Chemical control of two Phytophthora species infecting the canopy of Monterey pine (Pinus radiata)

Twelve active ingredients were screened for their ability to control foliage disease caused by Phytophthora kernoviae and Phytophthora pluvialis. Inhibition of mycelial growth and sporangial production of both pathogens were assessed in in vitro assays after exposure to three concentrations of each active ingredient. While most of these active ingredients inhibited mycelial growth in vitro, due to their widespread use, phosphite, copper oxychloride and metalaxyl‐M were selected for further study. Four rates of each active ingredient were applied to two Pinus radiata genotypes, and detached needle assays at 6 and 90 days post‐treatment were used to determine treatment efficacy and persistence. Untreated needles showed significantly larger lesions than all fungicide‐treated needles after exposure to P. pluvialis or P. kernoviae on both sampling dates. Efficacy and persistence of the three active ingredients did not increase with increase in concentration. Larger lesions were formed on more susceptible genotype after inoculation with both Phytophthora species, even when higher rates of active ingredients were applied. Phosphite, copper oxychloride and metalaxyl‐M have potential to protect commercially planted P. radiata from these two Phytophthora species.     

<Emphasis Type="Italic">In vitro</Emphasis> larvicidal effect of a hydroalcoholic extract from <Emphasis Type="Italic">Acacia cochliacantha</Emphasis> leaf against ruminant parasitic nematodes

The aim of this study was to evaluate the in vitro lethal effect of a hydroalcoholic extract (HAE) from Acacia cochliacantha leaf against three gastrointestinal nematodes species (Haemonchus contortus, H. placei and Cooperia punctata) of domestic ruminants. The HAE was assessed using five concentrations: 100, 125, 175, 150 and 200 mg/ml; 0.5% Ivermectin was used as a positive control and distilled water, as negative control. The data were normalized using the square root and analysed with a completely randomized design through ANOVA analysis using the general lineal model (GLM) of the SAS program. The HAE tannin content was determined through spectrophotometry (UV-visible) and the other major phenols, were identified by chromatographic processes. The results showed an in vitro larvicidal activity of the HAE against the three assessed nematode species with all assessed concentrations. A clear HAE increased concentration dependence effect was observed. The highest activity of the HAE was obtained at the highest concentration (close to 100%, P < 0.05). This result was similar to the one obtained with Ivermectin. On the other hand, the chemical analysis of HAE showed the presence of tannins, caffeoyls and coumaroyl derivates and quercetin as the main compounds. The results suggest that the HAE from this plant species possess in vitro anthelmintic properties. The identified compounds in this study would good candidates for further in vivo researches.     

Proanthocyanidins: target compounds as antibacterial agents

Grape seeds accumulate in huge quantities as byproduct during wine production and are therefore a cheap source for pharmacologically active agents. However, studies prove poor antibacterial activity, and results of analyses are sometimes contradictory. The aim of this study was, thus, to determine the antibacterial activity of grape seed extracts with special focus on the chromatographic characterization of active fractions. In the course of these investigations, extraction protocols were optimized so that microwave-assisted extraction (MAE) guaranteed highest preconcentration efficiency. Proanthocyanidins, monomeric flavonoid aglycones, as well as some of their glycosides could be identified within yielded extracts via high-performance liquid chromatography-mass spectrometry (HPLC-MS). By that means the coherence number of possible isomers of procyanidins was approximated by a newly developed equation. As far as antibacterial activity determined via screening tests is concerned, the extracts generally have been found to be positively responsive toward 10 different gram-positive and gram-negative bacteria strains. After fractionation of the raw extracts, proanthocyanidins P2, P3, P4 and gallate esters P2G and P3G (P = proanthocyanidin consisting of catechin and epicatechin units, n = oligomerization degree, G = gallate ester) were determined as active antibacterial agents toward 10 different pathogens. Only moderate activity was found for monomeric flavonoid fractions.     

