Field Trial Conditions Research Articles

LABORATORY AND FIELD EVALUATION OF THE INSECT GROWTH REGULATOR PYRIPROXYFEN (SUMILARV 0.5G) AGAINST DENGUE VECTORS

The insect growth regulator pyriproxyfen was tested against Aedes aegypti at 0.01 and 0.02 mg of active ingredient (AI) per liter of water in 60-liter earthern jars. Both concentrations provided 100% control for 4 months. In additional experiments where 10 liters of water were replaced fortnightly, 100% control was still obtained over 4 months with 0.02 mg AI/liter and greater than 93-100% control was obtained over 4 months with 0.01 mg AI/liter. In less-controlled field-trial conditions, pyriproxyfen at a dosage of 0.02 mg AI/liter provided 100% control for 10 wk against Aedes albopictus even though water was replaced either daily or weekly. Although the activity of pyriproxyfen declines after 10 wk, those tests in the plastic tubs showed much higher levels of sustained residual activity compared to those in the earthern jars. Pyriproxyfen did not have an impact on nontarget organisms.

Performance of 5th generation 8-VSB receivers

There has been a focused effort within the television broadcast industry to move the DTV receiver technology "state-of-the-art" forward to a better deal with the more difficult and complex receiving environments faced within the TV viewing environment. In this paper, we detail the approach taken which today provides the broadcast industry with a "breakthrough" 8-VSB receiver product that has "cleared the bar" of expected performance for the simple consumer-friendly reception of over-the-air digital television in most complex environments. There have been many field tests and studies performed since the adoption of the 8-VSB ATSC standard. Armed with a more complete understanding of the adverse environments where the prior 8-VSB receivers fell short of providing acceptable reception, it became clear that an architecturally advanced approach was needed. Having new and advanced methods of analyzing the captured RF signals, coupled with new-found capabilities of more accurately defining and applying such "real world" approximations in the realm of software simulation, led to an understanding of many modeled performance capabilities prior to hardware production. A variety of tools allowed the design team to depart from the generally accepted implementations of the past, and to deal in new ways with the infinitely complex array of variable ghost delays and amplitudes required to meet the needs of broadcasters and consumer electronics manufacturers alike. Affirming the knowledge about the need to deal with known interferences, resulting from an increasingly densely packed RF broadcast television spectrum is also highlighted. Field evaluation data is presented to confirm the conclusions. Providing correlation of results with laboratory simulations and tests with those "real world" conditions in various field trials conducted by multiple parties enables this technology to achieve quick acceptance in the marketplace.

RFLP mapping of quantitative trait loci controlling abscisic acid concentration in leaves of drought-stressed maize (Zea mays L.)

Abscisic acid (ABA) concentration in leaves of drought-stressed plants is a quantitatively inherited trait. In order to identify quantitative trait loci (QTLs) controlling leaf ABA concentration (L-ABA) in maize, leaf samples were collected from 80 F3:4 families of the cross Os420 (high L-ABA)×IABO78 (low L-ABA) tested under drought conditions in field trials conducted over 2 years. In each year, leaf samples were collected at stem elongation and near anthesis. The genetic map obtained with 106 restriction fragment length polymorphism (RFLP) loci covered 1370 cM, which represented approximately 85% of the UMC maize map. Sixteen different QTLs with a LOD>2.0 were revealed in at least one sampling. Across samplings, only four QTLs significantly influenced L-ABA, accounting for 66% of the phenotypic variation and 76% of the genetic variation among families. At these QTLs, the alleles which increased L-ABA were contributed by Os420. The two most important QTLs were mapped on chromosome 2 near csu133 and csu109a. The effects associated with the QTL near csu133 were more pronounced near anthesis. The support intervals of the four primary QTLs for L-ABA did not overlap the presumed map position of mutants impaired in ABA biosynthesis.

