Impact of cover crops on population density of the root-knot nematode Meloidogyne chitwoodi

Management strategies applied to reduce Meloidogyne chitwoodi populations below economic damage threshold depend strongly on measures taken during the intercrop period. Therefore, this study evaluated the reproductive potentials of M. chitwoodi on different cultivars of cover crops. Twenty-two different cultivars were evaluated against M. chitwoodi at low and high initial inoculum density in a pot experiment under controlled conditions. Fallow was used as control. Based on the reproductive factor, the cover crops were classified under five different categories: Non-host, Poor host, Maintenance host, Good host and Excellent host. In this study, at both low (10 second-stage juveniles (J2) 100 cm−3 soil) and high (100 J2 100 cm−3 soil) initial inoculum density of M. chitwoodi, fodder radish ‘Maximus’, ‘Contra’, ‘Dacapo’ and ‘Defender’, Italian ryegrass ‘Meroa’, rye ‘Matador’ and bird’s foot trefoil ‘Barguay’, ‘Franco’ and ‘Lotar’ were considered poor hosts reducing the M. chitwoodi population in the pot test based on reproductive factor (RF) values. Field experiments were carried out that confirmed most of our results in the pot experiments. However, the field experiments showed that the rotations in which the cover crops are implemented are influenced by weather conditions, previous crop grown, their growing period and initial population densities. Based on our findings, selected non- and poor-host cover crops could be recommended for integrated management of M. chitwoodi.