Pathogenic
PHYLLACTINIA GUTTATA
fungus with typical displays of powdery mildew but almost exclusively on the leafs. Rarely is necessary a specific treatment, because the pathogen is already controlled with other treatments.
GLEOSPORIUM
fungus that damages buds, which could dry out, involving also some branches. The damaged buds show a little darkened, with fungus on leafs. The most aggressive attacks are during damp years and into the plantations along the valley floors, where is necessary to treat in Autumn.
CYTOSPORA CORYCOLA
it shows mostly on old plants with the appearance of the characteristics red blots on the cortex of plants. The damaged plants show up difficulty to grow brunches. In this case it would be important to remove the attacked branches and to treat with products based on copper, to avoid the expansion of the pathology.
ARMILLARIA MELLEA
fungus that damages roots. The plants are not able to grow branches, there are not shoots and it is present a frequent wilting. It is recommended to remove completely the damaged plants, till the roots, and leave the hole opened in order to stop the fungus development. It is important to sprinkle some copper on the hole .
Acarus and insects
PHYTOPTUS AVELLANAE:
parasitic that damages internally the buds and causes the drying out. In the end of March/beginning of April happens the migration of the parasitic on other branches to damage the residual buds. The “Tonda Gentile “ variety is particularly sensitive to the parasitic, that could influence the current year productivity. The recommended treatment concerns products based on Sulphur during the migration period.
CURCULIO NUCUM
(nut weevil): the adults appear from April/May and, after a period of development, the female produce eggs inside the hazelnut shell. Each female set down about 20- 30 eggs and after an incubation period of ten days, the larva completes its development inside the hazelnut. After 30-35 days, the larva comes out from the shell. Usually, the nut weevil is controlled with treatments to fight the bug. A periodic check is necessary to monitor the adults number: if the number is high, it is needed to intervene with specific treatments.
BUG:
insect that can create a huge damage to the production. It is an insect equipped with little daggers, near the mouth, that are able to bite the fruit (hazelnut) through the shell. The bite makes the fruit disgusting. It is not easy control the phenomenon, due to intervene with different controls and different techniques. There are different types of bugs: each of these can create a huge damage.
- GONOCERUS ACUTEANGULATUS: it is a bug from our territory, really dangerous because it can damage the fruit in every growing step. There are some plants that could be used as lures to monitor the adults: whitethorns, roses, cherry-trees, peach trees and apricot trees. The bug appears from May/beginning of June and damages the seeds.
- COREUS MARGINATUS: it is not a typical bug specific of the hazelnut plant since it prefers wild an horticultural plants. It could be confused with the Gonocerus but there are some distinctive characteristics. It could seriously damage the horticulture. This species is particularly attracted by the whitethorn : a plant positioned at the edge of the loud can attract the major part of bugs and insects.
- PALOMENA PRASINA: it is different from the Gonocerus because, even if the eggs are deposed on the leaves, the young ones prefer grasses.
- NEZARA VIRIDULA: it is a bug that just sometimes occupies the hazelnut, it prefers horticulture. It is the classic green bug that we usually find in home.
- RAPHIGASTER NEBULOSA (grey bug): as the other bugs, it isn’t always present on the hazelnut. It uses the hazelnut leaves to lay down eggs, in fact, here we usually find the young ones.
- PENTATOMA RUFIPES: it is a typical bug lover of forest zones, that could attack hazelnut near woods. Usually they don’t provoke huge damages on the hazelnut production. They are periodically controlled to avoid an invasion of the species.
- HALYOMORPHA HALYS: it is an Asian bug that firstly appeared in North America and then in Europe. In 2012 was advised in Emilia-Romagna and in Veneto then in 2013 in an hamlet near Cuneo. Very dangerous bug for every culture and hardly invasive: each adult lay down about 200-300 eggs. In tropical areas, it can reach till 4-5 generations in a year, becoming devastating. In Italy, after its appearance, has expanded its occupation area, provoking serious damages. For what concern the hazelnut, the last year, it caused heavy damages in many areas of Piedmont. This bug is dangerous because, with its daggers, can reach the fruit completely formed, ready for the harvest. It is the brown marmorated stink bug we saw the last year in home. It is and extremely wanderer insect and it could live on 200 different species of plants, on the basis of its needs. After the first generation, in May/June, the second generation happens in June/August. This huge population will create damages the following year. In 2016 has been selected an insect (ooencyrtus telenomicida) that has the ability to eliminate the bug eggs by parasitizing them.
AGRILUS VIRIDIS
it is a beetle that happens a generation every year. The adults appear in May and their eggs are laid down on the cortex of the branches. The larvae are able to dig galleries inside the cortex, leading the dry out of the foliage. The plant difficultly can recover the hunts and it is intended to die. To limitate the damage it is necessary to cut all the branches and burn them up.Regular fertilization in vigorous plant can reduce the risk to be infected.