3.                   Introduction 

The World is desolation due to Food, Oil, Nutrient, Fuel, Ecological and Health [FONFEH] securities.  The food demand is expected to be doubled by  2050  because  of  steady  population increasing in spite of production environment and natural resources are continuously shrinking and deteriorating. Food crisis has aggravated further because of climate change and diversion of arable lands to urbanization, industrialization and for producing bio-fuel.  About 30% global emissions leading to climate change are attributed to agricultural activities, including land-use changes. There are projections that demand for food grains in India would increase to 345 mt in 2030. Hence in the next 15 years, production of food grains needs to be increased at the rate of around 5 mt annually, which a challenge to agriculturists. In such situation the Best Management Practice [BMP] with what farmers have is the greatest alternative methodology. The production losses due to pests is 33 % and the major pest weed  plant  alone  causes  [10.9  &11.5]  %  national  &  global  production  losses [1]. This is further vexing due to threats from invasive alien weed pest.  Climate change and the import of food grains & seeds are the two major causes for the invasion of weeds in India.  Management of these  invasive  weed  pests  are,  therefore,  urgently  needed  for  global  and national food and oil security.

3.1.              Invasive Weeds Biodiversity 

The biodiversity changing in weed pest due to climate change is the key factor for invasion of many alien weeds in newer ecosystem [2]. The invasive weed flora common in many countries are Ambrosia in Mediterranean region; Elatine in Japan, Polypogon in China, Phalaris in Mexico, Parthenium in Mexico, Conyza in America, Oryza rufipogon in Malaysia, Cyperus rotundus in India etc. 

In past only a few weed species like Eichhornia crassipes, in India was invaded because of its’ beautiful flower but thereafter in most of the SAARC countries, the pitiable quarantine system further  intensifying  this  problem as the  alien  invasive  plants  are  continuously  invading  through importing  of  seed  and  grains.  These are pernicious and spreading rapidly. One of the classical examples is Parthenium hysterophorus commonly observed in the roadside since last 3-4 decades is now encroaching in crop fields. 

The following invasive weed flora [Table 1] is documented of quarantine significance to India according to special provisions for quarantine weeds [class 3(12)] & schedule VIII of plant quarantine order 2005 [till 2016].

3.1.1.         Survey and Surveillance of Invasive weed 

The National Invasive Weed Surveillance (NIWS) Program me under Department of Agriculture & Cooperation, Ministry of Agriculture, government of India was launched in India through the Directorate of Weed Science Research (DWSR), Indian Council of Agricultural Research (ICAR) during 2008-10. In West Bengal, BCKV NIWS Centre was recognized by ICAR by awarding "Recognition Award (2010) to Principle Investigator Prof. R.K. Ghosh" for noticing five Invasive weeds verified by Botanical Survey of India, Kolkata and identifying some other invasive weeds (Table 2 and Figure 1) under this NIWS program me (Final Report 2008-10, NIWS, BCKV Centre). BCKV Centre made this survey in ten south Bengal districts (Burdwan, Hooghly, Howrah, Maldah, Murshidabad, Nadia, North & South 24 Paragnas and Purba & Paschim Medinipur) besides maintaining an ‘In house trial ‘of the collected wheat seeds from various FCI go downs, ration dealers and the consumers during 2008-10. An invasive weed museum (Figure 2) was also established at BCKV farm to document and acquaint these invasive & pernicious weeds to the farmers, scientists, students and common people.

Since 2008  research  has  been  conducting  to  find  out  the  new  invasive  weeds  through survey, study of invasive weed ecology & biology and their Ecosafe management through utilization and chemically by Ecosafe organic chemical herbicides. All these researches were conducted at on station (Viswavidyalaya farm,  Kalyani)  and  some  at  on  farm  (nearby  villages  of  Viswavidyalaya campus). 

