Temporal dynamics of guava root-knot nematode under the effect of different management methods

Abstract

Guava, Psidium guajava L., is one of the most produced fruit trees in tropical and subtropical regions but the presence of Meloidogyne enterelobii Yang & Eisenback (Order: Tylenchida, Family: Heteroderidae) in orchards reduces fruit productivity by up to 65%, justifying integrated management programs constantly searching for methods for its efficient and sustainable control. Thus, this study aimed to investigate the potential of chemical, biological, and resistance induction control methods to reduce the variables associated with M. enterelobii in guava orchards. This study was conducted in two areas with guava trees (cv. Paluma) naturally infested with M. enterelobii populations. Commercial doses of products based on Trichoderma harzianum (TRI), Ascophyllum nodosum+potassium hydroxide (EG), and fluensulfone (NI) were applied alone and in interactions in seven treatments+control. Soil and root samples from each treatment were collected monthly and the number of M. entorolobiieggs and individuals and normalized difference vegetation indices were quantified. Analyses conducted on R found that the joint use of TRI+EG reduced M. entorolobii by up to 50% at the soil level, further decreasing reproduction factors and that TRI obtained a 59% reduction at the soil level. Treatments with EG showed higher average productions. These results justify the importance of alternative methods and their possible association with chemicals to manage guava root-knot nematodes.