Manoel Mota dos Santos

Eficiência no uso de fósforo de variedades de arroz cultivadas em solos de várzea irrigada

Efficiency in the use of phosphorus by rice varieties grown in lowland soils Rice stands out as one of the most important crops in the world, because of its easy adaptability to distinct edaphoclimatic conditions. Rice is cultivated and consumed worldwide and stands out by the large production and cultivation area, playing strategic economic and social roles. In Brasil, the largest rice productions are obtained in lowland ecosystems. This work aimed to study the efficiency in phosphorus use by rice varieties in lowland areas in the southwest of Tocantins State. The treatments involved eight rice commercial varieties (BRS-Jacana, Best2000, BRS-Guara, BRS-Alvorada, BRA-01381, AN-Cambara, BRS 7-TAIM and EPAGRI-109), which were farmed in two distinct environments. In order to simulate environments with low and high phosphorus levels, P 2 O 5 was used at the levels of 20 and 120 kg ha -1 respectively. The experiments were carried out in a randomized complete blocks design, with four replications. Grain yield was used to classify the varieties regarding the efficiency in use and response to phosphorus application. Was shown that only the variety BRS-Alvorada was efficient in using phosphorus and responsive to its application.

Intercropping of Cowpea with Eucalyptus in Northern Brazil

Intercropping consist in growing two or more species with different vegetative cycles and architectures, simultaneously cultivated in same field and same period of time, not necessarily having been sown at the same time. The objective of this study was to evaluate different populations of cowpea development intercropped with Eucalyptus, in order to determine the number of rows of cowpea generates higher grain productivity. This work was carried out at Universidade Federal do Tocantins, in Gurupi, Tocantins, Brazil. The treatments were arranged for different densities of cowpea rows: eight rows, six rows, and four rows of cultivars BRS Nova Era and BRS Sempre Verde, also a control in conventional cropping. The cowpea sowing occurred after 12 months eucalyptus planting. The evaluated characteristics were Flowering (FLOW), Mass of 100 grain (GM), Number of grains per green pod (NGP), Chlorophyll Index (CI) and Grain yield (GY). The density of eight rows have obtained better results for most characteristics, being the density limiting factor for bean production could unfeasible the intercropping system. The BRS Nova Era responds better on most characteristics, probably for a better adaptation to the environment and hold superior characters than BRS Sempre Verde.