There has been heavy rain accompanied by strong winds in the key wheat-growing States of Punjab and Haryana. Chandigarh Met office has also predicted another western disturbance approaching on March 11 and 12.
- These rains have left farmers and experts worried as they fear the inclement weather may damage the standing crop.
- Affecting the quality and quantity of Rabi crops:
- High-Speed winds have also already flattened the wheat crop in many areas.
- Nearly 25-30% of his wheat crop was affected by the unseasonal rain.
- The region is seeing widespread damage to not only the wheat crop but also potato, mustard, and rapeseed.
- Fungal infections: The high amount of precipitation will lead to water stagnation which will lead to fungal infections. Water stagnation will also affect the potato crop that is lying in the field.
Cropping Seasons in India
Sowing: In winter from October to December
Harvesting: In summer from
April to June.
Sowing: With the onset of monsoon, June.
In between the rabi and the Kharif seasons.
Major Crops Cultivated
Northern States: Wheat, Gram, Rapeseeds and Mustard, Barley
Southern States: Rice, Maize, Ragi, Groundnut, Jowar.
Northern States: Rice, Cotton, Bajra, Maize, Jowar, Tur.
Southern States: Rice, Maize, Ragi, Jowar, Groundnut.
Northern States: Vegetables, Fruits and fodder crops.
Southern States: Rice, Vegetable and Fodder
Other details about cropping seasons in India
- Not seen in Southern India:
- This type of distinction in the cropping season does not exist in the southern parts of the country.
- Here, the temperature is high enough to grow tropical crops during any period in the year provided the soil moisture is available.
- In this region, the same crops can be grown thrice in an agricultural year.
- Rabi crops:
- The relatively low temperatures facilitate the cultivation of temperate and subtropical crops.
- The availability of precipitation during winter months due to the western temperate cyclones help in the success of these crops.
About Western Disturbances
- It is an extratropical storm originating in the Mediterranean region that brings sudden winter rain to the north-western parts of the Indian subcontinent.
- It develops in the north of the Tropic of Cancer (mid-latitude region), not in the tropical region, therefore they are called mid-latitude storms or extra-tropical storms.
- It is non-monsoonal precipitation originating over the Mediterranean Sea and western Asia and moving into India, along with the westerly flow.
- Extratropical storms are a global phenomenon with moisture usually carried in the upper atmosphere, unlike their tropical counterparts where the moisture is carried in the lower atmosphere.
- A characteristic feature of the cold weather season over the northern plains is the inflow of cyclonic disturbances from the west and the northwest.
- They cause the much-needed winter rains over the plains and snowfall in the mountains.
- Although the total amount of winter rainfall locally known as ‘maha was’ is small, they are of immense importance for the cultivation of ‘rabi’ crops.
What drives western disturbances?
- In the winter season, the subtropical jet (STJ) is bifurcated into two branches(one north and another south of Himalayas) due to physical obstruction of the Himalayas and Tibetan Plateau.
- The winds tend to descend over the north-western parts of India, due to ridge formation of the jet stream that leads to anticyclonic (with clockwise air circulation) conditions over North-West India.
- The Subtropical Jet drives the temperate low pressures over the Mediterranean Sea towards east across Afghanistan, Pakistan and reaches north-west India.
- These storms are temperate cyclones that move at the height of 2000 meters from the mean sea level.
- On average, 4 to 6 cyclonic waves reach north-western India between October and April each year.