Spray Period Research Articles

A Computer-controlled Spray Chill Unit for Red Meat Carcasses

A computer controlled and operated spray chill unit which can be used in future research studies for both spray chilling and decontamination of red meat carcasses is described. The unit consists of two parts: (1) an electromechanical system, and (2) a data acquisition/control system. Design concepts for the spray chill system are (1) versatility, (2) rapid change of spray parameters, and (3) computer control of the electromechanical system. An added feature is the computer data collection system for recording information related to each carcass (pH of muscle, surface and internal tissue temperatures, and weights of each half carcass during the cooling cycle; velocity, temperature, and humidity of the chill cooler air) and environmental data related to spraying conditions (time and duration of spray period and temperature of sprayed solution). Keywords. Decontamination, Dehydration, Meat, Quality control, Sanitation.

Soil chemical and microbial effects of simulated acid rain on clover and soft chess

Effects of simulated acid rain, comprised of HNO3 and H2SO4 in the mole ratio of 3:1, at pH 5.6, 4.5, 4.0 and 3.0, were tested on the grass, soft chess (Bromus mollis L.) and on clover (Trifolium subterraneum L. var. Woogenellup) in a sandy soil of granodiorite parent material. Soft chess was grown in unfertilized soil, whereas clover was grown in both unfertilized soil and soil fertilized with NH4NO3 and CaSO4·2H2O at the rates of 224 kg ha−1 N and 78 kg ha−1 S. Two acid-spray irrigation periods of 31 and 26 weeks duration, each delivering 400 mm and separated by a dry period of 23 weeks, simulated typical rainfall of northern California rangeland. Plants were harvested after each of the two spray periods. There were very few deleterious effects of acid rain on plant growth or soil and microbial processes. No significant (p<0.05) effects were shown by soil microbial biomass, CO2 production, nodules per unit weight of clover root, acetylene reduction, denitrification and nitrification potentials, or for soft chess plant weights, and N and P uptake. Mineralizable-N was unaffected also, except in one case. However, pH of soil to 10 mm depths was significantly lower in the pH 3.0 treatment after the first spray period, with a corresponding decrease in exchangeable soil Ca; these effects became significant at greater soil depth only after the second spray period. There were significant effects of acid treatments shown by clover, some of which may be advantageous. Treatments of intermediate acidity generally provided added N and S, which acted as fertilizers, and compensated for possible decreases in plant productivity attributable to acidity per se. There was also evidence of decreased P uptake in unfertilized soil at pH 3. In conclusion, effects of simulated acid rain were minimal, and in some cases were advantageous because of the added N and S having a fertilizer effect on plant nutrition and growth.

Combination studies of selected acaricides with zineb, mancozeb, or carbamate for mite control on citrus

Abstract Field experiments were conducted between 1981 and 1988 to evaluate the potential of zineb (zinc ethylene bisdithiocarbamate), mancozeb (a coordination product of zinc ion and manganese ethylene bisdithiocarbamate) and carbamate (ferric dimethyldithiocarbamate) in combination with one or more of the following acaricides: ethion, chlorpyrifos, dicofol, chlorobenzilate, propargite or formetanate for the control of the citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari:Eriophyidae). Treatments were applied to replicated single tree plots using a handgun from a truck-mounted sprayer or to replicated nine tree plots using an airblast sprayer during the postbloom, summer or supplemental fall spray periods. Mancozeb alone was slightly better than zineb alone in the suppression of P. oleivora. However, neither compound demonstrated sufficient activity to justify its use alone as an acaricide on citrus. The combinations of ethion, chlorpyrifos, dicofol or propargite with either mancozeb or zineb sh...

