Luiz Ernesto Azzini

Behavior of upland rice genotypes in the state of São Paulo, Brazil

The performance of promising strains of rice, generated through the genetic improvement program of the Instituto Agronomico (IAC), was evaluated for different environments. The experiments were set up in a randomized- block design with four replications, using experimental plots of 6m², during the periods 2006/2007, 2007/2008, 2008/2009 and 2009/2010, in the municipalities of de Capao Bonito and Mococa, both in Sao Paulo. The total variation of the data for grain-production was analyzed using ANAVA and ANADEV, and the significance of the effects of the interaction between genotype and environment were estimated for the two methodologies. The adaptability and stability of 16 genotypes of upland rice in eight environments were evaluated using the methods of Eberhart and Russell (1966), Lin and Binns (1988), and mixed-model (REML / BLUP). Using the harmonic mean of the relative performance of genotypic values (MHPRVG), the strains, IAC 2009, IAC 1829 and IAC 2005 were selected, with yields superior to 11; 10 and 6% respectively when compared to the general average, which matched results obtained by other methods.

Produtividade de cultivares de arroz irrigado resultanteda aplicação de doses de nitrogênio

The objective of this study was to evaluate the response of three rice cultivars to N fertilizers under irrigated conditions. Two field experiments were carried out in Mococa, SP, in 2000/01 and 2001/02. Rates of N (0, 90, 180, and 270 kg ha-1) were applied in the main plots and seedlings of three rice cultivars (IAC 101, IAC 103, and EPAGRI 109) were transplanted into the subplots. Nitrogen, as urea, was split in three applications: at transplantation, 20 and 40 days later. Except for the number of spiklets per panicle, yield components did not respond to N rates, although they varied for the different plant genotypes. IAC 103 presented the higher value for panicle fertility index and number of panicles per area, and the lower plant height, compared to IAC 101 and EPAGRI 109. Number of plants per area was the yield component most closely related with grain yield. Responses to N varied with the genotype. The highest rate of N to maximize economic return (218 kg/ha N and 6790 kg/ha grain yield) was observed for IAC 103. The corresponding rates for the other genotypes were 161 (EPAGRI 109) and 179 kg/ha N (IAC 101). These rates are higher than those currently recommended for waterlogged rice in Brazil.

Adubação nitrogenada e incidência de brusone em arroz de sequeiro

A field experiment was set up in Mogi Mirim, SP, in 2003/2004 to study the effect of N fertilizer on the incidence of rice blast, caused by Pyricularia grisea in two rice cultivars. The experimental design was a split-plot in randomized blocks with 4 replications. Rates of N sidedressed 40 days after seed germination (0, 50, 100, and 150 kg ha-1 N) were placed in the plots and rice cultivars (IAC 201 and IAC 202) in the subplots. Fertilization common to all treatments was applied in the seed furrow comprising 16, 56, and 32 kg ha-1 of N, P2O5, and K2O, respectively. An intense incidence of blast was observed. Rice plants were evaluated for severity of disease in panicles (using a grading system) and in seeds (by the blotter test), sterile spiklets, grain density and yield, and percentage of broken grain. The incidence of rice blast in seeds as well as the panicle blast disease severity were significantly higher in plants fertilized with N and were also higher for IAC 202 than for IAC 201. However, IAC 201 could not be considered resistant/ tolerant do P. grisea. A highly significant linear correlation coefficient was observed between incidence of P. grisea in seeds and disease severity in panicle. Grain yield was negatively correlated with blast incidence and severity, and with the percentage of sterile spiklets. Therefore, sidedressed N fertilization increased seed damage caused by P. grisea, the percentage of sterile spiklets, and the percentage of broken grains, thereby causing a decrease in rice yield (22% lower at the higher N rate) and grain density. The results of the present study suggest that the use of fungicides is necessary when rice cultivars susceptible to blast are fertilized with nitrogen.

Melhoramento do arroz: I: comportamento de cultivares e linhagens de arroz irrigado no estado de São Paulo em 1990/91 e 1991/92

Rice cultivars and selected lines were evaluated as to their yielding potential and several agronomic traits in the State of Sao Paulo, Brazil, during the years 1990/91 and 1991/92. The cultivar IAC 101 and the line IAC 1085 showed a good yielding potential and stability, leaf and panicle blast resistance, dwarfness, lodging resistance, and high level of head rice after milling. The line IAC 1085 also showed earliness which make it proper for late planting. The cultivars IAC 238, IAC 242 e IAC 100 also showed reasonable yielding potential mainly in 1991/92. The cultivar IAC 4440 showed high susceptibility to leaf and panicle blast. The lines IAC 1091 and IAC 1231 showed high resistance to panicle blast and can be used in future breeding programs as gene sources for that attribute.

