Phytosociology of some weeds of wheat communities around Kotli fields , Western Himalaya

There were ten plant communities of weeds in wheat fields of Kotli. The communities were EuphorbiaDesmostachya-Coronopus, Parthenium-Galium-Taraxacum, Zanthium-Bidens-Bothriochloa, Silybum – Amaranthus-Avena, Ranunculus-Silybum-Imperata, Oxalis-Cannabis–Vicia, Calendula-FimbristylisDesmodium, Taraxacum-Geranium-Poa, Phalaris-Geranium-Cynoglossum and Themeda-Cardus-Urtica. The soil texture differs from loam to clay loam, loam and sandy loam with basic pH. Organic matter was high in all the communities; saturation varied from 30 to 51%, Nitrogen differed from 0.53 to 0.87%, Phosphorus from 9 to 16 ppm, Potassium from 256 to 768 ppm; electrical conductivity varied from 2.3 to 5.6.


MATERIALS AND METHODS
Kalah, Tenda, Chowki, Thaler colony, Malahar, Dheri, Sarsawa, Panjeera, Dakhari, Chak Mir all localities lies 141 km from Muzaffarabad, were surveyed during May, 2009.Density, frequency and cover of each species were determined using 20, 0.5mx 0.5 m quadrats laid randomly in each community and importance values were determined (Malik et al., 2005).Plant communities were recognized on the basis of highest importance values of species and were named after the leading dominants following the Curtis and Macintosh, 1950 method.Nomenclature followed here is that of Stewart (1972).Soil was collected from each community up to the depth of 15 cm and analyzed physically and chemically in the soil and water research centre Kotli (Table 2).

Euphorbia-Desmostachya-Coronopus community
This community was recorded from Thaler colony at an altitude of 400 m.The dominants were Euphorbia

Parthenium-Galium-Taraxacum community
Dakhari fields at an altitude of 420 m were dominated by Parthenium, Galium Taraxacum having I.V of 39.3, 37.75 and 34.73 respectively.Oenothera rosea, and Phalaris minor having I.V of 32.5 and 31.92 were the co-dominant.
Cynodon, Melilotus and Medicago were the associated species.The remaining two species including Sauromatum and Avena were rare.The soil in this community was loamy having basic pH.Nitrogen 0.87%, Phosphorus 14 ppm, Organic matter was very high (1.75),E.C 2.5 (Table 2).

Zanthium-Bidens-Bothriochloa community
At an altitude of 460 m Zanthium-Bidens-Bothriochloa community was present.Importance values were 27.42, 24.37 and 23.62 respectively.Chrysanthemum indicum    and Dichanthium annulatum having I.V of 21.86 and 21.85 were the co-dominant, Agrostis, Rumex and Lathyrus were the associated species.The remaining two species including Evolvulus and Cyperus were rare.The soil in this community was loamy having basic pH.Nitrogen 0.72%, Phosphorus 11 ppm, Organic matter was very high (1.44),E.C was 2.7 (Table 2).

Silybum-Amaranthus-Avena community
Silybum-Amaranthus-Avena community was present in Malahar at an altitude of 490 m having I.V of 25.83, 23.19 and 23.15 respectively.Calatropis procera and Artemisia scoparia having I.V of 22.52 and 22.44 were the co-dominant.Trifolium, Chenopodium and Catabrosa were the associated species.The remaining two species viz Vetiveria and Anagallis were rare.The soil in this community was loamy having acidic pH.Nitrogen 0.87%, Phosphorus 16 ppm, Organic matter was 1.75, E.C 2.3 (Table 2).

Ranunculus-Silybum-Imperata community
From Dheri fields at an altitude of 500 m Ranunculus-Silybum-Imperata community was recorded having I.V of 30.52, 24.26 and 23.91 respectively.Lathyrus aphaca and Rumex hastatus having I.V of 23.62 and 23.55 were the co-dominant.Lepidium, Vetiveria and Scandix were the associated species.The remaining two species Mollugo and Sonchus were rare.The soil in this community was loamy having basic pH.Nitrogen 0.53%, Phosphorus 10 ppm, Organic matter 1.06, E.C 25 (Table 2).

