O sistema minirhizotron no estudo da dinâmica de raízes.

ABSTRACT: Root dynamic is an important component of agricultural e natural ecosystems. The minirhizotrons system is a multicomponent assembly used to study root dynamics in a nondestructive manner. Basically, transparent tubes are installed in the soil and the root intersections along the tube are recorded and measured with appropriated software's. In this review, the minirhizotron method was discussed based in the international literature. The potential, applications and limitations of this tool, and future uses in the Cerrado region was also discussed.bitstream/CPAC-2009/28920/1/doc_203.pd

Sintomas visuais de deficiências nutricionais em pinhão-manso Visual symptoms of nutrient deficiency in physic nut

O objetivo deste trabalho foi avaliar o crescimento e caracterizar os sintomas de deficiências de macro e micronutrientes em mudas de pinhão-manso (Jatropha curcas). As mudas foram cultivadas em solução nutritiva completa e, também, em soluções com omissão de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn ou Zn, pelo uso da técnica do elemento faltante. Foram avaliados os sintomas visuais de deficiência de nutrientes e a massa de matéria seca da parte aérea e das raízes, respectivamente aos 90 e 120 dias após a aplicação dos tratamentos. As omissões de macro e micronutrientes provocaram sintomas visuais de deficiência nutricional comuns a outras espécies. As deficiências limitaram a produção de massa de matéria seca na seguinte ordem: Ca>Mg>K>N>P>S, para macronutrientes; e Fe>Cu>Zn>Mn>B, para micronutrientes.<br>The objectives of this work were to evaluate the growth of physic nut (Jatropha curcas) and to characterize visual symptoms of macro and micronutrient deficiencies in seedlings. The seedlings were cultivated in nutritive solution containing all required macro and micronutrients and in solutions with omission of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn or Zn, using the missing element technique. Visual deficiency symptoms and seedlings dry weight were evaluated at 90 and 120 days after treatments, respectively. The absences of macro and micronutrients in physic nut caused in nutritional deficiency visual symptoms known to other species. The deficiencies restricted the dry matter production according to the following order: Ca>Mg>K>N>P>S, for macronutrients, and Fe>Cu>Zn>Mn>B, for micronutrients