Navegando por Autor "Uchôa, Francisco Paiva"

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Evaluation of a prototype of soil thermal solarizer for control of gall nematode in the production of coffee seedlings
(Universidade Federal de Lavras, 2023-02-23) Uchôa, Francisco Paiva; Vieira Junior, José Roberto; Fernandes, Cléberson de Freitas; Rocha, Rodrigo Barros; Espíndula, Marcelo Curitiba; Rudnick, Vaneide Araújo de Sousa; Silva, Dvany Mamedes da; Freire, Tamiris Chaves; Sangi, Simone Carvalho; Mariobo, Solange Aparecida Rodrigues
In coffee crops at Rondônia State of Brazil, there is an increase in phytonematode epidemics.Since most local coffe nurseries at Rondônia use soil as substrate for seedling production, this work aimed to test the minimum exposure time at 60 ºC to control of root-knot nematodes Meloidogyne incognita in soil by means of solar heating, using a solarizer, in an adapted version for better heating perfomance. The used solarizer prototype was built of a wooden box covered with metal sheets, thermal blankets, painted black, with aluminum pipes of 0.5 cm in diameter at the bottom of the box that circulates the water heated by the collector box. The soil was inoculated with a suspension of 1000 eggs + J2 of M. incognita per liter and placed in equipment with a capacity of 150 liters. Exposure times at a minimum temperature of 60 °C were evaluated, with 14 treatments: C1 (non-inoculated and not autoclaved), C2 (inoculated), C3 (non-inoculated and autoclaved) T0’, T15’, T30’, T45’, T60’, T180’, T360’, T720’, T1440’, T2880’ and T4320’ . The temperature was measured every 15 minutes using a skewer-type digital thermometer. The soil was removed according to the exposure time, and placed in 8-liter pots, in which clone 125 and BRS 2357 coffee seedlings, susceptible to M. incognita , were transplanted and growing in a greenhouse for 180 days. The experimental design used was DIC, with 6 replications, each seedling as na experimental unit. Reproduction factor (FR), number of eggs per plant (NOGR) and number of galls per gram of root (NGGR) were evaluated. The FR, NOGR and NGGR variables reduced with exposure time. All treatments showed an effect to control the population of M. incognita in infected soils, with 100% efficacy of pathogen eradication from the T45’ treatment, 60 minutes of exposure is recommended for the production of Coffea canephora seedlings. Taken together, thir work showed the high potential of thr solorizer to contribute in the root-knot nematode control to seedling production.
Resistance of Coffea canephora as a sustainable tool for Meloidogyne incognita control
(Universidade Federal de Lavras, 2022-12-29) Silva, Dvany Mamedes da; Vieira Júnior, José Roberto; Rocha, Rodrigo Barros; Espindula, Marcelo Curitiba; Rudnick, Vaneide Araújo de Sousa; Fernandes, Cléberson de Freitas; Uchôa, Francisco Paiva; Bastos, Jéssica Silva Felix; Freire, Tamiris Chaves; Sangi, Simone Carvalho; Fonseca, Aline Souza da
Many factors can affect coffee production, such as the root-knot nematode, a soil pathogen that can kill plants up to two years old. In infested areas, the cultivation of resistant genotypes is an economical and ecologically appropriate alternative. The present study aims to evaluate the resistance of Coffea canephora clones to Meloidogyne incognita. Evaluations were carried out in a greenhouse at Embrapa Rondônia (Porto Velho -RO) between September 2019 and November 2020. Genotypes were inoculated with M. incognita in four experiments with six replications with a completely randomized design. Root dry weight (RDW), the number of galls (NG) and the reproduction factor (RF) were evaluated. Eighty-six coffee clones were evaluated, with 50 clones showing resistance to Meloidogyne incognita and 36 clones showing susceptibility. Clones classified as resistant had an average reproduction factor of 0.33 with a range of 0.00 to 0.95, while clones classified as susceptible had an average reproduction factor of 3.48 with an amplitude ranging from 1.02 to 14.46. The number of galls was also higher in susceptible clones than in resistant clones. Considering the ten most cultivated clones, the genotypes GJ8, GJ25, P50, SK80, AS2, P42 and LB10 were classified as resistant, and the genotypes GJ3, GJ5 and SK41 were classified as susceptible. Taken together, the results identify resistant C. canephora clones as an important and sustainable tool for controlling M. incógnita.
Resistance of new Coffea canephora clones to root-knot nematode (Meloidogyne incognita) in the western amazon
(Editora UFLA, 2020) Rudnick, Vaneide Araújo de Sousa; Vieira Junior, José Roberto; Fernandes, Cleberson de Freitas; Rocha, Rodrigo Barros; Teixeira, Alexsandro Lara; Ramalho, André Rostand; Espindula, Marcelo Curitiba; Santos, Anderson Vieira; Anjos, Elize Francisca Mendes dos; Uchôa, Francisco Paiva
Root-knot disease is among the main diseases affecting coffee crop. The plant selection to the development new resistant cultivars is among one the most efficient methods of control. The present work aimed to quantify the resistance responses of Coffea canephora clones to root-knot nematode Meloidogyne incognita in the Western Amazon. For this, 17 previously selected clones were evaluated in three experimental trials, carried out in the municipalities of Ji-Paraná and Porto Velho, Rondônia. The resistance to root-knot nematodes M. incognita were evaluated by the numbers of gall in the roots (NG) and by the reproductive factor (RF). The resistance response was also interpreted according the genetic diversity of the clones based in their morphological traits. The clones BRS3210, C12, BRS2314, BRS3137 and BRS1216 are resistant to M. incognita with RF of 0.34, 0.62, 0.79, 0.86 and 0.98, respectively. BRS3213, C125, C15, BRS2336, BRS3220 and C09 clones were classified as susceptible, with RF of 1.93, 1.95, 2.00, 2.31, 2.32 and 2.35. The BRS3193, C160 and BRS2357 clones were classified as very susceptible, with RF values of 3.03, 4.41 and 5.82, respectively. The clustering based on the genetic diversity of morphological traits indicated that genotypes more similar to the Robusta botanic variety had lower RF. The hybrid plants showed intermediate degrees of resistance indicating the segregation for the character of the M. incognita resistance. The clones BRS3210, C12, BRS2299, BRS2314, BRS3137 and BRS1216 expressed resistance responses to M. incognita with potential for growing resistant genotypes in the Western Amazon.