Cucumber Field Research Articles

Screening of Some Botanicals for Eco-friendly Control of Cucurbit Fruit Fly (Bactrocera cucurbitae) Infestation in Experimental Cucumber Field

Cucurbit fruit fly (Bactrocera cucurbitae) is the major pest of Cucumber (Cucumis sativus L.), which severely damage the cucumber production. This study was carried to evaluate the efficacy of fourteen botanicals such as Chili (Capsicum frutescens), Garlic (Allium sativum), Onion (Allium cepa), Ginger (Zingiber officinale), Carrot leaves(Daucuscarota subsp. Sativus), Bitter gourd (Momordic acharantia), young Tomato (Solanum lycopersicum), Mahogany seed (Swietenia macrophylla), Eucalyptus leaves (Eucalyptus globulus), Black plum leaves (Syzygium cumini), Jackfruit leaves (Artocarpus heterophyllus), Neem leaves (Azadirachta indica), Black pepper (Piper nigrum) and Garden croton leaves (Codiaeum variegatum) to control the cucurbit fruit fly infestation in experimental cucumber (Green Rohini F1 Hybrid Cucumber) field during March 15, 2021– May 14, 2021. This study observed a less number of cucurbit fruit fly attack on cucumber fruits in Ginger treatment. In this treatment, only 7.06% fruits were infested by cucurbit fruit fly. The Ginger treatment reduced 14.17 times fruit fly infestation compare to control. However, a high number of cucurbit fruit fly infestations were found in Bitter gourd, young Tomato, Mahogany and Garden croton treatments. Cucurbit fruit fly infestation was low (12.50%) in Neem treatment. This treatment showed best performance on cucumber size (cm) and yield (gm). The lowest yield was found in Bitter gourd treatment. The Neem treatment kept about 3.54 times better performance in respect to cucumber yield than that of control treatment. Therefore, Neem leaves (Azadirachta indica) and Ginger (Zingiber officinale) extracts can be used as bio-pesticide for eco-friendly control of cucurbit fruit fly infestation in cucumber field.
 Environ. Sci. & Natural Resources, 13(1&2): 38-42, 2020

SDH mutations confer complex cross-resistance patterns to SDHIs in Corynespora cassiicola

Succinate dehydrogenase inhibitors (SDHIs) are one of the most frequently used fungicides in cucumber fields in China. Our previous studies indicated that the sensitivity profile of Corynespora cassiicola, the causal agent of Corynespora leaf spot, to different SDHIs varied greatly; however, the underlying mechanism remains unclear. The 50% effective concentration (EC50) values of boscalid, fluopyram, fluxapyroxad and isopyrazam in C. cassiicola collected from 2017 to 2020 shifted, with resistance frequencies of 79.83%, 78.43%, 83.19% and 49.86%, respectively. The sequence alignment of sdhB/C/D of resistant strains revealed that eight single amino acid mutations (B-H278Y/L, B-I280V, C-S73P, C-N75S, C-H134R, D-D95E and D-G109V), and three dual-mutations (B-I280V&C-S73P, B-I280V&C-N75S and C-S73P&C-N75S) conferred various SDHI resistance levels and cross-resistance profiles. The expression level of the sdhB/C/D gene and succinate dehydrogenase (SDH) activity in the mutants were significantly altered by the presence of SDHIs, compared with the wild type strain. Additionally, molecular docking results suggested that the missense mutation influenced the crystal structure of SDH and subsequently interfered with the interaction bonds and bond distances among the target protein and chemicals. In brief, amino acid mutations altered the fungicide response of target gene expression, SDH activity and the binding features of SDH-ligand complexes and subsequently conferred multiple resistance levels and complex cross-resistance patterns to SDHIs in C. cassiicola. The evaluation of C. cassiicola resistance to SDHIs provided a significant foundation for efficient chemical development and integrated CLS management strategies.

