Tonny José Araújo da Silva

RESPOSTA DE PLANTAS JOVENS DE LIMEIRA ÁCIDA ‘TAHITI’ A DIFERENTES NÍVEIS DE IRRIGAÇÃO

The aim of this study was to evaluate the effect of different irrigation levels on canopy and root growth, productivity, and fruit quality of young ‘Tahiti’ acid lime trees. The experiment was installed in Piracicaba, Brazil in a 1.0-ha orchard plot with ‘Tahiti’ acid lime trees, grafted on ‘Swingle’ citrumelo rootstock and carried out from August of 2002 to May 2005. Each treatment was assigned to a drip irrigation level, based on ETc as follows: T1) non-irrigated, T2) 25%, T3) 50%, T4) 75% and T5) 100% of ETc determined by weighing lysimeter presented in the orchard plot. Trunk diameter and tree height were evaluated monthly. The roots were evaluated when the trees were 30 and 48 months old. The yield and fruit quality was evaluated in 2004 and 2005. The results showed that irrigation did not influence root distribution in depth, and trees irrigated with 75% and 100% ETc showed horizontal root distribution concentrated until 0.6xa0m from the trunk. Irrigation did not improve the quality of fruit. Yield increased in all irrigated treatment, but the most efficient yield mean per unit of water applied was the 25% ETc treatment.

Sazonalidade do Balanço de Energia e Evapotranspiração em Área Arbustiva Alagável no Pantanal Mato-Grossense

The Pantanal has flood periods that model the landscape and act as a filter to the establishment and development of plants Anthropogenic or natural disturbances can alter the available energy distribution in the ecosystem. Due to the need of understanding the temporal variability of the energy balance in flood natural landscapes, the objective of this study was to analyze the seasonality of the energy balance in flooded shrub area consisting of Combretum lanceolatum Pohl in Mato Grosso Pantanal. The estimates of latent (LE) and sensible (H) heat flux, and evapotranspiration (ET) were obtained by the method of Bowen ratio between May 2012 and April 2013. The available energy was intended primarily to LE (64.1%), followed by H (35.8%) and almost zero to heat flow in soil (0.1%). The components of the energy balance showed strong seasonality, with highest LE in the wet season and highest H in the dry season. The evapotranspiration was lower during the dry season due to the lower soil water content and transpiration of dominant vegetation in the study area. Results suggest that the study area was limited by the availability of energy and water.

Nitrogen and potassium in production, nutrition and water use efficiency in wheat plants

Wheat ( Triticum aestivum L.) is a cereal used in food and feed for its nutritional properties. For nitrogen and potassium management, efficient use of water is required for greater availability and transportation of these nutrients. The objective of this study was to evaluate the effect of combinations of nitrogen and potassium doses in production, nutrition and water use efficiency in wheat. The experiment was held in a greenhouse with 8-dm3 pots using Oxisol collected at a depth of 0-0.2 m under Cerrado vegetation. Base saturation was raised to 60%. The experimental design was a randomized block in a 5x5 factorial arrangement with five doses of nitrogen (0, 100, 200, 300 and 400 mg dm-3) and potassium (0, 90, 180, 270, 360 mg dm-3) with four replications. Soil moisture was maintained by an auto-irrigation system (3 kPa pressure). The experiment was collected at 95 days after plant emergence. We evaluated the dry mass of ears, shoots and roots, the total dry matter, nitrogen and potassium in grains, and the consumption and efficiency in water use. An analysis of variance and regression test at 5% probability was conducted using SAS statistical software (SAS Institute, Inc., Cary, North Carolina). The nitrogen and potassium alone increased the dry mass of ears by 31.47% and 20.91%, respectively. There was an interaction of nutrients on the dry mass of the shoots and the total dry matter. Potassium increases the concentration of nitrogen. Nitrogen and potassium promote gains in production, nutrition and water use efficiency. Trigo ( Triticum aestivum L.) es un cereal utilizado en la alimentacion humana y animal por sus propiedades nutritivas. En la gestion de nitrogeno y potasio, el uso eficiente del agua es necesaria para la mayor disponibilidad y el transporte de estos nutrientes. Este estudio tuvo como objetivo evaluar el efecto de las combinaciones de nitrogeno y potasio en la produccion, la nutricion y la eficiencia en el uso del agua en trigo. El experimento se realizo en un invernadero con recipientes de 8 dm3. Usando Oxisol, recogido a una profundidad de 0-0,2 m de area bajo la vegetacion del Cerrado. La saturacion de bases se aumento a 60%. El diseno experimental fue de bloques al azar en arreglo factorial 5x5 con cinco dosis de nitrogeno (0, 100, 200, 300 y 400 mg dm-3) y potasio (0, 90, 180, 270 y 360 mg dm-3) con cuatro repeticiones. La humedad del suelo se mantuvo con un sistema autoirrigante (mantenido en el potencial de -3 kPa). El experimento foe cosecho despues de 95 dias de la emergencia. Se evaluaron la materia seca de las espigas, brotes, raices, y materia seca vegetal total; nitrogeno y potasio en granos; el consumo y la eficiencia en el uso del agua. Las variables se sometieron a analisis de varianza y prueba de regresion al 5% de probabilidad por el programa estadistico SAS. El nitrogeno y potasio, por separado, aumentaron el peso seco de las espigas, con incrementos de 31,47 y 20,91%, respectivamente. Hubo interaccion de nutrientes a la masa seca de la parte aerea y total. El potasio aumenta la concentracion de nitrogeno. El nitrogeno y el potasio promueven ganancias en la produccion, la nutricion y la eficiencia en el uso del agua.

NITROGÊNIO E POTÁSSIO EM CÁRTAMO: ÍNDICE DE CLOROFILA, CARACTERÍSTICAS BIOMÉTRICAS E USO DA ÁGUA

Safflower crops is usually intended for production of seeds to oil extraction. The objective of this work was to evaluate the chlorophyll index, biometric characteristics and water use efficiency of safflower plants grown under different nitrogen and potassium rates and controlled soil water tension. The experiment was conducted in a greenhouse, in pots containing 8 dm of a Oxisol. A complete randomized block experimental design in a 5x5 factorial arrangement was used, with four replications, consisting of five nitrogen rates (0, 60, 120, 180 and 240 mg dm) and five potassium rates (0, 50, 100, 150 and 200 mg dm). The safflower number of leaves, stem diameter, chlorophyll index, number of capitula, shoot, root and total dry weights, water consumption and water use efficiency were evaluated. Data were subjected to analysis of variance (F test) at 5% of probability and to polynomial regression. The nitrogen and potassium fertilization, as independent factors, affected the safflower plants. The chlorophyll index, biometric characteristics and water use efficiency of safflower showed better responses under nitrogen rates of 82 to 168 mg dm. The responses of chlorophyll index, biometric characteristics and water use efficiency of safflower increased 10 to 60% with potassium fertilization.