Resistance mechanisms of sugarcane cultivars to spittlebug Mahanarva fimbriolata

The spittlebug Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) is one of the most important pests of sugarcane in Brazil. Measures for population control are currently restricted to the use of chemical insecticides and fungus Metarhizium anisopliae, in part because very little information exists regarding resistance of sugarcane cultivars. Therefore, the aim of this study was to evaluate resistance mechanisms of 12 different sugarcane cultivars to M. fimbriolata to provide information for growers for pest management. Isolated buds of each cultivar were planted in pots and kept in a greenhouse for approximately three months. The pots were then moved to climate test chambers (26 ± 1 ºC; 70 ± 10 % relative humidity; 12 h photoperiod) to carry out laboratory tests to evaluate adult feeding and female oviposition preferences (using both free-choice and no-choice tests) as well as the effects of cultivars on nymph development and cultivars tolerance to pest attack. The least attractive cultivars for adult feeding were IACSP96-2042 and IAC91-1099. Cultivars IACSP96-2042, IACSP96-3060 and IACSP94-2101 received the fewest eggs in the free-choice and no-choice oviposition tests and exhibited some level of antixenosis resistance. Cultivar IAC91-1099 showed the highest level of antibiosis resistance with a nymph survival rate in the roots of only 20 %. Finally, cultivar IACSP94-2094 appears to be tolerant to M. fimbriolata, as it did not show significant reductions in aboveground biomass weight, despite showing reduced leaf chlorophyll levels following pest attack

Infestação de Diatraea spp. (LEPIDOPTERA: CRAMBIDAE) em variedades RB (República do Brasil) de cana-de-açúcar

O objetivo deste trabalho foi avaliar o comportamento de variedades RB (República do Brasil) de cana-de-açúcar em relação ao ataque de Diatraea spp. Foram utilizados os sistemas de cultivo de sequeiro e irrigado. As variedades estudadas foram: RB72454, RB867515, RB971755, RB951541, RB931003, RB92579, RB863129 e RB93509. Para o cultivo irrigado, incluiu-se a RB98710. As avaliações da porcentagem de intensidade de dano interno foram realizadas por ocasião da colheita, em 15 colmos de cada parcela. Todos os colmos foram abertos no sentido longitudinal, obtendo-se assim a porcentagem de entrenós danificados pelo complexo broca/podridão. As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. No primeiro ano de avaliação, no cultivo de sequeiro, a variedade RB971755 apresentou maior média de infestação de Diatraea spp. quando comparada com as demais variedades. No segundo ano a variedade RB931003 foi a mais atacada pela praga e nos dois anos subsequentes as variedades não diferiram entre si em relação ao ataque da praga. No cultivo irrigado, em cana planta, a variedade RB867515 apresentou maior infestação por Diatraea spp. e nos dois anos seguintes não houve diferenças significativas entre as variedades testadas. Em ambos os sistemas de cultivo, houve um decréscimo na produtividade da cultura durante as avaliações anuais. Os valores de % de infestação não apresentaram correlações significativas com os parâmetros agroindustriais avaliados em ambos os sistemas de cultivo. Infestation OF Diatraea spp. (Lepidoptera: Crambidae) in varieties of sugar caneAbstractThe aim of this study was to evaluate the variation of infestation Diatraea spp. in different varietiesRB (Republic of Brazil) of cane sugar in cropping systems for dryland and irrigated four and threeyears, respectively. The varieties studied were as follows: RB72454, RB867515, RB971755, RB951541,RB931003, RB92579, RB863129 and RB93509. For the irrigated system, the variety RB98710 was alsoincluded. Assessments of the percentage of intensity of internal damage were carried out at harvest,in 15 stalks in each plot. All stalks were opened longitudinally, thus obtaining the percentage ofinternodes damaged by the complex borer/rottenness. The results were submitted to analysis ofvariance and means were compared by Tukey test at 5% probability. In the first year of assessment,in rainfed crop, the variety RB971755 showed the highest average of infestation by Diatraea spp.when compared with all other varieties. In the second year the variety RB931003 was the mostattacked by the pest and for the subsequent two years the varieties did not differ in relation topest attack. In the first year, for the irrigated system, the most infested variety was RB867515. In thefollowing two years it was not possible to identify a variety with striking characteristic of preferenceby the sugar cane borer. In both systems, there was a decrease in crop productivity during annualassessment. The values of % infestation showed no significant correlations with the agroindustrialparameters evaluated in the two systems of cultivation