Changes in the sensitivity of <i>Corynespora cassiicola</i> to fungicides on cucumber plants in Okayama Prefecture, Japan, since the 2000s

In 2014, we collected 234 isolates of cucumber Corynespora leaf spot fungus (Corynespora cassiicola Berkeley & M.A. Curtis C.T. Wei) from 24 commercial cucumber fields in Okayama Prefecture, Japan and assessed their sensitivity to several fungicides. Among the tested strains, the proportion of thiophanate-methyl (T) highly resistant/dietofencarb (D) weakly and moderately resistant strains were 37% and 49%, respectively. Azoxystrobin (A)-resistant strains were 95%, whereas boscalid (B)-resistant strains were 39%. TD- and A-resistant strains were more widespread and more frequent than in 2000. B-resistant strains have only recently emerged.

ISOLATION OF AN ASCOMYCOTA FUNGUS FROM SOIL AND ITS IDENTIFICATION USING DNA BARCODE

In this study Ascomycota fungi was isolated from the soil collected from cucumber field. The micromorphological characters of the isolated fungus were muddling with overlapping characters and identification was unwhole. Hence, nuclear ribosomal internal transcribed spacer (ITS) region, the ideal molecular marker, accepted as DNA barcode for fungal identification was sequenced and compared with the existing GenBank, NCBI, database to identify the species. This sequence was deposited in GenBank, NCBI under the accession number MW945403. Based on the homology and phylogenetic analysis, the isolated fungus was identified as Acrothecium nigrum which is the first report of its presence in the cucumber field.

Host Finding Behavior of the Parasitoid Hadronotus pennsylvanicus (Hymenoptera: Scelionidae) for Egg Masses of the Squash Bugs Anasa tristis and Anasa armigera (Hemiptera: Coreidae) in Squash and Cucumber Fields.

Parasitoid foraging behavior is affected by habitat and host plant differences. Egg parasitoids also use a combination of oviposition-induced and host-derived cues to find host eggs. This study compared parasitism by Hadronotus pennsylvanicus (Ashmead) (Hymenoptera: Scelionidae) on two squash bug species, Anasa tristis (DeGeer) and Anasa armigera Say (Hemiptera: Coreidae), by placing sentinel squash and cucumber plants with egg masses of either of the two squash bug species in squash and cucumber fields in a 3-way factorial design. Host density of wild A. tristis egg masses in squash fields may have influenced parasitoid foraging behavior on sentinel plants. In the 3-way factorial design, parasitism was higher on sentinel squash plants and in squash fields overall. However, parasitism on A. armigera egg masses was highest on sentinel cucumber plants in squash fields and parasitism on A. tristis egg masses was higher on sentinel squash plants in either squash or cucumber fields and lowest on sentinel cucumber plants in cucumber fields. Results suggest that parasitoids were able to specifically orient to the combination of host plant and host cues associated with A. tristis egg masses on sentinel squash plants, but that they were more responsive to plant-induced cues associated with cucumber when searching for A. armigera egg masses. Parasitoids appear to utilize different combinations of host plant and host cues when searching for eggs of the two squash bug species.

Dissipation of spiroxamine residues in open field cucumber and dietary risk assessment

Summary Spiroxamine is one of the most used fungicides in the Mediterranean region, in significant uses such as open field cucumber. Residue trials in the Northern part of Egypt were conducted to investigate the dissipation of spiroxamine (SPX) in cucumbers according to the authorized Good Agricultural Practice (GAP) (1 × 75 g a.i. ha−1 at BBCH 85 to 89) and more critical use patterns. SPX was extracted from cucumbers using a modified QuEChERS protocol and residues were analyzed by liquid chromatography with tandem mass spectrometry (LC–MS/MS). The method was successfully validated with an LOQ of 0.001 mg kg−1. A steep decline of SPX residues in cucumbers fit a first-order decay process with a calculated t1/2 of approximately 2 days and almost complete degradation (99%) after 14 days. Chronic and acute exposure calculations were performed for cucumbers treated with SPX according to all tested GAPs employing two different approaches. In all cases a health risk after consumption of cucumbers was not identified.

The Diversity of Fruit Fly (Diptera: Tephritidae) on Combination of Attractant and Different Trap Height in Cucumber Field (Cucumis sativus L.)

