Effect of manipueira on tomato plants infected by the nematode Meloidogyne incognita

•We studied the effect of a liquid waste (manipueira) on Meloidogyne incognita/tomato.•Field trials were developed in winter and summer seasons in the state of Paraná, Brazil.•Significant reduction in galls, eggs and J2 occurred on tomatoes with manipueira.•Manipueira 50% was the best treatment for nutrition of tomato plants.•Manipueira 25% might be more suitable for large agricultural areas.

‘Manipueira’ is the common name of a liquid residue discharged from Manihot esculenta starch factories that is rich in nutrients and cyanogenic glycosides. The goal of this work was to study the nematicide effect of ‘manipueira’ in the control of Meloidogyne incognita in field grown with tomato plants during winter and summer seasons. The ‘manipueira’ used in this work was collected at a cassava starch factory located in Marechal Cândido Rondon, Paraná State, Brazil. For both assays (winter and summer), tomatoes were cultivated in areas naturally infested with M. incognita. The experimental design adopted was completely randomized with 4 treatments (manipueira diluted in water at 10% concentration, manipueira at 25%, manipueira at 50% and the control containing only water) and 4 replicates. The winter assay was set up in a field and cultivated with staked tomatoes cv. Santa Cruz KaDa under protection from cold. The summer assay was conducted in an open field with the cultivation of industrial tomato cv. Rio Grande. The variables assessed for both assays were dry mass and fresh mass of tomato shoots, number of galls and eggs per tomato root system, and fruit yield (g). For both assays the 10%, 25% and 50% manipueira treatments were superior to the control for all the variables analyzed. No statistical difference was found among manipueira treatments. Tomato plants showed improved development when manipueira was applied at 50% concentration.