Produtividade e reação à ferrugem e cercosporiose de progênies Icatu x Catimor em geração F4:5

Abstract

In order to select progenies productive and resistant to rust and less susceptibility to cercosporiose, a group of F4:5 progenies resulting from the crossing from Icatu and Catimor selections was evaluated. We evaluated 68 progenies equally divided in two experiments, besides two common controls - Catuaí Vermelho IAC 99 and CatuaíAmarelo IAC 62. The experiments were installed in February 2009 and conducted at the Experimental Farm of the Agricultural Research Company of the State of Minas Gerais - Epamig, located in the municipality of São Sebastião do Paraíso - Minas Gerais. A 6 x 6 lattice design was used, with three replications, consisting of 216 experimental plots in the two experiments, with a spacing of 3.2 x 0.80 meters. The experimental plot was composed of 6 plants. In the two experiments conducted, productivity evaluations, determination of the incidence and severity of rust and cercosporiose, visual analysis of productivity, rust and cercosporiose, % of sprouts, sieve% 17 and above were performed. Productivity was evaluated for seven harvests (2012/2013 to 2018/2019) and the other characteristics evaluated in the 2018/19 harvest. The methodology of the mixed models REML / BLUP was adopted and the selection gains for each progeny were calculated using the sum of points selection index (IMM) proposed by Mulamba and Mock (1978). To increase the reliability of the obtained results, a selection intensity of 20.58% (14 progenies) was used in the selection composition of the superior progenies. Progenies P36 [H 29-1-8-5 (III.5) plant 3], P26 [H 32-11-17-4 (I.4) plant 2], P35 [H 29-1-8-5 (III.5) plant 2], P41 [H 136-1-19-7 (III.28) plant 4], P1 [H 29-1-8-5 (I.5) plant 1], P7 [H 136-1-14-14 (II.23) plant 1], P10 [H 32-11-17-4 (III.4) plant 1], P12 [H 32-11-17-4 (III.4) plant 5], P3 [H 29-1-8-5 (I.5) plant 4], P27 [H 136-1-19-4 (II.27) plant 1], P38 [H 29-1-8 -5 (II.5) plant 4], P56 [H 29-1-14-5 (III.8) plant 4], P11 [H 32-11-17-4 (III.4) plant 2] and P66 [H 136-1-19-7 (I.28) plant 1] stood out as the most promising in the selection. The visual evaluation of productivity and severity was correlated to rust and cercosporiose with the traditional evaluation for these characters. It was concluded that the visual method was satisfactory to distinguish the best and the worst progenies for the three characteristics, with more reliability on the selection for productivity.