The main pest in the Cucurbitaceae family is the fruit fly. The common effort to control fruit flies is using a trap with methyl eugenol (ME) and cue lure (CUE) as an insect attractant. The trap height installation is also affecting the fruit fly population. The fruit fly population in the field has an important effect on the damage intensity in the commodity. This research objective was to study the distribution and diversity of fruit fly on the cucumber field with trap height installation and attractant combination. The used research method was Factorial Group Randomized Design (RAKF). The first factor was attractant combination of Metil Eugenol (ME) and Cue Lure (CUE) consisted of 6 treatment levels were K1 : 5 mL ME, K2: 5 mL ME + 1 mL CUE, K3: 5 mL ME + 3 mL CUE, K4: 5 mL ME + 5 mL CUE, K5: 5 mL ME + 7 mL CUE and K6 : 5 mL CUE. While the second factor was the high tramp installation consisted of 3 treatment levels were T1: 50 cm, T2: 100 cm, and T3: 150 cm. The treatment consisted of 3 replication on three different cucumber fields. The result showed discovered fruit fly species were eight species, B. dorsalis (Hendel), B. carambolae Drew & Hancock, B. occipitalis (Bezzi), Z. caudata (Fabricius), B. umbrosa (Fabricius), B. neocognata Drew & Hancock, Z. cucurbitae (Fabricius) and B. albistrigata (de meijere). The dominant fruit fly in each treatment in fruit fly fields was B. dorsalis (Hendel). The best treatment in trapping fruit fly was K1 (5 mL ME) with trap height installation T1 (50 cm). The diversity and species richness of fruit fly in the cucumber field was considered low and uneven.

The “neighbor avoidance effect” of microplastics on bacterial and fungal diversity and communities in different soil horizons

Microplastics are a new type of environmental pollutant, and pose a serious threat to soil ecosystems. It is important to study microplastics effects on soil microorganisms to better understand their effects on terrestrial ecosystems. Therefore, we collected soil and microplastic samples from corn, pepper, peanut and cucumber fields in Shunyi District, Beijing, China, and used Illumina MiSeq high-throughput sequencing technology to analyze bacterial and fungal community composition and diversity. We focused on microplastic surface and its surrounding “rhizosphere-like” soil in the 0–10 cm (humus) and 10–20 cm (eluvial) deep horizons. Microbial richness and diversity on microplastic surface were significantly lower than those in surrounding “rhizosphere-like” soil, and microbial richness and diversity were reduced to a greater extent in the humus horizon than in the eluvial horizon. Microplastics likely enriched the microbes involved in their biodegradation. The relative abundance levels of Cyanobacteria and Basidiomycota on microplastic surfaces were significantly higher than those in surrounding “rhizosphere-like” soil, while the relative abundance levels of Acidobacteria, Chloreflexi, and Mortierellomycota were higher in “rhizosphere-like” soil. Furthermore, the relative abundance levels of pathways related to human diseases, animal pathogen, and fungal parasites were significantly higher on microplastic surfaces than in “rhizosphere-like” soil. These results show that the microbial diversity, richness, community structure and function between microplastic surfaces and surrounding “rhizosphere-like” soil are significantly different, leading to a “rhizosphere-like neighbor avoidance effect” between microplastic surfaces and the surrounding soil.

Residue and distribution of fosthiazate in cucumber (Cucumis sativus L.) and dietary intake risk assessment for various populations

ABSTRACT The safety and risk of fosthiazate as nematicide in cucumber field were evaluated in this study. An analytical method for determining the residues of fosthiazate in cucumber was developed. Mean recoveries and relative standard deviations in all samples ranged 85.3 ~ 95.0% and 5.7 ~ 13.3%. The half-lives of fosthiazate in cucumber root, leaf and fruit were 4.71 ~ 5.50 days, 3.52 ~ 4.78 days and 3.32 ~ 3.96 days. The residues in cucumber fruits were below the maximum residue limit (MRL) in China, based on the application dose of 900 g a.i./ha and the pre-harvest interval of 14 days. The transfer rates of fosthiazate from cucumber root to leaf were 17.48 ~ 46.03%, which were significantly higher than those of root to fruit (8.81 ~ 26.52%). These results indicated that fosthiazate was mainly distributed in cucumber root, and it was difficult to be absorbed by the fruit compared to the leaf. The long-term dietary intake risk assessment results showed that the risk quotient (RQ) ranged 20.04 ~ 36.25% and were less than 100%, which indicated that fosthiazate has a low risk for long-term dietary intake of cucumbers. Overall, our results would be considered as important references for safe and reasonable use of fosthiazate, monitoring and assessing the food safety, and protecting consumer health.