3.1.2.         In House Trial 

From the wheat seed samples collected from different FCI go downs, ration dealers and consumer house the in-house  trial was  done  during  2008-09  at  Viswavidyalaya  farm. The ICAR experts visited the in-house trial at BCKV during 2009. The results (Table 3) showed that Phalaris minor was found in  the  wheat  samples  of  FCI  go down  and  from  consumer samples of  Nadia, Murshidabad and Maldah district, Polypogon monspeliensis was also found only from wheat sample of FCI  go down,  Nadia. Polygonum plebium was found in the consumer wheat samples of both Purba and Paschim Medinipur. Dianthus armeria was found in ration dealer wheat samples from Hooghly and consumer samples of Howrah. Trichodesma indicum was found in FCI go down sample of both South and North 24 Paragnas.                                                                                                   

Important Major Invasive Weed Pests Recorded in West Bengal in NIWS Program me 2008-10. 

Parthenium hysterophorus was found in all wheat samples of all surveyed districts. Only one each invasive weed plant Jatropha multifida was found at Nandi gram ADA office in the district of Purba Menipur while Cynoglossum lanceolatum in Government farm, Maldah. Only a plant of Solanum incanum was observed at the roadside of Kalyani University administrative   building,   Nadia   (NIWS   Final   Report,   BCKV   Center,   2008-10). 

The Solanum carolinense is  found  in  Southern  India  during  2009  (Final  NIWS  Report,  Bangalore &  Tamil  Nadu Centre,  2008-10).  Eriocaulon sieboldtianum was observed  at  bank  of  the  river  Ganga  at  Hooghly district during the RAWE program me of UG students, BCKV.

4.                   Research on Invasive Weeds Biology and Management 

Parthenium hysterophorous is locally known as Congress grass, White top, Bunogajor. Parthenium (having 17 species) may be confused with annual ragweed (Ambrosia artemisiifolia), perennial ragweed (Ambrosia psilostachya), burr ragweed (Ambrosia confertiflora) and lacy ragweed (Ambrosia tenuifolia). However, after flowering it can be distinguished from all these species by its ribbed stems and by white flower-heads (i.e. capitula). 

The flea banes (Conyza bonariensis, Conyza Canadensis and Conyza sumatrensis) are also reasonably similar, but do not have highly dissected leaves  or  ribbed  stems  and  their  seeds  are  topped  with  a  ring  i.e. Pappus of whitish hairs. Parthenium was first found at Pune, India in 1955 and in 1975 at Dankuni, West Bengal. It has been termed ‘National weed’ since 2005-06.  It is a shrub and completing three life cycles (February - May; June - September and October -January of which the former two has profuse growth but the later one has lesser growth) in a year. The plant mainly propagates by seeds. One plant contains 15,000-25,000  seeds  which  are  very  light  and  easily  disperse  by  air  and  water.  It grows well in moist condition but can’t tolerate water stagnation. The pollen Alleopathy, a rare phenomenon of inhibiting germination of pollen of other species in their respective stigma shown by Parthenium pollen may result in loss of yield of crops.  Parthenium is causing health hazards to human and animals.  It is reported for outburst of the diseases like tomato leaf curl, bud necrosis of groundnut and sunflower, stem  necrosis  of  groundnut,  powdery  mildew,  collar  rot,  leaf  spot,  milly  bug  and  rust  of  various crops.  Recently, Parthenium has  been  responsible  for  outburst  of  bud  necrosis  of  groundnut  in Andhra  Pradesh  and  some  parts  of  Karnataka. 

In  India,  it  is  estimated  to  lower  the  yield  of  field crops by 40% and forage crops by 90% in severely infested areas. In Australia its damage is put at16 million dollars per annum from pasture and crops. Pollen grains of Parthenium are reported to inhibit fruit set in tomato, brinjal, beans, capsicum and maize [3-4]. The biology study of Parthenium hyterophorus [5] at West Bengal revealed that it grows initially horizontally (not allow to germinate other plants) and thereafter vertically 3-5 ft with more than 15,000 very light seeds / plant. The density in roadside is more 40 m^-2(mean from 10 sites) in comparison  to  cropped  area  4.4  m^-2,  field  bunds  10.9  m^-2and  field  channels  7.8  m^-2. It has allele chemicals Sesquiterpene lactone (Parthenin, Hymenin, and Ambrosin etc.) and phenol and flowers particularly showed some allergy to animals.  Thus, it should be managed before flowering. Research proved that this alien weed could be managed by utilizing as compost [6], green manure [7], and making bio herbicides [8].  Parthenium is also controlled by Ecosafe organic chemical Glyphosate + Oxyfluorfen mixture @ 2 _g / lit water at pre - flowering stage. 

