Quantification of damage and yield losses caused by Root-knot nematode in lettuce in Brazil

Abstract

The objective of this work was to quantify damage and yield losses in lettuce parasitized by Meloidogyne javanica, as well as the growth characteristics of naturally cultivated field plants infested by this pathogen. The experimental area consisted of four seedbeds of 10.0x1.60 m cultivated with 160 plants in each, totaling 640 plants. The damages and yield loss were quantified in four evaluations (Ev1, Ev2, Ev3, and Ev4), with each evaluation corresponding to a cultivation cycle. The four plantings were made in the consecutive form. The fresh mass weight and dry mass weight (FMW and DMW, respectively), gall number (GN), and final population of the nematodes (FP) were evaluated. The population increase of M. javanica caused a reduction in the FMW and DMW in all evaluations. In Ev1 and Ev2, 100% of the plants were commercialized. In Ev3 and Ev4, 7% and 65% of the plants, respectively, could not be commercialized.

Quantification of Damage and Yield Losses and Management of Meloidogyne Exigua in Arabica Coffee Treated With Biofertilizers, Biopesticides and Chemical Nematicide

“…Coffee (Coffea arabica L.) has considerable economic importance for Brazil (Conab, 2022). However, even with the bene ts that it provides for the world agricultural sector, the crop presents some phytosanitary problems, including phytonematodes (Rabello et al, 2021;Zinger et al, 2021). Among the more than 90 species included in the genus Meloidogyne, in arabica coffee M. exigua Goeldi deserves to be highlighted (Salgado et al, 2015).…”

“…The term 'damage' caused by nematodes to a plant indicates any reduction in the quantity and/or quality of production (Zadoks, 1985), and yield losses are de ned as the reduction in nancial return, per unit of area, due to the action of harmful organisms (Bergamin Filho & Amorim, 1996; Rabello et al, 2021;Zinger et al, 2021).…”