Enhancing cereal crop production to feed the largely growing population is an important approach towards maintaining food security. Fertilizer management is the major component of crop production requiring special attention for sustainable application. Integrated nutrient management (INM) is an evolving idea, which appears to contribute to sustainable nutrient management. A field study was designed to see the impact of INM on a maize–wheat cropping system during winter (wheat) and summer (maize) season at Agronomic Research Farm, Bahauddin Zakariya University Multan, Pakistan. Both wheat and maize crops were grown consecutively along with full inorganic fertilizer (NPK) as well as with partial dose of fertilizer (25%, 50%, 75% NPK) supplemented with or without the addition of biochar (5 ton/ha). Data were collected regarding crop growth, yield and quality and further analyzed using MSTAT-C statistics software. Results revealed that the INM approach (75% of NPK + Biochar) enabled crops to improve dry matter production and its translocation towards sink which in turn boosted the crop productivity. This treatment improved dry matter (19%, 57%), grain weight (44%, 54%), grain yield (60%, 63%) and harvest index (30%, 29%) over the control in maize and wheat crops. It also improved the nutrient uptake in the plants which in turn improved the nutrient contents in the grains. Similarly, crops recorded higher system productivity (USD 790, USD 830) in both years and were found to be economically sustainable under INM. It was concluded that an INM strategy (75% of NPK + Biochar) can improve the productivity and sustainability of a maize–wheat cropping system to maintain the food security.
Flonicamid is a chordotonal modulator and novel systemic insecticide that has been used frequently for controlling a broad range of insect pests. The risk of flonicamid resistance was assessed through laboratory selection and determining inheritance pattern and cross-resistance potential to five insecticides in house fly, Musca domestica L. Very low to high flonicamid resistance in M. domestica populations was found compared with the susceptible strain (SS). A flonicamid-selected (Flonica-RS) M. domestica strain developed 57.73-fold resistance to flonicamid screened for 20 generations compared with the SS. Overlapping 95% fiducial limits of LC50 of the F1 and F1ǂ, and dominance values (0.87 for F1 and 0.92 for F1ǂ) revealed an autosomal and incomplete dominant flonicamid resistance. The monogenic model of resistance inheritance suggested a polygenic flonicamid resistance. The Flonica-RS strain displayed negative cross-resistance between flonicamid and sulfoxaflor (0.10-fold) or clothianidin (0.50-fold), and very low cross-resistance between flonicamid and flubendiamide (4.71-fold), spinetoram (4.68-fold), or thiamethoxam (2.02-fold) in comparison with the field population. The estimated realized heritability (h2) value of flonicamid resistance was 0.02. With selection mortality 40–90%, the generations required for a 10-fold increase in LC50 of flonicamid were 94–258 at h2 (0.02) and slope (3.29). Flonicamid resistance was inherited as autosomal, incomplete dominant, and polygenic in the Flonica-RS. Negative or very low cross-resistance between flonicamid and sulfoxaflor, clothianidin, flubendiamide, spinetoram, and thiamethoxam means that these insecticides can be used as alternatives for controlling M. domestica. These data can be useful in devising the management for M. domestica.
19 October 2022 in International Journal of Tropical Insect Science
Three standard foodstuff plastic packaging namely polyethylene (PE), polypropylene (PP), and polyvinylchloride (PVC) were evaluated for management of lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Resistance parameters in packaging were recorded as punctures, holes, penetrations, sealing defects, and invasions with two thicknesses and tested for two lengths of time . Damages like punctures, holes and penetrations by both insects were more in PE packaging however R. dominica made more penetrations in PP than in PE. For both insects sealing defects and invasions were predominant in PVC than in others. Thickness did not affect significantly damage types but significantly more holes and penetrations by R. dominica were in less thickness. Punctures and holes by R. dominica were more after less time period but other damages in packaging were more after more time period. However for T. castaneum all sorts of damages were seen more after more time period. Overall categorization between two insects showed R. dominica made more penetrations and T. castaneum made more invasions compared with their counterparts. Pictures were taken under camera fitted microscope to magnify punctures and holes in different packaging and thicknesses. Insect mortality due to phosphine was more in PP and PE packaging and least in PVC packaging and thickness effect was marginal. T. castaneum mortality was significantly more after 48 h than after 24 h. Damages extent in packaging and fumigation results showed PP to be the best of three packaging materials to manage these insects.
10 September 2020 in International Journal of Tropical Insect Science