Journal Of Crop Protection
Volume:11 Issue: 3, Sep 2022

Leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae), is one of the important woodboring pests whose larvae bore into twigs, branches, and trunks of various woody species, weakening and sometimes killing trees or shrubs. Recently it has caused severe losses of walnut trees in Iran. This pest overwinters as different larval instars inside trees. Overwintering larvae were collected monthly from October 2020 to March 2021 from Maragheh walnut orchards, northwestern Iran, to determine the presence of cryoprotectants and their changes during autumn and winter. Overwintering larvae accumulated sorbitol, trehalose, and myo-inositol during winter. During cold months there was approximately 11 fold and 7.5-fold increase in trehalose and sorbitol contents, respectively. Glycogen content was the highest in October and decreased significantly with decreasing ambient temperature. Our results suggest that the accumulation of sorbitol, trehalose, and myo-inositol plays an important role in the harsh-season survival of Z. pyrina.

Based on the chemical properties of herbicide and carrier water, water hardness might have different impacts on herbicide performance. A study was conducted in the greenhouse to determine the effect of chloride and bicarbonate forms of Mg+2 and Na+ on the performance of clodinafop-propargyl and sulfosulfuron for littleseed canarygrass control. The concentrations of bicarbonate and chloride forms of Mg+2 and Na+ had no significant effect on the ED50 of clodinafop-propargyl. The relative potency of clodinafop-propargyl, in the presence of all mineral salts, was 1.0 or had no significant difference from 1.0. On the contrary, increasing the mineral salts reduced the ED50 of sulfosulfuron significantly, especially in the presence of bicarbonate forms of Mg+2 and Na+. In this regard, the relative potency of sulfosulfuron as affected by 100 to 800 ppm Mg(HCO3)2 was about 0.5 to 0.7 times higher than control. This value was increased from 0.5 to 2.2 at 100 to 800 ppm sodium bicarbonate. Hence, the ranking of the mineral salts on improving sulfosulfuron performance was NaHCO3 > Mg(HCO3)2 > MgCl2 > NaCl. It is suggested that because of the lipophilic nature of clodinafop-propargyl, the presence of mineral salts did not affect the performance of this herbicide. It is concluded that, in determining the effect of water hardness on herbicide performance, in addition to chemical properties of herbicide, type of mineral salt, and its concentration, it is also essential to know the changes in the pH of the carrier water due to the mineral salts.

An effective in vitro approach to predict host resistance and pathogenicity of Fusarium species causing head blight (FHB) may improve resistance evaluation in wheat. The in vitro capacity of four Fusarium species to cause disease on young plant parts of six bread and durum wheat cultivars with known quantitative resistance was assessed using a coleoptile infection assay. Significant differences were detected in pathogenicity among Fusarium species and susceptibility/resistance levels among wheat cultivars. Only the resistance measured by coleoptile length (CL) was correlated with resistance criteria generated under in vitro (area under disease progress curve, r = -0.951), controlled (Type I and Type II, r = -0.813 and r = -0.907, respectively) and field (Type I during 2018/19 and 2019/20, r = -0.857 and r = -0.866, respectively) conditions. Moreover, the values of seed germination and CL components were significantly correlated with pathogenic indices obtained under several experimental conditions. CL predicts quantitative traits at the earliest and latest wheat development phases during disease invasion. Thus, CL may suggest a veritable potential of simple, quick, and trustworthy early screening of FHB resistance in wheat cultivars and the pathogenicity of Fusarium species.