Teor de amilose em genótipos de arroz

Caracterizou-se o teor de amilose em graos de arroz de sequeiro, divididos em 16 genotipos de ciclo precoce e 16 de ciclo tardio, com base em linhagens e cultivares do programa de melhoramento do Instituto Agronomico, colhidos de ensaios desenvolvidos no Centro Experimental de Campinas e na Estacao Experimental de Votuporanga. Os teores de amilose variaram de 16,2 a 29,3%, com predominância de teores intermediarios (20 a 25%). Um genotipo mostrou teor baixo (menor que 20%); dez, teores intermediarios; quatro, teores altos (maior que 25%) de amilose, em ambas as localidades, e os 17 restantes apresentaram comportamento variavel nos dois ambientes. Os dados demonstram que o teor de amilose e influenciado pelo genotipo, pelo local de plantio e pela interacao entre essas variaveis.

IAC 203 and IAC 204: new upland rice varieties for the State of São Paulo

The release of good yielding cultivars, which present low height, short cycle and responsiveness to new technologies, supports modern agriculture. The cultivars IAC 203 and IAC 204 are new options for upland rice cultivation for the State of Sao Paulo.

Comportamento de cultivares de arroz irrigado em relação a fungos manchadores de sementes

Em ensaios regionais instalados no ano agricola de 1980/81, em Tremembe e Pindamonhangaba (SP), determinaram-se, em 37 cultivares de arroz irrigado, os fungos responsaveis por manchas em sementes de arroz e o comportamento desses cultivares em relacao a cada fungo detectado. Amostras de sementes foram coletadas da producao total de cada parcela experimental, procedendo-se a separacao visual das sementes manchadas e sem manchas e, posteriormente, aos calculos da porcentagem de sementes manchadas e da porcentagem de perda de peso devida as manchas. Testes de patologia de sementes detectaram a presenca das seguintes especies de fungos: Alternaria sp. Cephalosporium sp., Cladosposium spp., Corynespora sp., Curvularia spp., Epicoccum spp., Fusarium moniliforme, Helminthosporium oryzae, Phoma spp., Pyricularia oryzae, Rhizoctonia solani, Rhynchosporium oryzae, Trichoconiella padwickii, Trichoderma sp. e Trichothecium sp. Diferencas altamente significativas entre o numero de sementes manchadas e sem manchas foram observadas para os fungos H. oryzae, Phoma spp., R. oryzae e T. padwickii nos dois locais, patogenos entao considerados os principais responsaveis pela manchas de sementes observadas. A analise conjunta das duas localidades para cada parâmetro revelou 32 cultivares com menor porcentagem de sementes manchadas do que o controle comercial, quatro cultivares com menor porcentagem de perda de peso devida as manchas, 24 com menor porcentagem de sementes com H. oryzae, seis com menor porcentagem de sementes com Phoma spp,, todos os cultivares com menor porcentagem de sementes com R. oryzae e onze com menor porcentagem de sementes com T. padwickii do que o controle comercial. Considerando todos os parâmetros avaliados na analise conjunta e obtidos para as duas localidades, concluiu-se que os cultivares PI-1291, PI-1356, PI-1377, IR 1544, P2-48, P2-S2, P2-S1-78, L-17-72 e GI-6904-6 apresentaram melhor comportamento que os demais, pois foram superiores ou iguais ao controle em todos os parâmetros analisados.

Performance of lowland rice cultivam to seed discoloration fungi

Em ensaios regionais instalados no ano agricola de 1980/81, em Tremembe e Pindamonhangaba (SP), determinaram-se, em 37 cultivares de arroz irrigado, os fungos responsaveis por manchas em sementes de arroz e o comportamento desses cultivares em relacao a cada fungo detectado. Amostras de sementes foram coletadas da producao total de cada parcela experimental, procedendo-se a separacao visual das sementes manchadas e sem manchas e, posteriormente, aos calculos da porcentagem de sementes manchadas e da porcentagem de perda de peso devida as manchas. Testes de patologia de sementes detectaram a presenca das seguintes especies de fungos: Alternaria sp. Cephalosporium sp., Cladosposium spp., Corynespora sp., Curvularia spp., Epicoccum spp., Fusarium moniliforme, Helminthosporium oryzae, Phoma spp., Pyricularia oryzae, Rhizoctonia solani, Rhynchosporium oryzae, Trichoconiella padwickii, Trichoderma sp. e Trichothecium sp. Diferencas altamente significativas entre o numero de sementes manchadas e sem manchas foram observadas para os fungos H. oryzae, Phoma spp., R. oryzae e T. padwickii nos dois locais, patogenos entao considerados os principais responsaveis pela manchas de sementes observadas. A analise conjunta das duas localidades para cada parâmetro revelou 32 cultivares com menor porcentagem de sementes manchadas do que o controle comercial, quatro cultivares com menor porcentagem de perda de peso devida as manchas, 24 com menor porcentagem de sementes com H. oryzae, seis com menor porcentagem de sementes com Phoma spp,, todos os cultivares com menor porcentagem de sementes com R. oryzae e onze com menor porcentagem de sementes com T. padwickii do que o controle comercial. Considerando todos os parâmetros avaliados na analise conjunta e obtidos para as duas localidades, concluiu-se que os cultivares PI-1291, PI-1356, PI-1377, IR 1544, P2-48, P2-S2, P2-S1-78, L-17-72 e GI-6904-6 apresentaram melhor comportamento que os demais, pois foram superiores ou iguais ao controle em todos os parâmetros analisados.