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SummaryRoot-knot nematodes, Meloidogyne spp., cause great losses to coffee crops in Brazil and worldwide. However, little is known about the physiological changes that these pathogens induce in coffee plants. The present work aimed to compare the physiological variables of coffee seedlings (Coffea arabica ‘Catuaí Vermelho IAC 144’) infected with Meloidogyne paranaensis or M. exigua with healthy coffee plants. Nematode-infected plants showed reductions in height and starch content in roots compared to healthy plants. In addition, the infected plants had a reduction in transpiration, stomatal conductance and CO2 concentration. However, only the coffee seedlings infected with M. paranaensis showed reduction in the rate of photosynthesis. Nematode-infected plants had lower leaf contents of P, K, Mn and Fe when compared to healthy plants. However, only coffee seedlings parasitised by M. paranaensis exhibited lower levels of Ca in the leaves. Therefore, M. paranaensis and M. exigua, with emphasis on M. paranaensis, alter the normal coffee seedling physiology.

ABSTRACT:The plants invasion of Conyza genus has occurred in several regions in Brazil and in the world, due to the selection caused by the continuous use of herbicides with the same active, causing losses in production. This work aims to evaluate the association of herbicides in the control of C. canadensis. The trial was carried out on a farm, in MG, in a Mundo Novo coffee plantation, in a randomized block design (RBD), with 7 treatments and 4 replications, totalizing 28 plots. The

One of the limiting factors in coffee production is the aureolated spot caused by the bacterium Pseudomonas syringae pv. garcae.  This work aimed to evaluate different Bayfolan® copper concentrations in the growth of two isolates of P. syringae pv. garcae in vitro.  P. syringae pv. garcae 157 and 59 isolates were used. Two experiments were carried out in a completely randomized design (CRD) with 7 treatments and 5 replications, in a total of 35 experimental units. Each experimental unit consisted of a Petri dish. For the installation of the experiment, Bayfolan® copper was added and homogenized into Kado 523 culture medium at concentrations of 0; 625; 1.250; 1.875; 2.500 and 3.000 ppm, and as positive control the product Kasumin® was used at 3.000 ppm concentration. Bayfolan® copper reduced the growth of the two isolates evaluated in vitro with increasing concentration. At concentrations of  2.500 and 3.000 ppm, Bayfolan® copper inhibited completely the growth of both isolates, similarly to the Kasumin® treatment. The research reveals that Bayfolan® copper is efficient to control P. syringae pv. garcae in vitro from concentrations of 2.500 ppm onwards.