The development of soybean cultivars adapted to different regions and generation technologies contribute to Brazil to increase its production, placing it as the second largest world producer and exporter of grain. Several factors have limited its production among these diseases, approximately 40 already identified in Brazil, especially powdery mildew (Erysiphe diffusa U. Braun & S. Takami), one of the most important, resulting in reductions of up to 40% in income susceptible cultivars. The study aimed to evaluate the severity of powdery mildew on soybean genotypes during seven seasons of evaluation, by analyzing disease progress, using regression. It was developed at the Federal University of Viçosa, Minas Gerais arranged in split plots inrandomized block design seven evaluations were performed by visual quantification of the level of infection of leaf area infected (NIAFI). Regression analysis was performed to check the progress of thedisease. The results showed that the method is efficient for such studies, showing clearly the evolution of the disease, and aiding in the discrimination of resistant and susceptible genotypes at the third assessment. Stood out as sources of resistance genotypes UFV-16, UFV-19, UFV 89-361826T2, FT-Abyara RC5 (F4), FT-RC6 Abyara (F2), FT-10 RC5 (F3), Doko RC, UFV UFV 95-4121333 and UFV 94-334268. FT-104 and FT-Crystalina stood out as susceptible and BR-16 and FT-Estrela as highly susceptible, while the other showed intermediate behavior.

The correct management of an irrigation system depends on reliable estimate of reference evapotranspiration (ETo). This paper aimed to evaluate the performance of some empirical equations used to estimate ETo under the climatic conditions of the municipalities of Anagé, Piatã and Ilhéus, located in the Southwest of Bahia State, Brazil. Climatic variables were used for the years 2006 and 2007 obtained through the automatic data collection platform of the Superintendence of Bahia Water Resources / National Institute for Space Research, in which he averaged variables for the two years. To compare the ETo values estimated by methodos of Penman Modificado FAO 24, Radiação, Blaney-Criddlle, Hargreves-Samani, Priestley-Taylor and Turc with the standard method Penman-Monteith (FAO 56) was performed by parameters of regression equation (b), determination coefficient (r²), correlation coefficient (r) estimated standard error (EEP), agreement index (d), index of confidence or performance (c) in daily, three, five and seven days scales. The best methods to estimate ETo for the climatic conditions of the three sites, depending on the indices and parameters studied were by the order: Blaney-Criddle, Penman Modified - FAO 24, FAO 24 Radiation, Turc, Priestly- Taylor and Hargreaves-Samani.

The Northeast, including Maranhão, there are great poles of development for the maize crop, due to a good potential for growth of agribusiness and marketing of agricultural production. In order to analyze the productivity of maize in this region and compare the average performance between different genetic classes, we analyzed different types of hybrids and open pollinated varieties. They were evaluated in two essays. The first, with 42 cultivars, 23 simple hybrids, 11 hybrids and 8 triple double hybrids. The second, with 40 cultivars, 12 simple hybrids, hybrid 7 doubles, 7 triples and 14 hybrid varieties of open pollinated. The design was a randomized complete block with two replications. Each plot consisted of two useful rows spaced 5.0 m at 0.90 m. The tests were grouped and the average productivity of the different gene classes was compared by t test and confidence intervals. On average, single-cross hybrids were superior to other types of cultivars. There was no difference between double and triple hybrids, but the two types of cultivars were higher than the group of open-pollinated variety. This result demonstrates the importance of the commercial exploitation of heterosis in maize. However, it is not possible to generalize on the recommendation of cultivars, because despite the obvious differences regarding the average yield on a small scale some simple and triple hybrids produced less than a few doubles and even hybrid varieties.

High yields in intercropped only be attained with the adequate selection of an adequate plants arrangement system; therefore the aim of this project was to investigate which plat arrangement would better perform in a common beans/castor bean intercropping system. The experimental design was a completely randomized bloc with five replicates and four simultaneous sowings: beans sown on the castor beans row; beans sown between castor beans rows; beans sown on the row and between castor beans rows, and common beans and castor beans in monocrop. Results obtained from castor beans crop yields were not affected when intercropped with common beans. This intercropping system with castor showed that common beans cv. Pérola on the row and between rows provided higher yield of the legume. In general, the intercropping of common beans+castor beans is more efficient than the single crop system.

Seed treatment with insecticides is a routine practice that helps control initial field pests. However there is little information on the effects of insecticides on physiological quality of soybean seeds. Thus, this paper was to evaluate the effect of seed treatment with insecticides on the germination and vigor of soybean seeds. The design was completely randomized consisting of 7 treatments with 4 repetitions. The seeds of the cv. M-soy-6101 were treated with the insecticide thiamethoxam on the rate of 0.15 kg of a.i./100 kg of seeds, fipronil in the rate of 0.37 kg of a.i./100 kg of seeds, imidacloprido in the rate of 0,10 kg of a.i./100 kg of seeds; [thiodicarb + imidacloprid] at a rates of 0.14 + 0.13 kg of a.i./ha-1, carbofuran of rate 0.52 kg of a.i./100 kg of seeds, acephate at a rate of 0.75 kg of i.a./100 kg of seeds and a control without treatment. The variables analyzed were: germination, emergence speed, root length and seedling and percentage of normal seedlings in the accelerated aging. In the greenhouse (pot of 6 dm-3 of soil) were obtained levels of phytotoxicity, height and dry mass of shoots. Treatment with insecticides thiamethoxam, fipronil and imidacloprid provides adequate quality of the seeds and do not negatively affect the early development of plants. Insecticides [imidacloprid + thiodicarb], acephate and carbofuran affect the germination and vigor of soybean seeds.