Biological monitoring and health surveillance of a group of greenhouse pesticide sprayers

Repeated extensive medical examinations were carried out in 11 workers spraying organophosphate (OP), carbamate and pyrethroid pesticides in greenhouses during the whole year and in 10 control persons. On a questionnaire their social, health and family status and their working conditions were recorded. Before and after a regular spraying period with pyrethroids for 3 months the following tests were carried out: urinalysis, haematology, immunoglobulin (Ig) G, IgA and IgM levels, whole blood cholinesterase (ChE) activity, serum 7-glutamyltransferase (GGT) activity, chromosome analysis and electrocardiography (ECG). Atmospheric concentrations of pyrethroids as well as their concentration in the blood and urine of pesticide workers were determined by means of gas-liquid chromatography (GLC). No abnormalities related to the work were found in the tests.

Population dynamics of some Pakistan mosquitoes: the impact of residual organophosphate insecticide spray on anopheline relative abundance.

Two rounds of residual organophosphate house spray regionally eradicated susceptible endophilic resting anophelines (Anopheles culicifacies, An. stephensi and An. subpictus) from rural villages in Punjab province, Pakistan. Partially exophilic resting species (An. annularis and An. pulcherrimus) also were eliminated from resting within the village, but persisted in bovid bait collections throughout the spray period. The abundance of the partially exophilic resting species returned to prespray levels shortly after insecticide efficacy declined (five to six weeks post-spray), while repopulation of the villages by the endophilic resting species required from 12 to 26 months. Malathion resistance developed rapidly in An. stephensi and resulted in treatment failures two years after this compound was first used for anopheline control in Pakistan.

Influence of temperature on the activity of AC 222,293 against Avena fatua L. and Alopecurus myosuroides Huds.

SummaryFoliage applications of AC 222,293 were more active against Alopecurus myosuroides Huds. plants growing at high (26/16°C day/night) compared to either medium (16/10°C) or low (11/7°C) temperatures. Soil activity was unaffected by temperature. Enhanced activity against A. myosuroides required exposure to the high temperatures for only 24 h immediately post spraying and correlated with the accumulation of greater levels of the biologically active acid in the apical meristem region during this period.Both foliage and soil activity of AC 222,293 were greatest against Avena fatua L. plants growing at medium (16/10°C) compared to either high (26/16°C) or low (11/7°C) temperatures. Foliar activity decreased slowly with increasing periods of high temperatures post spraying and then only at doses lower than those recommended for field use. Reduced performance at the high temperatures correlated with lower levels of the biologically active acid in the meristem region, despite greater uptake and translocation. This was due to increased metabolism of the parent herbicide and formation of metabolites other than the free acid.

Forestry workers involved in aerial application of 2,4-dichlorophenoxyacetic acid (2,4-D): exposure and urinary excretion.

Urinalysis was conducted on six volunteer workers involved in mixing and loading 2,4-D ester solutions into aircraft and in guiding the spray aircraft in two conifer release programs during 1981 and 1982. Exposures were reduced by wearing a full line of protective clothing. Two females and one male were involved in mixing the spray for 109 aircraft loads over an 11-day period in 1981. During the 1981 operation, the highest daily excretion of 2,4-D in the urine was 0.30, 0.94 and 9.59 μg/kg body weight for the three workers. In 1982, three male workers were involved, one diluting the concentrated solution and loading the aircraft, and two marking the swaths for aerial application over an 18 day period. The highest daily excretion of 2,4-D in the urine was 7.73, 8.37, 22.2 μg/kg body weight for the three workers. One of the authors, acting as a bystander, was directly sprayed in the 1982 season and 0.44% was absorbed based on urine analysis. The highest daily excretion of 2,4-D in his urine was 4.75 μg/kg body weight. For all seven people, the calculated exposure was less than the no-effect level of 10 mg/kg of body weight/day by a large margin of safety. The presence of 2,4-D in urine samples in the pre-spray period and its slow disappearance during the post spray period prompted further investigation. Swabs of internal surfaces of living quarters revealed deposits of 2,4-D from 0.7 to 288 μg/0.1m2 and on spray equipment from 0.7 to 184 μg/0.1m2.