Mechanical Starch Damage Effects on Wheat Flour Tortilla Texture

To investigate the effects of mechanically damaged starch and flour particle size on the texture of fresh and stored flour tortillas, two commercial hard red winter wheat flour samples were reground four times using decreasing roll gaps. Tortillas were made with a modified hot‐press procedure. Texture characteristics were measured after tortillas were stored 2 hr (fresh tortilla), 2 days, and 4 days. Damaged starch and particle size significantly affected (P < 0.05) flour water absorption, dough extensibility and resistance, and dough viscosity. As damaged starch increased and particle size decreased, the flour tortillas became less stretchable, the maximum force of Kramer shear decreased, and firmness and rollability increased. The effects of damaged starch and particle size on stretchability and Kramer shear were greater in fresh tortillas than in stored tortillas and became smaller as the storage time increased. However, the effects of damaged starch and particle size on rollability and firmness were smaller in fresh tortillas than in stored tortillas but became greater as the storage time increased.     

Effects of Temperature on Growth and Efficiency of Yolk Utilisation in Eggs and Pre-feeding Larval Stages of Atlantic Salmon

Three embryonic stages of Atlantic salmon (Salmo salar L.) were subjected to eight constant incubation temperatures (4, 7, 10, 12, 14, 16, 19 and 22 °C) exceeding the range usually experienced in natural conditions. A change in thermal tolerance during the embryonic and larval development was registered: pre-hatching stages showed an upper thermal limit at about 16 °C, while hatched larvae survived until 22 °C. Temperature significantly affects developmental rate, resulting in a faster development and, consequently, lower yolk weight percentage at higher temperatures. We found positive relationships between incubation temperature and body size (length and weight) in the less developed stages, in which some yolk remained, but size decreased at increasing temperatures when yolk was completely exhausted.     

Effect of Flour Extraction Rate on White and Red Winter Wheat Flour Compositions and Tortilla Texture

Wheat flours commercially produced at 74, 80, and 100% extraction rates made from hard white winter wheat (WWF) and hard red winter wheat (WRF) were used to produce tortillas at a commercial-scale level. Flour characteristics for moisture, dry gluten, protein, ash, sedimentation volume, falling number, starch damage, and particle-size distribution were obtained. Farinograms and alveograms were also obtained for flour-water dough. A typical northern Mexican formula was used in the laboratory to test the tortilla-making properties of the flours. Then commercial-scale tortilla-baking trials were run on each flour. The baked tortillas were stored at room and refrigeration temperatures for 0, 1, 2, and 3 days. Maximum stress and rollability were measured every day. Tortilla moisture, color, diameter, weight, and thickness were measured for each treatment. Finally, tortilla acceptability was tested by an untrained sensory panel. Analyses of variance (ANOVA) were performed on the data. WWF had higher protein content, dry gluten, sedimentation volume, and water absorption than the WRF. The WWF was the strongest flour based on farinograph development time and alveograph deformation work. It also produced the most extensible dough measured with the alveograph (P/L). Flour protein and ash contents, water absorption, and tenacity increased directly with the flour extraction rate. Both WWF and WRF performed well in commercial-scale baking trials of tortillas. Tortillas made with both types of flours at 74 and 80% extraction rates had the best firmness and rollability. However, tortillas made with WWF 80% had the best color (highest L value). Tortillas prepared with 100% extraction rate flour were also well accepted by the sensory panel, had good textural characteristics, and became only slightly firm and slightly less rollable after three days of storage at room temperature.     