Oryza rufipogon [9] is  normally  taller  than  Oryza sativa, having  numerous awned  grain  per  panicle  that  drops  during  maturity  (also  known  as  Jharadhan).  The  scourge  is commonly  known  by  different  names  in  various  Asian  countries,  viz. Kha Nok (Thiland), Sharei (Korea), Jhoradhan (Bangladesh), Lua Lon (Vietnam), Padiangin (Malaysia) or Akamai (Japan), etc. The biology studies of the Oryza rufipogon (Ph.D.  Thesis project work, Swapan Kumar Barman, BCKV 2013) revealed that it is almost phenol typically alike cultivated rice. If the infestation rate of a crop  is  35%  or  more  the  average  yield  losses  is  to  the  tune  of  60%.  Only  one  plant  of  was  first observed  &  identified  in  West  Bengal  at  BCKV  Research  Farm,  Kalyani  during  October  2007 (reported and published in APWSS Newsletter Vol. 1 No. 1 2008). The plant height is maximum 118 and minimum 55 cm with an average of 86.5 cm; average no. of tillers / plant 56.5; no. of panicles / plant 52.5; maximum panicle length 25 cm and minimum 17 cm with an average 21 cm; the awn length 3-7 cm; no. of spikelets / panicle 9; no. of spikes / spikelet on an average 19; the test weight0.975 g and normally152 day’s duration in kharif season. The grain setting of Oryza rufipogon in Gangetic inceptisol was found only during June sowing.  It is mainly found during rainy season. Initially it is very difficult to identify with cultivated paddy.  It can be grown even in water stagnant situation thus suitable for breeding purpose. This weed plant is controlled effectively by utilizing as compost. 

Elatine triandra, locally called Chotanunia, is a dicotyledonous broadleaf annual, stem 3-15 cm  long,  dichotomous,  branching;  prostate,  leaves  lance late,  opposite  with  short  petiole  and stipules and small flowers at axils. Moisture helps to propagate easily both by seed and plant parts. This weed is generally reddish purple in color, succulent and has soft and short internodes. It has been first observed on 2002 at village Kantabelia of district Nadia in West Bengal.  Elatine is now invaded in many areas of all south Bengal districts because of its rapid propagation by any parts ofPlant 

Ambrosia psilostachya DC. (Family - Asteraceae), is commonly known as Western Ragweed or Cuman Ragweed. This annual invasive weed is noticed on road sides in Pura villages of Turuvekere taluk, Tumkur District, Karnataka (about 4 km from Muniyur) during 2013 only. It invaded probably through transportation of soil. This plant looks like Ambrosia trifida. It generally prefers moist soil, found in all type of soil and in all habitats. Fruiting and flowering occurs during August-October. It propagates and dispersed primarily by root and seed. It is one of the most dangerous weeds in the world. 

Trichodesma indicum [Family - Elatinaceae], is generally found in upland and aerobic situation. Commonly known as‘Chatpati’ as after maturity the seeds when anyone keeps in their hand jump little. Whole plant at young stage very soft, later mature gradually becomes hard. Looks like Bergia carpensis and found in Viswavidyalaya farm, Kalyani during 2009-10 in wheat field of NIWS poly house trial. 

Polypogon monspeliensis L. Desf [Family -Poaceae (Gramineae)], an annual grass mostly found in crop fields and bunds. The inflorescence is looking like Imperata cylindrical but color is blackish- brownish. Invaded from China and found in Viswavidyalaya farm, Kalyani during 2009-10 in wheat field of NIWS poly house trial. Now it is observed in many dry tracts of India. 

4.1.              Management Through Utilization of Invasive Weed 

(As Compost, Green Manure, Bio Herbicides, and Herbal Medicine etc) 

4.1.1.         Compost Making 

All the invasive weeds like other weeds are suitable for making compost at initial stage. For using invasive  weeds  in  Vermicompost  at  first  chopped  the  weed  plants  into  small  pieces  and spread the material on the ground to a thickness of 10 cm layer. Over this spread Trichoderma viridi and spray urea at 0.5% solution (Generally 5 kg urea per ton of weed material). This sequence of layers is repeated up to a meter high and finally plastering should be done by with mud or clay soil. Keep the moisture level at 50-60%. After two weeks, a thorough mixing must be given. The compost will be ready for field application after 40-45 days.  It is a good source of nutrient and helps to maintain soil properties through aggregate formation. 