The actual paper was carried out aiming to evaluate the effects of nitrogen, phosphorus and potassium on the growth and seeds production of castor bean (Ricinus communis L.), cultivar BRS Nordestina and BRS Paraguaçu. For each cultivar an experiment was conducted in a greenhouse, in Campina Grande, PB. Each experiment was conducted on a 2 x 2 x 2 factorial design completely randomized resulting 24 experimental units, subjected to the following levels of fertilization: nitrogen (200 and 300 kg ha-1), phosphorus (150 and 250 kg ha-1) and potassium (150 and 250 kg ha-1). Plant height, stem diameter, number of leaves and leaf area were measured at 20, 40, 60, 80, 100, 120, 140 and 160 days after planting. At the end of the experiment the weight of seeds was measured. Nitrogen was the nutrient that promoted the highest growth and yield for both cultivars; the phosphorus and potassium application did not influence the stem diameter, leaf area and the yield of castor bean; the highest plant height was obtained with the treatment N1P1K1 (200-150-150 kg ha-1).

The goal of this paper was to verify the influence of two water regimes on the phytotechnical, production, and agroindustrial indicators in three varieties of sugarcane. The experiment was conducted at the Experimental Farm of the State University of Montes Claros - Unimontes, with design of randomized blocks in a split plot scheme. The treatments were two water regimes (irrigated and non-irrigated) and three sugarcane varieties (RB 72-454, SP 79-1011 e SP 80-1842) randomly distributed in four blocks. The phytotechnical and production variables analyzed were plant height, stalk diameter and shoot biomass yield, and the agroindustrial variables were soluble solid and fiber content. Data were subjected to analysis of variance with application of Ftest and the means were compared among themselves by Tukey test. At conditions which the experiment was realized, the plant height, the shoot biomass yield, the soluble solids and fiber content were efficient indicators for the selection of sugarcane varieties to tolerance to water deficit. Among the indicators studied, only the stalk diameter did not respond to soil water availability. Among the varieties, only SP 79-1011 showed indifferent to water availability on the shoot biomass yield.

The absence of fissure between palea and lemma of the husk rice grain, is an important character to avoid infestation by insect plague on storage. In the current paper 14 genotypes of upland rice were evaluated in three places of Pernambuco state; Palmares, Vitória de Santo Antão and Carpina counties. It was used randomized complete block design with four replications and the evaluations were made using 250 grains from each plot. The statistical analyses were made by software Genes and the average was compared by Tukey test with 5% of probability. The genotype x environment interaction was significant for the three places and the genotype BRSMG curinga was one of the most resistant and the PB 5 was one of most susceptive and, the difference on loss potential between both genotypes varies from 24.10 to 44.75% on tree places. Therefore there was variability among genotypes for resistance furthermore there was high difference on the loss potential in case infestation by insect plague during grain storage.

Aiming to evaluate gas exchange and concentration of macro and micronutrients in leaves of physic nut grown under saline conditions, an experiment was conducted in protected ambient adopting a randomized block design in factorial scheme combining five levels of irrigation water salinity ECw (0.6; 1.2; 1.8; 2.4 and 3.0 dS m-1) and two levels of phosphorus (135 and 200 g plant-1) and with four replications. Each plant was grown in pots with a capacity of 200 L. The gas exchange rates (leaf temperature, transpiration, stomatal conductance and photosynthesis) were obtained using a portable photosynthesis meter (IRGA), in the fourth expanded leaf from the apex of the plant. To determine the nutrient content of the plant, the limbo located between the fourth and fifth leaf below the inflorescence was used. The determination of nutrients followed the methodology described by Silva (1999). It was found that the salinity level of irrigation water affected the variables of gas exchange and accumulation of the minerals which has following sequence: K > N > Ca > Cl > Na > Mg > P > S > Fe > Mn > Zn > Cu. With the exception of copper all evaluated nutrients and increased with increasing salinity of irrigation water. The lowest dose of P2O5 used was sufficient to allow the development of the plant during the experimental period, there was no effect of its increase in photosynthetic parameters evaluated.

In the Northeastern part of Brazil, the mosaics caused by viruses, emerge as the most important diseases for the cowpea, thus becoming a limiting factor of production. Genetic resistance has been considered as the best alternative of controlling Cowpea severe mosaic virus. Thus, the aim was to evaluate the F3 population behavior developed for the resistance against different isolated CPSMV collected from different areas of cultivation. Leaf samples presenting cowpea mosaic symptoms were collected from plantations from the states of Pernambuco and Paraiba. There was inoculation on susceptible cultivars of cowpea kept in house vegetation. The isolates were also diagnosed by reactions RT-PCR using specific primers. Of the 185 F3 plants inoculated 183 plants were resistant to different isolates of CPSMV.