Sustainable long-term weed control strategies with glyphosate programs in hazelnut (Corylus avellana L.) orchards in Turkey

Abstract

Hazelnut (Corylus avellana L.) is native to the Black Sea coast of Turkey as a tree or shrub on the steep slopes of the mountains. The high rainfall and fertile soils in the Black Sea region favors the establishment of many annual and perennial weed species. Weed management is critical in hazelnut production to reduce competition, conserve nutrients for the trees, and improve hand harvesting efficiency. Two different experiments were designed for control of Rubus canescens, Pteridium aquilinum and Convolvulus arvensis at both greenhouse and field conditions. Seven different treatments were arranged in a randomized complete block design with six replications under greenhouse conditions. Field experiments were initiated in spring 2014 and conducted through 2015 in three different (Samsun, Giresun and Düzce) hazelnut orchards through the Black Sea Region of Turkey. The result from greenhouse experiment showed that the most effective treatment was glyphosate 1.8 kg ha-1 + MCPA 1.8 kg ha-1 to control R. canescens, P. aquilinum and C. arvensis at 56 days after treatment (DAT). In the field in both years, considerable variations in the susceptibilities of weed species to the different herbicide treatments were observed. Consequently, the combination of a glyphosate 1.08 kg ha-1 + MCPA 1.08 kg ha-1 application in March, included as a standard herbicide mix, String Trimmer + glyphosate 2.16 kg ha-1 in early August, that is commonly used in hazelnut, was the most effective treatment overall. © 2018 International Society for Horticultural Science. All Rights Reserved.