At DWR, ICAR, M.P and BCKV, West Bengal.  Attempt was made to utilize Parthenium by making compost. As Parthenium is now invaded entire India the best possible way to manage it by making compost.  The procedure of Parthenium Compost preparation is as follows [6] 

➢Make a pit of 3 ft depth (four layers each having 9” depth) x6 ft width x 10 ft length. It should be in open and shady upland place. Cover the base surface and side walls of the pit by stone chips or make  soil  surface  compact  to  protect  the  absorption  of  compost  nutrients  by  the  soil  surface  by using lime. 

➢Use 40 kg dry soil and 30 _kg well decomposed dry FYM / Vermicompost in each layer. Collect young Parthenium plants from nearby areas and spread 50 _kg on the surface of the pit in each of 4 layers of this pit. The allelochemical `Parthenin’ acts as a growth regulator. 

➢Sprinkle 500 _g Urea or 3 kg Rock phosphate over this for each time and spray 10 lit of water on the surface of each layer. 

➢ Add Tricho derma viridi @ 50_g in each layer and Repeat this type of biomass layer till 4 layers. 

➢Cover the pit with soil, dung and husk making a 1- 1.5 ft dome shape and keep it for 4-5 months. 

➢For  packaging  in  bags sieve  the  final  well  decomposed  compost  with  2  cm  x  2  cm  mesh.  The compost is ready for use. Testing of this compost was made in field crops and found good results. 

Following same process utilization of Oryza rufipogon along with the field crop weeds may also be possible by making ‘Field side Compost’.  In  such  case  the  compost  pit  may  be  varied  in  size according  to  number  of  weeds  or  available  space  in  any  ecosystem.   The weeds present in the fallow land may also be utilized for making compost. The research data showed the dry weight of 234.86 g m^-2 was available from fallow or wasteland weed (mean of 10 locations).

                                                Preparation of Parthenium compost.

Application of 3-5 t ha^-1of this eco-friendly balanced “Parthenium compost’ or “Field side compost” in the crop, vegetables or Orchards showed no harmful effects not only in soil and succeeding crops but also no resurgence after  application in the field.   It is less costly than the traditional FYM, oil cakes or even from the Vermicompost (Table 4). Recently attempt has been taken to improve the quality of compost making from various weed floras. The  ‘Eichhoparth Compost’  (mixture  of Eichhornia crassipes and  Parthenium hysterophorus 50:50  ratio)  is  also  more  nutrient  rich  and suitable for utilizing both these invasive weeds. This will create employment opportunities in the rural areas. Some  field  experiments  were  also  conducted  at  the  University  research  farm  to  find  the efficacy of these composts and the results are promising for sustainable soil health improvement as well as lowering the inorganic fertilizer dose and keeping the productivity a sustainable increase in all crops grown in sequence.

4.1.2.         Green Manure 

Young non-flowered Parthenium plant could be used as green manure to enrich the soil health and improving crop productivity. Research experiments conducted at BCKV, West Bengal, India [7] revealed that  in major three crop sequences CS₁ - black gram (summer) - transplanted paddy (kharif) - onion (Rabi); CS₂-sesame (summer) - transplanted paddy (kharif) - Bengal gram (Rabi) and CS₃- okra (summer) - transplanted paddy (kharif) - rapeseed (Rabi),  the  nutrient  level  N₁(recommended  dose  of  fertilizer+ green  manuring  with  young  non- flowered  Parthenium hyterophorus)  under  CS₁recorded maximum  rice equivalent  yield  in  all  the three seasons 2.99 t ha^-1in summer; 5.45 t ha^-1in kharif and 16.21 t ha^-1in Rabi showing   N₁ CS₁ recorded maximum benefit : cost ratio in all the three seasons. The two-year productivity data under three  nutrient  levels  showed  that  the  highest  average  productivity  of  54.54  _kg  ha^-1day^-1was observed in N₁ treatment in case of all the crop sequences. Thus, utilization of biomass as green manure might have the potential to improve crop productivity. A similar finding was also recorded at Karnataka, India in rice ecosystem. The soil micro flora revealed that continues use of Parthenium as GM  with  recommended  NPK  is  beneficial  for  soil  health  as  well  as  advantage  on  total  biological yield. The effect of treatments on the population of Bacteria (CFUX10⁶g^-1) of soil was presented in Table 5.

