The treatments must be performed with cupric salts (Bordeaux mixture, oxychloride, tribasic sulphate ... at the doses indicated on the label).
How to cure walnut
Forcure the walnutand to prevent the appearance of various bacterial diseases, it is possible to intervene in the presence of conditions favorable to their development (frequent rains, excessive humidity ...) by carrying out a preventive treatment based on cupric salts as described above. In any case, it is always advisable to carry out the appropriate thinning pruning and intervene when spots appear on the leaves and on the walnut husk.
For attacks by aphids, larvae (nut fly, woodruff ...) and other insects, we refer you to the article dedicated toDiseases of the walnut.