Oxalis-Cannabis-Vicia community
From Chowki at an altitude of 510 m Oxalis-Cannabis-Vicia community was recorded having I.V of 25.4, 23.77 and 20.87 respectively.Ranunculus muricatus and Polygonum molliaeforme having I.V of 19.95 and 18.92 were the codominant.Saccharum, Lepidium and Verbena were the associated species.The remaining two species viz Conyza and Malvestrum were rare.The soil in this community was loamy having basic pH.Nitrogen 0.87%, Phosphorus 13 ppm, Organic matter was 1.75, E.C 2.7 (Table 2).

Calendula-Fimbristylis-Desmodium community
At an altitude of 520 m from the fields of Chak Mir Calendula-Fimbristylis-Desmodium community was present having I.V of 31.06,29.81 and 29.65 res-pectively.Zanthium strumarium and Catabrosa aquatica having I.V of 28.94 and 27.9 were the co-dominant.Avena, Parthenium and Bidens were the associated species.The remaining two species viz Viola and Urtica were rare.The soil in this community was clayey loam having basic pH.Nitrogen 0.72%, Phosphorus 15 ppm, Organic matter was 1.44, E.C 5.6 (Table 2).

Taraxacm-Geranium-Poa community
From Sarsawa fields at an altitude of 580 m Taraxacum-Geranium-Poa community was present having I.V of 44.92, 39.39 and 35.41At the base (400 m) Euphorbia-Desmostachya-Coronopus was dominant with clayey loam soil having basic pH and high organic matter.The dominant weeds are annuals that can easily be eradicated before flowering and fruiting.From 420 to 500 m Parthenium, Galium, Taraxacum, Zanthium, Bidens, Bothriochloa, Silibum, Amaranthus, Avena, Ranunculus, Imperata, Oxalis and Vicia were dominant species with loamy soil and high organic matter.Most of the species in these localities were annual except Bothriochloa and Imperata.
Avena fatua, Cynodon dactylon, Calendula officinale, Ranunculus muricatus, Cannabis sativa and Imperata cylindrica are allelopathic plants which can suppress the growth of other plants and are susceptible (Hussain et al., 1987;Zebun Nisa, 1984;Hussain and Khan, 1987;Inam et al., 1989;Allien, 1979;Qurashi et al., 1987).From 510 to 600 m species such as Calendula, Fimbristylis, Themeda, Cardus and Urtica were dominant weeds with clay loam and sandy loam with high organic matter.Poa annua is a cosmopolitan plant which exists everywhere, Phalaris is a notorious weed.Themeda is also an allelepathic weed that suppresses the other species found in its vicinity.It is a fine fodder grass (Malik et al., 2005).

Conclusion
Annual weeds were dominant in the era that can be controlled by eradicating then before flowering and fruiting.Weeds reduce the crop yield production.Several control mechanisms could be employed to control weeds.

Table 2 .
Physical and chemical characteristics of soil from 10 communities recorded from Kotli during May, 2009.

Table 3 .
Weeds in the wheat fields of Kotli recorded duringMay, 2009.
respectively.Lepidium Capitatum and Phalaris arundinacea having I.V of 35 and 30.42 were the co-dominant.Trifolium, polygonum and Rumex were the associated species.The remaining two species viz, Ranunculus and Sauromatum were rare.The soil in this community was loamy having basic pH.Nitrogen 0.53%, Phosphorus 9 ppm, Organic matter 1.06, E.C 4.5 (Table2).Malvestrum coromandelianum and Poa annua having I.V of 25.06 and 24.88 were the co-dominant.Medicago, Mollugo and Oxalis were the associated species.The remaining two species viz Parthenium and Imperata were rare.The soil in this community was clayey loam having basic pH.Nitrogen 0.72%, Phosphorus 11 ppm, Organic matter 1.44, E.C 5.0 (Table2).