A greenhouse experiment was conducted to examine the influence of Phelipanche aegyptiaca on vegetative growth, rate of photosynthesis, chlorophyll fluorescence and leaf chlorophyll content of 35 cucumber genotypes. High demand of assimilates by P. aegyptiaca caused significant reductions in shoot and root dry weight, leaf number, leaf area and plant height in all cucumber genotypes. Once plants were infected by P. aegyptiaca, the leaf chlorophyll content, the photosynthesis rate and the maximum quantum yield of PSII chemistry were significantly less than control, thus implying a reduction in carbon assimilation, photosynthesis efficiency and susceptibility of infected plants to photoinhibition. P. aegyptiaca traits were significantly affected by cucumber genotypes. There was no correlation between P. aegyptiaca traits with the reduction percentage of cucumber shoot dry weight. However, there were correlations between underground attachments number plant-1 (UAN) and percentage of cucumber root dry weight reduction (-0.58), total attachment number plant -1 (TAN) and the percentage of reduction of root dry weight (+0.39). In accordance with the results obtained, the genotypes were classified into 3 groups. It was demonstrated that the genotype number 22 (Khassib) behaved differently to other genotypes and, in particular, they suffered less damage from the presence of P. aegyptiaca.

This study aimed to assess the insecticidal properties from leaf extracts of Chromolaena odorata L. and Leonotis nepetifolia (L) R.Br. on the third instar larvae of tobacco leaf-eating Spodoptera litura (F.). Leaves of both plant species were extracted with three solvents, acetone, methanol, and water, then tested for ovicidal, antifeedant, and larvicidal activity at 0.5, 1, 2.5, 5, and 7%. The methanol extract (5%) of C. odorata was found more active for ovicidal (73.33 ± 0.57%), antifeedant (82.45 ± 0.16%), and larvicidal (68.33 ± 0.05%) activities against S. litura. Similar results were noted from methanol extract (5%) of L. nepetifolia for ovicidal (71.33 ± 0.41%), antifeedant (71.77 ± 0.73%), and larvicidal (73.33 ± 0.08) activities. Phytochemical screening revealed a significant amount of alkaloids and phenolics in methanolic leaf extracts of both plants. Besides, thirty-one bioactive compounds from the methanolic extract of C. odorata and sixteen compounds from L. nepetifolia were identified by GC-MS analysis. The recorded compounds are phenols, fatty acids, esters, and essential oils with insecticidal properties. The insecticidal compounds detected from GC-MS and quantitative phytochemical analysis might be attributed to the high insecticidal potential (Ovicidal, antifeedant and larvicidal) of C. odorata and L. nepetifolia. Therefore extensive research on C. odorata and L. nepetifolia is needed in phytopesticide development against Spodoptera litura.

Among specimens collected from some parts of East Azerbaijan and West Azerbaijan provinces, Iran, during 2017-2019, nine species of the genera Coniosternum Becker, 1894; Cordilura Fallén, 1810; Gimnomera Rondani, 1866 and Scathophaga Meigen, 1803 were identified. Three species of Gimnomera dorsata (Zetterstedt, 1838), Scathophaga inquinata (Meigen, 1826), and Scathophaga islandica (Becker, 1894), are reported as new records of the Iranian insect fauna. A key to the studied species, along with their diagnostic characters, geographical distribution, supplementary figures, and an updated checklist of the Iranian Scathophagidae, are given.

In this study, the nutritional indices of the larval stages of Helicoverpa armigera were determined on four vegetable crops under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, with a 16:8 (L: D) h photoperiod). The third instar larvae reared on potato showed the highest value of efficiency on the conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) (8.281 ± 0.767% and 11.016 ± 1.142%, respectively). The highest (0.129 ± 0.014 mg/mg/day) and lowest (0.069 ±0.012 mg/mg/day) relative growth rate (RGR) of the fourth instar larvae were obtained on potato and tomato, respectively. Data indicated that the highest value of (ECI) and (ECD) for fourth instar larvae were on tomato (12.361 ± 2.258% and 18.588 ± 3.834%, respectively). The lowest value of the relative consumption rate (RCR) and approximate digestibility (AD) of the fifth instar was recorded on tomato (0.592 ± 0.063 mg/mg/day) and potato (51.85 ± 4.607%), respectively. The ECI and ECD values of the fifth larval instar were the highest on tomato (12.477 ± 1.333% and 17.624 ± 1.609%, respectively). Overall, among different host plants tested, the highest ECI and ECD of all the larval instars were observed on tomato (9.813 ± 0.692% and 12.506 ± 0.882%, respectively), and the lowest values (3.735 ± 0.201% and 5.463 ± 0.426%) were on artichoke. Tomato and artichoke were the most nutritionally suitable and unsuitable host plants, respectively, for H. armigera.