Effect of Feeding Frequency and Romet‐Medicated Feed on Survival, Antibody Response, and Weight Gain of Fingerling Channel Catfish Ictalurus punctatus after Natural Exposure to Edwardsiella ictaluri

Abstract The efficacy of restrictive feeding regimes and Romet®‐medicated feed (formulated at 40.5‐mg Romet‐30 premix/kg feed) fed at 2.0% body weight was evaluated under field trial conditions for the treatment of naturally induced Edwardsiella ictaluri infections in fingerling channel catfish. After detection of an Edwardsiella ictaluri epizootic, fish were fed medicated and non‐medicated feed every day, every other day and every third day for the duration of the experiment. In addition, experimental treatments also included fish that were completely withheld from feed and those provided Romet‐medicated feed for five consecutive days followed by non‐medicated feed fed daily. Feeding frequency and diet significantly affected survival and weight gain. Survival was greatest among fish that were completely withheld from feed or that were fed medicated feed every other or every third day. The use of non‐medicated feed every other or every third day was equally as effective for reducing Edwardsiella ictaluri associated mortalities as feeding Romet‐medicated feed on a daily basis. Feeding fish Romet‐medicated feed for five consecutive days was not an effective treatment. Agglutinating antibody titers against Edwardsiella ictaluri were significantly lower in all groups of fish fed Romet‐medicated feed for the duration of the experiment. These data indicate that feeding frequency is a primary factor affecting the severity of Edwardsiella ictaluri infection and that prolonged consumption of Romet‐medicated feed may suppress antibody production.

Alkalinity Tolerance of Woody Species Used in Bauxite Waste Rehabilitation, Western Australia

AbstractGlasshouse trials, using trickle irrigation and increasing levels of NaOH‐induced alkalinity, identified species that could be expected to tolerate the high‐pH conditions of bauxite processing waste residue sites. Of 29 taxa tested, the most tolerant were Casuarina obesa, Melaleuca lanceolata, M. armillaris, M. nesophila, Eucalyptus loxophleba, E. halophila, E. platypus, Tamarix aphylla, and a particular clone of E. camaldulensis; E. spathulata, E. tetragona, E. preissiana, E. gomphocephala, E. diptera, and E. occidentalis proved to be relatively sensitive to severe alkaline conditions. Tolerance appeared to relate to an ability to maintain root membrane function, nutrient uptake balance, and ultimately root tissue structure while under increasing levels of alkalinity stress. Species normally inhabiting alkaline soils tended to have increased growth rates in nutrient irrigation conditions between pH 8 and 10 compared with control plants irrigated with nutrient solutions of pH values near 7.4. However, once the irrigation solutions reached pH 12 and the buffering capacity of the soil appeared to be exceeded, the condition of susceptible plants rapidly declined and death followed. Sensitive plants initially showed symptoms related to nutrient deficiency, followed by wilting and death as the root systems failed. Field trial conditions in the bauxite residue impoundments at Kwinana, Western Australia, include soils with pH values as high as 11.00. In general, the relative survival and growth of seedlings after eight months were predicted by the response under glasshouse trial conditions. Appropriately designed stress trials can be important ecological techniques in choosing species most capable of surviving difficult environmental conditions in the rehabilitation of damaged landscapes.

Field Trials of Sarafin- and Romet-Medicated Feeds for Treatment ofEdwardsiella ictaluriInfections in Channel Catfish

Abstract The efficacy of Sarafin®- and Romet®-medicated feeds fed at 1% body weight was evaluated under field trial conditions for the treatment of naturally induced Edwardsiella ictaluri infections in channel catfish Ictalurus punctatus. When administered daily for 5 d, Sarafin-medicated feed at a dose of 10 mg Sarafin/kg of fish and Romet-medicated feed at a dose of 50 mg Romet/kg of fish significantly increased survival to 73 and 71%, respectively, compared with 64% in fish fed nonmedicated feed. All dead fish tested from both medicated and nonmedicated treatments were positive for E. ictaluri. Fish fed either Sarafin- or Romet-medicated feed gained significantly (P < 0.05) more weight than did nonmedicated fish. Weight gains of medicated fish were indicative of reduced morbidity in the population. Weight gain differences between fish fed Sarafin and those fed Romet was not significant. A significant decrease in the number of fish deaths occurring in groups fed either Sarafin- or Romet-medicated feed w...

