Three experiments were conducted in the agricultural year of 2007, aiming to estimate the genetic divergence, using the Mahalanobis' generalized distance, and the test of competition of six populations of corn in the municipalities of Arapiraca, Rio Largo and Viçosa, of Alagoas State. The experimental was in the randomized blocks design with seven treatments and four repetitions. There was the formation of two different groups where, it was conclued that is small genetic divergence between the populations of corn. A group was formed by six populations and the other group by the "Asa Branca" variety. The people "Viçosense" and "Rio Largo" were closer genetically (D2 = 1.70), while the longest distance has been detected among the population Alagoano and witness Asa Branca (D2 = 67.27). The average yield of grains ranged from 2,885 kg ha-1 to 3.461 kg ha-1 in the "São Luiz" and "Viçosense" populations, respectively, with overall average of 3,207 kg ha-1, although not statistically differ.

The aim of this study was to evaluate the growth and spatial distributions of Croton urucurana (sangra-d`água) in Dourados-MS. They had been marked, using systematic systematic sampling, 15 plots of 100 m2 in which had been identified all individuals of Croton urucurana that they had been to classified phase of development in young, youthful and adult. To classify the species in the spatial patterns the Payandeh index was used. It was verified 943 individuals with aggregate spatial distribution in the area in study. C. urucurana is in regeneration process with has predominance of young and youthful individuals, 54.1% and 28.4%, respectively, in relation to the adult individuals (17.5%).

Because of the damages caused by Dalbulus maidis (Delong & Wolcott, 1923) on crop corn, had been evaluated the effect of insecticides applied on the desiccation management (MD), seed treatment (TS) and foliage spray (PF) to the 10 days after the emergency (DAE), on D. maidis. The assays had been developed in Fundação Chapadão in Chapadão of Sul (MS) city, from 29/10/04 to 27/02/05, with experimental design of randomized blocks, with ten treatments and four replicates. The used treatments had been: monocrotophós and cypermethrin (MD), thiodicarb + imidacloprid, thiametoxan, clothianidim, imidacloprid and acetamiprid (TS), cypermethrin + thiametoxan and endossulfan + NaCl (PF), in the recommended dosages, and one control without insecticide. It was carried counting of the number of D. maidis, calculating the insecticides efficiency to 14, 20, 28 and 40 DAE. For D. maidis, the use of the insecticides in TS and PF had been efficient in the 14 DAE, being imidacloprid (TS) and cypermethrin + thiametoxan (PF) had presented, respectively, 72 and 61% of efficiency to the 40 DAE, demonstrating residual effect.

The research had the objective to determinate the ideal substrate for the germination of pitaya seeds in laboratorial conditions. The experiment was carried out in the Unesp - São Paulo State University - Campus of Jaboticabal - Brazil, using seeds that were extracted of a ripe fruit and testing the substrates: filter paper; vermiculite; sand; commercial substrate with pinus (Plantmax); coconut fiber (Amafibra); soil, sand and manure in the proportion of 3:1:1, being that the filter paper provided the largest values to percentage of germination among them, showing be the more appropriate.

The research was carried out to evaluate the quality of waters used in the irrigation of agricultural areas of Congo region, Paraíba State, Brazil. The water samples were collected in Cordeiro dam, in wells and in river, in two periods of the year, rainy (May/2006) and dry period (December/2006) and analyzed under the qualitative aspects of salinity, sodicity and toxicity of ions. For the studied conditions and in agreement with the evaluated parameters in both periods, most of the samples of water, as for the salinity, were considered normal for the use in the irrigation since special practical of soil and water management are adopted; as the toxicity of the ion sodium, more than 40% didn't present restriction to the use. In relation to the toxicity of the ion chloride, in the rainy period, 61% of the samples didn't indicate restriction to the use for irrigation and in the dry period, 44% presented restriction varying from low to moderate.