Comportamento de genótipos de cana-de-açúcar em relação ao complexo broca-podridão causado pela ação de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) e microorganismos

O comportamento de genótipos de cana-de-açúcar em relação ao complexo infeccioso causado pelo ataque da broca Diatraea saccharalis e microorganismos, os danos provocados pelo complexo broca-podridão a cada genótipo e a influência do período em que a cultura permanece em campo sobre as infestações da praga foram avaliados em ensaios plantados simultaneamente e colhidos em duas e três épocas. Os tratamentos foram representados pelos genótipos de elite do Programa de Melhoramento Genético do Centro de Cana-de-açúcar do Instituto Agronômico de Campinas (IAC): IACSP99-1306, IACSP98-2072, IACSP99-3357, IACSP98-5008, IACSP98-5012, IACSP96-7603, IACSP00-8198 e pela cultivar RB867515, que estavam presentes em todos os experimentos. Na Usina Moema, além dos genótipos citados anteriormente foram adicionados também RB966928; CTC17; IACSP95-3028 e RB855453, na primeira época; RB92579; IACSP95-5000; CTC15 e SP81-3250, na segunda época; e RB876030, IAC87-3396, RB935744 e SP83-2847, na terceira época de avaliação. Já na Usina Guarani, no ensaio a ser colhido na primeira época foram adicionados os genótipos RB855453; CTC17; CTC9 e RB966928; RB935744, CTC14, CTC19 e RB832847 também foram estudados na segunda época. Todos os genótipos foram muito infectados pelo complexo broca-podridão, porém houve diferenças significativas entre eles. Os genótipo IACSP00-8198 e IACSP98-5008 apresentaram as maiores intensidades de infecção, enquanto o IACSP993357, a menor. Apesar dos ensaios colhidos em agosto e outubro tenham ficado em campo 3 e 5 meses, respectivamente, mais do que o ensaio colhido em maio, não houve diferenças entre eles...The behavior of sugar cane genotypes in relation to the infection complex caused by the attack of sugarcane borer stalk Diatraea saccharalis and microorganisms, the damages caused by the infection complex to each genotype and the influence of the period that the crop remains in field on the infestation of the pest were evaluated in experiments that were planted simultaneously and harvested in two and three different times. The treatments were represented by elite genotypes Breeding Program Center Cane sugar Agronomic Institute of Campinas (IAC): IACSP99-1306-2072 IACSP98, IACSP99-3357, IACSP98-5008, IACSP98-5012, IACSP96-7603, IACSP00-8198 and by the cultivar RB867515 that were present in all experiments. In the Moema Mill, besides the aforementioned genotypes were also added RB966928; CTC17; IACSP95-3028; RB855453 and in the first season, the RB92579; IACSP95-5000; CTC15 and SP81-3250, in the second season, and RB876030, IAC87-3396 , RB935744 and SP83-2847, at the third time of evaluation. In the Guarani Mill, the test to be harvested in the first season were added genotypes RB855453; CTC17; CTC9 and RB966928, and RB935744, CTC14, CTC19 and RB832847, were studied in the second season. All genotypes were hard attacked by the complex drill-rot, however had significant differences between them. The genotype and IACSP98 IACSP00-8198-5008 showed the highest intensity of infestation, while IACSP993357, the lowest. Despite the trials harvested in August and October have been in field 3 and 5 months, respectively, more than the essay collected in May, there were no differences between them and the intensity of infection since, between May and October and the rainfall conditions... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Reaction of sugarcane cultivars to sugarcane borer

