I.
Introduction
Weeds
are plants that grow in unintended locations and exhibit remarkable
adaptability and competitiveness [1]. They may be native or non-native,
invasive or non-invasive, and can be classified as either noxious or relatively
harmless. Invasive weed species, in particular, can significantly alter
vegetation composition, disrupt ecosystem structures, and impact overall
ecosystem functions [2]. These non-native species have the potential to
outcompete and dominate native plant
communities,
often leading to substantial ecological imbalances [3].
Weeds
pose a major challenge to agricultural productivity, competing with crops for
essential resources such as nutrients, water, and space. This competition can
lead to yield reductions ranging from 12% to 51% [4-6]. In addition to
competing for resources, weeds serve as hosts for plant pathogens, further threatening
agricultural productivity.Their ability to form mutualistic relationships with
insect pollinators enables them to spread rapidly and invade new habitats,
affecting both natural and agricultural ecosystems [7]. Some weed species also
release toxic or allelopathic compounds into the soil, negatively impacting the
growth of surrounding plants and posing risks to human and animal health [8].
Identification
of weeds is basic step for weed management by using herbicides, due to its
selective nature. All the weed species cannot be killed by a single herbicide.
Selection of herbicides also depends on the types of crops and fields
(cultivated and uncultivated) where weeds to be controlled. So identification
of weed species is key factor for weed management.
II.
Materials and
Methods:
i.
Study Area
Weed flora Survey was carried out during the
month of April and May 2023 in GGDSD College, located in Palwal district, which
lies in the northern region of Haryana. The landscape of Palwal district is
predominantly composed of extensive, fertile agricultural plains, supporting a
variety of crops and vegetation
ii.
Methodology
The study was conducted on the College campus during
March and April to assess weed flora in both cultivated and uncultivated areas.
The quadrate method was employed for vegetation analysis, following the
approach described by Misra [9].
To systematically document weed species, 1 m² quadrats
were randomly placed across different areas of the campus. The number of each
weed species present within each quadrat was carefully recorded. Identification
of weed species was performed using standard floras and available literatures [10]. The classification of identified weeds
was carried out according to the criteria established by Cooke [11] and Yadav
and Sardesai [12].The frequency, density, and abundance of the recorded weed
species were calculated using standard ecological formulae to determine their
distribution and dominance within the study area.
III.
Result and discussion
A
total of 29 distinct weed species were identified during this survey. These
species were categorized based on their occurrence in cultivated and
uncultivated areas and were further analyzed for their frequency, density, and
abundance (Table 1). A significant observation was the dominance of the
Asteraceae family within the overall weed composition. As most of weeds belong
to Asteraceae (6 species) family, followed by Amaranthaceae (4 species), Fabaceae (2 species), Malvaceae (2 species), Poaceae (2 species), Solanaceae (2 species) and single species was
found from Apiaceae , Apocynaceae, Cannabaceae,
Euphorbiaceae, Lamiaceae, Oxalidaceae,
Papaveraceae, Phyllanthaceae, Plantaginaceae, Polygonaceae and Rannunculaceae [13] also observed Asteraceae as dominant family in their campus study. These plants show adaptability and competitiveness in the ecological
context of urban lawns [14]. Among 29
species, majority weeds are invasive except Artemisia annua, Veronica anagallisaquatic,
Rannunculus sceloratus, Calotropis procera, Cannabis sativa, Coleus graveolens and Centella asiatica (Table
2). This survey revealed the following
findings-
i.
Weed Flora in Cultivated Areas :
In
cultivated areas, a total of 20 different weed species (Table 1) were recorded.
Among these, the most frequently encountered species included Erigeron
bonariensis, Taraxacum officinale, and Malva parviflora, along with Parthenium
hysterophorus and Artemisia annua. Erigeron bonariensis
exhibited the highest density, followed by Amaranthus viridis and Malva
parviflora. In terms of abundance, species such as Melilotus indicus,
Cannabis sativa, Oxalis corniculata, and Amaranthus viridis were the
most prevalent.
ii.
Weed Flora in Uncultivated Areas:
In
uncultivated areas, 19 weed species were identified (Table 1). The most
frequently occurring species included Achyranthes aspera and Cannabis
sativa, followed by Sida rhombifolia and Parthenium hysterophorus.
Based on density, Achyranthes aspera and Cannabis sativa were the
most dominant species, followed by Parthenium hysterophorus and Sida rhombifolia.
Regarding abundance, species such as Amaranthus viridis, Chenopodium album and
Leymius arenarius were commonly found.
iii.
Weeds Common to Both Cultivated and Uncultivated
Areas :
Ten
weed species, such as Parthenium hysterophorus, Amaranthus viridis, Parthenium
hysterophorus, Solanum nigrum etc. were found in both cultivated and
uncultivated areas, indicating their adaptability and invasive nature. These
observations are detailed in Table 1. and Fig. 1.
All
unwanted plants are called weeds but all weeds are not unwanted. Many weeds
have medicinal properties which are found in cultivated and uncultivated
fields. In rural areas, even today people use weeds for their primary health care,
as these plants have better acceptability and compatibility with the human body
and minimum side effects [15]. Important medicinal uses of all the weeds
observed from cultivated and uncultivated fields are listed in Table 2.
Fig.
1. Common weeds of cultivated and
uncultivated fields