PHYTOTOXIC EFFECT OF AQUEOUS EXTRACTS OF DIFFERENT PLANT PARTS OF SPHAERANTHUS INDICUS ON GERMINATION AND SEEDLING GROWTH OF ELEASINE CORACANA

GAP iNTERDISCIPLINARITIES – Volume – IV, Issue – III July September 2021 15 https://winterdisciplinarities.org/ PHYTOTOXIC EFFECT OF AQUEOUS EXTRACTS OF DIFFERENT PLANT PARTS OF SPHAERANTHUS INDICUS ON GERMINATION AND SEEDLING GROWTH OF ELEASINE CORACANA B. A. Kumbhar and P. J. Dabgar Gujarat Arts and Science College, Ahmedabad (Gujarat) India.   Abstract The phytotoxic influences of water extract of different plant parts of Sphaeranthus indicus (Burandu) were tested by growing test crop of Eleasine coracana (Nagli) for seedling growth. Significant differences in the growth of the test crop were observed. The hypocotyl growth of test crop depressed significantly at high concentration (6%) aqueous extract of different plant parts of S. indicus was found after 10 days. Redicle length of Nagli crop was stimulated in 2% shoot aqueous extract of Sphaeranthus indicus whereas other concentrations of all aqueous extracts of Burandu weed show phytotoxic effects as compared to control after ten days. Shoot and Root dry weights of food crop were reduced by Burandu residue. Test crop Nagli was more sensitive to root aqueous extract while less sensitive to shoot aqueous extract of Sphaeranthus indicus.


INTRODUCTION
The term allelopathy was introduced by Molisch in 1937 and is derived from Greek words allelon of each other and pathos to suffer and mean the injurious effects of one upon the other. Allelochemicals are present in virtually all plant tissue, including leaves, flowers, fruit, roots rhizome, seed and pollen. In the current work, the effects of leaf aqueous extract of certain weeds are studied on seed germination of a common wheat crop.
"Allelopathy has been defined as the inhibitory or stimulatory effects of a plant or microorganism on other plants through the release of chemical compounds into the environment." Allelopathic interactions between plants have been studied in both managed and natural ecosystems.
Weeds are one of the most serious problems in agriculture production. The identification of harmful and beneficial weeds can be done by studying their allelopathic effects on crops. Several workers have shown that allelopathy plays an important part in weed and weed interaction (Rejila and Vijayakumar, 2011; Eyini M, Jayakumar M, Pannirselvam S, 1989; Oudhia P, SS Kolhe and RS Tripathi, 1998 and Oudhia P. 1999) and weed/ crop interaction (Akmal M, Vimala and Aslam,) Survey conducted on a diversity of ruderal vegetation of several plants showed that in the vicinity of several plants no plants were present or very few plant species were able to survive. Some plants are Lantana camara, Eupatorium odoratum , Alternanthera sessilis , etc .
The allelochemicals in a weed may occur in all plant parts or may remain concentrated in roots, rhizomes, stems, leaves, flowers, inflorescence, pollen, fruits or seeds. They may be released in the environment through volatilization, leaching, root exudates or decomposition of residues. The amount of allelochemicals in a plant or a plant part has been reported to depend upon radiation, the mineral status of soil, temperature, presence of other allelopathic agents in the environment, age of plant parts, presence of pathogens and predators and also on the genetic characteristics of the plants (Rice 1984).
Sphaeranthus indicus is a spreading weed that belongs to the family Compositae and is found especially in the Nagli crop fields. The allelopathic effect of this weed was not studied on major crops especially on Nagli crop so far. The present study was, therefore carried out to intending to know the effects of this weed on germination and seedling growth and in turn to identify some of the allelopathic substances that are present in S. indicus and to assess the level of phytotoxicity. The present investigation was carried out to further test the allelopathic nature of Burandu against Nagli crop to determine the phytotoxic effect of aqueous extracts of Sphaeranthus indicus (Burandu) weed species on seed germination and seedling growth of Eleasine coracana (Nagli).

MATERIALS AND METHODS
Aqueous extract of different parts of Burandu was prepared by digesting 10 gm of air-dried plant material in 100 ml of distilled water for 24 h at 25 0 C±3 0 C. It was filtered through Whatmann filter paper no. 1 of the volume of the filtrate made to 100ml (Dhavan and Narwal, 1994). Different dilutions such as 2%, 4% & 6% of the extract were prepared from this stock solution.
The seeds of Nagli crop were soaked for 24h in different concentrations of the extracts for seedling growth. For control seeds were soaked in distilled water only. The seeds of crop sterilized by dipping in the solution of 0.1% HgCl2 (Mercury chloride) for 1 min followed by 3-4 washing under running tap water to remove residues of HgCl2 and dried in folds of ordinary filter papers. In each Petri dish containing Whatmann no. 1 filter paper was kept at the bottom and thereafter 10 seeds arranged at equal distance on the top of the filter paper. The Petri dishes were covered with glass covering. The whole set of experiments was kept undisturbed at room temperature of 25 0 C± 5 0 C. Treatments were arranged in a completely randomized design with four replications. Grown shoot and root branches of Nagli were oven-dried for 72 hours and then their dry weight was measured. High concentration (6%) in not only the root extract but also in the leaf and inflorescence aqueous extracts which decreased shoot lengths i.e. 0.39cm and 0.48cm respectively indicating the reduced hypocotyl growth 82.51% and 78.48% respectively as compared to the control (2.23cm) after ten days. It concludes that when the increasing concentration of weed extracts the shoot lengths were decreased. Shoot aqueous extract of Sphaeranthus indicus (Burandu) does not show any effects on the hypocotyl growth of Eleasine coracana (Nagli). The most toxic effect in hypocotyl growth of Nagli was found is that root aqueous extract followed by another aqueous extract (Table-1). These findings are supported by Chung and Miller (1995).    Root length was relatively more sensitive to autotoxic allelochemicals than was shoot length. These results are in agreement with earlier studies reporting that water extracts of allelopathic plants were more pronounced effects on radicle growth than on hypocotyl growth or shoot growth interaction. Such an outcome might be expected, because it is likely that roots are the first to absorb the allelochemicals or autotoxic probability compounds from the environment (Turk, M Seedling weight: Radicle dry weight tended to decrease as the extract concentration increased (Table 4). Compared with the control, radicle dry weight (  The phytotoxic effects were usually subject to concentration. Among the test crop species, reduced root and shoot