The Residual Behavior of Chlorothalonil and Metalaxyl in The Egyptian Cucumbers Fields Infested with Downy Mildew Using The High-Performance Liquid Chromatography (Hplc) and Quechers Method. سلوک متبقيات الکلوروثالونيل والميتالاکسيل فى حقول الخيار المصابه بالبياض الزغبى بإستخدام جهاز الکروماتوجراف السائل عالى الأداء HPLC)) بإستخدام طريقة الـQUECHER.

The dissipation rate of the commercial fungicide with two active ingredients (Chlorothalonil 64% + Metalaxyl 8%) that was approved by the agriculture pesticides committee was evaluated in the cucumber fields infested with downy mildew in Egypt using HPLC analytical system. The experiment was designed in randomized block design. After spraying at the recommended rate of applications, the samples of cucumber were chosen randomly from treated and un-treated plants after the interval of zero time(2hours), 1, 3, 7,10, and 14 days. The technique was validated at different fortification levels (0.01, 0.5, and 0.1 μg mL−1). The recoveries of both fungicides Chlorothalonil and Metalaxyl were 87.6 and 95 %. The results showed that the initial residues (zero time) were 4.38and 3.21 mg/kg-1. All detected residues significantly decreased upon time elevated. The residues extracted by an optimized QuEChERS coupled with HPLC analytical system were accurate and acceptable The limit of quantitation was 0.05 for both fungicides. The dissipation curves of both Chlorothalonil and Metalaxyl followed the first-order kinetics. The half-life’s (t½) values were 0.89 and 1.1days in, respectively. Under the optimized condition, the residues of Chlorothalonil and Metalaxyl in cucumber were below the codex maximum residue limit (0.5 and 3 mg/kg-1). Consequently, the pre-harvest intervals (PHI) in cucumber were seven days for the fungicide.

Keanekaragaman Hama dengan Kultur Teknis Berbeda Pada Lahan Mentimun (Cucumis Sativus) Di Desa Tanjung Seteko, Indralaya Utara, Kabupaten Ogan Ilir, Sumatera Selatan

There are many types of vegetables that are nutritious for health and metabolism, including cucumbers. Cucumbers are included in the vegetable category because cucumbers are often used as fresh vegetables or pickles. Cucumber cultivation is inseparable from pests and diseases. Pest management efforts must be carried out based on consideration of ecosystem stability. One of the techniques for controlling pests in cucumber plants can be done with technical culture. The research practice aims to determine the effect of technical culture on the diversity of pest types, population and intensity of cucumber pest attacks on two different fields in Tanjung Seteko Village, Inderalaya. The research was conducted with a sampling method to determine the population, intensity and pest attack. The research was carried out on two different fields of age and variety. Data analysis was performed using the t test at the 5% confidence level. Pests found in cucumber fields, namely, Aulacopho ra sp., Succinea sp., Valanga sp., And Leptoglossus sp. Based on observations in the field, technical culture in the village of Tanjung Seteko has a significant effect on the population and intensity of the attack of Succinea sp., Valanga sp. and Leptoglossus being Aulachopora sp. no significant effect.

Dissipation kinetics and safety evaluation of pyraclostrobin and its desmethoxy metabolite BF 500-3 in a cucumber greenhouse agroecosystem

