Responses of Hazelnut Trees to Organic and Conventional Managements in the Dryland

Abstract

Hazelnut trees (Corylus avellana L.) give yields without any more reduction under dryland. However, it is not known how plant water status and gas exchanges response to organic management under the dryland. In an attempt to answer this question, such responses, which are leaf water potential (LWP), stomatal conductance (gs) and photosynthetically active radiation (PAR) of hazelnut trees, were studied under organic and conventional managements in the dryland conditions. It was also investigated possible effects of those parameters on organic and conventional hazelnut trees vs. SWC and atmospheric stress (i. e., air vapour pressure deficit-VPD). Organic hazelnut trees had slightly higher ET and yield, and lower SWC than conventional hazelnut trees. However, generally, slightly higher LWP and gs values were obtained for conventional hazelnut trees while the value of VPD was higher in organic hazelnut orchards. LWP, PAR, gs response to SWC and VPD and relationships between each others were generally imperceptibly higher in organic hazelnut trees than conventional hazelnut trees but no stronger responses and relationships. Plant canopy measurements were mostly parallel with the results obtained values of ET, yield, SWC and VPD. Precipitation during the year influenced both hazelnut orchards managements to have higher yield and keep life alive. However, it could be emphasized that hazelnut trees under organic and conventional hazelnut managements required supplement irrigation to avoid summer water stress, and for providing fruit fulling and accumulation of reserves for the following year. Finally, it can be conclude that organic farming is a good alternative for hazelnut orchards in dryland.