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The objectives were to study the behavior of fifteen pre-commercial upland maize hybrids, analyze their agronomic performance regarding grain yield, and evaluate productivity components, as well as morpho-agronomic characteristics, in the Midwest Region of Brazil. Two experiments were conducted in the municipalities of Formosa-GO and Planaltina-DF, 2016/17 crop year. Both consisted of five pre-commercial maize hybrid platforms (HPA252, HPB262, HPB621, HPB646, and HPD354). Each platform consisted of three different versions: conventional, transgenic with a Bt gene that expresses the protein Cry1F, and transgenic with two Bt genes that express the proteins Cry1F and Cry1AB. The experiment was randomized blocks with four replications. The experimental plot was four lines five meters long considering the two central lines as useful. The lines were spaced 0.75 meters apart, and the final density was five plants per linear meter. To estimate grain yield, the plots were harvested, and the weight was extrapolated to kg.ha-1. The moisture was standardized at 14%. Data were submitted to analysis of variance, and the means were compared by Tukey test at 5% probability using the Sisvar software. Grain yield between treatments ranged from 8,381 to 12,908 kg.ha-1, and the average yield was 11,234 kg.ha-1. The parameters evaluated were divided into two groups. The first group contained parameters determining grain yield: grain depth, thousand grains weight, number of rows of grains, number of grains per row, and grain yield. The second group contained morpho-agronomic parameters that directly interfere with resistance to lodging and plant breaking: plant height, ear insertion height, and mean stem diameter. There was no direct effect of the transgenes on the evaluated hybrids since the classification of productivity was not divided into conventional and transgenic classes. It is suggested that the HPA252YH, HP621H and HP646H versions be discarded because grain yield performance was unsatisfactory compared to their respective conventional and transgenic counterparts. The parameters GD and W1000 are more effective for grain yield estimation than NR and NG. It was observed for HP621H that, in addition to a lower grain yield, there was a significant reduction in stem diameter, indicating a possible reduction in lodging tolerance and/or plant breaking when exposed to adverse climatic conditions such as windstorms. For the HPD354H version, the release of the transgenic counterpart HPD354YH is preferentially indicated since the H version had a significant reduction in stem diameter and a possible greater tolerance to lodging and/or plant breaking under the same conditions.

The intensity of rice diseases in regions with poor levels of silicates (Si) in the soil, together with high control costs, can make the cultivation of rice unfeasible. Surprisingly, there are scarce research data available regarding the influence of Si on ricediseases in tropical lowland regions. Therefore, the aim of this study is to determine the effect of three silicon sources on rice yield and disease management. Three experiments were carried out from December 2005 to April 2006 at an experimental field area located inFormoso do Araguaia, Tocantins state, Brazil. Each experiment consisted of one silicon source (powder, granular or liquid) and the treatments consisted of six Si doses. All the treatments were performed in a completely randomized block design. The data presented in this study provide evidence that Si applications in Si-deficient soils of lowland regions, depending on the application source, dose and disease intensity, can decrease the severity of brown spot and the incidence of panicle blast. Calcium silicate effectively reduced the brown spot and the panicle blast, which resulted in an increased rice yield. In contrast, Ca and Mg silicate and potassium silicate did not show an efficient control of rice diseases nor an increase in productivity.A intensidade de doenças do arroz em regiões com solos pobres em silício, aliada aos altos custos de controle, podem inviabilizar economicamente o cultivo do arroz. Por existir poucas pesquisas avaliando a influência do silício nas doenças do arroz em regiões tropicais de terras baixas, esse estudo objetivou avaliar o efeito de três fontes de silício na produção e manejo de doenças do arroz. Três experimentos foram realizados entre dezembro de 2005 e abril de 2006, em um campo experimental localizado em Formoso do Araguaia, Estado do Tocantins, Brasil. Cada experimento consistiu da avaliação de um fator (fonte de silício em pó, granular ou líquido), conduzido emdelineamento experimental de blocos inteiramente casualizados com seis níveis (doses de silício). Os resultados obtidos mostram que a aplicação de silício em solos deficientes desse elemento, em regiões de terras baixas, promove redução da severidade da mancha parda e aincidência da brusone das panículas, dependendo da fonte de silício, dose e pressão da doença. Silicato de Ca reduziu efetivamente a mancha parda e a brusone, resultando em aumento da produtividade. Entretanto, silicato de Ca e Mg e o silicato de potássio nãomostraram eficiência no controle das doenças ou aumento da produtividade.