Pyraclostrobin (PYR), a fungicide of the strobilurin class, is used to control many different kinds of fungal diseases in greenhouses and on agricultural fields. In the present study, an efficient method was established for simultaneously determining PYR and its metabolite BF 500-3 in cucumber fruits, leaves, and soil matrices using QuEChERS pretreatment coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The residue levels and dissipation kinetics of PYR were determined under greenhouse conditions. The recoveries ranged from 89.8 to 103.6% with relative standard deviations (RSDs) of 3.6-7.5% at three spiking levels. The results demonstrated that PYR dissipated quickly in the cucumber field with half-lives (DT50) of 2.14-4.17days on different sites and in different matrices. The residue of its metabolite BF 500-3 was very low and showed a trend of first increasing and then decreasing. The degradation rate of PYR in soil was the fastest, followed by that on cucumber fruits and leaves. The terminal residue of PYR at an application rate of 150g a.i. ha-1 (the maximum recommended rate) in cucumber fruits was below the maximum residue limit (MRL) of 0.5mg/kg established in China. However, the application of the fungicide at 225g a.i. ha-1 (1.5× the maximum recommended rate) resulted in residues that were above the MRL 1day after the final application, which is an unacceptable risk. Therefore, the application dosage of PYR at the recommended rates was safe to human beings and animals.

Effect of variable storage periods of male annihilation technique (MAT) lure on their attractancy to tephritids, fruit flies, Bactrocera spp. (tephritidae: Diptera)

The data on number of fruit flies trapped per week for a period of 7 weeks were taken at cucumber field var., Pusa Sanyog. It can be inferred from the data that irrespective of container, the mean number of trapped fruit flies was found to be significantly more in lure stored for 10 days (259.25 flies/trap/7 weeks) and was at par those stored for 15 days (184.75 flies/trap/7 weeks). Overall mean numbers of fruit flies trapped at other storage periods were found at par. The trap catch of males in parapheromone traps is affected by a large number of factors including the abiotic factors of the environment which indirectly alter the target insect i.e., fruit fly and behavior of the target pest. The maximum trap catch at 10 days storage period could be ascribed due to peak activity of the pest during this period. The critical examination of data indicated a consistent trapping between 127.5–142.5 flies/trap/7 weeks at 5, 20, 25 and 30 days storage period. Efficacy on different insecticide revealed that wooden pheromones lures containing spinosad as insecticide resulted in attracting maximum fruit fly population (88.65 flies/trap/weeks) followed by malathion (28.32 flies/trap/weeks) and Lambdacyhalothrin (8.67 flies/trap/weeks).

Exploring the communities of bacteria, fungi and ammonia oxidizers in rhizosphere of Fusarium-diseased greenhouse cucumber

Long-term greenhouse vegetable cultivation commonly incurs soil-borne diseases, which seriously threaten the sustainability of greenhouse production system. Rhizomicrobiome plays an important role in ensuring plant health and driving soil nutrient cycling. However, how rhizomicrobiome respond to the occurrence of soil-borne disease is still not completely clear. Increasing knowledge involved would benefit to the prevention of soil-borne disease in intensive greenhouse production by providing the insight into soil microbial ecology. Herein, with the help of a continuously cultivated greenhouse cucumber field, soil physicochemical and biochemical properties and the abundances (quantitative real-time PCR) and communities (high-throughput amplicon sequencing) of bacteria, fungi, ammonia-oxidizing archaea (AOA) and bacteria (AOB) in the rhizosphere of healthy and Fusarium-diseased cucumbers were investigated. Diseased cucumber rhizosphere had significantly higher available nutrient contents and acidity compared to healthy cucumber rhizosphere, but significantly lower microbial activity and nitrification capacity. Although there was no significant difference in the abundances of bacteria, fungi, AOA and AOB, diseased cucumber rhizosphere had more abundant Fusarium oxysporum. For bacteria, only community richness in diseased cucumber rhizosphere was significantly lower than that in healthy cucumber rhizosphere, whereas for fungi both community richness and Shannon diversity were significantly lower. Community structures of bacteria, fungi, AOA and AOB all significantly differed between healthy and diseased cucumber rhizosphere. Particularly, healthy cucumber rhizosphere had more abundant beneficial microbes (Bacillus and Penicillium) and putative biocontrol microbes (Mycothermus) as well as Nitrosospira briensis Clade-related AOB. These results revealed significantly different rhizomicrobiome between Fusarium wilt diseased and healthy cucumbers under long-term intensive greenhouse cultivation, and suggested that rhizomicrobiome may play an important role in the occurrence of Fusarium wilt disease of cucumber. The findings obtained here also provided potential directions towards the prevention of soil-borne diseases and the improvement of N turnover in diseased soil by manipulating rhizosphere microbiome.

