Sufficiency ranges and crop nutrient removals for peppermint (Mentha X piperita L.) established from field and pot fertilizer experiments

Peppermint is an important aromatic and medicinal plant used across the world in pharmaceutical, cosmetic and food industries. However, there is a lack of agronomic research on this crop which hinders the implementation of best agricultural practice at farm level. Plant analysis, for instance, cannot be used as a tool to implement a suitable fertilizer recommendation program, since sufficiency ranges and crop nutrient removals have not yet been established. Thus, the main objectives of the present work were to assess the response of peppermint to varying nitrogen (N), phosphorus (P), potassium (K) and boron (B) rates, to establish sufficiency ranges from macro, micronutrients and SPAD-readings and to estimate crop nutrient removals in the aboveground biomass. Field trials and pot experiments were conducted from 2013 to 2015 in a wide range of conditions involving 12 N, P, K or B fertilizer trials and a total of 48 cuts of biomass. Nitrogen fertilization increased dry matter yield of peppermint on the vast majority of sampling dates. In contrast, P, K, or B did not produce a significant effect on dry matter yield in any of the experiments. The sufficiency ranges set for macronutrients N, P, K, Ca and Mg are respectively 32.0 – 42.0, 1.2 – 4.5, 10.0 – 30.0, 7.0 – 23.0, and 4.0 – 10.0 g kg^?1. Those for micronutrients B, copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn) are respectively 20 – 200, 5 – 25, 100 – 600, 25 – 300, and 30 – 200 mg kg^?1. Sufficiency range for SPAD-readings is 45 – 50 SPAD units. All these ranges were established for the commercial harvesting date. The amounts of N, P, K, calcium (Ca), and magnesium (Mg) removed in aboveground biomass are respectively 22.7, 1.6, 26.4, 16.4 and 4.8 kg Mg^?1 of dry biomass.     

Influence of Sugarcane Straw on Aminocyclopyrachlor Leaching in a Green-Cane Harvesting System

The straw on the soil in the green cane harvesting system acts as a physical barrier to the action of the pre-emergence herbicides. However, some herbicides have physico-chemical characteristics to pass through the straw in water solution. The aim was to evaluate the influence of different densities of sugarcane straw on the leaching of aminocyclopyrachlor in a tropical soil (Oxisol—Typic Hapludox) in a system of green cane harvesting. The experiment was carried out using glass columns filled with soil, with and without sugarcane straw (0, 5, 10, and 20 t ha^?1) on the top of the soil. ¹⁴C-aminocyclopyrachlor was applied followed by 200 mm of simulated rain for 48 h. The herbicide was detected in all soil layers (0–30 cm), and in the leachate (>?30 cm), in small trace amounts (≤?0.21%) in all treatments, showing that aminocyclopyrachlor undergoes a high degree of leaching in the clayey soil. In the absence of straw, 39% of the herbicide remained in the upper layer (0–5 cm). In the presence of straw, the herbicide was distributed through the soil profile, mainly from 0 to 25 cm. Forty percent more herbicide was retained in the straw with 20 t ha^?1 of sugarcane straw. Thus, it is concluded that the straw in high amounts retains aminocyclopyrachlor, but does not prevent it from reaching the soil; the high solubility of the herbicide and intense rainfall in a short period of time are factors that contribute to the herbicide passing through this barrier.     

Physiological responses of Eucalyptus spp. hybrids to infection by Ceratocystis fimbriata

In Brazil, the selection and planting of eucalyptus clones resistant to Ceratocystis fimbriata is the pre‐eminent control strategy for the wilt pathogen. However, little is known about host defence responses associated with resistance of eucalyptus to C. fimbriata infection. In this work, enzymatic activity, sugars, lignin, total phenols and phenolic compounds involved in the defence response of eucalyptus clones resistant (RC) and susceptible (SC) to the Ceratocystis wilt were evaluated. Changes were detected in the sugars produced by RC clones, with higher concentrations occurring compared with SC. A similar response occurred with lignin content at 28 days after inoculation (dai) in RC plants. SC plants had an increase in polyphenol oxidase and peroxidase activities at 7 dai. In contrast, RC plants demonstrated high activity of the same enzymes at 2 and 4 dai, decreasing afterwards. There was no difference in phenylalanine ammonia‐lyase activity between resistant and susceptible clones. Hydroxycinnamic acid concentration was higher in RC than in SC; however, there was no difference between RC and SC in flavonoid concentrations. RC had high concentrations catechin, chlorogenic acid and caffeic acid. Histochemical tests demonstrated the presence of phenolic compounds and lignin, at higher intensities, in xylem of RC plants. Inoculation with C. fimbriata induced defence responses in both resistant and susceptible eucalyptus clones, but both the intensity and speed of the responses were higher in RC. Alterations in the concentrations of sugars and lignin, as well as certain enzymes and phenolic compounds, could be used to predict the relative susceptibilities to Ceratocystis wilt of different phenotypes of eucalyptus clones.     

