Browsing by Author "Kaur, Shalinder"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Chemical Characterization and Phytotoxicity of Foliar Volatiles and Essential Oil of Callistemon viminalis(Har Krishan Bhalla and Sons, 2017) Bali, Aditi Shreeya; Batish, Daizy R.; Singh, Harminder Pal; Kaur, Shalinder; Kohli, R.K.We investigated the chemical composition and phytotoxicity of foliar volatiles (directly released from the macerated leaves) and essential oil extracted from the leaves of Callistemon viminalis against four weed species. Essential oil (EO) and foliar volatiles caused reduction in germination, seedling growth and dry matter accumulation in Bidens pilosa, Cassia occidentalis, Echinochloa crus-galli and Phalaris minor. Bidens pilosa was found to be the most sensitive towards foliar volatiles and EO, whereas C. occidentalis was the least sensitive. The chemical analyses of foliar volatiles and EO revealed the presence of 1,8-cineole and ?-pinene as the main monoterpenes. The study concludes that volatile components of C. viminalis possess phytotoxicity against weeds and thus may hold promise for the management of weeds under sustainable agriculture. ? 2017, Har Krishan Bhalla & Sons.Item EMF radiations (1800 MHz)-inhibited early seedling growth of maize (Zea mays) involves alterations in starch and sucrose metabolism(Springer, 2016) Kumar, Arvind; Singh, Harminder Pal; Batish, Daizy R.; Kaur, Shalinder; Kohli, R.K.The present study investigated the impact of 1800-MHz electromagnetic field radiations (EMF-r), widely used in mobile communication, on the growth and activity of starch-, sucrose-, and phosphate-hydrolyzing enzymes in Zea mays seedlings. We exposed Z. mays to modulated continuous wave homogenous EMF-r at specific absorption rate (SAR) of 1.69±0.0 × 10−1 W kg−1 for ½, 1, 2, and 4 h. The analysis of seedlings after 7 days revealed that short-term exposure did not induce any significant change, while longer exposure of 4 h caused significant growth and biochemical alterations. There was a reduction in the root and coleoptile length with more pronounced effect on coleoptile growth (23 % reduction on 4-h exposure). The contents of photosynthetic pigments and total carbohydrates declined by 13 and 18 %, respectively, in 4-h exposure treatments compared to unexposed control. The activity of starch-hydrolyzing enzymes—α- and β-amylases—increased by ∼92 and 94 %, respectively, at an exposure duration of 4 h, over that in the control. In response to 4-h exposure treatment, the activity of sucrolytic enzymes—acid invertases and alkaline invertases—was increased by 88 and 266 %, whereas the specific activities of phosphohydrolytic enzymes (acid phosphatases and alkaline phosphatases) showed initial increase up to ≤2 h duration and then declined at >2 h exposure duration. The study concludes that EMF-r-inhibited seedling growth of Z. mays involves interference with starch and sucrose metabolism.Item Phytotoxic effects of volatile oil from Artemisia scoparia against weeds and its possible use as a bioherbicide(Elsevier, 2010) Kaur, Shalinder; Singh, Harminder Pal; Mittal, Sunil; Batish, Daizy R.; Kohli, R.K.A study was conducted to assess the bioherbicidal activity of volatile oil hydrodistilled from Artemisia scoparia Waldst et Kit. (red stem wormwood; Asteraceae) against five weed species, viz. Achyranthes aspera, Cassia occidentalis, Parthenium hysterophorus, Echinochloa crus-galli, and Ageratum conyzoides. Emergence and seedling growth (in terms of root and shoot length) were significantly reduced in a dose–response bioassay conducted in sand impregnated with Artemisia oil (at ≥10, 25, and 50 μg Artemisia oil/g sand). In general, the root length was inhibited more as compared to the shoot length and the inhibitory effect was greatest in P. hysterophorus followed by A. conyzoides and least in C. occidentalis. Post-emergence application of Artemisia oil (2%, 4%, and 6%, v/v) on 6-week-old weed plants caused visible injury (1- and 7-days after spray) ranging from chlorosis to necrosis to complete wilting of plants. Among the sprayed test weeds, the effect was greatest on E. crus-galli and P. hysterophorus. Artemisia oil treatment resulted in a loss of chlorophyll content and cellular respiration in test weeds thereby implying interference/impairment with photosynthetic and respiratory metabolism. Artemisia oil caused a severe electrolyte leakage from E. crus-galli (a monocot) and C. occidentalis (a dicot) indicating membrane disruption and loss of integrity. The study concludes that Artemisia oil has bioherbicidal properties as it causes severe phytotoxicity and interferes with the growth and physiological processes of some weed species.Item Phytotoxicity and weed management potential of leaf extracts of Callistemon viminalis against the weeds of rice(Springer, 2017) Bali, Aditi Shreeya; Batish, Daizy R.; Singh, Harminder Pal; Kaur, Shalinder; Kohli, R.K.We explored the phytotoxicity of Callistemon viminalis leaf extracts (LE; 0.5, 1, 2 and 4%) towards germination and early growth of rice (Oryza sativa L.) and its associated weeds [Echinochloa crus-galli (L.) Beauv., Cyperus rotundus L., Leptochloa chinensis (L.) Nees. and Commelina benghalensis L.], under laboratory and greenhouse conditions. In a laboratory assay, leaf extracts (4%) inhibited germination (40–52%), root length (36–85%), shoot length (37–64%), dry weight (27–67%) and chlorophyll content (20–42%) in all the weeds. Under greenhouse conditions, 2% leaf extracts (LE) + Butachlor (well-known herbicide; H; 50% E.C.; 2:1, v/v) severely affected the emergence and biomass of all the weeds. However, there was no effect on the growth and yield attributes of rice. Moreover, upon 2% LE + H treatment, the plant height and number of grains per plant increased significantly and the effect was comparable to the recommended dose of Butachlor. The results suggested the presence of water-soluble allelochemicals (mainly phenolics) in the leaf extracts that could be responsible for the observed inhibitory effect. Based on the study, it could be concluded that C. viminalis leaf extracts hold good potential for possible weed management, and further research could be done to develop it as an alternative to synthetic herbicides in sustainable agriculture under field conditions.