Effects of Fertilizers on Development of Root-Knot Nematode, Meloidogyne java']javanica

Root-knot nematodes (Meloidogyne spp.) are known as one of the most important pests of summer crops. Although the use of synthetic nematicides is as a traditional effective method for their control, but heavy costs and adverse environmental effects are the concerns of this strategy. Hence, as an eco-friendly approach, an experiment was conducted to control Meloidogyne javanica infestation on tomato seedlings using four fertilizers including a chemical fertilizer (NPK), an organic fertilizer (Humic acid), a semi-organic fertilizer (Agro-health) and a bio-fertilizer (Azotobarvar-1). Nematicidal capacity of the fertilizers was evaluated on M. javanica populations in vitro and in vivo assays, as well as the effect of the fertilizers on plant growth properties were measured in a free-nematode assay. The fertilizers increased second instar juveniles (J(2)s) mortality and decreased egg hatching in vitro. The highest J(2)s mortality rate was found in Agro-health (64.4%), NPK (56.9%), Azotobarvar-1 (51.8%) and Humic acid (48.6%), respectively. Also, the highest reduction on nematode activity (galls, egg masses, and the reproduction factor) was observed in Agro-health (16.4%), NPK (23.8%), Azotobarvar-1 (26.7%) and Humic acid (30.0%) treatments, respectively, in vivo. According to the results, using Agro-health at the dose of 8 g kg(-1) soil led to an acceptable level of nematode control. Although the fertilizers were not as effective as synthetic nematicides in controlling Al javanica, some of them could be a good alternative to nematicides, because, along with the effect of repressive on the nematode, they also improved host plant growth indices. (C) 2020 Friends Science Publishers