Aildson Pereira Duarte

Desempenho de semeadoras-adubadoras de soja em Latossolo Vermelho muito argiloso com palha intacta de milho

Como a dificuldade da semeadura da soja sob grande quantidade de palha do milho safrinha intacta, sem a fragmentacao ou incorporacao dos residuos, em solos muito argilosos, tem desmotivado a utilizacao do sistema plantio direto pelos agricultores da regiao paulista do Medio Paranapanema, objetivou-se, com este trabalho, comparar o desempenho quanto ao embuchamento, bem como avaliar a qualidade da semeadura entre semeadoras-adubadoras original e adaptada, na cultura da soja. O sistema modificado proporcionou menor numero de paradas do conjunto trator-semeadora, em funcao de embuchamento. As frequencias de solo exposto e profundidades de deposicao da semente e do sulco em ambas as semeadoras e, ainda, o numero de plantas emergidas para a semeadora-adubadora modificada, apresentaram diferenca significativa entre as linhas de semeadura. O desempenho das duas semeadoras-adubadoras avaliadas nao foi satisfatorio quanto a largura de revolvimento do solo e a uniformidade da profundidade de deposicao da semente.

Desempenho de híbridos top crosses de linhagens S3 de milho em três locais do Estado de São Paulo

The present work aimed to evaluate the performance end high parent heterosis of 27 hybrids of partially endogamic lines (S3) obtained from commercial hybrids, using top cross squemes with testers (IA 33). Also, the general combining ability (GCA) of the lines was evaluated. The 27 top cross hybrids, two commercial checks and the tester were evaluated by complete block design with three replications, in two years (2005/2006 e 2006/2007), and three locations (Campinas, Mococa and Palmital) of Sao Paulo State. The evaluated traits were: plant height (AP), ear height (AE), percentage of broken and loged plant (AC+Q), ear yield (PE) and grain yield corrected of 14% moisture (PG). Top cross hybrids of high yield performance that outperformed or did not differ from the commercial check were observed. Therefore top cross hybrids with high yield performance and with advantage of small production cost were identified. Also line S3 with high value of GCA were observed.

FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize

This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid.

Changes in morphological composition according to the maturity stage in corn cultivars for silage production

The objective of this experiment was to evaluate the dry matter (DM) content and the percent participation of fractions that compose the plant in corn cultivars harvested at different maturity stages. A randomized block design with an 8 × 6 × 2 factorial scheme composed of eight harvesting times, six corn cultivars and two harvest years (2001/2002 and 2002/2003) was used. Cultivars CO 32, AG 5011, P 3041, DKB 333B, AG 1051 and Z 8550 were harvested when they reached 50% male flowering; 15 days after this date and later, each week, totalizing eight harvesting times. The plants reached the recommended DM content for silage production (32 to 35% DM) between 92 and 112 days after sowing (DAS) at the evaluated years. The maturity advancement resulted in increases in DM content in stem (from 16.9 to 28%), DM content in leaves (from 23.2 to 48.8%), DM content in cob (from 10 to 55.5%), and DM content in grains (from 50.4 to 70.9%). Furthermore, it resulted in increases in cob (from 1.6 to 9.2%) and grain proportion (from 0 to 43.4%), and decrease in stem (from 63.4 to 29.5%) and leaves proportion (from 27.5 to 10.8%). The corn cultivars showed distinct growing pattern for the evaluated variables. Therefore, plants harvested at different physiologic states can only be compared with fractions participation with considerable discernment, once the harvesting time can modify significantly the plant morphological composition.

Densidade, teor de óleo e produtividade de grãos em híbridos de milho

Existe grande variabilidade das cultivares de milho quanto a densidade de graos no mercado brasileiro, mas se conhece pouco sobre seus teores de oleo. Objetivou-se estudar a variabilidade do teor de oleo nos graos de hibridos de milho e verificar a existencia de correlacao entre a produtividade, a densidade e o teor de oleo. Desenvolveram-se, na safra 2002/2903, dois experimentos de avaliacao de cultivares, em Assis e Adamantina (SP), utilizando o delineamento em blocos ao acaso com 39 hibridos simples e triplos. Foram utilizadas dez espigas por parcela, as quais foram secionadas transversalmente na regiao mediana para amostragem de graos, na face exposta. Avaliaram-se a produtividade dos genotipos, a massa de cem graos, a proporcao de graos boiantes em solucao-padrao de nitrato de sodio, o peso volumetrico e o teor de oleo dos graos pelo metodo de espectrometria de ressonância magnetica nuclear (RMN). Procedeu-se a analise de variância dos dados e a comparacao das medias pelo teste de Skott-Knott a 5%. Calcularam-se correlacoes de Pearson entre o teor de oleo e os demais parâmetros avaliados, utilizando o programa SAS. Os teores de oleo variaram entre 38 a 60 g kg-1. O valor medio de massa volumetrica foi relativamente elevado (796 e 801 g L-1) devido a predominância de cultivares com graos de aparencia dura. As correlacoes obtidas no experimento evidenciam que hibridos de graos mais densos tendem a ter maiores teores de oleo (r = 0,34 a 0,40). Tres hibridos, no entanto, proporcionaram graos menos densos e teores de oleo relativamente elevados. As cultivares com maior produtividade tiveram menor teor de oleo, embora o indice de correlacao tenha sido baixo (r = -0,24). Concluiu-se que existe variabilidade genetica do teor de oleo nos graos suficiente para discriminar grupo de materiais com teores mais elevados. O teor de oleo correlacionou-se positivamente com a densidade de graos, porem com valores discrepantes e extremos de oleo dentro dos grupos de menor e maior densidade.