The geometric -morphometric method has become a vital tool for examining shape and size variation s . The current study analyzed the effect of gamma radiation on wing characteristics of sterile and normal Medflies, C. capitata , on landmark -and outline -based geometric morphometric s. In landmark -based, there were significant differences in weight matrices as shape variable , but the centroid size as size variable was statistically non -significant between the two populations. PCA of the sterile and normal populations manifested a clear distinction from the result s. MANOVA further ascertained significant wing shape differences between sterile and normal populations. In the outline -based approach, PCA of the contours revealed that 10 out of the 80 principal components effectively explained shape attributes. The statistical tests were utilized to introduce the significant influence considered in the sterile insect technique (SIT) because , in the long run , these changes may distort the result s of SIT project.

Wax y -leaved mustard Boreava orientalis Jaub. and Spach. has recently become farmland invasive weed in the Kurdistan province , Iran. Hence this study was conducted better to understand the seed germination ec ology of B. orientalis. Therefore, in this study, the effect of temperature and osmotic potential, salinity , and burial depth on seed germination and seedling emergence of B. orientalis was investigated in the Weed Research Laboratory of the University of Kurdistan in 2020 . Seed germination of B. orientalis was determined at 10, 20, 30 , and 35 °C. Boreava orientalis seeds were germinated in an aqueous solution with the osmotic potential of 0, 3, 6, 9 , and 12 MPa. The levels of salt stress consisted of control 0, 50, 100, 150, and 200 mM. The burial depths were 0, 3, 6, 9 , and 12 cm. The results revealed that germination started at 5 ºC with 0 osmotic potential , and no germination occurred at 30 and 35 °C with different osmotic potentials. The Lowest germination was at 30 and 35 °C; the highest was at 0 Mm NaCl concentration, and the lowest was at 200 Mm of NaCl. The highest germination was at 0 depth , and the lowest was at 12 cm. T hese results indicate that the germination of this weed species is sensitive and thus greatly reduced under drought and high -temperature conditions. It was also sensitive to both salinity stress and deep burial.

Damping-off disease caused by Phytophthora melonis is the most common disease of cucumber seedlings Cucumis sativus L.. To study the efficacy of 8-hydroxy quinoline sulfate (Beltanol®) in control of cucumber damping-off disease, glasshouse experiments were carried out with six treatments at research stations in Tehran, Alborz, and Semnan provinces in Iran. Treatments included 0.3, 0.4, and 0.5 ml∙l-1 of Beltanol as the experimental fungicide, metalaxyl+mancozeb (Rosalaxyl® WP 72%; FRAC code 3 + M03) at 2 g∙l-1 as the standard fungicide along with inoculated and untreated and non-inoculated (healthy) controls. Cucumbers were cultivated from seed in trays, and treatments were applied twice. Once after seed sowing and second time at the 2-leaf stage. Disease incidence was recorded at the 4-leaf stage. Beltanol at 0.3 ml∙l-1 had the least effect among fungicides, with nearly 50% of treated plants showing signs of disease. Application of Beltanol at 0.4 and 0.5 ml∙l-1 decreased disease incidence by 59.55 and 64.47% compared to the inoculated control, respectively. Rosalaxyl® performed better than Beltanol and reduced disease by 83.55%. However, to provide alternatives for proper fungicide rotations, Beltanol at the rate of 0.4 ml∙l-1 may manage damping-off disease in cucumber.