Effect of the vegetation type in the space between rows of pear trees on the abundance of plant-feeding nematodes

Abstract

Fruit production of the Río Negro and Neuquén Upper Valley, Argentina, represents an important source of income due to high export levels. Plant parasitic nematodes are among the agents that can affect pear trees particularly in the presence of diverse host weeds. The aim was to study the abundance of plant parasitic nematodes in a pear orchard in two positions: a) space between rows of pear trees with three different soil coverage: spontaneous vegetation (VE), Medicago sativa+grasses (MG) and Festuca arundinacea (Fe) and b) space between plants without vegetation due to herbicide application, in two growing seasons 2012/2013 and 2013/2014. Also, soil analysis included organic matter content, exchangeable potassium and dry matter values. The lower number of nematodes was recorded in the space between pear plants free of weeds. The records of endoparasite nematodes were higher in the space between rows with VE (15.3%) compared to the others (4%). Nematode abundance was higher for c-p2 group than c-p3 group, consistent with soil disturbed by fertilization and herbicide application. The Simpson diversity index (nematodes) was higher in VE suggesting greater suitability for nematodes due to higher host diversity. The index of plant parasitic nematodes did not differ between spaces between rows. Organic matter content (4%), exchangeable potassium content (1.85 cmolc kg-1) and dry matter (14.3 t ha-1) were highest in MG.