Silicon, Potassium and Nitrogen Accumulation and Biomass in Corn under Hydroponic Conditions

The aim of the research was to evaluate the effect of the interaction of silicon, potassium, and nitrogen on the foliar area, the accumulation of these elements in the aerial part and the dry biomass in corn plants. The research was developed under hydroponic conditions in Jaboticabal Sao Pablo, Brasil using the 30A77HX hybrid. Two silicon concentrations were evaluated (0 and 2 mmol L−1); two concentrations of potassium (1 and 12 mmol L−1) and four nitrogen concentrations: (1, 10, 15, and 20 mmol L−1). A completely randomized design was used, with factorial arrangement 2 × 2 × 4 and three replications. The foliar area, the dry biomass and, nitrogen, potassium, and silicon content were determined. The application of silicon at a high concentration of K causes an increase in the accumulation of K, which is reflected in an increment of the total dry biomass in the plants of corn, while excess and a deficit of N diminish the accumulation of Si in the aerial part of the plant, which is more evident at a low concentration of K in the nutritious solution, affecting the accumulation of the total dry biomass

Desarrollo de la mancha foliar por Bipolaris maydis (teleomorfo: Cochliobolus heterostrophus) en maíz dulce, en función de nitrógeno, potasio y silicio en invernadero

This work aimed to evaluate the development of the southern corn leaf blight caused by Bipolaris maydis, a common disease in sweet corn, depending on the dose and the accumulated nitrogen, potassium, and silicon, under greenhouse conditions. The treatments consisted of five doses of nitrogen (0, 200, 400, 800, and 1,200 kg/ha), application or not of potassium (240 kg/ha), and application or not of silicon (380 kg/ha). A completely randomized design with factorial arrangement 5 x 2 x 2 and three repetitions was used. All the treatments were inoculated on day 30 with a suspension of 2 x 105 conidia by mL of B. maydis. On day 42, the accumulated N, K, and Si were measured, as well as the infection percentage and the area under the disease progress curve (AUDPC). The treatments that received fertilization with Si and K showed higher accumulation of N, K and Si, and lower levels of disease intensity and AUDPC. The accumulated N, K, and Si exhibited variations compared to the fertilization interactions of K with N, and Si with N; however, the levels of the disease variables were lower in the fertilization with K or Si, combined with the doses of 0, 200 and 400 kg/ha of N.El objetivo del trabajo fue evaluar el desarrollo de la mancha foliar causada por Bipolaris maydis, enfermedad común e          n maíz dulce, según la dosis y el acumulado de nitrógeno, potasio y silicio, en condiciones de invernadero. Los tratamientos consistieron en cinco dosis de nitrógeno (N) (0, 200, 400, 800 y 1.200 kg/ha), aplicación o no de potasio (K) (240 kg/ha) y aplicación o no de silicio (Si) (380 kg/ha). Se empleó un diseño experimental completamente aleatorizado con esquema factorial 5 x 2 x 2 y tres repeticiones. Se inocularon todos los tratamientos a los 30 días con una suspensión de 2 x 105 conidios por mL de B. maydis. A los 42 días se midió la acumulación de N, K y Si, así como el porcentaje de infección y el área bajo la curva de progreso de la enfermedad (ABCPE). Los tratamientos que recibieron fertilización con Si y K presentaron mayores acumulados de N, K y Si, y niveles más bajos de intensidad de ataque y ABCPE. Los acumulados de N, K y Si presentaron variaciones frente a las interacciones de la fertilización de K con N, y de Si con N; sin embargo, los niveles de las variables de la enfermedad fueron menores en la fertilización con K o Si, combinadas con las dosis de 0, 200 y 400 kg/ha de N

Effect of the phosphate fertilizer with filter cake on soil microbial activity and phosphorous uptake in sugar cane

