Secondary metabolite produced in some plants can provoke alterations in the development of other plants or even other organisms. The aim of this paper was to identify possible allelopathic effects and biologic control of Achatina fulica Bowdich with aqueous extracts of Morus rubra L. leaves. For obtaining the aqueous extract, we used previously dried leaves in concentration of 1g 10 mL-1. Five concentrations of each aqueous extract were tested (10, 30, 50, 70 and 100%) and compared to control (0.0%), distilled water. The aqueous extracts of Morus rubra showed up allelopathic potentialities on the seed germination and in the growth of the shoot and the root system of the tested species, considering that the reduction in the germination and initial growth increased with the rising of the aqueous extracts concentrations used and, in the biologic control, only in the final mass of A. fulica. The results indicated the existence of allelopathic effect, but not molluscicide of M. rubra.

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 theExperimental Farm of the State University of Montes Claros - Unimontes, with design of randomized blocks ina split plot scheme. The treatments were two water regimes (irrigated and non-irrigated) and three sugarcanevarieties (RB 72-454, SP 79-1011 e SP 80-1842) randomly distributed in four blocks. The phytotechnical andproduction variables analyzed were plant height, stalk diameter and shoot biomass yield, and the agroindustrialvariables 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 paper aimed to evaluate the allelopathic potential of Jurema (Mimosa tenuiflora (Willd.) Poir.) on seed germination and seedling growth of lettuce. The study consisted of two experiments, each arranged in a completely randomized design with five treatments and four replications of 20 seeds: 1) stem bark extract of M. tenuiflora obtained in hot water (100 °C) and at concentrations of 0%, 25%, 50%, 75% and 100% of standard extract, 2) stem bark extract of M. tenuiflora obtained in cold water and the same concentrations. The extract was obtained by standard 50 g of bark in 500 mL of distilled water. We evaluated the germination percentage (G), germination speed index (GSI), percentage of normal seedlings (NP) and abnormal (PA), shoot length (CPA) and root (CR) in lettuce seedlings. All extracts were analyzed for pH and conductivity. The germination of lettuce was high (> 97%) and no significant difference between means of G and IVG in different concentrations of the extract pattern. No allelopathic activity of M. tenuiflora on the germination of lettuceseeds. The hot extract cause greater percentage of abnormal seedlings in lettuce. The aqueous extracts of bark of M. tenuiflora have phytotoxic effects on seedling growth of lettuce, and in higher concentrations drastically affect the length of the root and shoot.

Given the pressure on biodiversity, due to its use in an unsustainable way, particularly in the Caatinga biome, and the need to restore the popular knowledge, is that this paper was developed in order to conduct a survey of medicinal plants used by the community of Laços, Tanhaçú, in the state of Bahia. And identify, among these, those species that are found in the National Forest Contendas Sincorá, the city of Contention Sincorá, Bahia. The data collecting was done through interviews, having as a tool the use of questionnaires. The vegetal species mentioned by the community and found in the Conservation Unit were collected and sent for identification. The community were cited 92 species of plants used for medicinal purposes, of which only 10.9% were found in the conservation area and, among them, the species Bidens pilosa, known as ¿carrapicho de agulha¿, was the most cited (52.4%), followed by Amburana cearensis (27.7%), popularly known as ¿umburana macho¿. The paper showed that target community of the study uses many medicinal plants to treat their illnesses, however, few species were found in the National Forest Contendas do Sincorá.

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.

The aim of this paper was to evaluate the persistence of herbicides in weed management in pre and post emergence soybean and evaluate its effects on corn grown in succession. In field experiments we adopted the randomized block design with four replications, being appointed nine treatments (doses in kg ha-1): imazaquin (0.161 kg ha-1), diclosulam (0.035 kg ha-1), sulfentrazone (0.600 kg ha-1) and flumioxazin (0.050 kg ha-1) in pre emergence applications, and chlorimuron-ethyl (0.015 kg ha-1), imazethapyr (0.060 kg ha-1), imazethapyr (0.100 kg ha-1) and fomesafen (0.250 kg ha-1) applied post emergence soybean and a control without herbicide. Variables of phytotoxicity, plant height, dry matter accumulation of shoot and grain yield were evaluated. The results showed that imazethapyr (0.1 kg ha-1) and diclosulam (0.035 kg ha-1) caused a reduction in corn yield of 15.02% and 70.65% respectively. The residual activity was not sufficient to cause negative effect on grain yield for corn cultivar 30K75Y in the Cerrado region.

This paper aimed to verify the presence of black-fly of citrus in the state of Pernambuco in Brazil and wordwide. The material with symptoms were collected in the metropolitan area of Recife/PE and subsequently led to the identification in the Insect Biology Laboratory of the Federal Rural University of Pernambuco - UFRPE on February 4, 2011. The samples collected from the branches of citrus and bilocular, found the presence of eggs, nymphs, "pupae" and adults of Aleurocanthus woglumi, confirming its occurrence in the state of Pernambuco. The presence of blackfly of citrus had been detected in the city in the state of Pernambuco as Timbaúba, Bom Jardim, Macaparana, Axes, Orobo, São Vincent Farrer and Itambé in citrus plants. Before that had a suspect in the Valley Siriji/PE, now it is in the metropolitan area of Recife, therefore we can confirm that the material collected and identified in the metropolitan area of Pernambuco is A. woglumi.

The aim of this paper was to evaluate biochemical activities related to promotion of plant growth of isolates of the genus Bacillus originated from areas under maize cultivation, and to evaluate the genetic similarity among the isolates using PCR-based RAPD markers. Several strains of the genera Bacillus were isolated from twenty distinct maize production areas of the State of São Paulo, Brazil. Forty isolates were obtained and characterized as antagonistic to plant pathogenic fungi, production of auxin (IAA), phosphate solubilization in vitro and root colonization. The potential for phosphate solubilization was not identified in any of the isolates. In addition, the majority of the isolates did not show any antagonistic effect against Fusarium oxysporum and Colletotrichum truncatum. Based on root colonization, six Bacillus isolates were selected to evaluate their growth-promotion activities in maize. All the six isolates increased root growth, while only one isolate did not promoted shoot growth and nutrient uptake in plants when compared to control. Low genetic similarity among the selected isolates was detected by RAPD analysis using eleven primers. Our results showed the utility of the in vitro selection criteria used in this study for screening of Bacillus sp. with plant growth-promoting activity, as they may reduce the number of Bacillus isolates required at the final screening stage in field.

The paper aimed to examine the equity investment in shrimp production, a typical farm of the western region of Rio Grande do Norte, using the following criteria for project selection: Net present value (NPV), Internal Rate of Return (IRR), payback and Cost/benefit analysis (C/B). In a complementary manner it has evaluated the likelihood of change in Net Present Value and Internal Rate of Return, through the risk analysis. In the risk analysis input variables (inputs) were considered: the price paid to producers per Kg of shrimp and price of Kg of ration HD-35%, which represents 36.42% of the total cost per production cycle. The selected variables or (outputs) were the Net Present Value at 12% and 6%, and the Internal Rate of Return. The results of investment analysis, without considering price risk were: R$ 214,943.93 NPV 12% NPV 300,819.13 6%, 60% IRR, payback of two years and 1,4 Interface B/C. The survey results indicate that shrimp farming represents for the rural sector of Rio Grande do Norte, a leading alternative investment, considering that the average IRR, considering the risks of price, was 35.21%, ie any other investment would only be desirable, in comparison with investment in shrimp production, if present rate of return higher than 35.21%.