Effects of nitrogen fertilization on development,flowering, and mineral nutrition of potted Costus productus Gleason ex Maas

Due to the lack of information on mineral nutrition of ornamental plants, especially tropical species, we aimed to evaluate the effects of nitrogen fertilization on development, flowering, and mineral nutrition of potted Costus productus. Plants were cultivated along 1 year under protection in Ubatuba, São Paulo State, Brazil, and submitted to five treatments that corresponded to increasing nitrogen doses (0.0, 1.2, 2.4, 3.6, and 4.8 g N plant^?1). Evaluated plant variables were potted development, height, dry matter of aerial part, number of inflorescences, and nutritional status. Analysis of variance and linear and polynomial regressions were performed for definition of the best adjustments according to the combination of significance and greater determination coefficient. The nitrogen fertilization positively influenced development, flowering, and mineral nutrition of potted C. productus plants, and the dose of 4.8 g N plant^?1 promoted best results     

Helminthiasis characterization and anthelmintic efficacy for ewes and lambs raised in tropical semiarid region

In this study the helminthiasis and anthelmintic effectiveness in ewes and lambs were evaluated in a semiarid region of Brazil. Twelve sheep farms were investigated using semi-structured questionnaires and fecal egg count (FEC) reduction test was employed to analyze the profile of anthelmintic resistance. Groups of at least 10 animals with FEC ≥ 300 were selected. After 12 h of fasting, homogeneous groups of lambs or ewes were treated with albendazole, levamisole moxidectin, or oxfendazole and control groups were not treated. Feces were collected before treatments and 14 days after, and larvae genera were identified after cuprocultures in both periods. Extensive grazing was the predominant creation system, using hybrid Santa Ines animals. The separation by age was promoted in 75% of herds; however, maternity pickets there were only in three farms. The strategic treatments were performed only in 8.4% of sheep farms and 16.6% used the anthelmintic efficacy test and alternated anthelmintic classes after 1 year. The initial FEC means for lambs were significantly higher than ewe FEC averages. For lamb tests, moxidectin and levamisole showed higher efficacy (p ≤ 0.05) than benzimidazoles. For ewe tests, moxidectin and levamisole showed efficiencies >75%. Haemonchus spp. and Trichostrongylus spp. were the most frequent nematodes before treatments and the genus Haemonchus was the most prevalent after anthelmintic treatments (p < 0.05). Variations of anthelmintic susceptibility were observed for categories and herds evaluated, which emphasizes the importance of the effectiveness tests for the choice of anthelmintics for ewes and lambs.     

Roughage levels impact on performance and carcass traits of finishing Nellore cattle fed whole corn grain diets

This study was carried out to evaluate the effects of chopped hay levels in high-concentrate diets with whole corn grain (WCG) on performance and carcass traits of finishing Nellore cattle. One hundred and eight 24-month-old Nellore intact males (453 ± 75 kg) were fed one of three WCG-based diets that differed in roughage level: without roughage (WCG), with 5% chopped hay included (WCG5), or with 12% chopped hay included (WCG12) in a block design (based on initial body weight) for 86 days. Animals fed WCG5 or WCG12 had significantly improved on final body weight, dry matter intake, average daily gain, feed efficiency, hot carcass weight, and dressing percentage when compared to those fed WCG. The Longissimus muscle area (P = 0.1108), backfat thickness (BFT; P = 0.6089), and rump fat thickness (P = 0.1798) were not affected by roughage levels. Therefore, using WCG diets without roughage negatively affects the performance of feedlot Nellore cattle but does not affect carcass traits and does lead to the minimum BFT required by the industry.     