Heterose e seus componentes em híbridos de populações F2 de milho

The potential of 28 hybrids maize F 2 population, obtained from a complete diallel among eight F 2 populations, along with the eight parental F 2 populations and two commercial controls were evaluated for agronomic traits, heterosis and its compo - nents. The experiments were developed in 2008/09, in Campinas, Mococa and Palmital, Sao Paulo State, Brazil. The experi - mental design was in randomized blocks, with three replications. The agronomic traits male flowering, ear height and grain yield were evaluated. The grain yield was adjusted to 14% of moisture. Individual and grouped variance analyses were made considering the fixed model, with the means being compared by the Tukey test. The Gardner and Eberhart (1966) model was used in the diallel analysis. It was observed that the effect of heterosis and its components were highly significant. Consider - ing the grain yield, populations F 2 AG8060, F 2 Fort, F 2 A2555 are promising in hybrid combinations, with high values of parental heterosis. The population F 2 DAS2B710 had the greatest parental heterosis effects. There was heterosis manifestation for grain yield, mainly for hybrid F 2 A2555 x F 2 Fort. It was confirmed the potential of F 2 population hybrids as an alternative to the commercial maize production with medium to low technological input.

Agregação de Latossolo Vermelho sob diferentes sistemas de preparo do solo, após um único cultivo com girassol

The objective of the present research was to evaluate the effect of single sunflower crop on soil aggregation under different tillage systems. Four tillage systems were used: heavy disk harrow + leveling harrow (GA), leveling harrow (GN), sowing on straw (SP) without tillage (PD), in the autumn-winter, and chisel plow + leveling harrow in the spring-summer cultivation, except for PD treatment. The research was conducted under field conditions in Candido Mota and Pedrinhas Paulista, Sao Paulo State. Soybean was sowed in the spring-summer season and sunflower in the autumn-winter. The soil aggregates were evaluated before sowing and after sunflower harvest. The use of sunflower crop induced a better soil aggregation in both places, for all tillage systems.

DESEMPENHO AGRONÔMICO DE CULTIVARES DE MILHO NA REGIÃO NORTE/OESTE DO ESTADO DE SÃO PAULO - SAFRAS 2015/16 E 2016/17

Foram avaliados 30 cultivares de milho nas safras de 2015/16 e 2016/17, em 10 ambientes. Empregou-se o delineamento de blocos ao acaso com quatro repeticoes. As parcelas foram constituidas de quatro linhas de 5,0 m de comprimento utilizando-se as duas centrais para as avaliacoes. O espacamento entre linhas foi de 0,8 m e a populacao inicial de plantas de 62500 plantas por hectare. A produtividade de graos de milho foi elevada com cultivares superando 11 t ha-1 de graos em alguns ambientes. Os hibridos que atingiram maiores produtividades, considerando a analise conjunta dos 10 ambientes, foram 2B810 PW, AG 8088 PRO2, JM 2M60, MG 652 PW com produtividade superior a 9000 kg ha-1. Contudo, a produtividade de graos nao deve ser considerada isoladamente para definir a escolha da cultivar que melhor se adequa ao sistema de producao.

CONTROLE DA LAGARTA-DO-CARTUCHO EM MILHO TRANSGÊNICO NA SAFRINHA EM SÃO PAULO: DEZ ANOS DE USO

A lagarta-do-cartucho continua sendo uma das principais pragas na cultura do milho. O objetivo deste trabalho foi compilar os resultados da eficiencia das tecnologias Bt disponiveis (Yieldgard, Herculex, YieldGard VTPro, YieldGard VTPro2, Viptera 3, Optimum Intrasecta e Powercore) no controle da lagarta-do-cartucho, Spodoptera frugiperda (Smith) no milho safrinha ao longo de oito anos em experimentos de cultivares no estado de Sao Paulo. No periodo de 2008 a 2010 foram realizados oito experimentos especificos para estudo das tecnologias transgenicas Bt e no periodo 2011 a 2017 foram avaliados sete ensaios da rede de competicao de cultivares de milho IAC/APTA/CATI/Empresas em diferentes regioes do estado de Sao Paulo. Os danos da lagarta-do-cartucho nas plantas foram avaliados atraves de uma escala de notas de danos visuais (escala de Davis). As tecnologias diferiram quanto ao ataque da lagarta. As primeiras tecnologias foram perdendo a eficiencia de controle da lagarta-do-cartucho ao longo do tempo e depois de cinco anos nao diferiram das cultivares convencionais. Algumas tecnologias ainda apresentam controle satisfatorio, embora seu tempo de adocao seja menor. A tecnologia Vip3 vem mantendo a eficiencia de controle da lagarta-do-cartucho