Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Corn (Zea mayz L.) seeds of twelve lots of different acquisition years were used to study the relation among the measurements of electrical conductivity (EC) and pH of the soaking water and the germination in laboratory, under normal conditions (NC) and accelerated aging (AA) of seeds. A randomized complete block design was used with four replications, an analysis of variance was applied and differences among seed lots were detected by Least Significant Difference Test. Seed lots showed high percentage of germination at eight days of evaluation in (NC) and the unfavorable effect of AA was demonstrated. Dry shoot and radicle weights showed significant differences among the lots. Values of EC were related to percentage of germination in laboratory under AA. Seed lots that showed high percentage of germination in laboratory, previous AA, presented low values of electrical conductivity, therefore, this test could be good indicative of the behavior of corn seeds under extreme or unfavorable conditions of germination. The test of pH did not show direct relation with the seed emergency in laboratory. 

Este trabalho foi desenvolvido com o objetivo de avaliar a qualidade física e sanitária de sementes de milho em duas colhedoras operando em velocidades distintas e em amostras coletadas em diferentes locais na máquina. Utilizou-se um esquema fatorial 2x2x2, delineamento inteiramente casualizado com quatro repetições. Os tratamentos foram constituídos por duas colhedoras (New Holland TC 57 e New Holland TC 59), operando em duas velocidades (4 km h-1 e 5 km h-1) e dois locais de coleta das amostras (entrada do tanque graneleiro e saída do tubo de descarga). Para todos os tratamentos avaliou-se: pureza, porcentagem de sementes quebradas, danificadas e a presença de fungos associados às sementes. Houve interação significativa entre os fatores, apenas na obtenção das médias de sementes puras. Constatou-se, principalmente, a presença de Fusarium sp., Cladosporium sp., Aspergillus spp. e Penicillium sp. Menores perdas foram observadas quando se utilizou a colhedora TC 57 à velocidade de 4 km h-1. Não houve diferença entre velocidades para perdas qualitativas de sementes colhidas pela colhedora TC 59. Sementes colhidas pelas duas colhedoras e nas duas velocidades testadas apresentaram diferenças quanto à presença de fungos, mostrando maior incidência nas sementes coletadas na saída do tubo de descarga. 

This study evaluates the genotoxic injury in the species Colossoma macropomum (“Gamitana") when exposed to the pesticide Fipronil, for which we used the micronucleus test (MN). We workwed with juveniles in the third stage, placed in glass tanks, which were exposed to 3 different concentrations of fipronil (C1: 0.075 mg /L, C2: 0.15 mg /L and C3: 0.30 mg /L), evaluated at 24 and 48 h. Peripheral blood was used which made the spread. The counting of micronuclei and abnormalities was made on the basis of 1000 cells. The average rate of micronuclei indicates that 0.075 mg / L the average frequency is twice the control. With regard to abnormalities of the core, was found more frequently at 48 h of exposure.

The establishing of roses in hydroponic systems implies development propagation techniques that are efficient, economical and that produce homogeneous populations in a short time. In this work, were evaluated the effects of different substrates (peat, agrolite and vermiculite, a 1:1 v/v mixture of peat and vermiculite and two 1:1 v/v and 1:3 v/v mixture of gravel and coconut fiber); two levels of light (548 y 274 μmol.m-2.s-1) and leaf persistence on cutting (0, 5, 10, 15, 20 y 25 days after establishment) on rooting, root and axial bud developments of commercial variety of rose. The vermiculite had the best results, showed the highest number of cuttings alive and rooting percentage (60%). The light levels, leaf persistence as the interaction, were also significant. The highest rooting percentage, longer roots and better axial bud development was found with 548 μmol.m-2.s-1. Regarding leaf persistence on cutting was found that less than 10 days, the cuttings become necrotic and eventually died. There was also an inverse effect on root and bud development when the leaf persists more days, the root length was increased but axial bud decreased. In conclusion, for enhanced cuttings rooting success of rose, is required use vermiculite as substrate, with good light and leaf persists on cutting at least 15 days.

The aim was to study the progress of the yellow spot, brown spot and leaf rust in wheat cultivar FUNDACEP 50 in Passo Fundo. Was evaluated the incidence of yellow spot [Drechslera tritici-repentis (Died) Drechs.] brown spot [Bipolaris sorokiniana (Sacc.)] and leaf rust [Puccinia triticina (Eriks)]. Values obtained were integralized as Area Under the Disease Incidence Progress Curve (AUDIPC) and to analyze the progress of the disease was considered the disease progress rate (r), which was obtained with the Logistic and Gompertz. Determination coefficients were high (0.93 to 0.98), as well as the mean square error (4.0706 to 7.6831). The r were 0.02 to 0.22 units, while the accumulated AUDIPC 787.5, 1216.3 and 1338.8 units for yellow spot, brown spot and leaf rust, respectively. The two models used satisfactorily explain the progress of yellow spot and brown spot, while the Gompertz explains better leaf rust.