El objetivo del trabajo fue evaluar el efecto de diferentes dosis de fertilizante fosfatado con la adición de cachaza sobre la actividad microbiana del suelo, y el contenido de fósforo en el suelo y en plantas de caña de azúcar. El experimento se condujo en condi- ciones de invernadero en Jaboticabal Brasil en 2013, usándose plántulas de caña de azúcar (variedad "CTC 05"). Las unidades experimentales estuvieron constituidas por macetas cargadas con un Hapludox. Se empleó un diseño completamente aleatorizado, con el arreglo factorial de 5x2 y tres repeticiones. Los tratamientos fueron cinco dosis de fósforo: 0, 50, 100, 200 y 400 mg dm -3 y dos niveles de cachaza (ausencia y presencia). Se evaluaron la actividad respiratoria, la fosfatasa ácida y la deshidrogenasa, el carbono soluble, el pH y el tenor de P en el suelo, así como el P acumulado en las plántulas. Se encontró interacción entre las dosis de P y la cachaza para todas las variables, excepto para el pH y el carbono soluble. El fosfato con la adición de cachaza aumentó la actividad microbiana y el fósforo disponible en el suelo, reflejándose en la mayor acumulación de P en las plantas.The objective of the work was to evaluate the effect of different doses of phosphate fertilizer with the addition of sugar cane industry filter cake on the soil microbial activity and soil and plant P concentration in sugar cane. The experiment was carried out in vegetation house at Jaboticabal, Brazil, in 2013, and the sugar cane seedlings variety "CTC 05"was used as tests plant. The experimental units were pots containing Hapludox. A completely randomized design was used, with factorial arrangement of 5x2 and three repetitions. The treatments were five phosphorus doses: 0, 50, 100, 200 and 400 mg dm -3 and two levels of filter cake (absence and presence). Soil respiration, acid phosphatase and dehydrogenase activity, soluble carbon, pH value, soil and plant P concentrations. There was interaction among doses of P and filter cake application for all the variables, except for the pH. The phosphate with the addition of filter cake application for all the variables, except for the pH. The phosphate with the addition of filter cake increased the microbial activity, the value of the pH and de P concentration in the soil, being reflected in a higher accumulation of P in the seedling.Fil: Saucedo Castillo, Orlando. Universidad Central "Marta Abreu" de Las Villas (Cuba)Fil: Prado, Renato de Mello. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Castellanos González, Leónides . Universidad de Cienfuegos (Cuba)Fil: Ely, Nahas. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Silva Campos, Cid Naudi. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Silva, Gilmara Pereira Da. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Assis, Luis Carlos. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil

Application technology of boron via foliar and its effects on cotton crop phenology / Tecnologia de aplicação de boron através de foliar e seus efeitos na fenologia da cultura de algodão

Boron can be applied to cotton crops together with pesticides. Producers have allied medium and fine droplets to low application rates, which can lead to low boron deposition on the leaves. This work aimed to evaluate the spray deposition and absorption of boron leaf application on a cotton crop, by varying the surfactant and the application rate, comparing the effects on the crops’ phenology and yield. Boron was applied using a backpack sprayer pressurized with CO2. Spray deposition was estimated based on the mass balance methodology. Plant leaves were collected for analysis at 17 days after application. The use and variation of the application technology affect micronutrient B absorption by leaf spray application. The application rate of 120 L ha-1 with siliconized surfactant adjuvant provides higher spray deposition on cotton plants and consequently higher boron absorption. The application rate of 70 L ha-1 without siliconized surfactant adjuvant provides lower boron absorption

Nitrogen doses in topdressing affect vegetation indices and corn yield

Nitrogen is the main nutrient required by corn crop, especially in Cerrado soils. Remote sensing techniques can be used to generate additional information now of nitrogen fertilization recommendation. This work investigated the association of plant height and dry matter phenological variables together with NDVI, REDEDGE, SAVI, and IV 760/550 vegetation indices (VIs) with corn grain yield, under different N doses. Sowing occurred in November 2016, at a spacing of 0.45 m between rows and a 60,000 ha-1 plant population. Four N doses (0, 80, 160, and 240 kg of N ha-1) were applied at phenological stage V4. The experimental design consisted of randomized blocks, containing four N doses in topdressing and 16 replications. The active optical sensor Crop Circle ACS-470 was used to obtain the VIs. The NDVI, SAVI, and RE indices have a high positive association with each other and with the variables plant height and dry matter. Polynomial regression equations were adjusted between the variables in response as doses of N. Afterwards, they were estimated as correlations between variables and results expressed through the network of correlations. Finally, a multivariate analysis of canonical variables was performed to understand the interrelationship between the variables and each dose of N applied. NDVI and RE have a positive relationship of moderate magnitude with grain yield in corn crops