Leaf proteins as markers useful in the genetic improvement of coconut palms

There is a need to identify genetic markers that can assist coconut (Cocos nucifera L.) breeding programs. With that objective, electrophoretic patterns of leaf peroxidases, endopeptidases and coomassie blue stained proteins were analysed in four cultivars (‘West African Tall’, ‘Rennell Tall’, ‘Malayan Yellow Dwarf’, ‘Cameroon Red Dwarf’), and in the hybrids PB121 (‘Malayan Yellow Dwarf’ × ‘West African Tall’) and PB111 (‘Cameroon Red Dwarf’ × ‘West African Tall’). The polymorphisms detected fit the expression of two alleles of a dimeric peroxidase, two alleles of a monomeric endopeptidase, and a pair of active and null alleles of a coomassie blue stained protein. Four distinctive genotypes were identified. One for each of the tall cultivars, another for both of the dwarf cultivars, and the last for both of the hybrids. Applications of the markers in breeding programs, and in research concerning reproductive biology and phylogeny, are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Objective Texture Measurements of Commercial Wheat Flour Tortillas

Texture is a property of major importance in the evaluation of baked products. To determine a sample of commercial ranges for stretchability, rollability, firmness, and Kramer shear cell measurements for wheat flour tortillas using the TA‐XT2 texture analyzer, three separate sets of five tortilla brands purchased from stores in Manhattan, KS, were evaluated. Two brands had two formulations, regular and fat‐free. Significant differences (P < 0.05) in stretchability, firmness, and Kramer shear cell occurred between regular and fat‐free tortillas of one tortilla brand. Significant differences (P < 0.05) also were found among the sets of some tortilla brands. Kramer shear cell and stretchability measurements are recommended because Kramer shear cell measures the force combined with compression, shearing, and extrusion. Stretchability measurements were repeatable and are an important textural property of wheat flour tortillas. Ranges for textural properties for commercial wheat flour tortillas were determined, as well as the variability of the textural methods used.     

Understanding Consumer Preference for Functional Barley Tortillas Through Sensory,Demographic, and Behavioral Data

Consumption of whole grains as part of a health‐promoting diet is encouraged among Americans due to beneficial nutrients and phytochemicals. The main objectives of this study were to investigate the effect of whole barley flour particle size on consumer acceptance of whole grain and soluble fiber‐enriched tortillas; to examine the effect of demographic and behavioral data on consumer acceptance; and to establish relationships between consumer acceptance and survey results to identify market opportunities among particular groups of consumers. Four experimental tortillas and two representative commercial brands were tested by 95 untrained panelists using a 9‐point hedonic scale for appearance, color, flavor, texture, and overall acceptability. Demographic and behavioral data on age, gender, ethnicity, frequency of tortilla consumption, daily effort to include fiber in the diet, consumption of tortillas containing ≥1 g of dietary fiber/serving, consumption of low‐fat tortillas, and tortilla brands and type used were collected. Potential market segments for these tortillas include older consumers (41+), women, Hispanics, and Asians, and frequent tortilla consumers. A response surface relating flavor and texture to overall acceptability produced almost equivalent results to the multivariate PLS results in terms of predicting overall acceptability, which facilitates analysis and interpretation.     

Native oak retention as a key factor for the conservation of winter bird diversity in managed deciduous forests in northern Italy

Birds can serve as useful model organisms to investigate community level consequences of forestry practices. In this study we investigated the relationships between wintering bird communities and habitat and landscape characteristics of lowland managed forests in Northern Italy. This area is characterized by the spread of the black locust, an alien species that has been favored by forestry practices at the expense of natural oak forests. Birds were censused in winter by point counts in randomly selected plots of 50 m radius. We first addressed bird community–habitat relationships by means of habitat structure measurements, then we investigated bird community–landscape relationships by using GIS techniques. We used generalized linear models (GLM) to test for the effects of habitat and landscape variables on bird community parameters (namely bird species richness, diversity and abundance). Bird community parameters were influenced by oak biomass and tree age, and by oak area and core area, while the other forest habitat types showed less influence. In forest management terms, the main conclusion is that the retention of native oaks is the keyfactor for the conservation of winter bird diversity in local deciduous woods. At the habitat level black locust harvesting may be tolerated, provided that old, large, native oaks are retained in all local woodlots to preserve landscape connectivity and foraging resources. At the landscape meso-scale, large native oak patches, should be preserved or, where necessary, restored. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.