The objective of the present work was to determine the vitamin content C in different parts from the fruit; pulp, rind and pulp more rind, in four states of maturation: green, mature green, mature and over mature. The fruits were obtained from the Collection of Germoplasma of the Agrarian Experimental Station San Roque of the INIA Loreto, Peru. The technique used for the determination of vitamin content C was Liquid High Chromatography Performance (HPLC) with phase column reverse. The results indicate that the greater vitamin contents C are in the rind and the states of over mature and mature. And vitamin C contained according to maturation states adjusts to a curve of cubical regression, as much for pulp, rind and pulp more rind with 87%, 90% and 98 % of effectiveness; respectively. When moving from a state of maturity to another, the vitamin C content is increased in 515.43 mg in each 100 g of rind sample. The obtained results indicate that camu camu is a potential vitamin C source, located mainly in the rind of the fruit.

The work was developed in the plot Y1 of Institute of Amazonian Research Peruana-IIAP Ucayali, located between latitudes 8 º 22 '31''south latitude and 74 º 34' 35'' west longitude and altitude of 154 m. It has a soil with low fertility Ultisols (organic matter 1.4%, phosphorus 0.4ppm, potassium 25ppm, pH 4.58, high aluminum content of 6 meq/100 g and CIC of 6.72 meq/100 g of soil). The objective was to determine the phenology and fruit yield candid plant of camu camu of 7 years of age from a mixture of seeds, using 5 treatments by the technique of fertigation through a drip irrigation system (RG). We used a randomized complete block design (RCBD) with 3 replications of 5 treatments and 15 experimental units with 15 floors each, the treatments were T0 [Without irrigation and fertilization], T1 [Drip irrigation without fertilization], T2 [60-40-80/NPK more RG], T3 [120-80-160/NPK more RG], T4 [240-160-320/NPK more RG]. To standardize the material is made of fructification pruning and defoliation manual. We evaluated the reproductive phenology, flower buds No. of No. of small fruits, fruit No. of harvest, fruit weight in g and t.ha-1 performance. It was possible to standardize the phenological stages of outbreaks of issuance until the harvest ending the production cycle in 205 days. The results show no statistically significant differences, it was finally determined that the T2 was 4.8 t.ha-1 doubling the T0 which makes it more cost effective than other treatments. 

The aim of this study was identified by amplification of microsatellite alleles of the Major Histocompatibility Complex BoLA Class II associated with resistance and susceptibility to Boophilus microplus in cattle, Junín, Peru. We collected blood sample of 47 cattle, as well as specimens of B. microplus during the months of march, april and may 2009 in the morning, the right side of each animal. Genomic DNA extraction was performed by the method of Phil Summers (1995) and amplification of microsatellites DRB3.2, DRB31 and BM1815 was by PCR in an automatic sequencer. Data were evaluated using the program POPG 32. We identified alleles A, B and C related to resistance and susceptibility to B. microplus in cattle both in the BoLA locus BoLA DRB3.2 as BM1815. Allele frequencies were estimated: the DRB3.2 locus allele frequency was 0.2742, allele B was 0.5000 and the C allele was 0.2258, in the DRB31 locus allele frequency was 1.0000 and at the BM1815 locus allele frequency was 0.3295, allele B was 0.5909y the C allele was 0.0795. We conclude that the alleles A, B and C loci BM1815 DRB3.2 and Major Histocompatibility Complex Class II BoLA are associated with resistance to B. microplus in cattle and DRB31 locus allele is associated with susceptibility.

One of the important reasons for the decay of the production of artichoke is for the disease known with the name of oidium or oidiosis or ash, " Leveillula taurica ", which provokes powdery formations in the back of the leaves, and then they invade the bundle.; inducing to a loss of mass to foliate, death of the plant and reduction in performance. With the purpose of being able to offset the effect of infection and advance of the mushroom it raise the work of investigation which was to determine the suitable dose of the sulphur for the control of oidiosis (Leveillula taurica) in the culture of artichoke Cynara scolymus L var. imperial. The experiment was carried out in Victor Larco District, Trujillo, La Libertad; soil of texture clayey, a system of irrigation being used by gravity which frequency of irrigation is fortnightly for the conduction of the culture. There was used a Design of Complete Blocks at random, with four treatments and a witness, and with four repetitions. There was realized an analysis of variance and Duncan's test by a level of significant of 5 %. The results showed that the applied treatments of sulphur reduce and control the advance of the mushroom, being the best the T2, with dose 1 kg/cil. It concludes that these treatments are adapted to there be applied in the culture of artichoke for the control of oidium (Leveillula taurica).

This study aimed to identify and quantify the causal agents of fungal leaf blights, and compare different assessment methods for disease quantification. The experiments were conducted with 20 medium cycle cultivars in Passo Fundo, Saint Augustus and Vacaria counties with three replications in randomized blocks. For evaluation 20 leaves were collected per plot, at flowering stage. Disease severity was estimated by the percent diseased leaf area and lesions number per leaf. For fungus etiology, twenty five discs of each leaf sample containing a lesion were subjected to a humid chamber. After three days incubation fungi identification was performed under a dissecting microscope. The mean incidence, number of lesions and severity data were subjected to analysis of variance and means compared by the Tukey’s multiple test at 5% significance level. The severity and lesions number were the most efficient criteria to fungal foliar disease, predominantly Bipolaris sorokiniana, Drechslera siccans, D. tritici-repentis and Stagonospora nodorum. The cultivars with the highest incidence rates were not the same as that presented the greatest number of injuries and severity. Join the appearance D. siccans and the resurgence of S. nodorum.