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Summary Pratylenchus brachyurus is considered one of the most important plant pathogens of soybean and corn in Brazil, mainly found in areas where no-tillage is practised. Nematophagous fungi are used as an alternative for chemical nematicides in the management of nematodes that affect these crops in Brazil. This study evaluated the fungi Pochonia chlamydosporia, Trichoderma sp. and Duddingtonia flagrans for the biocontrol of P. brachyurus in soybean and corn. The first and second experiments were carried out using soybean, and five isolates of P. chlamydosporia (Pc-3, Pc-4, Pc-10, Pc-35 and Pc-49), one of Trichoderma sp. (T-10), an isolate of D. flagrans (AC001) and a mix (MIX) of all the isolates. In the third experiment using corn, three isolates of P. chlamydosporia (Pc-3, Pc-10 and Pc-35) and one isolate of Trichoderma sp. (T-10) were compared. In the first experiment, the isolates Pc-3, Pc-10, Pc-35 and T-10 reduced the total population of P. brachyurus up to 43.7% when compared with the control treatment. In the second experiment, the isolates Pc-10, T-10 and the MIX reduced the total population of P. brachyurus up to 58.7% when compared with the control. In the third experiment, the isolates reduced the total population of P. brachyurus in corn when compared with the control treatment, except for D. flagrans, which was not able to control P. brachyurus in any experiment. The P. chlamydosporia (Pc-3, Pc-10, Pc-35) and Trichoderma sp. (T-10) isolates were shown to be promising for the control of P. brachyurus in soybean and corn.

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Summary Root-knot nematodes (Meloidogyne spp.) are responsible for various significant crop losses, which require taking integrated control measures. The present study aimed to identify a possible sustainable approach to the management of Meloidogyne javanica in vegetable crops using an organic compound based on pequi (Caryocar brasiliense) fruit residues. A pot experiment was conducted using cultivars of tomato and lettuce susceptible to M. javanica, with three amendments including inorganic fertiliser, cattle manure and five doses of organic compost with pequi residues. All treatments were inoculated with second-stage juveniles of M. javanica to simulate the root-knot nematode disease in field conditions. Increasing doses of organic compost with pequi residues from 5 kg m−3 to 30 kg m−3 promoted a significant decrease in the nematode population in both cultures evaluated. Organic compost (30 kg m−3) reduced the numbers of galls and eggs of M. javanica by 41.6 and 46.5% in tomato roots, and by 80.3 and 59.2% in lettuce roots, respectively, compared with non-treated control. Organic compost also increased crop development considerably. In general, there was a 43.0% increase in plant development compared to non-treated control. Hence, organic compost of pequi residues could be an alternative to toxic chemical nematicides and recommended as eco-friendly management of M. javanica in vegetable crops.

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Meloidogyne paranaensis is a species of root‐knot nematode that affects coffee (Coffea arabica L.) tree growth by causing severe damages to the plant root. This study evaluated the agronomic performance of Coffea arabica progenies in an M. paranaensis‐infested field and assessed the compatibility of resistant C. arabica genotype 28‐I‐4 (GEN28) as rootstock for susceptible cultivars. Experiment 1: under field conditions, six progenies were analyzed; the controls were ‘IPR100’ as resistant and ‘Catuaí Vermelho IAC 144’ (CtV144) as susceptible. Experiment 2: under greenhouse conditions, combinations of grafts and rootstocks between susceptible CtV144 and GEN28 were evaluated regarding their resistance to M. paranaensis alongside their noninoculated counterparts. For this, M. paranaensis reproduction factor (RF), total population of the nematode per gram of root system, growth parameters, gas exchange, and water potential (ψpd) were evaluated. In Experiment 1, resistant C. arabica progenies were more vigorous, productive, and showed a population of M. paranaensis threefold‐times lower than that observed in roots of susceptible CtV144. Among the resistant progenies selected in the field experiment, GEN28 was chosen for physiological compatibility study with the traditional cultivar CtV144. In Experiment 2, the CtV144 grafted onto GEN28 led to resistance to M. paranaensis, as well as a higher leaf area and ψpd as compared with nongrafted CtV144. Therefore, the GEN28 holds suitable characteristics to be used as a new Coffea arabica rootstock applied to production of resistant seedlings to Meloidogyne paranaensis nematodes. This technology represents an alternative to keep up coffee activity in infested areas.