Infection by Neopestalotiopsis spp. occurs on unwounded eucalyptus leaves and is favoured by long periods of leaf wetness

Brazil is the leader in the global ranking of forest productivity; however, one of the major challenges to eucalyptus production is the existence of fungal diseases. A severe epidemic caused by pestalotiopsis-like fungi was observed in a forest nursery in Brazil, causing a huge impact on the eucalyptus micropropagation stages. The aims of the present study were to identify the causal agents associated with pestalotiopsis leaf spot and dieback in eucalyptus, assess their pathogenicity to different commercial clones, and evaluate which conditions favour conidial germination and infection by the pathogens. Multilocus phylogenetic analyses using ITS, TEF and TUB identified the isolates as members of Neopestalotiopsis and segregated them into three species. Isolates from all Neopestalotiopsis spp. caused symptoms on unwounded eucalyptus leaves and disease development was strongly dependent on long leaf wetness periods (≥72 h). All four commercial clones tested were susceptible to the pathogen. These results clearly dispute the commonly held assumption that pestalotioid fungi are weak and opportunistic pathogens. This is the first report of different phylogenetic species of Neopestalotiopsis causing dieback, leaf and stem lesions in eucalyptus cuttings and provides a basis for developing novel disease management strategies in forest nurseries.     

Short-term toxicity of insecticides residues to key predators and parasitoids for pest management in cotton

The cotton ecosystem comprises various arthropod pest and natural enemies with simultaneous occurrence irrespective of growing region. The use of insecticides with reduced impact on natural enemies is a major goal to conserve them and, therefore, to reduce populations of arthropod pests. The survival of twelve key natural enemies for cotton pest management exposed to dried residues using the highest and lowest recommended rates representing old and new insecticides recommended to control cotton pests (chlorantraniliprole, chlofernapyr, spinosad, lambda-cyhalotrin, methidathion, pymetrozine, and thiamethoxam) was determined. The study included parasitoids [Aphelinus gossypii Timberlake, Bracon vulgaris Ashmead, Lysiphlebus testaceipes (Cresson), Telenomus podisi (Ashmead), Trichogramma pretiosum (Riley)] and predators [Hippodamia convergens Guérin-Méneville, Euborellia annulipes (Lucas), Podisus nigrispinus (Dallas), Solenopsis invicta Buren), Orius insidiosus (Say), Chrysoperla externa Hagen and Eriopis connexa (Germar)], with two different cohorts for these last two species. All natural enemies exposed to methidathion exhibited 100% mortality. Thiamethoxam, lambda-cyhalothrin and chlorfenapyr also caused high mortality of P. nigrispinus, S. invicta, H. convergens, O. insidiosus and all tested parasitoids. Among the natural enemies, E. annulipes exhibited high survival when exposed to all tested insecticides, except methidathion. Chlorantraniliprole and pymetrozine caused overall lower impact on the natural enemies tested followed by spinosad; hence, they are options for cotton pest management. Furthermore, the outcomes highlight the implication of knowing the background susceptibility of the species tested when addressing the impact of insecticides on natural enemies.     

Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) genetic resources: a case of high iron and zinc

Cassava hybrids from interspecific crosses with Manihot caerulescens Pohl, M. pseudoglaziovii Pax and Hoffmann and M. dichotoma Ule showed a very high iron and zinc content in both roots and leaves, e.g. 98.15 mg kg⁻¹ in roots of the interspecific hybrid cassava-M. caerulescens versus 12.17 mg kg⁻¹ in a cassava cultivar. This promising results show the potential of wild Manihot species for micronutrient enhancement of cassava.     

An Experimental Study of the Diesel Biodegradation Effects on Soil Biogeophysical Parameters

The purpose of this study was to understand the dynamic conditions of soil/organic mixtures in order to contribute to the study of remediation processes at hydrocarbon spill sites. Induced polarization (IP) and physical, chemical, and microbiological parameters for uncontaminated and artificially contaminated soil samples with diesel oil were evaluated under controlled conditions (constant temperature and soil moisture) during a period of 12 months. In contaminated samples, the resistivity and IP parameters (chargeability and polarizability) decreased during 8 months and remained relatively stable between 8 and 12 months. The observed reduction on resistivity and IP parameters was related to the increase on the granular aggregation of the soil and a decrease on total porosity, caused by diesel-degrading microorganisms. The behavior of the IP parameters observed after 8 months can be explained by a reduction in the microbial activity and, consequently, a decrease of the degradation rate of diesel. In the studied loamy soil with high content of organic matter (96.16 g/kg), the results demonstrate that IP time domain measurements can be used in the evaluation of the evolution of the hydrocarbon degradation even when the concentration is not very high.     

Assessment of serological tests for the diagnosis of canine visceral leishmaniasis

An immunoenzymatic assay (ELISA), an indirect immunofluorescence antibody test (IFAT) with different antigens (ELISA-Leishmania chagasi, ELISA-L. major-like, IFAT-L. chagasi and IFAT-L. major-like), and an immunochromatographic test were assessed for the diagnosis of canine visceral leishmaniasis (CVL). Serum samples from 144 dogs from an endemic area for visceral leishmaniasis in the municipality of Rio de Janeiro were tested. The sensitivities of the serological tests were 93%, 100%, 73%, 60% and 93%, with specificities of 87%, 92%, 77%, 96% and 92% for the ELISA-L. major-like, ELISA-L. chagasi, IFAT-L. major-like, IFAT-L. chagasi and the immuno chromatographic test, respectively. ELISA-L. chagasi was the best test for the diagnosis of CVL, but the immunochromatographic test could be a useful alternative as it offers simple and rapid diagnosis without the need for a specialized laboratory.     