Acibenzolar-S-methyl doses and application methods to Pratylenchus brachyurus control in maize

Pratylenchus brachyurus is one of the main limiting factors of agricultural yield in annual crops, particularly due its difficult management. Methods to reduce populations are constantly sought, and the use of resistance inducers deserves attention. Thus, the study aimed to assess the effect of acibenzolar-S-methyl (ASM) application in different doses to P. brachyurus control in maize. Initially, 1000 specimens of P. brachyurus were inoculated in maize for the multiplication. After 60 days, the aerial part (AP) was discarded and maize was sown under the treatments: seed treatment (ST), application in the AP and ST?+?AP, in the doses of 0.125, 0.25, 0.5 and 1.0?g i.a./L. Vegetative and nematological parameters were assessed 60 days later. ASM did not affect plant growth, but reduced nematode population in all the treatments. The treatment methods did not differ and reduced the number of nematodes/g root by 64.25 to 80.14% compared to the control. The doses of 0.6, 0.51 and 0.65?g i.a./L promoted the most reductions in the number of nematodes/g root when applied in ST, AP and ST?+?AP, respectively. Thus, we recommend the use of ASM applied on shoot in a dose of 0.50?g i.a./L.     

Larvicidal effects of a chitin-binding vicilin from Erythrina velutina seeds on the mediterranean fruit fly Ceratitis capitata

Chitin-binding vicilin from Erythrina velutina seeds was purified by ammonium sulfate followed by affinity chromatography on a chitin column and gel filtration on Superose-6-10-300-GL. The Erythrina velutina vicilin, called EvV, is a tetrameric glycoprotein composed of 1.85% carbohydrates and M r of 216.6 kDa, consisting of two subunits of M r of 54.8 and two subunits of M r of 50.8 kDa. The EvV homogeneity was confirmed in native PAGE where it was observed to be a unique acid-protein band with slow mobility in this gel. Effect of EvV on C. capitata larvae was examined by bioassay and its mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV when added to diet caused strong effect on mortality (ED50 of 0.14%) and larval mass (WD50 of 0.12%). These deleterious effects were associated to the binding to chitin structures present in peritrophic membrane and to gut epithelial cells, and its low digestibility in C. capitata digestive tract. These results are the first demonstration of a proteinaceous bioinsecticide from plant origin effective against C. capitata larvae. EvV may be part of the pest management programs or an alternative in plant improvement program.     

Degradation of the herbicide sulfentrazone in a Brazilian Typic Hapludox soil

The herbicide sulfentrazone is classified as highly mobile and persistent and this study aimed to examine degradation of this compound on a Typic Hapludox soil that is representative of regions where sulfentrazone is used in Brazil. Soil samples were supplemented with sulfentrazone (0.7 μg active ingredient (a.i.) g^?1 soil), and maintained at 27 °C. Soil moisture was corrected to 30%, 70%, or 100% water-holding capacity (WHC) and maintained constant until the end of the experimental period. Soils without added herbicide were used as controls. Aliquots were taken after 14, 30, 60, 120, 180, and 255 days of incubation for quantitative analysis of sulfentrazone residues by gas chromatography. Another experiment was conducted in soil samples, with and without the herbicide, at different temperatures (15, 30, and 40 °C), with moisture kept constant at 70% of WHC. The sulfentrazone residues were quantified by gas chromatography after 14, 30, 60, and 120 days of incubation. Sulfentrazone degradation was not affected by soil moisture. A significant effect was observed for the temperature factor after 120 days on herbicide degradation, which was higher at 30 °C. A half-life of 146.5 days was recorded. It was observed that the herbicide stimulated growth of actinomycetes, whereas bacterial and fungal growth was not affected. The microorganisms selected as potential sulfentrazone degraders were Rhizobium radiobacter, Ralstonia pickettii, Methylobacterium radiotolerans, Cladosporium sp., Eupenicillium sp., and Paecilomyces sp.     

Industrial Pollution of Environmental Compartments in the Sinos River Valley, RS, Brazil: Geochemical–Biogeochemical Characterization and Remote Sensing

Two environmental relief compartments from Sinos Valley, Rio Grande do Sul State, Brazil, interpreted in the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images, are contaminated, in different ways, by two industrial landfills. One of the landfills is located in a fluvial plain with thin superficial sediments made of expansive clays. In this landfill, metals like Cr, Co, Ni, Cu, Pb, Zn, and Ba, have concentrated more than that of other landfill, which is located on a low hill in a sedimentary arenitic terrain. The metals have also accumulated in plant tissues in the investigated areas. Plants have accumulated more Mn, Zn, Ba, and Cu.