This research was conducted to evaluate the physiological and sanity quality of melon (Cucumis melo L.) seeds used in agricultural region Assu-Baraúna-Mosssó in the Rio Grande do Norte. For seed lots each from the hybrids Goldex and Vereda were used. Research was conducted at the Seed Analysis Laboratory and Irrigation Agricultural of the Department of Crop Science of the UFERSA from August 2006 to July 2007. The physiological quality was evaluated by the germination, first count germination, accelerated aging, emergence speed index, electrical conductivity and seedling emergence, beyond the seed moisture content. The sanity was determinated by the method of filter paper with freezer, in four replications with 100 seeds per lot and completly randomized design. From the results obtained, it was concluded that first count germination, accelerated aging, electrical conductivity and seedling emergence tests only identified low and high seed lot from the hybrids Goldex and Vereda. The electrical conductivity test is most indicated to estimation of melon seed physiological potential, it was also possible to reduce the imbibition period of seeds prior this test. The pathogens associated with melon seeds were Aspergillus spp., Fusarium sp. and Macrophomina sp. and the physiological quality of seeds was not affected with the microrganisms presence.

The effect of the plant resistance inducer acibenzolar-S-methyl on in vitro mycelial growth and sporulation of Curvularia eragrostides was evaluated, as well as the time and dosage of its application for the pathosystem yam x C. eragrostides. Five concentrations: 250; 125; 62.50; 31.25 and 15.12 ppm were evaluated for mycelial growth and sporulation of C. eragrostides. The ASM was sprayed onto the leaves of yam plants, at a concentration of 10 g, 20 g, and 30 g of the active ingredient (i.a.) per 100 liters of water, at time intervals of 10, 15, and 30 days before pathogen inoculation. Mycelial growth and sporulation of C. eragrostides was not affect by ASM, at the concentrations of 62.5; 31.25, and 15.12 ppm. Application of ASM was most effective at the dose of 15 g a.i./100 l of water, at 15 days before pathogen inoculation, providing protection against C. eragrostides, with a decrease of up to 76.15 % in yam leaf spot severity.

With the objective of increasing the percentile of rooted cuttings and the quality of the newly formed root system through the treatment of cuttings with AIB and sucrose, the present study took place. The experiment was conducted in an intermittent mist chamber located in the experimental orchard at UFLA, in Lavras, MG. The herbaceous cuttings of cv. Paluma were collected in the orchard of UFLA in March of 1999. The prepared cuttings with 2 nodes and 1 pair of leaves reduced to half were treated with AIB in immersion for 24 hours at concentrations of 0, 100, 200 and 300 mg.L-1, 2% sucrose being added or not. After the treatment the cuttings were planted in polyethylene sacks with sand as a substrate. The layout used was it entirely casual with 4 repetitions and 15 cuttings per plot. From the evaluations it was concluded that: a) the concentration of 300 mg.L-1 of AIB provided the best result for the percentage of rooted cuttings as well as for the number and average weight of the dry root matter. b) The presence sucrose didn't present a significant effect on the characteristics analyzed. c) The simple permanence of the leaves on the cuttings didn't influence their rooting. d) In those cuttings treated with 300 mg.L-1 of AIB, it was not necessary for the leaves to persist for 60 days.

The present work had as objective verifies different methods for evaluation of the physiologic potential of gherkin seeds. Two lots of seeds aged were used artificially, in water, being obtained for each lot, six quality levels. The seeds aged artificially to the temperature of 41ºC by 0, 8, 16, 24, 32 and 45 hours and high relative humidity were submitted to the germination tests, first count of the germination and vigor. The first germination count, accelerated aging (41ºC/48h) and seedling emergence was efficient in evaluating physiological quality of gherkin seeds.

The present research if developed in an area of 7 ha that it was divided in seven equal sub-parcels and it had as objective to evaluate the effect of itinerant agriculture by means of drill and forest fire of the lenhosa vegetation, with subsequente plantation of maize and beans, for up to two years followed of rest for up to five years on the edafic fauna. In the period of rest these areas had been used as area of maintenance of ten sheep matrices. To the side of these systems an established secondary bush has 50 years was used as control. Had been installed traps type "Pitfal" for the collects of the fauna of the soil in the period of abundant rain and the dry period. The forest fires carried through in the treatments cultivated with maize and beans, had contributed for a drastic reduction in the diversity of the soil fauna. The group's formicidae and coleopters had been gifts more abundantly in all the handling systems what it exactly shows its presences in caatinga in adverse conditions. The period of collects of the fauna of soil influenced in the evaluated biological attributes.