Effectiveness of deltamethrin for protecting olives from attack by the beetle Phloeotribus scarabaeoides (Scolytidae)

Deltamethrin, a pyrethroid insecticide, was tested in both the laboratory and the field, with the aim of controlling the olive bark beetle, Phloeotribus scarabaeoides (Bernard), in living olive trees. In the laboratory, bark beetle adults were exposed to olive twigs treated with different concentrations of deltamethrin. Among these concentrations, dosage at 0.05% produced 100% mortality in the scolytids after 13 weeks. This dosage of deltamethrin, applied in the field, protected olive trees from scolytid attack during the whole emergence period.     

Effects of domestication on structural polysaccharides and dietary fiber in nopalitos (Opuntia spp.)

Domestication is an evolutionary process that modifies morphological, physiological, chemical and genetic features of wild plants, and is a product of artificial selection. A gradient of domestication can be appreciated in species of the Opuntia genus. There are wild species like O. streptacantha, others semi-domesticated like O. hyptiacantha O. megacantha and O. albicarpa, or other like O. ficus-indica with the highest degree of domestication. At the same time, some structural polysaccharides have been associated with plant drought and freeze resistance. This study aimed at quantify five groups of structural polysaccharides in 14 variants of nopalitos (edible young cladodes of flat-stemmed spiny cacti consumed as vegetables) of Opuntia spp. in a domestication gradient. Given that extreme environment is less frequent under cultivation than in the wild, we hypothesized that structural polysaccharides in nopalitos are reduced throughout the domestication process. The experiment was conducted as a completely randomized design with a 5?×?14 two-factor factorial treatment structure, with four replications. Mucilages, pectins, hemicelluloses and cellulose were extracted and dietary fiber content was calculated. ANOVA of data was performed, pair wise comparisons of species and variants were conducted by Tukey test and principal components analysis was carried out. Mucilages were higher in O. ficus-indica (12% of total dry mass) and pectins, loosely and tightly bound hemicelluloses in O. streptacantha (2.5, 9 and 3%, respectively). All five species had similar content of cellulose (5.1% dry mass); but, O. streptacantha presented more dietary fiber. Higher pectins and both loosely and tightly bound hemicelluloses content in wild species can be related to genotype and the persistence of reaction to a wild environment. Mucilages which are one of the main characteristics of consumer preference and loosely bound hemicelluloses could have impact for selection during Opuntia domestication.     

Pressurized liquid extraction and HPLC quantification of folic Acid in fortified wheat flours

A pressurized liquid extraction (PLE) method using phosphate buffer as solvent was applied for folic acid (FA) extraction from fortified wheat flours and was compared to a standard solid-liquid extraction (SLE) method. Extracted FA was quantified by reverse phase high-performance liquid chromatography (RP-HPLC) hyphenated with a phenyl column and an absorption photometric detector (λ = 280 nm). Detection and quantification limits were 0.12 and 0.4 ng, respectively, corresponding to 0.06 and 0.2 μg g(-1) of analyzed wheat flour. Equivalent FA contents were found by both extraction methods, but a single PLE allowed a total recovery of FA content, whereas at least three successive SLEs were needed to achieve a total recovery of FA. The obtained results indicated that PLE is a rapid and efficient technique for FA extraction from fortified wheat flour.     

Characterization of Swine Wastewater by Toxicity Identification Evaluation Methodology (TIE)

Since swine wastewater is used by farmers for soil fertilization, evaluation of toxic compounds or micro-contaminants of separate streams is required. This paper uses the toxicity identification evaluation (TIE) procedure for the physicochemical and ecotoxicological characterization of swine wastewater. To distinguish the most important toxic compounds, a physicochemical characterization and phase I-TIE procedure were performed. The acute toxic effect of swine wastewater and treated fractions (phase II-TIE) were evaluated using Daphnia magna determining 48-h LC₅₀. Results show a high level of conductivity (23.5 μS cm⁻¹), which is explained as due to the concentration of ions, such as ammonium (NH₄⁺–N 1.6 g L⁻¹), sulfate (SO₄²⁻ 397.3 mg L⁻¹), and chlorine (Cl⁻ 1,230.0 mg L⁻¹). The acute toxicity of the swine wastewater was evaluated on D. magna (48-h LC₅₀ = 3.4%). Results of the different water treatments indicate that anionic exchange treatments could reduce 22.5% of swine wastewater’s acute toxicity by reducing chlorine (to around 51%) and conductivity (8.5%). On the other hand, cationic exchange treatment increased acute toxicity on D. magna (% RT = −624.4%), by reducing NH₄⁺–N (around 100%) and total nitrogen (95.5%). This finding suggests that part of the toxicity comes from anionic compounds, such as chlorine.     

New phenolic compounds hydrothermally extracted from the olive oil byproduct alperujo and their antioxidative activities

The application of a novel process based on the hydrothermal treatment of olive oil waste (alperujo) led to a final liquid phase that contained a high concentration of simple phenolic compounds. This study evaluated the effects of time (15-90 min) on the composition of the phenolic compounds isolated at a fixed temperature of 160 °C. Phenolic compounds were extracted with ethyl acetate. Both qualitative and quantitative HPLC analyses of the extracts showed variation of the concentrations of phenolic compounds with time. In addition, new phenols that were not present in the untreated control have been characterized. The antioxidant activities of different phenolic extracts was measured by various assays conducted in vitro: antiradical capacity (using DPPH and ABTS radicals), ferric reducing power (P(R)), inhibition of primary and secondary oxidation in lipid systems, and other tests, such as inhibition of tyrosinase activity. The results show that the phenolic extracts inhibited oxidation in aqueous and lipid systems to a significantly greater extent than the untreated control, and they performed as well as or better than vitamin E in this capacity.     