4.1.3.         Bio Herbicides 

Raw or aqueous extracts of many invasive weeds in their young stage are common and useful as bio pesticides [10]. For methanol extracts the procedure of bio herbicide preparation with the Calotropis gigantean and Parthenium hysterophorus was based on the Sox let’s procedure. The solid materials are extracted by repeated washing (percolation) with an organic solvent, usually hexane, methane or petroleum ether, etc. under reflux in special glassware. Dry Calotropis and Parthenium powder is placed into a porous cellulose thimble.  The cartridge is placed in an extraction chamber, which is suspended over a flask containing the solvent and below a condenser.  The  flask  is  heated  and  the  solvent  evaporates  and  moves  up  into  the  condenser, where  it  cools  enough  to  become  a  liquid  that  seeps  into  the  extraction  chamber  containing  the Calotropis and Parthenium powder sample. 

The extraction chamber is designed so that when the solvent surrounding the sample exceeds a certain level it overflows and trickles down into the boiling flask. At the end of the extraction process, which lasts a few hours, the flask containing the solvent is   removed   along   with   the   Calotropis and   Parthenium extract.   Finally,   the   solvent   in   the flask evaporates leaving the plant materials extract below. Solvent extracted plant materials powder uses  one  or  more  organic  to  remove  the  active  ingredient    and  other  ingredients  of  the  plant materials powder. Adding surfactant (nonionic) e.g.   Tween- 80, Tween- 20, S -145 etc., organic solvents; emulsifier; filler and adjuvant the final spray solution was prepared and this was used to spray in the crop field [11].

Plant extracts  with  allelochemicals  (Table  6)  from  some  invasive  weeds  containing  different allelochemicals like phenols, acid etc. are using as non-selective herbicide. Similarly, fatty acids like pelargonic acids (succinic, lactic or glycolic acid) are using to control annual pests; essential oils use as non-selective contact herbicide to control many weed pests.  Many research experiments have been conducting in this aspect in India [12, 8], Australia [13], Japan [14-15], China [16] and many other countries. One of the interesting research findings at Japan that some native rice cultivars  contain allelochemicals (Momilactones) which can able to suppress the weed species Echinochloa or  invasive weed Oryza rufipogon.  At  BCKV, West Bengal since 2001 many  experiments  were  conducted  in  various  ecosystem  (anaerobic  and  aerobic)  with  different doses(5-100 ml/ liter water) and results are satisfactory with PE application adding surfactant while in  recent  years  100  ml/  liter  water  dose  showed  more  efficacy  (Table  7).  Moreover, in anaerobic ecosystem these botanical herbicides proved better in comparison to aerobic ecosystem. This may be due to presence of phenolic compounds that acts more in sufficient moist soil. It has been further observed  that  these  botanical  herbicides  can  be  mixed  with  synthetic  organic  herbicides  and  the results showed this mixture proved synergistic effect in some cases. Therefore, as PE application in zero  or  minimal  tillage  (conservation  agriculture)  managing  weeds  these  mixtures  may  be  more suitable rather than only non-selective contact synthetic organic herbicides.

The important research findings on transplanted SRI weed management during summer 2010 and2011 by applying botanical herbicides as Raw Extract (RE), Raw Leaf Extract (RLE), Aqueous Extract(AE)  and Methanol  Extract  (ME)  revealed  that  all  botanicals  treatments  (9  Treatments)  on  an average recorded 28 % yield advantage (Table 8) over Weedy Check (WC).

