Use of organic amendments in the management of root-knot nematode in lettuce

Abstract

Root-knot nematodes, Meloidogyne spp., are among the most important parasites of the lettuce crop. Managing these organisms is difficult due to limitations in genetic (use of resistant cultivars) and chemical control. Thus, new practices should be sought to reduce their reproduction. The present study aimed to evaluate the application of organic amendments in the control of Meloidogyne incognita in lettuce. At first, tomato plants were inoculated to establish an initial population in the soil. After 60 days, the aerial part was discarded, and the lettuce seedlings were transplanted into pots. Two days after transplanting, the treatments bokashi, crambe cake, whey protein, cottonseed composted and shredded wood chip composted were applied at 20 g or 20 mL per pot. Water was applied as control treatment. After 70 days, bokashi and crambe meal reduced the number of eggs/g of root and promoted plant growth. Results obtained with whey protein, cottonseed meal and composted shredded wood chip did not differ from those obtained with the control treatment. Bokashi and crambe cake are effective in the M. incognita control under controlled conditions.

Dosages of bokashi in the control of Meloidogyne javanica in lettuce, in greenhouse

“…The beneficial effect of bokashi on lettuce growth was previously reported when 20 g of the product were applied per pot with 2 L of soil, with increases in doses from 0.66 to 26.15 g and 2.52 to 26.71 g, in experiments conducted in different periods (Dias-Arieira et al, 2015). In addition to lettuce, bokashi promoted increase in the vegetative growth of tomato plant when used in the substrate composition for seedlings (Zandron et al, 2003) or in planting (Roldi et al, 2013).…”

“…Above these doses, there was increase of nematodes, possibly due to toxic effect on the plants discussed previously. Recently, it was reported that the application of 20 g of bokashi/pot containing 2 L of soil reduced the M. incognita reproduction in lettuce in two experiments conducted in different periods (Dias-Arieira et al, 2015). In tomato, the reproduction of M. incognita was also reduced with the use of 20 g/plant: the number of eggs+J2/g decreased from 5857.8 to 251.4 in treated and non-treated plants, respectively, and the presence of castor bean cake being considered one of the likely factors that act on nematodes (Roldi et al, 2013), since the efficiency of castor bean cake in the control of plant-parasitic nematodes was demonstrated in several studies involving different pathosystems (Dutra et al, 2006;Lopes et al, 2009;Roldi et al, 2013).…”

“…Despite the positive results obtained for the control of nematodes in vegetables with the use of organic matter (Lopes et al, 2009;Roldi et al, 2013;Dias-Arieira et al, 2015), some promising sources, such as bokashi, have not been properly assessed, and information about doses and times of application is needed. Roldi et al (2013) found that bokashi (organic compound produced by fermentation of grain mixtures) had the potential to control M. incognita in tomato plants, significantly reducing the number of galls and eggs of the nematode and improving plant growth.…”

Crambe Cake to Meloidogyne javanica Control in Lettuce

“…Thus, adding organic matter to the soil is one of the most efficient methods for the sustainable control of nematodes affecting vegetables; different organic wastes showed nematode management potential (Lopes et al, 2009;Nazareno et al, 2010;Roldi et al, 2013;Dias-Arieira et al, 2015). The organic matter addition also presents other benefits such as natural enemy population increase and improvements in the physical and chemical properties of the soil, including base saturation, porosity and water conductivity, which allow plants to develop better, as well as to become more resistant to these pathogens (McSorley & Gallaher, 1995;Oka, 2010).…”

“…Crambe (Crambe abyssinica Hochst) is another crop whose cake presents nematode control potential (Dias-Arieira et al, 2015;Tavares-Silva et al, 2015). The species is an oleaginous brassica, which presents oil conversion efficiency; the crambe oil is characterized by its high erucic acid content-a long-chain fatty acid used to make chemical products (Erikson & Bassin, 1990;Pitol et al, 2010).…”