The objective of this study was to evaluate the reaction of ten sugarcane cultivars to Diatraea saccharalis under field conditions, using a randomized block design with treatments in factorial 2x10 with six replications. The first factor was represented by two levels of infestation (infested and not infested) by borer and the second one, by the ten sugarcane varieties (IAC87-3396, IAC91-1099, IACSP93-3046, IACSP94-2101, IACSP94-2094, IACSP94-4004, IACSP95-5000, IACSP96-3060, IACSP96-2042 and SP91-1115). The experiment was evaluated in two crop cycles: plant crop and first ratoon. All cultivars were attacked by the borer, being IACSP94-4004, IACSP96-2042 and SP91-1115 the most damaged cultivars with the highest infestation index. During the plant crop, plots infested by the borer presented higher fiber content than the ones not infested. During the first ratoon, non infested plants produced 10% less and presented lower purity and higher content of reducing sugars than the non-infested plants

MIRMECOFAUNA EM SABIÁ (Mimosa caesalpiniaefolia Benth) (FABACEAE) EM RIO LARGO, ESTADO DE ALAGOAS

This study aims to identify the diversity of mimercofauna sabiá in an area of the municipality of Rio Largo, Alagoas. There were 17 species of ants belonging to six subfamilies. Atta opaciceps (Borgmeier, 1939) was the most abundant species. Camponotus blandus (Fr. Smith, 1858), Camponotus atriceps (Fr. Smith, 1858) and Pheidole sp.2 gp. aberrans

Infestação de Diatraea spp. (LEPIDOPTERA: CRAMBIDAE) em variedades RB (República do Brasil) de cana-de-açúcar

The aim of this study was to evaluate the variation of infestation Diatraea spp. in different varieties RB (Republic of Brazil) of cane sugar in cropping systems for dryland and irrigated four and three years, respectively. The varieties studied were as follows: RB72454, RB867515, RB971755, RB951541, RB931003, RB92579, RB863129 and RB93509. For the irrigated system, the variety RB98710 was also included. Assessments of the percentage of intensity of internal damage were carried out at harvest, in 15 stalks in each plot. All stalks were opened longitudinally, thus obtaining the percentage of internodes damaged by the complex borer/rottenness. The results were submitted to analysis of variance and means were compared by Tukey test at 5% probability. In the first year of assessment, in rainfed crop, the variety RB971755 showed the highest average of infestation by Diatraea spp. when compared with all other varieties. In the second year the variety RB931003 was the most attacked by the pest and for the subsequent two years the varieties did not differ in relation to pest attack. In the first year, for the irrigated system, the most infested variety was RB867515. In the following two years it was not possible to identify a variety with striking characteristic of preference by the sugar cane borer. In both systems, there was a decrease in crop productivity during annual assessment. The values of % infestation showed no significant correlations with the agroindustrial parameters evaluated in the two systems of cultivation.O objetivo deste trabalho foi avaliar a variação da infestação de Diatraea spp. em diferentes variedades RB (República do Brasil) de cana-de-açúcar nos sistemas de cultivo sequeiro e irrigado durante quatro e três anos, respectivamente. As variedades estudadas foram: RB72454, RB867515, RB971755, RB951541, RB931003, RB92579, RB863129 e RB93509. Para o cultivo irrigado, incluiu-se a RB98710. As avaliações da porcentagem de intensidade de dano interno foram realizadas por ocasião da colheita, em 15 colmos de cada parcela. Todos os colmos foram abertos no sentido longitudinal, obtendo-se assim a porcentagem de entrenós danificados pelo complexo broca/podridão. Os resultados foram submetidos à análise de variância (ANOVA) e as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. No primeiro ano de avaliação, no cultivo de sequeiro, a variedade RB971755 apresentou maior média de infestação de Diatraea spp. quando comparada com as demais variedades. No segundo ano a variedade RB931003 foi a mais atacada pela praga e nos dois anos subsequentes as variedades não diferiram entre si em relação ao ataque da praga. No cultivo irrigado, em cana planta, a variedade RB867515 apresentou maior infestação por Diatraea spp. e nos dois anos seguintes não houve diferenças significativas entre as variedades testadas. Em ambos os sistemas de cultivo, houve um decréscimo na produtividade da cultura durante as avaliações anuais. Os valores de % de infestação não apresentaram correlações significativas com os parâmetros agroindustriais avaliados em ambos os sistemas de cultivo