Similarly,  in  another  experiment  during  2010-11  the  botanical  treatments  showed  a  better  weed management  than  the  untreated  control  with  an  average  of  7.8-72.7% higher  productivity  in cultivated   crops   Sesamum indicum,   Vigna radiata   and   Vigna mungo experimented   at   this Viswavidyalaya (Table 9). No phyto toxicity was observed among the crop species from any of the botanicals used. The soil micro flora population was also recorded to be greater in botanicals treated plots than herbicide treated plots [17].  Working with Echino chloacolona extract [18] also found similar results at south India.

The probable mechanism of action may be (I) Protein Synthesis - Microtubule assembly inhibitors that  inhibits  the  assemblification  of  microtubules,  polymerization  of  tubulin (the  major  protein content) which is very much essential for formation of cell wall. As a result, arrestation of cell division, formation of polynucleates cells and eventually inhibition of root and plant growth. 

(II)  Fatty  acid  (Lipid)  Biosynthesis: ACEase  (Acetyl  Elongase) inhibition  (Very  long  fatty  acid  chain inhibition).  The  chemicals  inhibit  the  cell  division  and  elongation  in  seedling  shoots  before  they emerge   above   ground   and   (iii)   Un couplers   (Membrane   Disruption):  Inhibition   of   Oxidative Phosphorylation 

Botanicals  are  having  very  weak  phenolic  acids,  but  these  will  be  recognizably  acidic  properties particularly in moist  soil. A Hydrogen ion can break away from the -OH group and transfer to a base. The position of equilibrium lies well to the left.

Phenolic acids may lose a hydrogen ion because the phenoxide ion (and Hydroxonium ion) formed is stabilized to some extent. The negative charge on the oxygen atom is de-localized around the ring through resonance action. The more stable the ion is, more likely it is to form. One of the lone pairs on the oxygen atom overlaps with the delocalized electrons on the benzene ring. Formation of stable phenoxide ion triggers its acidic nature which attacks the long chain and causes ACEase inhibition [8]. 

4.1.3.1.    Herbal Medicine 

It  has  been  observed  that  wide  scope  of  preparing  the  Herbal  Medicine  from  many  weeds  like Jatropha multifida (Dettol Plant), Hibiscus subdarifa, (Tak Bhindi), Pergularia daemia (Chagalbati), Croton sparsiflorus (Bon  marich), Leucas  aspera (Swetdhron),  Cynodon dactylon (Dub  ghash), Cyperus rotundus (Muthaghash), Tridax procumbans (Mahavringaraj),    Heliotropium indicum (Hatisur),  Centella asiatica (Thankuni),  Allium  vineale (Bon  onion),  Gynandropsis  pentaphylla (Dantan plant),, Ocimum basilicum (Bon Tulsi), Biophytum sensitivum (Life plant), Cannabis sativum (Bhang), Leonurus sibiricus, (Lal dhron), Artemisia capillaries (Rag weed),  Tephrosia purpurea (Bon neel), Physalis minima, (Bon Makao), Ageratum haustonianum (Ghandhali) etc.. Some findings are Heliotropium indicum (Hatisur)  leaf  extract  is  used  against  Jai  Bangla  eye  disease;  Heliotropium indicum (Hatisur)  juice  mixing  with  Calotropis gigantea (Akanda)    Juice  + Brassica  juncea (Mustard) oil against Scabies disease; White latex of Pergularia damea (Chagalbati) against Sweti disease; Calotropis leaf and stem latex   use with slightly hot kerosene oil against swallow and pain; Solanum  torvum (Choto  bon  begun)  fruit  against  bat  disease;  Croton  sparsiflorus  and  Jatropha multifida against cut and wounds [19]. 

Beside the  above  leading  uses,  Eichhornia and  Parthenium are  using  as  biogas;  Jatropha  in biodiesel,  Eclipta oil  as  hair  dye,  Cyperus rotundus nut  oil  as  incense  in  agarbatti  preparation, Parthenium  hysterophorus,  Eichhornia crassipes,  and  Leptadenia pyrotechnica (Khimp  plant  of family  Asclepiadaceae)  are  widely  using  for  Paper  pulp,  Table  cushion,  Basket,  Cork  etc.  Oryza rufipogon may be used as breeding purpose with local HYV to produce deep water / Shallow water/ Flash flood stagnant rice varieties [6]. 

