ABSTRACT
The objective of the study was to evaluate the resistance to rust in coffee cultivars developed by research institutes of Brazil in Paraná state. Resistance to the local leaf rust races was assessed in high disease intensity field conditions at Londrina and Congonhinhas in 2009 and 2010.The cultivars were developed by the EPAMIG/UFV, IAPAR, IAC and MAPA/Procafé. The resistant standard 'IAPAR 59' and the susceptible standards Catuaí Vermelho IAC 144' and 'Bourbon Amarelo' were used. A randomized block design with three replications and plots with 10 plants was used. A scale from 1 to 5 based on the rust intensity was used to evaluate the resistance. The Catiguá MG 1, Catiguá MG 2, IAPAR 59, IPR 98, IPR 104, Palma II, Paraíso H-419-10-6-2-5-1, Paraíso H-419-10-6-2-10-1, Paraíso H-419-10-6-2-12-1, Pau Brasil MG 1 and Sacramento MG 1 cultivars presented complete resistance to rust at Londrina and Congonhinhas. The cultivars derived from the Catucaí germplasm were susceptible or showed different levels of partial resistance. Partial resistance to the rust was observed in several coffees derived from "Hibrido de Timor". 'Acauã' and 'Obatã IAC 1669-20' presented complete resistance at Londrina, but at Congonhinhas, they were partially resistant, indicating that different rust races have occurred at these two locations.
ABSTRACT
The aim of this study was to evaluate the coffee germplasm of the Paraná Agronomic Institute (IAPAR) for resistance to the coffee-berry-borer. Preliminary field evaluation was performed in August 2004 and the fruits of less damaged genotypes in the field were evaluated under controlled condition with obligated and free choice experiments established in a randomized complete design with three replications. The genotypes were evaluated fifteen days after infestation with one borer per fruit in Petri dishes. The data were analyzed by the Scott-Knott means test at 1 percent and by the χ2 test. Statistical analysis indicated that Coffea kapakata, Psilanthus bengalensis, C. eugenioides and genotypes with C. eugenioides genes were resistant. These genotypes presented low frequency of bored grains. C. eugenioides and C. kapakata could present resistance at epicarp level but not in the grain. P. bengalensis could present resistance also in the grains.
O objetivo deste trabalho foi identificar fontes de resistência genética a H. hampei em diferentes espécies de café do banco de germoplasma do Instituto Agronômico do Paraná (IAPAR), Londrina, PR. Foram realizadas avaliações preliminares de campo, para posterior testes de confinamento e de livre escolha, em laboratório, instalados em delineamento inteiramente casualizado com três repetições. Os genótipos foram avaliados quinze dias após a infestação com uma broca por fruto em placas de petri. Os dados foram analisados pelo teste de médias Scott-Knott a 1 por cento e pelo teste de χ2. Foi observado que C. eugenioides, C. kapakata e P. bengalensis constituem importantes fontes de resistência à broca, pois apresentaram menor freqüência de grãos brocados. Os dois primeiros podem apresentar substâncias voláteis antagônicas à broca na casca e a resistência de P. bengalensis pode estar também no grão.