Effect of two sources of zinc on the physiological quality of seed and nutrition of rice (Oriza sativa) seedlings

Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg-1), and a control treatment of zinc in the form of sulfate (40 g kg-1). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition of the rice cultivar. Zinc sources did not change the germination; however, the oxide form provided better seed vigor, except for the highest dose (160 g kg-1). The increase in the dose of zinc oxide increased the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize the seeds vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, which is the traditional source used by producers. Highlights Zinc (Zn) coating does not affect germination, but influences the vigor of rice seeds. The Zn sources affect the Zn concentration in the shoot dry matter. Both ZnO and ZnSO 4 showed higher shoot dry matter, when compared with the absence of Zn in rice seeds. Oxide zinc (ZnO) promotes greater root dry matter of rice when compared with zinc sulfate (ZnSO 4 ).Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg-1), and a control treatment of zinc in the form of sulfate (40 g kg-1). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition of the rice cultivar. Zinc sources did not change the germination; however, the oxide form provided better seed vigor, except for the highest dose (160 g kg-1). The increase in the dose of zinc oxide increased the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize the seeds vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, which is the traditional source used by producers. Highlights Zinc (Zn) coating does not affect germination, but influences the vigor of rice seeds. The Zn sources affect the Zn concentration in the shoot dry matter. Both ZnO and ZnSO 4 showed higher shoot dry matter, when compared with the absence of Zn in rice seeds. Oxide zinc (ZnO) promotes greater root dry matter of rice when compared with zinc sulfate (ZnSO 4 )

Agronomic performance of cotton and soybean cultivated under different cover crops and lime and gypsum doses

Soil management with the use of lime and agricultural gypsum can influence the development and yield of cotton and soybean crops. The use of cover crops avoids soil degradation and ensures nutrient cycling on the soil surface. In most cultivated species, the application of lime and agricultural gypsum provides corrections in the sub-surface soil, keeping the nutrients available. This study aimed to (i) verify whether cotton and soybean cultivated in succession to cover crops affect its agronomic performance and (ii) evaluate the influence of lime and gypsum doses on the agronomic performance of these crops. Two experiments were performed. The first experiment consisted of cotton cultivated in the off-season, and the second, of soybean cultivated in the regular season. The experiment was carried out under three plant residues (Urochloa ruziziensis, Pennisetum glaucum, and fallow area), combined with lime and gypsum doses. The experiment consisted of a completely randomized block design with four replications. For the cotton crop, only the gypsum doses influenced the variables plant height, initial and final population, and yield. Cover crops did not influence the agronomic performance of cotton and soybeans. The increase of lime doses resulted in a linear increase in cotton and soybean yield. The highest gympsum dose improved the agronomic performance of cotton plants; however, it only influenced the height of soybean plants

Efecto de la fertilización fosfatada con cachaza sobre la actividad microbiana del suelo y la absorción de fósforo en caña de azúcar (Saccharum spp.)