Detection of Airborne Sporangia of Pseudoperonospora cubensis and P. humuli in Michigan Using Burkard Spore Traps Coupled to Quantitative PCR.

Cucurbit downy mildew (CDM), caused by the oomycete pathogen Pseudoperonospora cubensis, is a devastating foliar disease on cucumber resulting in reduced yields. In 2004, the pathogen re-emerged in the United States, infecting historically resistant cucumber cultivars and requiring the adoption of an intensive fungicide program. The pathogen cannot overwinter in Michigan fields but because of an influx of airborne sporangia CDM occurs annually. In Michigan, spore traps are used to monitor the presence of airborne P. cubensis sporangia in cucumber growing regions to guide the initiation of a fungicide program. However, Pseudoperonospora humuli sporangia, the causal agent of downy mildew on hop, are morphologically indistinguishable from P. cubensis sporangia. This morphological similarity reduces the ability to accurately detect P. cubensis from spore trap samples when examined with the aid of light microscopy. To improve P. cubensis detection, we adapted a qPCR-based assay to allow the differentiation between P. cubensis and P. humuli on Burkard spore trap samples collected in the field. Specifically, we evaluated the specificity and sensitivity of P. cubensis detection on Burkard spore trap tapes using a morphological-based and quantitative-PCR (qPCR)-based identification assay and determined whether sporangia of P. cubensis and P. humuli on Burkard samples could be distinguished using qPCR. We found that the qPCR assay was able to detect a single sporangium of each species on spore trap samples collected in the field with Cq values <35.5. The qPCR assay also allowed the detection of P. cubensis and P. humuli in samples containing sporangia from both species. However, the number of sporangia quantified using light microscopy explained only 54 and 10% of the variation in the Cq values of P. cubensis and P. humuli, respectively, suggesting a limited capacity of the qPCR assay for the absolute quantification of sporangia in field samples. After 2 years of monitoring using Burkard spore traps coupled with the qPCR in cucumber fields, P. humuli sporangia were detected more frequently than P. cubensis early in the growing season (May and June). P. cubensis sporangia were detected ∼5 to 10 days before CDM symptoms were first observed in cucumber fields during both years. This research describes an improved sporangial detection system that is key for the monitoring and management of P. cubensis in Michigan.

The impact of 1-MCP on growth and yield of cucumber in open field

In order to explore the preliminary effect of 1-MCP application at seedling stage on the growth effect and yield of open field cucumber, this experiment conducted cultivation experiments on three application periods (leaf spraying at one leaf stage, 2 days before planting, spraying after the third harvest), two treatment times (one treatment, two treatment), and two management methods (removing the first and second female flowers, and conventional management). The results showed that in the open field cucumber cultivation experiment, the application of 1-MCP at seedling stage could promote the growth of cucumber, and the T4 treatment was the best, and the second treatment was better than the first treatment; T4 (0.35 mL 1-MCP + treatment 2 days before colonization + after the third harvest + routine management) treatment scheme had the best effect.

Influence of Different Cucumber Varieties on the Occurrence of the Piercing-Sucking Insect Pests in Fayoum Governorate

The present experiments were conducted in a private cucumber field in Ibshwai, Fayoum governorate during the two successive years (2018 and 2019) to examine the influence of different cucumber varieties on the occurrence of the piercing-sucking insect pests in Fayoum governorate. Cucumber variety Reda F1 hybrid followed by variety Sweet Cransh F1 hybrid attracted the highest average number of the cotton aphid Aphis gossypii followed by the cotton whitefly Bemisia tabaci, the leafhopper Empoasca decedens, the green peach aphid Myzus persicae and the potato leafhopper Empoasca decipiens during the two years 2018 and 2019. Cucumber variety Hayel F1 hybrid followed variety Mayadine F1 hybrid hosted the lowest average number of the aforementioned insect pests during the two years. Cucumber variety Hayel F1 hybrid followed by Mayadine F1 hybrid, Reda F1 hybrid and Sweet Cransh F1 hybrid hosted the lowest average number of the green sting bug Nezara viridula followed by the cotton mealybug Planococcus solenopsis and the onion thrips Thrips tabaci during the two years. Cucumber variety Hayel F1 hybrid had the lowest rate of occurrence (23.3 and 23.5 %) followed by Mayadine F1 hybrid (24.6 and 23.9 %) during the two years 2018 and 2019, respectively.

