अंगूर के बाग के खरपतवार तथा उनका नियंत्रण कैसे करें
In India Grape (Vitis venifera L.) is the one of the most important horticultural crop. It is cultivated on an area of 1.11 lakh / ha. In India grape is grown from tropical, subtropical to temperate climate. Major grape growing state of India are Maharashtra, Karanataka, Andhrapradesh ,Tamil Nadu, Panjab, Uttar Pradesh and Harayana. Among them Maharashtra is leading state in production and cultivation of grapes. In the total production of the grapes in India Maharashtra shares the 60% of total production. The average yield in Maharashtra is 12 ton/ha but still it have been chance for increase the average yield. Though, there are many factors responsible for production of quality yield, one of them is weeds growing in vineyard. The cultural practices in grape production required huge manpower as compared to other crops. Approximately, 25-30% of the production cost (amount) are utilized for labour and chemicals are used for control on weeds in vineyard.
A weed may defined as ‘any plant growing where it is no wanted’ or ‘a plant out of place’ or an unwanted plant by and large, any plant species amidst cultivated plants belonging to other species and it causing economic and health hazards are consider as the weed. Weeds have greater adaptability to adverse environment and great potential for upholding when compared with cultivated plant species. In the process of survival they compete with the main crop for the nutrient and water. It is also reported that some weed are alternate host for the insect pest and disease causing organisms. On the other hand, weeds play and vital role in avoid the water logging condition and maintain the aeration of soil unfavorable condition in vineyard, in the wet condition through the transpiration .
Weed Flora of grape
In India grapes are cultivated in different soil and cultural conditions. Weed flora varies according to climatic condition, characteristics of soil and biodiversity of that region. Therefore the weed flora of grape, growing region to region, are different from each other. The weed flora also depends on the training system of the vineyard. The variety and density of weeds are more in vineyards where vines are trained to vertical trellises such as T,V,Y or tatura due to availability of uninterrupted sunlight.
In 1980 Krishna Sastry have been reported 378 weed species in vineyard of Karnataka region . Irrespective of the agroclimatic conditions, Parthenium hysteroporus L. , Cyanodon dactylon L., Kena( Commelina benghalensis, Portulaca oleracea L. Amaranthus spp. and Cyprus rotundus L. are major weed found in Indian vineyard.
Weed growth and multiplication:
Weed growth and multiplication in grapes depends upon the season, training system of vines and irrigation system of vineyard. Naturally the weed growth is high in the rainy season compare to the winter and summer season. However the weeds are grown in the surface irrigation system in vineyard. Compared to the surface irrigation weeds grown under the drip irrigation system. The distribution of the weed also depend on the types of soil i.e. In black cotton soil Cyprus rotundus and Cynodon dactylon are found more difficult for their control than the light soil vineyard in Maharashtra.
Farmyard manure and compost are the main source of weed seeds transform from the outside places, particularly broad leaves weeds . Cynodon dactylon multiplies by runners, Cyprus rotundus multiplies by deep nut rhizomes. Other broad weed seeds are dispersed by animals, water and by air for their multiplication .
Methods for control the weeds in vineyard
Weeds removed by cultural practices from the field or killing by using the chemicals are termed as weed control.
Before plantation of new vineyard, the soil should be ploughed two-three times deeply for controlling the most problematic weeds viz. Cynodon( Harali) and Cyprus ( lavala). After ploughing to collect the roots and rhizomes of these two weed and burnt it after drying. This kind of practice can avoid increasing population of weed in first 2-3 years. In general, first 2-3 years weeds population are more because of canopy of vine is not fully developed. The density of weed is found less in Bower system of training as compare to the others i.e. ‘Y’, T and V.
Hand weeding is the most effective way for control the weeds in vineyard. But most drawback of this system is that required more manpower and it is not available every time. It has to be done in repetitions after 20-25days regularly in the year. Approximately, 40-50 labours are required for one hoeing over an area of one hectare and 8-9 times hoeing is required in entire year.
Mechanical methods of control, in trends in India, is cultivation by bullock drawn or Tractor drawn implements. This is very effective method where the limitation in availability of labour. A blade harrow or tinned harrow which cut only depth 8-10cm. inter-cultivation is the beneficial in weed control but disadvantageous in other aspects. It can disturb the soil structure and the soil micro- organisms. The heavy machinery like tractors can make soil compact and decrease the aeration in heavy soil. It also effect on the growth and multiplication of earthworm and other beneficial organism in soil.
Nutrients like boron and nitrogen will leach out with the water, but other nutrient tends to get fixed in the surface soil. So it is essential to cultivation with disc harrow in regular interval for mix the soil and pushes such nutrients into the deeper layers. Therefore, keeping the views of advantage and disadvantages intercultivation should be done precisely.
Mulching is also one of the methods for control weeds in vineyard. In addition to this it is also beneficial in conservation of soil moisture. In the mulching polythene, sugar cane trashes, straw of cereal crops have been used. The polythene mulching is much effective for control the weed but it may be bad effect on soil aeration, other hand the organic material control the moderate weed but it increases the moisture of soil, organic matter in soil and aeration of soil. This condition is favorable for growth of beneficial micro- organism in soil. Organic mulching not only control the weed but also provide the better environment for advantageous root and increase yield as compare to polythene mulching.
Chemical weed control
Due to increasing in fuel prices, less availability of labour and shortage of organic material now a day’s chemical control of weeds are very popular method in India. This method is most popular because of less labour requirement and effectiveness.
Paraquat (1, 1’dimethy-4,4- bipyridylium) dichloride):
It is non –selective herbicide used as the post –emergence weedicides to kill all types of the weeds. It is the only herbicide in CBI register list for control the weeds in grape vineyard. It is the contact herbicide and very minute amount of residue found in the soil. It is destroying the chlorophyll of any plant. It is highly effective when weeds are 15-20 cm in height. Due to the very safe weedicide it is used in majority of vineyard in India. The recommended dose for effective use of paraquat dichloride is 2.0 kg a.i/ha. For the effective control of weeds spraying should be done be done before the flowering stage of weed.
Dr. S. D. Ramteke* , Ravindra Kor and Mahadev Bhange
Plant Physiology Division, National Research Center for Grapes, Pune
Pune Solapur road, Manjari farm , Pune-412307