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Belém, Brazil

Agronomic performance of sorghum, millets, maize, black oats, wheat, barley, brachiaria grass, forage turnip, grain amaranth, quinoa, kenaf, sesame, sunflower, wild sunflower, pigeon pea and Crotalaria spectabilis was evaluated in sowings after summer cropping and winter, under irrigation in the Brazilian Savannah high lands. The study aimed at biomass production with impacts on soil protection and management, and source of forage, added value grains and raw material. Experiments in complete randomized blocks were conducted at three locations, with previously selected genotypes. Evaluations were based on the following parameters: plant cycle (number of days between emergence and maturity), plant height, biomass production and grain yield. Some species showed more yield stability, such as Brachiaria brizantha, sorghum, pearl millet and kenaf, and the difference for the two locations may be related to soil fertility. Plant growth and biomass production showed no effect of photoperiod, except for sesame. Grain yield indicates the potential for added value in less exploited crops for the Brazilian agriculture, such as quinoa and grain amaranth. Source

Cardoso A.D.,State University of Southwest Bahia | Alvarenga M.A.R.,Federal University of Lavras | Melo T.L.,Engenheiro Agronomo | Viana A.E.S.,State University of Southwest Bahia | Matsumoto S.N.,State University of Southwest Bahia
Revista Ciencia Agronomica

With the purpose of assessing the leaf greenness of potato under application times and doses of nitrogen and potassium, this experiment was carried out in the municipality of Mucugê-BA.Three doses of N and K were used (75% of the recommended dose; the recommended dose according to soil analysis; 125% of the recommended dose). Five application times (100% upon planting; 1/3 upon planting and 2/3 upon tuberization; 50% upon planting and 50% upon tuberization; 1/3 upon planting, 1/3 upon tuberization and 1/3 25 days after tuberization; 1/4 upon planting, 1/4 upon tuberization, 1/4 25 days after tuberization and 1/4 50 days after tuberization were utilized. The experimental design was factorial (5 x 3), with plots arranged in randomized blocks with four replications. Tubercles from Ágata, Monalisa and Vivaldi cultivars, uniformly budded, were planted with spacing of 0.8 x 0.3m on a prepared soil as recommended for the culture. Was measured, throughout the cycle, the leaf greenness of potato, 30, 55 and 80 days after planting, using the indirect chlorophyll meter SPAD. The doses of N and K did not influence SPAD index, in potato cultivars over the cycle. The SPAD index can be used as a tool to indicate the most correct time for tubercule potato harvest. Source

Schanoski R.,Engenheiro Agronomo | Righi E.Z.,Federal University of Santa Maria | Werner V.,Federal University of Santa Maria
Revista Brasileira de Engenharia Agricola e Ambiental

The goal of this work was to evaluate the losses on the cutting platform, the separation and cleaning systems and total losses in mechanical harvesting of soybeans in the municipality of Maripá-PR considering the age of the combines, displacement speed and operator training. 39 machines in 25 farms were evaluated. It was observed that 79% of the machines lost more than 60 kg ha-1. The air humidity, the untrained operators and deficient maintenance and regulations were the most important factors in defining the losses. The machines with longer timer of use presented tendency of more losses in the harvest. Source

Pereira F.B.,Engenheiro Agronomo | DoVale J.C.,Federal University of Tocantins | Carneiro P.C.S.,Federal University of Vicosa | Fritsche-Neto R.,Federal University of Vicosa
Revista Ceres

The genetic improvement of N (EUN) and P (EUP) use efficiency is a less expensive and more sustainable way to obtain satisfactory grain yields. However, the lack of knowledge about the relationship among the determinant characters of nutrient use efficiency has made the use of early and indirect selection difficult. Therefore, the objective of this study was to identify the relationship among the determinant characters of nitrogen and phosphorus use efficiency in maize. In this study, 14 lines and 39 single-cross hybrids were tested in two experiments with low and high N and P availability, in a completely randomized simple factorial design with two replications. The experiments were conducted in a shade house. Were used PVC cylindrical tubes with 4 dm3 capacity filled with two types of substrate, according to the experiment. The nutrient solutions were provided from the seventh day after transplanting, applying 250 ml tube- 1 every two days. Plants were harvested at the stage of six fully expanded leaves (V6) to evaluate the traits: shoot dry mass, specific root area, lateral and axial root length and the two components of EUN and EUP, i.e., the utilization (EUt) and uptake efficiency (EAb). According to the analyses of variance and path analysis of the collected data, EUN and EUP were not significantly influenced by the root traits. The main determinant character of EUN and EUP is shoot dry mass, regardless of the nutrient availability. Source

Rezende F.C.,Federal University of Lavras | Arantes K.R.,Engenheiro Agricola | Oliveira S.R.,Engenheiro Agronomo | de Faria M.A.,Federal University of Lavras
Coffee Science

An experiment was carried out in Lavras/MG aiming to evaluate the effects of different irrigation periods on total yield, volumetric yield, and bean ripening uniformity from coffee (Coffea arabica L.) (Cv. Topazio, MG1190) that was submitted to a severe pruning 65 months after planting. The orchard was implanted in 1.8 x 0.7m spacing and was drip irrigated. A complete randomized experimental design with six treatments and four replications was implemented. Treatments corresponded to six different irrigation periods. Applied irrigation depth was equivalent to 100% of the balance including the evaporation depth from a class "A" pan and the precipitation depth measured during the time interval between two successive irrigations (ECA-P). Fertilization with nitrogen and potassium was split in 4 applications under canopy throughout the period from October to March. Data from the 2002/2003 2003/ 2004 harvest, were analyzed. Results indicated that accumulated productivity tends to be larger under the treatments receiving irrigation from April to July but retard coffee bean maturation. Irrigation increases the volumetric yield. Coffee quality (bean size and defects) from the first harvest was better than second harvest. Source

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