Abstract The aim of this study was to assess the effect of subdoses of 2,4-D + picloram on the emergence and initial growth of Hymenaea stigonocarpa. Three experiments were carried out. In the first one, the seeds were planted in sand with residues of 2,4-D + picloram (0; 0.02; 0.10; 0.20 and 0.40 L ha -1 ). The second experiment was conducted with seedlings, using the same treatment of experiment I. In experiment III, the seeds were planted in Red Latosol contaminated with subdoses of 2,4-D + picloram (0; 0.02; 0.08; 0.24; 0.48 and 0.96 L ha-1). The contamination of the sand substrate with subdoses of 2,4-D + picloram inhibits the emergence and senescence of Hymenaea stigonocarpa plants. Moreover, when seeds of this species were cultivated in Red Latosol with residual doses between 0.04 and 0.96 L ha-1, emergence and emergence speed index declined.

RESUMEN El cultivo de tomate presenta un alto potencial productivo pero puede afectarse debido al estrés biótico y abiótico. Se ha informado un aumento de la resistencia de la planta a las condiciones de estrés con la aplicación foliar de compuestos minerales del suelo, sin embargo, aún es necesario comprender mejor cómo reacciona la planta al uso de este compuesto. Por lo tanto, este estudio evaluó el efecto de la aplicación foliar del compuesto mineral del suelo sobre los atributos fisiológicos y de crecimiento de las plantas de tomate. Este experimento se llevó a cabo en Lagoa Formosa / MG durante 2016. Se usaron diferentes tasas del compuesto mineral del suelo durante el ciclo del cultivo, lo que constituye cuatro manejos distintos. El manejo consistió en diferentes dosis del compuesto mineral en cuatro etapas después del trasplante de las plántulas de tomate. El diseño experimental utilizado fue de bloques al azar. Se realizaron las siguientes evaluaciones fisiológicas: proteína soluble total, peróxido de hidrógeno, actividad de la enzima nitrato reductasa, ureasa, superóxido dismutasa (SOD), peroxidasa, fenilalanina amoniaco liasa y peroxidación lipídica (LP). Las evaluaciones de crecimiento fueron biomasa vegetal y rendimiento. La aplicación foliar del compuesto mineral del suelo aumentó la actividad de la enzima SOD en 4,17 y 6,25%. El uso del compuesto mineral del suelo también aumentó la actividad de LP y redujo la actividad de las enzimas antioxidantes. La aplicación foliar de compost mineral del suelo a dosis de 0,5; 0,750; 1,0 y 1.0 kg ha-1 a los 15, 25, 40 y 60 días después del trasplante, respectivamente, aumentó el rendimiento de tomates de mesa al 20%.

ABSTRACT The tomato crop has a high productive potential that can be depleted by biotic and abiotic stresses. Increased plant resilience to stress conditions has been reported with foliar applications of soil-mineral compounds; however, it is necessary to better understand how plants react to the use of this compound. Thus, this study evaluated the effect of foliar applications of a soil-mineral compound on the physiological and growth attributes of tomato plants. This experiment was carried out in Lagoa Formosa/MG during 2016. Different rates of the soil-mineral compound were used during the crop cycle, forming four distinct managements. The management consisted of different doses of the mineral compound in four stages after transplanting the tomato seedlings. The experiment design used randomized blocks. The following physiological evaluations were performed: total soluble protein, hydrogen peroxide, nitrate reductase enzyme activity, urease, superoxide dismutase (SOD), peroxidase, phenylalanine ammonia lyase, and lipid peroxidation (LP). The growth assessments were plant biomass and yield. Foliar applications of the soil-mineral compound increased the activity of the SOD enzyme by 4.17 and 6.25%. The use of the soil-mineral compound also increased the LP activity and reduced the antioxidant enzyme activity. The foliar application of the soil-mineral compost at doses of 0.5, 0.750, 1.0 and 1.0 kg ha-1 at 15, 25, 40 and 60 days after transplanting, respectively, increased the yield of the table tomatoes by 20%.

RESUMO Nos últimos anos, houve rápido crescimento na utilização de substâncias que buscam aumentar a produtividade de soja, como as citocininas, seja por alterações fisiológicas ou morfológicas. Objetivou-se avaliar o efeito da época de aplicação de citocinina na forma de cinetina, na cultura da soja. O experimento foi realizado em condições de campo, utilizando-se quatro tratamentos (controle e cinetina nos estágios vegetativos V4, V6 e V4 + V6), com cinco repetições, em blocos inteiramente casualizados. Foram realizadas avaliações fisiológicas (atividade de nitrato redutase e peroxidase, teor de H2O2 e peroxidação de lipídios) e fenométricas (massa de matéria seca de raiz e folhas), além da produtividade. A aplicação de cinetina em V4, V6 ou V4 + V6 proporcionou incremento na atividade da enzima nitrato redutase, redução do estresse (avaliado por meio da peroxidação lipídica e teor de peróxido de hidrogênio) e aumento no teor de massa de matéria seca. Todas essas características repercutiram no aumento da produtividade. Contudo, os efeitos mais expressivos foram causados pela aplicação de cinetina em V6, que proporcionou incremento de 20 % na produtividade, em relação ao controle.