Local variation in the population dynamics of Glossina palpalis palpalis (Robineau-Desvoidy) (Diptera: Glossinidae). II. The effect of insecticidal spray programmes

AbstractAn analysis of the population changes of Glossina palpalis palpalis (R.-D.) during and after two insecticide trials in Ivory Coast revealed that the effects of insecticide application depend very strongly on the characteristics of the population ecology of the fly, which showed considerable local variation. At sites with high fly populations and low natural mortality rates, the populations declined rapidly during the spray period as the insecticide killed a large proportion of the local, mainly resident, population. The high resilience of the populations, however, permitted rapid recovery, largely through reinvasion from neighbouring areas, so the reduction in fly numbers lasted for only 3–4 months at a time of year when, in the absence of insecticide, the population showed a significant seasonal decline lasting for up to three months. At other sites, with low populations and high natural mortality rates, the local populations were supported chiefly by immigrants and therefore insecticides only affected a very small proportion of the total population and thus did not cause an immediate decline in fly numbers. The low resilience of these populations, however, means that any repeated low additional mortality (such as that caused by removal trapping or deterioration of environmental conditions) would cause the populations to decline. Thus at both types of site, but for rather different reasons, single or short-term insecticide applications had a limited effect on the populations, and longterm, repeated control procedures are considered to be the only ones likely to reduce the populations significantly; through economic necessity these must rely on low-technology devices such as insecticide-impregnated screens or traps.

Effect of malathion-bait sprays on biological control of insect pests of olive, citrus, and walnut

The effect of malathion-bait sprays, directed against Mediterranean fruit fly (Ceratitis capitata [Wiedemann]), on biological control of selected non-target insects was investigated in northern California during 1982 and 1983. In Stanislaus County, 19 applications of malathion-bait spray were applied over a period of 7 months; following cessation of the spray program, increases of olive scale (Parlatoria oleae [Colvee]) and black scale (Saisettia oleae [Olivier]) on olive and of brown soft scale (Coccus hesperidium Linn.) and black scale on citrus were detected, compared to population levels of these scales in the adjacent unsprayed zone. The secondary outbreaks of these scales were attributed to destruction of natural enemies (chiefly parasites) by malathion. The outbreaks of black scale (citrus and olive) and brown soft scale were not apparent until 1 year after the first application of malathion-bait spray, or 5 months after the last application. Populations of cottony-cushion scale (Icerya purchasi Maskell), citrophilus mealybug (Pseudococcus calceolariae [Maskell]) and citricola scale (Coccus pseudomagnoliarum [Kuwana]) remained at low levels on citrus in the spray zone; no treatment effect on these species was detected. Latania scale (Hemeberlesia lataniae [Signoret]) on olive was apparently suppressed by the sprays. Walnut aphid (Chromaphis juglandicola [Kaltenbach]) in Commercial walnut orchards was less abundant in the spray zone 2 months after the last application of malathion-bait; no suitable explanation for this was available. In the city of Stockton, a secondary outbreak of walnut aphid occurred in the spray zone (during the spray period) whereas an outbreak of black scale on olive was detected shortly after the spray program ended. These outbreaks were attributed to destruction of natural enemies by malathion. In general, concentrations of malathion-bait sufficient to kill most adult parasites tested were less toxic to the pest species tested. These results indicate that future (medfly) eradication programs which employ numerous sequential applications of malathion-bait spray can be expected to disrupt a substantial portion of the biological control which exists in the target zone.

Effect of Early Sprays on Control of Powdery Mildew Fruit Russet on Apples

Effect of Early Sprays on Control of Powdery Mildew Fruit Russet on Apples

Effects on Nontarget Arthropods of Malathion Bait Sprays Used in California to Eradicate the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Dystera: Tephritidae)

Evidence of bait attraction, direct kill, and population reduction of nontarget arthropods was obtained by comparing gardens in two Malathion bait-sprayed sites with those in an untreated city and an unsprayed natural area. A variety of polyphagous and carnivorous arthropods were attracted by the baits, and in most cases fewer numbers were caught in treated than in control areas. Some phytophagous insects (Homoptera, Apidae, and Lepidoptera) apparently maintained or increased their populations during or after the spray period. Populations of calypterate muscoid flies were probably unaffected by the sprays.