A finger-stick assay for determination of immunity to hepatitis A: a preliminary report

A simple and reproducible method for determining immunity to hepatitis A has been developed, using whole blood obtained by finger-stick and fixed on small discs. This method permits screening of large populations of candidates prior to active or passive immunization, avoiding the discomfort and difficulty of venipuncture, especially in children. The technique involves a finger-stick with a blood lancet, collection of 20 microliter whole blood on a paper disc which is then dried at room temperature. Perforated discs are incubated with phosphate buffered saline and the eluate is then tested for anti-HAV using the HAVAB assay. Results of anti-HAV assays from finger-stick samples obtained from adults and from children, showed 100% conformance with the homologous venous serum samples obtained at the same time. The lower threshold for detection of anti-HAV by this method is currently below 100 mIU/ml, as compared to 20 mIU/ml by the modified HAVAB method. In conclusion, we have developed a simple and reliable method for determination of immunity to HAV using whole blood obtained by finger-stick and fixed on paper discs. Samples can be collected under field trial conditions, without immediate need for laboratory facilities for separation and storage of serum samples. This sampling method, which is mainly intended for qualitative determination of anti-HAV in HAV immune subjects, especially under field trial conditions, is rapid, economical, efficient and acceptable to populations that are generally apprehensive of conventional venipuncture specimen collection methods.

A dot-elisa intended for the specific and simultaneous detection of antibodies directed to antigens derived from toxoplasma gondii, rubella virus, cytomegalovirus, and type 1 and type 2 herpesviruses

A procedure for the routine and simultaneous laboratory detection of IgG antibodies produced in humans in the course of various infectious diseases is described. The procedure, based on dot-enzyme-linked immunosorbent assay (ELISA), used single nitrocellulose strips onto which several antigens were dotted in close proximity. Optimal conditions were specified that allowed the unequivocal and simultaneous detection of IgG antibodies specifically directed against Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes simplex virus type 1 and type 2 antigens. This technique has proved to be simultaneously specific, sensitive, and reliable, and it has been applied to prenatal screening of sera from pregnant women. It is suggested that this technique should also be used for the screening of large numbers of sera under field trial conditions.

Growth and Yield of Barley Isopopulations Differing in Solute Potential1

The active accumulation of solutes by osmotically stressed plants is thought to be an adaptive response that increases the ability of drought‐ or salt‐stressed plants to maintain leaf water content, turgor, and possibly growth. In an earlier study we developed two barley (Hordeum vulgare L.) isopopulations differing in solute potential (ψs), and these isopopulations were characterized for their response to salt stress in the growth chamber. At each stress level tested, the low‐ψs population had about 0.1 MPa lower ψs. In the present study we used these isopopulations to test the effect of genetic differences in ψs on growth in well‐watered and drought‐stressed conditions in the greenhouse and field. When grown in the greenhouse, the low ψs population had a slower rate of leaf production and accumulated significantly less total aboveground dry matter by midanthesis than did the high‐ψs population. This difference (up to 35%) was greatest in optimal environmental conditions (adequate water, high irradiance, warm temperatures) and decreased in less favorable environments. The growth differences were not associated with differences in partitioning of dry matter to the leaves or differences in water use efficiency. The growth disadvantage of the low‐ψs population was also observed for grain yield (11–44%) and total aboveground biomass production (10–25%) under dryland and irrigated conditions in multisite field trials. Thus the development of a barley isopopulation with constitutively lower ψs resulted in a reduction in yield potential.

