AA
Prof. Dr. Sebahat Sullivan, a faculty member of the Plant Protection Department at the Faculty of Agriculture, Ondokuz Mayıs University (OMU), mentioned that this year, hazelnut cones are very prevalent, and farmers need to remove and dispose of the cones manually.
Sullivan pointed out to an AA reporter that despite Turkey's leading position in hazelnut production globally, the yield per unit area remains quite low. She emphasized that hazelnut cone mites are among the most significant pests causing this low productivity. "These creatures, invisible to the naked eye and about one-tenth of a millimeter in size, not only cause abnormal formations known as 'cones, fungi, or roses' in fruit-bearing buds but also lead to bud shedding and drying of shoots, directly affecting the yield. Especially in varieties sensitive to this pest, such as tombul, mincane, and uzunmusa, damages can reach up to 70%. Farmers who grow these varieties in their orchards need to be more cautious in their pest control efforts. If applied for two consecutive years, chemical and mechanical controls will significantly reduce the damage from cones," she said.
Sullivan continued by explaining that the prevalence of this pest has increased significantly in all provinces where hazelnuts are grown in recent years, leading to a lot of male (catkin) and female (calyx) flowers drying up due to the pest's damage during winter. "When catkins dry up, adequate pollination cannot occur, leading to shedding in both newly formed fruits and shoot buds. The shedding of catkins, calyxes, newly formed fruits, and buds results in tip dieback in shoots. Hazelnut cone mites are the main cause of tip dieback seen in hazelnuts, and it should not be forgotten that if these infected buds were to develop normally, each would have become a nut. Moreover, cones are also wintering places for hazelnut weevil larvae. Therefore, it is essential to combat this pest in orchards where there is a high prevalence. There are two types of control methods against hazelnut cone mites: mechanical and chemical."
Sullivan noted that mechanical control, the method of collecting and disposing of cones in winter or early spring, is quite effective against cone mites. "Cones should be removed and dropped on the ground when they become more visible, especially at the end of February and beginning of March, without leaves. They should not be burned, buried, put in plastic bags, thrown away, or removed from the orchard. The interior of the cones also serves as a shelter for other beneficial mites and insects. Beneficial mites and insects inside the cones, being active even in winter, can leave the dried cones after they are dropped to the ground and continue their activities by feeding on other organisms. Hazelnut cone mites, found in thousands inside each cone, move very slowly and are quickly affected by adverse environmental conditions, so they cannot leave the cones and die due to lack of food in the dried cones."
Sullivan emphasized that chemical control, conducted between the end of April and the beginning of May, should not be done randomly. It is essential to count cones in orchards before deciding on chemical control, stating that there should be 5 cones per branch for chemical control to be necessary; if fewer, spraying is not required. "The optimal time for spraying is a one-week period at the end of April and the beginning of May when mites leave the cones, and migration to newly formed buds is intense. During this period, the shoot tips have 4-4.5 leaves, new buds are the size of half a pinhead, and newly developing fruits are the size of lentils. Spraying should be done as soon as possible, considering weather conditions, and all parts of the branches should be covered to ensure full coverage. Wettable sulfur, which has no negative impact on environmental health and beneficial insects, is allowed in organic farming and is effective against hazelnut powdery mildew, which has been a major problem in hazelnut orchards in recent years, can be used. Sulfur should be applied only once during this period, at a rate of 800 grams per decare, and if an atomizer is used, the equipment should be set to spray 50 liters of water per decare. Since chemical control following mechanical control is important for hazelnut yield and quality, producers need to be meticulous about this issue."
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