Accumulation of endosulfan residues in fish and their predators after aerial spraying for the control of tsetse fly in Botswana

AbstractResidues of endosulfan insecticide (α‐ and β‐isomers, and ‘endosulfan sulphate’) in fish and their predators were measured during and after operations to control tsetse fly in the Okavango Delta, Botswana. Six ultra‐low‐volume doses of endosulfan 35% e.c. (6–12 g a.i. ha−1) were applied from the air in a period of 12 weeks over 2500 km2. The concentration of residues found in living fish was up to 0.19 mg kg−1 wet wt in caudal muscle, and usually &lt; 0.8 mg kg−1 wet wt in pooled viscera (maximum 2.8 mg kg−1). These values returned to near‐normal within 3 months after cessation of spraying, but residues were still detectable after 12 months. By comparison, fish killed by spraying contained a maximum residue level (whole‐body) of 1.5 mg kg−1 wet wt. The residue level in fish was approximately proportional to their fat content. Lean fish were more susceptible to poisoning than fat fish. The proportion of the ‘endosulfan sulphate’ metabolite in fish increased at least six times with respect to the parent isomers (α+β) during the period of spraying, but more advanced stages of metabolic breakdown were not monitored. Residue levels in fish predators (fish‐eating birds and crocodiles) were similar to those in their prey, and the risk to them was consequently low.

Atrazine: Its use in corn production and its loss to stream waters in Southern Ontario, 1975–1977

In a farm-to-farm survey of 11 agricultural watersheds averaging 4279 ha, it was found that on average 18% of the watersheds were devoted to corn production and 73% of this production was treated with atrazine at a mean rate of 1.7 kg/ha. Flow volumes in the 11 streams were gauged and waters were monitored for atrazine and its metabolite desethylatrazine between May 1975 and April 1977. These two compounds were detected in 80% of the stream waters at a mean concentration of 1.4 μg/l. Seasonal variations in concentration were observed. Peak residues occurred in streams shortly after the main spray period and after a secondary fall spray period. During the winter season, concentrations declined below 1 μg/l. Losses of applied atrazine were greatest on clay and least on sandy soils. The highest losses (60%) were caused by storm runoff events and especially in the January to April period. Spills accounted for 20% of the atrazine loss and the major period when this occurred was May to August. Losses due to base flow associated with drainage accounted for 20% and varied little over the year.

Apple, Orchard Insecticide Studies, 1976

Abstract This test was conducted at the Agway Orchard, Fabius, NY, on dwarf rootstock apple trees of the varieties, Mcintosh, Red Delicious, Macoun and Cortland. Single rows (each 1/10 acre) of 22 trees were sprayed to run-off with hand-gun sprays at IX concentration using platform sprayer dilute equivalent of 300 GPA from first to ninth cover starting at 1/2” green. Blocks G &amp; H received 1.5 tons/acre of dolomitic lime and Nitrogen; all trees received 6-8 oz of Urea 45/tree spread evenly on ground under branches Apr20 to May01’76. Between first and second cover and second and third cover, all trees received equivalent of 15 lbs Epsom salts/100 gallons in sprays. In Spring, when grass and weed growth was 3" tall, Paraquat + Simazine were band sprayed (3’ band) under trees. Benlate 50W was used as standard fungicide when insecticides were not combined with fungicides. Fruit was sampled at first cover and at normal variety harvest dates to assess insect damage. A total of 100 fruit per variety from three trees was composited at harvest to assess late season (cover spray period) insect injury. The average percent insect injury was pooled for 300-fruit samples for damage resulting from apple maggot, plum curculio, oblique banded leafroller, green fruitworm and tarnished plant bug.

A prospective study of the effects of ultralow volume (ULV) aerial application of malathion on epidemic Plasmodium falciparum malaria. II. Entomologic and operational aspects.