Tropical production of tilapia ( Sarotherodon aurea) and tomatoes ( Lycopersicon esculentum) in a small-scale recirculating water system

An integrated fish and hydroponic tomato production system was evaluated for use in the US Virgin Islands. The system was constructed from readily available materials, and designed to minimize capital costs, energy and water use, and the technological skill needed for operation. Tilapia ( Sarotherodon aurea) and tomatoes ( Lycopersicon esculentum) were cultured outdoors for 181 days in a closed system containing 7.34 m 3 of water. Water quality suitable for fish production was maintained by aeration, biological filtration, sedimentation, hydroponic vegetable production and the addition of make-up water. Fish metabolites, wasted feed, and small quantities of inorganic fertilizers served as nutrient sources for tomato production. Fish survival (97.5%) and growth (2.54 g per day) were excellent with 63.6 kg of fish averaging 521 g each recovered at harvest. The total yield of ripe tomato fruit was 87.0 kg, of which 87.4% was marketable. The yield and quality of fruit produced hydroponically exceeded that produced under field trial conditions. Capital costs for the complete system were estimated to be US$612 (1979). Electrical energy and water use were 9.12 kWh day −1 and 2.6% of the total volume per day, respectively. Cost and return projections indicate the system could be operated on a profitable basis in the US Virgin Islands.

Sugarbeet Fruit Germination and Emergence under Moisture and Temperature Stress1

Poor fruit germination and emergence of sugarbeet (Beta vulgaris L.) due to moisture and temperature stress can limit satisfactory stand establishment. Our objective was to evaluate laboratory procedures which measure germination and emergence potential under moisture and temperature stress and to use these tests for development of fruit treatments for improving field emergence under stress conditions.Germination tests were conducted on blotter paper using polyethylene glycol 600 osmotic solutions to induce moisture stress. Emergence through a 2.5 cm layer of greenhouse soil mix (Ascalon sandy loam and peat, 1:1 V/V) was used to evaluate the effect of fruit treatments on emergence under moisture and temperature stress. The soil mix, initially at —1/3 bar matric potential, dried to —10 to —5 bar matric potential during the course of the test. Emergence through a 3.3 can layer of packed silica sand (3.5% water — wt/wt) was used to evaluate treatments under temperature, moisture and impedance stress tests conducted at 9, 15, or 26 C. Field trials were used to confirm results of laboratory tests.Germination of sugarbeet fruit decreased with increas. ing osmotically simulated moisture stress from 0 to —7 bar water potential after which no germination occurred. Increasing the moisture stress from 0 to —4 bar potential decreased the rate of germination, but not the final germination percent, while both rate and final germination percent decreased sharply as moisture stress went from —4 to —8 bars. Removal of the pericarp decreased the water requirement for germination at a given rate by 2 bars, indicating that the pericarp is a major factor limiting germination and emergence under moisture and temperature stress.Treatment of the fruit with 1.0 N HCI for 2 hours significantly improved germination and emergence under moisture and temperature stress conditions in laboratory and field trials. Excessive acid treatment damaged the true seed. The acid treatment did not improve the emergence where impedance was the major stress or in the absence of moisture and temperature stress. Temperature affects not only the rate and extent of germination, but also the moisture requirement. The sugarbeet fruit germination at —5 bar matric potential and 26 C was equal to that at —1 bar and 9 C.The germination of untreated fruits of eight cultivars ranged from 26 to 72% at —1 bar matric potential and 9 C, and from 6 to 20% at —5 bar and 9 C. Acid treatment improved germination of all cultivars, but low germinating cultivars were improved the most.

YIELD AND QUALITY OF CATSUP PRODUCED TO A STANDARD SOLIDS AND CONSISTENCY LEVEL I. METHOD OF DETERMINING THE AMOUNT OF TOMATO SOLIDS REQUIRED

A method has been developed to determine the amount of tomato solids required to make a batch of catsup which contains a given level of total solids at any specified Bostwick consistency. It was developed to determine factors that control the yield and quality of catsup obtainable from any any raw material and the effect of the processing procedures used for producing the tomato pulp required for its production. It was also developed for evaluating the production capability of recently released varieties grown under field trial conditions. These subjects will be discussed in a subsequent paper.

