Home > Efficacy of Entomopathogenic Fungi and Their Combinations With Some Selective Insecticides Against Bemisia Tabaci Genn. and Tetranychus Urticae Koch on Cotton
Efficacy of Entomopathogenic Fungi and Their Combinations With Some Selective Insecticides Against Bemisia Tabaci Genn. and Tetranychus Urticae Koch on Cotton
The cotton whitefly, Bemisia tabaci Genn. and Two-Spotted Spider Mites (TSSM), Tetranychus urticae Koch are emerging as important sucking pests of cotton crop. The indiscriminate use of pesticides against insect pests have resulted in the development of resistance among these pests as well as environmental and health hazards. The use of microbial control agents is an important approach to combat this menace. The present study was therefore, carried out to determine the efficacy of some strains of entomopathogenic fungi viz., Metarhizium anisopliae, Isaria fumosorosea, Lecanicillium muscarium and Beaveria bassiana against all immature stages of whitefly and eggs and adult females of TSSM in the Department of Entomology at University of Agriculture, Faisalabad, Pakistan and Department of Pure and Applied Ecology, Swansea University, Swansea U.K. for the bioassays on whitefly. The potential of various entomopathogenic fungi was evaluated on 2 nd instar nymphs of whitefly and four of them were found promising. The detailed studies were carried out on other immature stages of whitefly with the promising strains. The dose- mortality response was observed by using serial dilutions, 1×10 5 to 1×10 8 conidia mL -1 against most susceptible stage using detached leaf immersion method for whitefly and spraying the detached leaf for bioassay with TSSM. All tested fungal isolates caused mortality in the tested stages of both insects under consideration except eggs of whitefly for which very low susceptibility was observed. The L. muscarium (V17) isolate was highly virulent among the tested ones for whitefly nymphs while Pf (n32) isolate was highly virulent against both the stages of TSSM. The mortality of each stage was recorded daily up to 8 days for both the insects under study. The % mortality significantly differed based on fungal isolates, stage of the insect and conidial concentrations. The % mortality increased with increasing the dose of conidial concentration of each fungal isolate in each insect. For whitefly, the most virulent isolate, (V17) has LC 50 value of 1.9×10 5 conidia mL -1 and it killed about 89.58 % of the treated second instar nymphs 8 days post treatment while its LT 50 value at higher concentration is 4.03 days. For TSSM, the most virulent isolate was Pf (n32) with lowest LC 50 value of 9.1 × 10 4 conidia mL -1 on 8 th day and LT 50 value of 4.58 days at 1×10 8 conidia mL -1 . It killed about 82.16 % of the inoculated females 8 days post treatment. The xresults indicated that L. muscarium and I. fumosorosea strains have potential as microbial control agent against cotton whitefly and mites, respectively, in Pakistan. The studies were also carried out to determine the LC 50 values and also efficacy of some commercial insecticides and acaricides against whitefly and TSSM in the laboratory. Four different insecticides were evaluated in the lab against 2 nd instar nymphs of whitefly on cotton. All the tested insecticides caused significant mortality of whitefly from 3-5 days post treatment. However, the most effective insecticides for whitefly, up to 5 days were Mospilon ® and Confidor ® with very low LC 50 values while others were also equally effective but with high LC 50 values. Similarly, the chlorfenapyr 36 SC, pyridaben 15 EC and fenpyroximate 5 SC proved to be the best miticides among the tested ones for the control of TSSM based on their LC 50 values. The nine commercial pesticides and their effects on germination of conidia and mycelial growth of highly efficacious fungal strains viz., I. fumosorosea and L. muscarium were investigated in vitro. There was a significant variation in conidial germination as well as mycelial growth by all tested pesticides depending upon the dose of pesticide and type of fungus. Among the pesticides tested azocyclotin was proved to be highly toxic to germination of spores as well as mycelial growth followed by pyridaben, acetamiprid and propergite while buprofezin was the least toxic. Isaria was proved to be more sensitive at field recommended doses than Lecanicillium strain to all pesticides. Generally, among all pesticides used the insecticides were more compatible to fungi than acaricides although these also inhibited germination of spores and fungal growth to some extent. The combined application of pesticides with selective fungi proved to be synergistic giving more control than used alone. The combined effects were tested under greenhouse conditions on potted plants. Buprofezin, acetamiprid, imidacloprid and diafenthuron were used against 2 nd instar nymphs of whitefly while chlorfenapyr, pyridaben and fenpyroximate were used against TSSM. Only buprofezin and imidacloprid insecticides showed synergistic effects and others additive while no one showed antagonistic results. Chlorfenapyr combined with fungus yielded highest mortality among acaricides tested. However, further investigations under field conditions may reveal more comprehensive results.