4.1.4.         Management through Ecosafe Organic Chemical Herbicides 

The invasive  weeds  along  with  general  weed  biodiversity  in  University  campus  area,  municipal areas, roadsides, government offices like ICAR fodder farm,  BSF, NTPC, Airport, Singur operation etc. In West Bengal were managed through various programmes undertaken during last one decade proved satisfactory results by using sole or mixture of Glyphosate 41 SL @ 3.5 _kg ha^-l, Glyphosate71 SG @ 3 _kg ha^-l, Paraquat dichloride 24 SL or EC @ 2 _kg ha^-l, Glyphosate 71 SG + Oxyfluorfen 23.5 EC @ 2 _g liter^-1water, Glyphosate 71 SG @ 3 _kg ha^-l+ 2,4 D EE @ 500 _g ha^land Diuron 80WP @ 15 _kg ha^-l [20, 1]. Repetition of 2-3 sprays annum^-1is essential for good control. 

4.1.5.         On Farm Trials and Awareness Programmes 

The on farm  trials  conducted  in  the  nearby  villages  of  University  campus  on  the  agri skill development of Parthenium compost preparation, bio herbicide raw extract preparation (Figure 3) and application  on  transplanted  SRI,  use  of  Cyperus nut  oil  in  agarbatti  preparation etc. Through awareness and demonstration program me. All these programmes proved pleasing results as farmer’s acceptance on managing invasive weed plants through utilization or chemical is promising. To create more awareness among the common peoples including the farmers is another alternative for mass eradication of these invasive weeds. In India during the last few years many awareness programmes have been conducted by Ministry of Agriculture, Government of India; Indian Council Of Agricultural Research  (ICAR);  Directorate  Of  Weed  Science  Research  (DWSR);  Directorate  of Agriculture  in  different  States  etc.  At  West  Bengal  more  than  100  such  Programmes  have  been conducting per annum by Bidhan Chandra Krishi Viswavidyalaya (BCKV) during the last five years through Directorate of Extension Education; Krishi Vigyan Kendra and Adhoc projects sponsored by Corporates  or  ICAR.  The Weed Science, Department of Agronomy alone has been conducting around 25 such awareness programmes per annum at various districts of West Bengal since 2006-07 [4,9,19,21] organized by the author. The benefits of these awareness programmes are reported to be satisfactory.

5.                   Final Consideration 

In conclusion Invasion of plants is a natural phenomenon. Survey and Surveillance is essential to find out their spreading. Research is to be done to find out its limitation through possible uses. Awareness is needed to campaign about it’s possible management through utilization and lastly all sectors  of  the  society  - the  scientists  and  officers  of  Institutions,  Government  &  NGOs,  farmers, students, and even the public  should be involved in managing these invasive plants with  keeping environment  safe.  Both  Central  and  State  government  should  make  sustainable  policies  to  stop invasion and for managing invasive weeds in consultation with scientists.

Figure 1: Important Invasive Weed Flora Identified During NIWS Program me.

Figure 2: Invasive weed Museum at BCKV farm.

Figure 3: On Farm Management of Invasive Weed through Botanicals and Chemical Herbicides.

1.                   Ghosh RK, Ghosh A, Mondal D, Bandopadhyay P (2017) Book Annual Planning of Weed Pest                               Management in System Agriculture. Published from BCKV, ICAR Fund.

2.                   Bhowmick PC (2006) Current status of herbicide resistant weeds around the globe. Journal of Crop and Weed 6: 33-43.

3.                   Directorate of Weed Science Research (DWSR), ICAR (2010) Compost making from Parthenium - Technical Extension Bulletin.

4.                   Ghosh RK (2009) Invited Paper on Weed utilization- Workshop at DWSR, ICAR, Jabalpur October 20-21.

5.                   Dolai AK, Bera S, Ghosh RK, Bhowmick MK, Pal D (2013) Biology and infestation of Parthenium hysterophorus L. in new alluvial zone of West Bengal - a survey. Journal of Crop and Weed 9: 216-217.

6.                   Ghosh RK, Bera PS, Pal D, Pal S, Kundu CK, et al. (2013) Book Agronomy Practical Manual Published from BCKV, ICAR fund.