Nitrogen‐use efficiency of young citrus trees as influenced by the timing of fertilizer application

The aim of this study was to improve the fertilizer‐nitrogen‐use efficiency (NUE) for a sustainable citrus production where yield, fruit quality, and environment are reconciled. A soil pot experiment was conducted using 5‐year‐old orange trees (Citrus sinensis cv. Navel Lane Late) to determine the response of NUE to timing of N‐fertilizer supply. An equal N rate (50 g tree^–1) following two seasonal supply distributions was tested: (1) ENS (early supply from March to June of 75% of the N rate, with the remaining 25% administered between July and October) and (2) LNS (late supply of the bulk of the N rate with 25% between March and June and 75% between July and October). Labeled fertilizer (5 atom% ¹⁵N excess) was applied in order to accurately quantify N uptake, its partitioning among plant–soil compartments and NUE at the end of fruit drop and at fruit maturity. LNS resulted in a significant increase in NUE in both stages (up to 19% at the end of fruit drop and 9% at fruit maturity), while also increasing summer/autumn flush development. ENS showed lower fruit abscission, an enhanced final fruit load (up to 45%), and a more profuse development of spring flush. It is worth mentioning that LNS led to higher ¹⁵N content in the majority of the tree storage organs available for next spring growth resumption. The amount of ¹⁵N remaining in the soil of ENS trees at the end of the trial, which represented 16% of the supplied ¹⁵N, was 1.5‐fold higher than that of LNS trees as a result of the lower NUE of the former. Irrespective of the seasonal distribution of the fertilizer, mean ¹⁵N recovery in the soil–plant system at the end of the trial was about 71%. The results clearly confirm that the N seasonal distribution curve affects NUE in young citrus trees and NUE increases when the bulk of supply of the N rate is delayed to the summer months.     

Utilization of Marine Waste to Obtain β-Chitin Nanofibers and Films from Giant Humboldt Squid Dosidicus gigas

β-chitin was isolated from marine waste, giant Humboldt squid Dosidicus gigas, and further converted to nanofibers by use of a collider machine under acidic conditions (pH 3). The FTIR, TGA, and NMR analysis confirmed the efficient extraction of β-chitin. The SEM, TEM, and XRD characterization results verified that β-chitin crystalline structure were maintained after mechanical treatment. The mean particle size of β-chitin nanofibers was in the range between 10 and 15 nm, according to the TEM analysis. In addition, the β-chitin nanofibers were converted into films by the simple solvent-casting and drying process at 60 °C. The obtained films had high lightness, which was evidenced by the CIELAB color test. Moreover, the films showed the medium swelling degree (250–290%) in aqueous solutions of different pH and good mechanical resistance in the range between 4 and 17 MPa, depending on film thickness. The results obtained in this work show that marine waste can be efficiently converted to biomaterial by use of mild extractive conditions and simple mechanical treatment, offering great potential for the future development of sustainable multifunctional materials for various industrial applications such as food packaging, agriculture, and/or wound dressing.     

Investigating geostatistical methods to model within-field yield variability of cranberries for potential management zones

Cranberry harvesting methods give only one yield value per field making characterization of within-field variation, the usual first step in precision farming, difficult. Time-consuming berry count yield and fruit rot estimations are the best “ground truth” indication of yield variation within fields. Correlations and coincidence of binary classifications based on less expensive methods such as enhanced vegetation index (EVI) from imagery, and area to point (AtoP) kriging of useable, poor quality and trash yields were compared with this “ground truth”. In general AtoP kriged values gave higher correlations and kappa statistic values with berry counts and fruit rot than EVI. Geostatistical disaggregation of per field yield totals using AtoP kriging with EVI as an external drift (AtoP^KED) was also investigated. Factorial kriging was used to separate the several scales of variation in “ground truth” and EVI data and determine which ones were most spatially coherent/manageable and which related best to the AtoP kriged data. The spatial trend component of pre-harvest berry counts and AtoP kriging of yields both gave a good initial definition of spatially coherent, relatively permanent management zones. They were related to topography and depth of water table in the soil which are key factors governing cranberry yield. AtoP kriging or AtoP^KED are recommended for defining management zones as they are less expensive than berry counts. The value of AtoP kriging to precision farmers for other crops to map soils at the farm scale with some imagery and just one bulked soil sample per field or use nutrient levels associated with each polygon of traditional soil survey maps is discussed in the conclusions.     

The Effect of Low Salinity Water with Different Ionic Composition on the Growth and Survival of Litopenaeus vannamei (Boone, 1931) in Intensive Culture

The effects of four different ionic composition low salinity water (T₁, T₂, T₃, and T₄), on growth and survival of Litopenaeus vannamei marine shrimp juveniles were investigated. Shrimp culture in seawater (T_m) was used as control treatment. The results indicated that there were no significant difference (P < 0.05) in growth, survival, production, and feed conversion ratio (FCR) of L. vannamei juveniles reared in the different treatments, but significant differences (P < 0.05) were observed between each of them when compared with seawater (T_m). After 84 days, culture shrimp grew from 0.02 to 7.58 g in T₁. The lowest growth rate was attained in T₃ (0.57 g/week), in which potassium and calcium ions concentrations were the lowest (0.58 and 28.00 mg/L, respectively). The recorded survival rate (76.35% to 79.55%) is considered well for the 84 days growout period, although it was 7.6% lower than that recorded in the control treatment. Although there were no significant differences (P < 0.05) in growth with respect to the ionic composition of the four treatments, there was a trend of increasing growth in relation with the ionic ratio found in the seawater (T_m). This aspect should be evaluated more closely in future research.