اندر کنڈے باہر پھل تیرے پول گئے نیں کھل ساڈا وطن ٹھکانہ نہیں توں نہ ساڈے پچھے رُل سچ کڑاکے کڈھ دا جد جندرے جاندے سارے کھل وٹ عاشق دے کڈھن پئے پتلے لک دے نال کڑُل مان حسن دا کرنا کیہ پونا ایں جد اٹی مُل نت بناویں یار نویں تینوں گئے پرانے بُھل تیریاں اندر یاداں جو میرا اے سرمایہ کُل
COVID 19 is a recent and global pandemic. Preventive medicine is not very popular in Pakistan. With the limited resources, an average Pakistani would spend on a medical treatment rather than on a preventive drug. In Pakistan, booster shots are recently made available only to those who can pay for the cost of the vaccine. A Utilitarian approach has been adopted at various levels since the pandemic emerged by health care organizations and the government. The purpose was to maximize the benefits and minimize the risk of harm. It is the need of the hour to think about health equity and justice in a pluralistic way and refrain from initiating booster shots for elite of a resource-poor country. This pandemic will never end if a maximum number of people are not vaccinated in each country. This is only possible if there is an equitable distribution of vaccines.
Agriculture is badly affected by heavy metals toxicity. To reduce the hazardous effects of metals, it needs remediation methods which are energy efficient, economically viable and environment friendly like “phytoremediation”. Some crops having potential to extract metals ions from soils without much polluting the edible part. Quinoa (Chenopodium quinoa willd), a pseudo cereal, being a facultative halophyte has the ability to survive under the metal contaminated soil. The research has been carried out in agro ecological conditions of Faisalabad comprised of two experiments i.e. (i) Screening of quinoa lines for heavy metal extraction(ii) Evaluation of the growth and yield of quinoa lines under heavy metals contaminated soil. Experiment I was conducted in net house, department of Agronomy, University of Agriculture, Faisalabad during 2013-14. While Experiment II was carried out at two different fields of problem soils at (Chakera Farm (UAF) and Chakera village) and normal soil at Agronomy Research Area Farm, University of Agriculture, Faisalabad. Contaminated soils were selected on the base of soil analysis. Data regarding growth, morphological, biochemical, yield and nutritional aspects were recorded using standard procedures. All quinoa lines survived at 50 and 100 mg/kg and produced seeds. Results showed that translocation of heavy metals increased from root to shoot with increase in soil metal concentration in all lines with trend A2>A1>A7>A9, however A2 line was most hyper accumulator in leaf as compared to root. In 2nd experiment, four quinoa lines were allowed to grow in three fields under RCBD split plot arrangement. Maximum seed yield (4100 kg ha-1) was obtained by A7 which was statistically similar to A2 line (3648 kg ha-1) obtained from Chakera Farm (UAF) having sewage water application. While low yield was obtained from A9 (1482 kg ha-1) at normal soil (control). Both A7 and A2 lines exhibited higher biomass and seed yield at three fields. Both fields having sewage water application resulted higher growth and superb seed yield of quinoa lines as compared to control. Higher level of antioxidants, proline, carotenoids and phenolic content of A7 and A2 helped to withstand metal stress and might be cause of high yield under both normal and metal contaminated fields. Seed quality was substantially affected by heavy metal concentration in both contaminated fields. Metals concentration determined in seed samples of A7 was high as compared to A2. Hence A2 may be said as nutritionally superior quinoa line as metals levels were within permissible level set by FAO/WHO.