Influence of Sowing Dates on the Aphid Species Attacking Cucumber Crop in Fayoum Governorate

The present experiments were conducted in a private cucumber field in Ibshwai, Fayoum governorate during the two successive years (2018 and 2019) to evaluate the influence of sowing dates on the aphid species that attacking cucumber crop in Fayoum governorate. The cotton aphid Aphis gossypii reached the highest peak of abundance in March sowing date in the fourth week of April 2018 (916 individuals/sample) and in the first week of May 2019 (1083 individuals/sample). While, in August sowing date, A. gossypii reached the highest peak of abundance in the fourth week of October 2018 and 2019 with 671 and 783 individuals/sample, respectively. Moreover, in October sowing date, A. gossypii reached the highest peak of abundance in the second week of November 2018 and in the third week of November 2019 and represented by 934 and 1214 individuals/sample, during the two years, respectively. The green peach aphid, Myzus persicae recorded the highest peak of abundance in March sowing date in the second week of April 2018 (317 individuals/sample) and in the fourth week of April 2019 (324 individuals/sample). While in August sowing date M. persicae recorded the highest peak of abundance in the second week of October 2018 and in the fourth week of September 2019 and presented by 428 and 302 individuals/sample, respectively. Meanwhile, in October sowing date, M. persicae recorded the highest peak of abundance in the second week of November 2018 and 2019 and presented by 183 and 124 individuals/sample, respectively.

ENVIRONMENTAL PESTICIDE RESIDUES AND HEALTH BIOMARKERS AMONG FARMERS FROM GREENHOUSES OF ERBIL CUCUMBER CROPS

This study was aimed to determine the residual concentrations of pesticides used in greenhouse cucumber fields and their effects on the farmers that spray it. Sixteen active cucumber greenhouse fields with 96 people (75 sprayers and 21 volunteers as control) randomly had been selected. In all selected greenhouses, abamectin, thiamethoxam, pyridabin, and spirodiclofen pesticides were used, their cucumber with leaves and groundwater collected in December 2017, March, June, and September 2018 with workers blood samples, were immediately brought to the laboratory. Results showed the occurrence of residual pesticides in the plant and groundwater samples with a highest level in the plant samples, while decreased in water samples. That is in comparison with control, sprayer blood results showed that cholinesterase activity decreased significantly meanwhile, liver function enzymes: serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase, direct and total serum bilirubin increased significantly. The kidney function test revealed that the mean serum urea concentration in the sprayers was considerably increased compared to the controls, while there was no significant change between the sprayers and the control serum creatinine. Slight variations in the declining number of red blood cells; however, white blood cells have significantly risen to their upper limit within normal ranges.

Carmine spider mite Tetranychus cinnabarinus control: Laboratory and field efficacy and biochemical characterization of 2, 4-di-tertbutylphenol and ethyl oleate

Natural pesticides are potential alternatives to conventional chemical pesticides. Recently, studies on pesticide–pest interactions have combined empirical biochemical measurements and practical field experiments. In this study, we performed laboratory and field efficacy analysis and biochemical characterization of two phytochemicals (2,4-di-tertbutylphenol (DTBP) and ethyl oleate (EO)) for carmine spider mite Tetranychus cinnabarinus control. DTBP and EO controlled mites by inhibiting egg hatchability and showed significant residual toxicity in laboratory tests. The control efficacy was confirmed in eggplant and cucumber field trials in three provinces in China. Oxidative stress induced by antioxidant enzymes (superoxide dismutase and peroxidase) and detoxification metabolism (involving carboxylesterase and/or mixed-function oxidase) may be involved in the response of mites to DTBP and EO. This study demonstrates the potential of DTBP and EO as effective acaricides for the control of spider mites and provides researchers a better understanding of acaricide–mite interactions.