An Optical Fiber Video System

A general discussion is made of optical fiber video systems from the viewpoint of system design concepts, transmission schemes, etc. Among possible analog CATV systems, the Higashi-Ikoma Project is reviewed as an optical fiber video system application. The essential components and basic technologies required for optical fiber video systems are reviewed. System performance is reviewed by considering some of the typical field trial conditions.

Grain-yield evaluation of ‘Kopara 73’ and ‘Takahe’ wheat cultivars

Abstract Grain yield performance of two recently released wheat cultivars, ‘Takahe’ and ‘Kopara 73’, was evaluated under field trial conditions during the 1972–1973 and 1973–1974 wheat-growing seasons. Where powdery mildew (Erysiphe graminis) occurred, greater (by 9%) yield increases were obtained with ‘Takahe’ than with ‘Aotea’. The corresponding grain-yield increase under mildew-free conditions was 3.4%. Consistent yield increases (mean 6.7%) were measured for the reselection ‘Kopara 73’ compared with the initial bulk ‘Kopara’ release. Relative to ‘Aotea’ and ‘Takahe’, ‘Kopara 73’ mean yield increased by 13.4% and 7.0% respectively. Grain-yield responses to applied nitrogen were similar for ‘Aotea’ and ‘Takahe’, but both were inferior to that for ‘Kopara 73’. No cultivar x superphosphate interactions were recorded.

Growth of broilers fed on diets containing dried poultry manure

Synopsis Sixty 7‐d‐old male broiler chicks were housed in individual metabolism cages and offered one of six purified diets for 14 d. The diets were formulated to have the same ME contents but had different nitrogenous supplements: diet A, was the basal diet, containing PRG essential amino acid (EAA) mixture equivalent to 15 g N/kg; B, basal+12% glutamic acid (GA); C, basal plus EAA mixture equivalent to EAA content of 20.09% DPM; D, basal + EAA+12% GA; E, basal + 20.09% autoclaved DPM; F, basal + 20.09% unautoclaved DPM. The rank order of final body weights at 21 d of chicks fed on these diets were D(292 g) > B(258 g), (F254 g), E(253 g) > C(206 g) > A(180 g), (P<0.05). Chicks fed on diet C had better food conversion efficiencies (FCE) than those fed on diet A (0.449 and 0.374 respectively) and D was better than B (0.592 and 0.533 respectively). In a second experiment, carried out under field trial conditions using commercial‐type diets formulated to contain DPM, 24 groups, each of about 40 male or female broiler chicks, were given diets containing 0% (P) or 5% (Q) DPM from 1 d of age for 4 weeks. From 4 to 8 weeks one of three diets with 0% (R), 5% (S) or 10% (T) DPM was fed according to a 2 (sexes) x 2 x 3 factorial design. Between o and 4 weeks feeding DPM had no significant effect on body weight or food consumption, but birds fed diet Q had an improved FCE (P<0.05). Between 4 and 8 weeks birds fed on S and T were heavier than the controls at 6 weeks, but this increase was not significant at 8 weeks (P> 0.05). Food consumption was not affected, but the FCE improved with increasing inclusion of DPM. At 8 weeks of age birds fed on Q, were heavier than birds fed on diet P.

On the Relationship Between Soil Moisture and Osmotic Potential in Maize and Sugar Beet Plants

AbstractInvestigations on the relationship between soil moisture and maize and sugar beet plant osmotic potential were carried out during three years under field trial conditions. It was established that between soil moisture and osmotic potential there is an inverse ratio dependence, expressed in significant correlation coefficients (r =−0.84** for maize and r =−0.88** for sugar beet on an average). The correlation appears more striking in the lower third of the active moisture range, where slight variations in soil moisture determine important changes in osmotic potential. The possibility of using the osmotic potential as an index in estimating plant water requirement is asserted and the limit values indicating a good water supply in maize and sugar beet plants are established according to growth stages.