7.                   Dolai AK, Ghosh RK, Bhowmick MK, Ghosh PK (2015) Improving beneficial micro flora population in soils of predominant crop sequences through Parthenium utilization. Journal of Crop and Weed11: 208-212.

8.                   Ghosh RK, Kumar A, Ghosh A, Mondal D, Karmakar C, et al. (2016) Bash of Botanical herbicides in Annual Planning of Weed Pest Management for Eco-Efficient Sustainable Agriculture. Journal of Crop and Weed12:168-174.

9.                   Ghosh RK (2010) Key note address on “Invasive weeds threats and strategies in Gangetic Inceptisol of India”. Proceeding of the 2nd International Workshop on Invasive plants in the Mediterranean Type regions of the World. Organized by European Environment Agency during at Trabzon, Turkey 02-06 August 71-76.

10.                Ghosh RK, Shamurailatpam D, Ghosh A, Sentharagai S, Labar A et al. (2015) Prospects of botanical herbicides in system intensification. Indian Journal of Weed Science 47: 401-407.

11.                Jana PK, Ghosh RK, Kole RK (2011). Efficacy of Botanicals Plant Extract on Weed Pest Management in System of Rice Intensification: 3rd International Bio pesticides Conference (BIOCICON 2011) Organized by Crop Protection Research Centre, Department of Advanced Zoology and Biotechnology, Palayamkottai, and Centre for Plant Protection Studies, Tamil Nadu Agricultural University (TNAU), Coimbatore November, 28-30.

12.                Asthini (2008) the effects of Methanolic extract of Eucalyptus cameldulensis Dehnh. On growth and germination rates of Chino podium album L. Indian Journal of Medicinal and Aromatic Plants, 24:293-303.

13.                Navie SC, McFadden RE, Panetta FD, Adkins SW (2005). The effect of CO2 enrichment on the growth of a C3 weed (Parthenium hysterophorus L.) and its competitive interaction with a C4 grass (Cenchrus ciliaris L.) Plant Prot. Q 20: 61-66.

14.                Yoshiharu F (2015) Allelochemicals and natural products from weeds. Int Con on “Weed Science for Sustainable Agriculture, Environment and Biodiversity, 13-16th October, 2015 at Hyderabad, India Extended Summary.

15.                Suzuki M, Tominaga T, Kato-Noguchi H (2015) the potent allelopathic substances of cogon grass rhizome extract. Proceeding of 25th Asian-Pacific Weed Science Society Conference on “Weed Science for Sustainable Agriculture, Environment and Biodiversity”, Hyderabad, India, during 13-16 October, Organized by Indian society of weed science3: 571.

16.                Chen (2009) Alleopathy of leaves of Parthenium hysterophorus L. on Ablution theophrastii and Echinochloa crusgalli (L.) Beauv. Acta-Phyto phylacica 36: 77-81.

17.                Nongmaithem D, Pal D, Ghosh RK, Jana PK (2011) A study on management of weeds in summer sesame (Sesamum indicum L.) through natural plant extracts in Proceeding of 3rd International Bio Pesticides Conference (BIOCICON 2011), Tamil Nadu Agricultural University (TNAU), Coimbatore; November 28-30.

18.                Rao AS (2008) Effect of Time and Dose of Post-emergence Herbicides on Echino chloacolona (L.) Link in Black gram Grown as Relay Crop. Indian Journal of Weed Science 40:24-26.

19.                Ghosh RK (2009) Parthenium Compost - an Eco friendly Balanced Bio fertilizer: Leaflet published from BCKV in both Bengali and English version.

20.                Ghosh RK, Mallick S, Bera S, Barman S, Jana PK, et al. (2011) Ecosafe Management of Invasive Weeds in Gangetic Inceptisol of India. Proceeding of 23rd Asian-Pacific Weed Science Society (APWSS) International Conference Organized by APWSS and IWSS at Sebel Cairns in North Queensland, Australia 25 - 30 September 2011 with focus on the theme "Weed Management in a Changing World" 35.

21.                Ghosh RK, Dalai AK, Pal D (2008) Weed utilization as medicine. Paper presented in the National Symposium on Medicinal Plants FTCBCKV March 2008.