ABSTRACT A fast growth in the use of substances that increase soybean yield through physiological or morphological changes, such as cytokinin, has taken place in recent years. This study aimed at assessing the effect of the application time of cytokinin as kinetin on soybean crops. The experiment was carried out under field conditions, using four treatments (control and kinetin at the vegetative stages V4, V6 and V4 + V6), with five replications, in completely randomized blocks. Physiological (nitrate reductase and peroxidase activity, H2O2 content and lipid peroxidation) and phenometric parameters (leaf and root dry mass), as well as yield, were evaluated. The application of kinetin at V4, V6 or V4 + V6 increased the activity of the nitrate reductase enzyme and reduced stress (evaluated via lipid peroxidation and hydrogen peroxide content), in addition to raising the dry matter content. All these characteristics resulted in increased yield. However, the most significant effects were caused by the application of kinetin at V6, which increased yield in 20 %, in relation to the control.

O objetivo deste trabalho foi calibrar uma câmara prática e de baixo custo, para quantificar a amônia volatilizada do solo. A calibração da câmara foi realizada pela técnica do balanço do isótopo 15N. A amônia volatilizada foi capturada por uma câmara semiaberta livre estática (SALE), confeccionada a partir de garrafa de plástico transparente de politereftalato de etileno (PET) de 2 L. O interior da câmara apresentava livre circulação de ar, e possuía uma lâmina de espuma de poliuretano, com 2,5 cm de largura e 25 cm de comprimento, pendurada verticalmente, com a extremidade inferior inserida em frasco com solução ácida, que mantinha a espuma saturada. A recuperação do 15N-NH3 no coletor aumentou de forma linear com o aumento da taxa de volatilização de NH3 do solo. Os testes de campo mostraram eficiência de 57% na recuperação do N-NH3 volatilizado do solo. O intervalo de coletas das espumas pode variar de um a seis dias, sem comprometer a eficiência do sistema. Para estudos de campo, com uso do método proposto, o fator de correção de 1,74 deve ser usado para estimar a real taxa de volatilização de amônia do solo.

The objective of this work was to calibrate a practical and low-cost chamber for the quantification of ammonia volatilization from soil. The chamber was calibrated using the 15N isotope balance technique. The volatilized ammonia was captured by a semi-opened free static chamber built with a 2 L ethylene polyterephthalate (PET) plastic bottle. The inner side of the chamber had free-air circulation and a stripe of polyurethane foam, with 2.5 cm wide and 25 cm long, hanged vertically with the lower end inserted in a bottle containing acid solution, which kept the foam moistened. The recovery of 15N-ammonia by the chamber increased linearly with the increase in the rate of soil ammonia volatilization. Field tests showed an efficiency of 57% in the volatilized ammonia recuperation. The sampling interval of foam can vary from one to six days without impairing the system efficiency. For studies in the field using the proposed method, a correction factor of 1.74 should be used to estimate the real rate of ammonia volatilization from soil.

Três fontes protéicas alimentares foram tratadas com transglutaminase microbiana (EC 2.3.2.13) e as características físico-químicas como reatividade, solubilidade, emulsificação e grupos amino livres dos polímeros formados foram avaliadas. Amostras de caseína láctea (CL), proteína isolada de soja (PIS) e de proteína animal hidrolisada (PAH), foram incubadas com a enzima por uma ou duas horas. CL e PIS mostraram uma redução na solubilidade de 15% e 24% respectivamente, enquanto PAH não sofreu alteração de solubilidade. A quantidade de nitrogênio livre na forma amina apresentou uma redução de 7%, 3% e 2% para PAH, CL e PIS respectivamente. CL e PIS demonstraram baixa atividade emulsificante quando tratadas enzimaticamente, porém as emulsões formadas se mostraram estáveis, em contraste com PAH que não alterou suas propriedades emulsificantes.

Three sources of food proteins were treated with microbial transglutaminase (EC 2.3.2.13) in order to assess changes in the physicochemical properties of reactivity, solubility, emulsification, and free amino groups of the formed polymers. Samples of lactic casein (LC), isolated soy protein (ISP), and hydrolysed animal protein (HAP), were incubated with the enzyme for one or two hours. LC and ISP showed a reduced solubility of 15% and 24% respectively, with HAP showing no alteration on solubility. Amino nitrogen content was 7%, 3% and 2% reduced for HAP, LC and ISP respectively. LC and ISP demonstrated lower emulsifying activity when they were enzymatically treated but the formed emulsions were stable, contrasting with HAP, which exhibited no changes in emulsifying properties.