ABSTRACT
The species Jatropha curcas is a rustic plant, adapted to several edaphoclimatic conditions, being constantly explored in marginal conditions, however, ensuring production will be greater with the use of irrigation and fertile soil, when it'll be necessary to research the possibility of its cultivation with saline water. Therefore the present study aims at assessing the effect of the electrical conductivity of irrigation water on the morphophysiological answers of seedlings from J. curcas L. The work was conducted in shade with 50% of solar radiation interception at the State University of Goiás. The experiment was set up following a completely randomized design with four treatments and five repetitions. Sowing occurred in four-liter containers containing soil, sand and manure in the ratio of 3: 1: 0.5 respectively. During the seedling stage (60 days), the plants were subjected to four treatments: plants irrigated daily with 150 ml of deionized water containing NaCl, and electrical conductivity of 0.0 dS m-1 (T1), 3 dS m-1 (T2), 6 dS m-1 (T3) and 9 dS m-1 (T4). The high concentration of salt reduced the free energy of the water, making it limiting. The water limitation caused a reduction in the leaf area and in the number of leaves, contributing to the reduction of perspiring area and the maintenance of tissue hydration. The high electrical conductivity of irrigation water reduced the seedling growth J. curcas, however, plants of J. curcas can be irrigated with saline water of conductivity less than or equal to 3 dS m-1 without significant damage to vegetative growth.
Subject(s)
Saline Waters , Jatropha/growth & development , Agricultural IrrigationABSTRACT
O objetivo deste trabalho foi avaliar os efeitos de diferentes fontes e doses de N no desenvolvimento e produtividade da cultura do milho doce (Zea mays convar. saccharata var. rugosa). O experimento foi desenvolvido na Fazenda São Domingos, localizada no município de Palmeiras de Goiás, GO, no ano agrícola de 2010/2011. O delineamento experimental utilizado foi o de blocos casualisados, com parcelas subdivididas, em três repetições, totalizando 36 tratamentos, tendo a área de cada subparcela 25,6 m2 (3,2 x 8 m). Cada fonte de N (Novatec® , Uréia e Sulfato de Amônio) correspondeu a uma parcela, sendo as subparcelas formadas pelas doses de N (0, 50, 100, 150 kg ha-1). Durante o período de florescimento da cultura, foram avaliados os seguintes componentes morfológicos: altura de inserção de espiga e diâmetro do colmo. A colheita foi realizada em 11/03/2011, entre os estádios de grão leitoso e pastoso, onde as espigas foram colhidas e identificadas por tratamento. Em seguida, foram analisadas as seguintes variáveis: diâmetro de espiga e de sabugo, número de fileiras de grão por espiga, numero de grão por fileiras, numero de grãos por espiga, comprimentos de espiga e de grão, população final de plantas por hectare, número de espigas por hectare e massa verde de espigas com palha por hectare. A cultura do milho doce cultivado nas condições edafoclimáticas do município de Palmeiras de Goiás, GO, responde positivamente ao aumento da adubação nitrogenada, independentemente da fonte de N utilizada.
This work aimed to assess the effects of different sources and dosages of nitrogen (N) in the development and productivity of sweet corn (Zea mays convar. saccharata var. rugosa). The experiment was carried out at São Domingo Farm, in Palmeiras de Goiás, state of Goiás, during the agricultural season of 201011. It was used the experimental design of random blocks with parcels subdivided in three replications, which required 36 treatments, the area of each parcel being of 25.6 square meters (3.2 m/8 m). Each N source (Novatec™, urea, ammonia sulfate) corresponded to a parcel. The sub-parcels were formed by the following N dosages: 0, 50, 100, and 150 kilos per hectare. During the flowerage period, the following morphological elements were assessed: plant and ear height and stalk diameter. The harvest took place in March 3, 2011, between the milk grain and dough grain stages. Ears were cropped and then identified through treatment. After that, the following variables were assessed: ear and cob diameter, number of grain per row, grain and ear length, plants final population per hectare, number of ears per hectare, and corn straw green mass per hectare. The growing of sweet corn in the soil and climate characteristics of Palmeiras de Goiás responded positively to the increase of nitrogen fertilizer no matter what the N source may be.