Correlation of testicular artery Doppler velocimetry with kinetics and morphologic characteristics of epididymal sperm in dogs

Sperm quality can be affected by a reduction in testicular blood flow, which can be measured by Doppler ultrasonography. The aim of this study was to correlate the Doppler velocimetry of the testicular artery with kinetics of the epididymal spermatozoa in dogs. Twenty-two dogs (44 testicles) were evaluated by Doppler ultrasonography in five regions of the testicular artery before orchiectomy. Spermatozoa were recovered by the epididymal tail compression technique and analysed for kinetics on a computer-assisted semen analysis (CASA system). Morphology (modified Karras) and sperm membrane integrity were analysed by eosin–nigrosine staining. Data were analysed by Pearson's correlation test (p < .01). The mean total motility was 69.0% ± 17.7, progressive motility was 43.7% ± 14.7, average path velocity (VAP) was 127.0 µm/s ± 20.7, curvilinear velocity (VCL) was 221.0 µm/s ± 31.1, and sperm velocity index (SVI) was 389.9 ± 56.1. There were positive correlations between the peak systolic velocity (PSV) in the proximal supratesticular region with the SVI (r = .529), VCL (r = .555) and VAP (r = .473), and a negative correlation with the percentage of slow spermatozoa (r = −.463). The results suggest that the testicular artery blood flow velocity can positively affect the speed of spermatozoa movement. For the first time, we have correlated sperm kinetics with the Doppler evaluation of the testicular artery in dogs.     

Ovarian responses of dairy buffalo cows to timed artificial insemination protocol,using new or used progesterone devices,during the breeding season (autumn–winter)

This study evaluated the effect of new or used P4 devices on the ovarian responses of dairy buffalo that were administered an estradiol (E2) plus progesterone (P4)‐based timed artificial insemination (TAI) protocol during the breeding season. On the first day of the TAI protocol, 142 cows were randomly assigned to receive one of the following: a new device (New; 1.0 g of P4; n = 48); a device that had previously been used for 9 days (Used1x, n = 47); or a device that had previously been used for 18 days (Used2x, n = 47). Ultrasound was used to evaluate the following: the presence of a corpus luteum (CL); the diameter of the dominant follicle (ØDF) during protocol; ovulatory response; and pregnancies per AI (P/AI). Despite similar responses among the treatments, there was a significant positive association of the ØDF during TAI protocol with ovulatory responses and number of pregnancies. In conclusion, satisfactory ovarian responses and a satisfactory pregnancy rate were achieved when grazing dairy buffalo were subjected to the TAI protocol in breeding season, independent of whether a new or used P4 device was used. Furthermore, the presence of the larger follicle was associated with a higher ovulation rate and higher P/AI following TAI.     

Phosphorus requirements for 60- to 100-kg pigs selected for high lean deposition under different thermal environments

Two experiments were conducted to determine the requirement of available P (aP) of pigs selected for high lean deposition during summer (maximum and minimum temperatures of 29.8 ± 3.6 and 21.3 ± 1.1°C, respectively; Exp. 1) and winter (maximum and minimum temperatures of 24.7 ± 2.1 and 9.1 ± 1.6°C, respectively; Exp. 2). Pigs (66.5 ± 2.8 kg, Exp. 1; and 61.1 ± 0.6 kg, Exp. 2) were randomly allotted to 5 dietary treatments. Exp. 1 had 5 pens/treatment and Exp. 2 had 6 pens/treatment, and all pens had 2 pigs. Treatments were composed of a corn-soybean meal basal diet and 4 diets with additional dicalcium phosphate to obtain 5 aP concentrations (0.122, 0.187, 0.252, 0.317, and 0.382% in Exp. 1, and 0.135, 0.200, 0.265, 0.330, and 0.395% in Exp. 2). Pigs were allowed ad libitum access to their respective diets for 30 d. In Exp. 1, increasing aP improved ADFI and ADG (quadratic, P < 0.05), with maximum responses obtained at 0.226 and 0.256% of aP, respectively. Increasing aP improved (P < 0.05) G:F. A broken-line analysis indicated that G:F was maximized (P < 0.05) at 0.295% of aP or 9.04 g of aP/d. Increasing aP also increased (quadratic, P < 0.05) P and Ca (g/kg) in the metacarpals with maximum responses obtained at 0.314 and 0.272% of aP, respectively. The percentage of ash in the metacarpals continued to increase (linear, P < 0.05) with increasing aP. In Exp. 2, ADG and G:F improved (linear and quadratic, P < 0.05) as aP increased in the diet. A broken-line analysis indicated that G:F was maximized (P < 0.05) at 0.316% of aP or 10.58 g of aP per day. However, increasing aP had no effect on ADFI. Percentages of ash, P, and Ca in the metacarpals increased (linear, P < 0.05) with increasing aP. In conclusion, results of this experiment indicated that finishing pigs (60 to 100 kg) kept in a thermoneutral environment require 0.316% aP in the diet (10.58 g/d) to maximize G:F, but the requirement is only 0.295% aP (9.04 g/d) when pigs are under heat stress.