The objective of the work was to evaluate the effect of different doses of phosphate fertilizer with the addition of sugar cane industry filter cake on the soil microbial activity and soil and plant P concentration in sugar cane. The experiment was carried out in vegetation house at Jaboticabal, Brazil, in 2013, and the sugar cane seedlings variety "CTC 05"was used as tests plant. The experimental units were pots containing Hapludox. A completely randomized design was used, with factorial arrangement of 5x2 and three repetitions. The treatments were five phosphorus doses: 0, 50, 100, 200 and 400 mg dm-3 and two levels of filter cake (absence and presence). Soil respiration, acid phosphatase and dehydrogenase activity, soluble carbon, pH value, soil and plant P concentrations. There was interaction among doses of P and filter cake application for all the variables, except for the pH. The phosphate with the addition of filter cake increased the microbial activity, the value of the pH and the P concentration in the soil, being reflected in a higher accumulation of P in the seedling.  El objetivo del trabajo fue evaluar el efecto de diferentes dosis de fertilizante fosfatado con la adición de cachaza sobre la actividad microbiana del suelo, y el contenido de fósforo en el suelo y en plantas de caña de azúcar. El experimento se condujo en condiciones de invernadero en Jaboticabal Brasil en 2013, usándose plántulas de caña de azúcar (variedad "CTC 05"). Las unidades experimentales estuvieron constituidas por macetas cargadas con un Hapludox. Se empleó un diseño completamente aleatorizado, con el arreglo factorial de 5x2 y tres repeticiones. Los tratamientos fueron cinco dosis de fósforo: 0, 50, 100, 200 y 400 mg dm-3 y dos niveles de cachaza (ausencia y presencia). Se evaluaron la actividad respiratoria, la fosfatasa ácida y la deshidrogenasa, el carbono soluble, el pH y el tenor de P en el suelo, así como el P acumulado en las plántulas. Se encontró interacción entre las dosis de P y la cachaza para todas las variables, excepto para el pH y el carbono soluble. El fosfato con la adición de cachaza aumentó la actividad microbiana y el fósforo disponible en el suelo, reflejándose en una mayor acumulación de P en las plantas

Liquid nitrogen fertilization on the yield and phenologic variables of narrow-row cotton

Slow-release liquid nitrogen fertilizer sources have been around since 1970. However, this technique is not widely used in the field, probably due to the low cost per ton of nitrogen in the solid form. This study aimed to evaluate the combination of the conventional and slow-release nitrogen fertilization on the yield and phenological variables in a narrow-row cotton crop. Treatments consisted of the combination of the nitrogen fertilizer applied as topdressing in solid form (via soil) and pulverized in the liquid form (via urea formaldehyde - UF): 0% of solid N + 0% of liquid N (0S0L); 100% of solid N + 0% of liquid N (100S0L); 75% of solid N + 25% of liquid N (75S25L); 50% of solid N + 50% of liquid N (50S50L); 25% of solid N + 75% of liquid N (25S75L); e 0% of solid N + 100% of liquid N (0S100L). The cotton crop was phenotypically evaluated at 35, 70, and 130 DAE (Days after emergence) and at the harvest time. The variation between the source of the solid nitrogen fertilizer applied to the soil (ammonium nitrate) and the liquid Nitrogen fertilizer applied by spraying (UF) affects the phenology, physiology, and yield components of the narrow-row cotton crop. The highest yield of the narrow-row cotton crop under the experimental conditions was achieved when 25% of the dose of the solid nitrogen fertilizer was applied as topdressing via soil, and 75% of the dose of the slow-release nitrogen fertilizer was sprayed. This technique provides higher profitability of the produced cotton in relation to the conventional application of the N solid fertilizer via soil

Relationship between vegetation indices and agronomic performance of maize varieties under different nitrogen rates

Precision agriculture is a set of techniques that assist the monitoring of the agronomic performance of the maize crop by using vegetation indices. This study aimed to verify the relationship between vegetation indices, plant height, leaf N content, and grain yield of three maize varieties, grown under high and low N as topdressing. The experiment was carried out at the Fundação de Apoio à Pesquisa Agropecuária de Chapadão (Fundação Chapadão), located in the municipality of Chapadão do Sul, during the 2017/2018 season. The experiment consisted of a randomized block design with four replications, arranged in a 3x2 split-plot scheme. The first factor (plots) corresponded to three open-pollinated maize varieties (BRS 4103, BRS Gorotuba, and SCS 154), and the second factor (subplots) consisted of two N rates applied as topdressing (80 and 160 kg- 1). All the evaluated variables showed varieties x N interaction. Vegetation indices in maize varieties were influenced by the N rate applied as topdressing. Normalized Difference Vegetation Index (NDVI) and Soil-adjusted Vegetation Index (SAVI) showed a higher correlation with plant height. At the same time, Normalized Difference Red Edge (NDRE) had a stronger association with leaf N content