A resistência induzida é um método alternativo de controle de doenças. Entretanto, há poucos estudos relacionando o uso destes produtos e outros métodos alternativos à produtividade das plantas e às características físicas e químicas dos frutos. Objetivou-se avaliar a severidade de doenças, as características físicas e químicas de frutos e a produtividade de plantas tratadas com produtos alternativos e fertilizantes foliares. Plantas de maracujazeiro BRS Gigante Amarelo clonadas, em campo, foram submetidas, por um ano, a pulverizações quinzenais com: água (testemunha), Cuprozeb® (fungicida-padrão), acibenzolar-S-metil - ASM, Agro-mos®, fosfito de potássio, fosetyl-Al, gesso agrícola e CPAC-GE (produto em teste). O delineamento foi o em blocos casualizados, com quatro repetições e 20 frutos por repetição. Para o estudo da produtividade, utilizaram-se quatro repetições e seis plantas úteis por parcela. As colheitas ocorreram de novembro/2008 a abril/2009. As severidades foram avaliadas com escala de notas. Houve redução da severidade da virose, verrugose e bacteriose em todos os tratamentos, com exceção do Cuprozeb® para virose. Não foi observada redução da antracnose. Frutos com maior massa fresca foram obtidos com aplicações de gesso agrícola (236,83 g), CPAC-GE (234,10 g), fosetyl-Al ( 233,79 g), fosfito de potássio (230,64 g) e Agro-mos® (221,15 g). Os mesmos resultados foram observados para diâmetro transversal e massa de polpa. Não houve diferenças significativas entre tratamentos para diâmetro longitudinal e espessura de casca. Quanto às características químicas dos frutos, com exceção do Cuprozeb®, que não diferiu significativamente da testemunha, todos os produtos proporcionaram incremento no teor de sólidos solúveis. Maior acidez titulável foi obtida com Cuprozeb®, gesso agrícola, Agro-mos®, fosetyl-Al e ASM. Não foi constatada alteração no pH dos frutos. Em relação à produtividade, maiores quantidades de frutos por planta foram obtidas com fosfito de potássio (162,38 frutos), seguido pelo gesso agrícola (111,13 frutos) e CPAC-GE (102,50 frutos). Maiores produtividades (kg/ha), considerando 1.600 plantas/ha, foram alcançadas com fosfito de potássio (40,19 t/ha), seguido pelo gesso agrícola (30,48 t/ha) e CPAC-GE (29,04 t/ha).Inducing resistance is an alternative to control of plants diseases. However, there are few studies relating the effect of these products on yield and physical and chemical fruit characteristics. The aim of this work was to evaluate diseases severity, fruit physical and chemical characteristics and yield of passion fruits plants treated with alternative products and foliar fertilizers. Cloned plants of passion fruit cultivar BRS Gigante Amarelo were sprayed at each fifteen days, during one year with water (control), Cuprozeb® (standard fungicide), acibenzolar-S-metil - ASM, Agro-mos®, potassium phosphite, fosetyl-Al, gypsun and CPAC-GE (product in test). Experimental design was randomized blocks with four repetitions and six useful plants per repetition. For analyzing the physical and chemical characteristics were utilized four repetitions of twenty fruits. Harvestings of fruits were made from November, 2008 to April, 2009. For analyzing the disease severities was utilized a diagrammatical grade scale. All products were efficient in reducing the severity of woodiness virus severity, fruit-scab and bacteriosis, excepting the Cuprozeb® that was not effective to control the woodiness virus. Neither product was effective to control of fruit anthracnose. The applications of gypsum (236,83 g), CPAC-GE (234,10 g), fosetyl-Al (233,79 g), potassium phosphite (230,64 g) and Agro-mos® (221,15 g) induced the higher fruit fresh mass. Similar results were observed to transversal diameter and fruit pulp weight. There were not effect of those products on fruit longitudinal diameter and peel thickness. Concerning to fruit chemical characteristics, excepting Cuprozeb®, all products increased juice soluble solids levels. Gypsum, Agro-mos®, fosetyl-Al and ASM increased the juice titratable acidity, but there were not alteration of juice pH. Concerning the yield, the higher quantities of fruits per plant were obtained with applications of potassium phosphite (162,38), gypsum (111,13) and CPAC-GE (102,50). The best fruit yields were induced by field applications of potassium phosphite (40,19 t/ha), gypsum (30,48 t/ha) and CPAC-GE (29,04 t/ha).

The intensity of rice diseases in regions with poor levels of silicates (Si) in the soil, together with high control costs, can make the cultivation of rice unfeasible. Surprisingly, there are scarce research data available regarding the influence of Si on rice diseases in tropical lowland regions. Therefore, the aim of this study is to determine the effect of three silicon sources on rice yield and disease management. Three experiments were carried out from December 2005 to April 2006 at an experimental field area located in Formoso do Araguaia, Tocantins state, Brazil. Each experiment consisted of one silicon source (powder, granular or liquid) and the treatments consisted of six Si doses. All the treatments were performed in a completely randomized block design. The data presented in this study provide evidence that Si applications in Si-deficient soils of lowland regions, depending on the application source, dose and disease intensity, can decrease the severity of brown spot and the incidence of panicle blast. Calcium silicate effectively reduced the brown spot and the panicle blast, which resulted in an increased rice yield. In contrast, Ca and Mg silicate and potassium silicate did not show an efficient control of rice diseases nor an increase in productivity.