In a large-scale study in the Miragoane Valley of Haiti, designed to test the effects of aerial ultralow volume (ULV) malathion on epidemic Plasmodium falciparum malaria, spray operations resulted in an immediate and sharp decline in numbers of the vector, Anopheles albimanus. The adult population of this mosquito remained at less than 1% of previous levels until several weeks after a 50-day spray period (27 October-16 December 1972) during which six cycles were completed. The study area offered ideal conditions of wind, temperature, humidity, and mountain barriers. Mosquitoes in the area were highly susceptible to malathion. Results indicated that aerial ULV treatment with malathion can reduce A. albimanus populations rapidly and effectively when applications are made over an area as large as 20,000 acres. Preliminary results showed that effective control was not achieved in areas one-quarter that size; these areas were not sufficiently large, and infiltration of mosquitoes from adjacent untreated areas was possible.

Lymphocyte chromosome analysis of agricultural workers during extensive occupational exposure to pesticides

Lymphocyte cultures from 42 pesticide applicators and 16 controls were scrutinized for chromosomal aberrations during the midwinter ebb in pesticide spraying operations, and again during the peak summer period of intense spraying activity. Cultures prepared from the exposed individuals during the heavy spraying period showed a marked increase in the frequency of chromatid lesions. This trend was especially noticeable among workers exposed primarily to herbicides. A few chromatid exchange figures were also noted among the exposed group. Also discussed is the need for better methods of estimating the potential mutagenic threat, if any, of such observed clastogenicity.

Lymphocyte chromosome analysis of agricultural workers during extensive occupational exposure to pesticides

Lymphocyte cultures from 42 pesticide applicators and 16 controls were scrutinized for chromosomal aberrations during the midwinter ebb in pesticide spraying operations, and again during the peak summer period of intense spraying activity. Cultures prepared from the exposed individuals during the heavy spraying period showed a marked increase in the frequency of chromatid lesions. This trend was especially noticeable among workers exposed primarily to herbicides. A few chromatid exchange figures were also noted among the exposed group. Also discussed is the need for better methods of estimating the potential mutagenic threat, if any, of such observed clastogenicity.

Seasonal Escalation of Organophosphorus and Carbamate Resistance inAnopheles albimanusby Agricultural Sprays

Levels of resistance to organophosphorus and carbamate insecticides in larvae of Anopheles albimanus Wiedemann within the cotton-growing area of E1 Salvador were studied over a 2-year period, 1970–72. Sampling was done in June and February of each year, i.e., at the beginning and end of the cotton-spraying season. Resistance to parathion, methyl parathion, malathion, fenitrothion, carbaryl, and propoxur was found to rise during the spray period and to decline somewhat during the nonspray period, revealing an escalatory pattern which attained remarkably high levels by February 1972. Organophosphorus resistance manifested a lower degree of decline than carbamate resistance under both laboratory and field conditions during the nonspraying season. This decline was attributed to unequal integration of the respective resistance genes with fitness factors. Resistance to malathion, propoxur, and fenitrothion in A. albimanus in Central America emphasizes the need for coordination of pest-control efforts in agriculture and public health. Since these insecticides are considered the most promising as substitutes for DDT and dieldrin in malaria eradication, it is obvious that their prior and extensive use in agriculture in malarious areas tends to jeopardize their subsequent usefulness against anopheline mosquitoes.

Optimum period of fungicide spraying for the control of rice bacterial leaf blight

Optimum period of fungicide spraying for the control of rice bacterial leaf blight

THE EFFECTS OF SUMITHION AND PHOSPHAMIDON ON POPULATIONS OF FIVE CARABID BEETLES AND THE SPIDERTROCHOSA TERRICOLAIN NORTHWESTERN ONTARIO AND INCLUDING A LIST OF COLLECTED SPECIES OF CARABID BEETLES AND SPIDERS

AbstractIn an attempt to control the spruce budworm in northwestern Ontario, Sumithion and Phosphamidon were sprayed from the air in June 1968. Some carabid beetles and one spider were studied to assess the effect the insecticides had on forest floor arthropods in mixed boreal forest. A sudden decrease in collected specimens both in and out of the spray area 1 week prior to spraying was probably due to reduced activity caused by heavy rainfall, but during and following the spray period there were fewer specimens collected in the spray area than in the control area.