Key Points to Ponder:
- What’s the ongoing story- The Union Agriculture Ministry has announced that it had set up a committee to monitor the situation arising from the increase in temperatures and its impact, if any, on the current wheat crop.
- The Secretary, however, said there won't be an impact of rise in temperature on early-sown varieties and even heat resistant varieties have been sown in large areas this time.
- Why a committee to monitor the situation arising from the increase in temperature and its impact?
- The move comes amid a forecast by the National Crop Forecast Centre (NCFC) that maximum temperature in major wheat producing areas barring Madhya Pradesh was higher-than-average of the last seven years during the first week of February.
- Even the Met Department has projected above-normal temperature in Gujarat, Jammu, Himachal Pradesh and Uttarakhand, in next two days.
- The committee has been set up to monitor the situation arising due to increase in temperature on the wheat crop. The committee will issue advisories to farmers on adopting micro irrigation.
- Wheat Production in India-Wheat is a Rabi or Kharif Crop?
- Wheat is a major rabi crop.
- Wheat production in India-Know the statistics
- Wheat production is estimated to hit a record at 112.18 million tonnes in the 2022-23 crop year (July-June).
- Wheat production had declined marginally to 107.74 million tonnes in the previous year, due to heat wave conditions in some states.
For Your Information- Wheat is a typically a 140-145 days crop planted mostly in November – before the middle of the month in Punjab, Haryana, Rajasthan and Madhya Pradesh (post the harvesting of paddy, cotton and soybean) and the second half and beyond in Uttar Pradesh and Bihar (after sugarcane and paddy). If sowing can be preponed and taken up from around October 20, the crop isn’t exposed to terminal heat, with much of the grain-filling being completed by around the third week of March. It can, then, be comfortably harvested by the month-end.
- Know more about “mild vernalisation requirement” wheat variety
- Vernalisation requirement refers to the low temperature requirement of the plants to bloom.
- Recently, the country has been facing several issues with respect to the production of wheat crops.
- Last year the wheat production had been affected due to the less winter rainfall and high temperature.
- Wheat prices had shot up due to the less production.
- Due to the climate change the temperature increased and it hinders the germination, flowing and growth of the wheat crops.
- To tackle this problem, the Indian Council of Agricultural Research, had launched a climate-smart wheat variety called the HD-3385.
- The major wheat producing states like Rajasthan, Punjab, Haryana & MP sow in early November. However, UP & Bihar sow in late November.
- So, the heading (flowering) starts 140-150 days (by mid-March).
- Heading requires 20 to 25 degrees Celsius of temperature. High heat damages the grain producing ability.
- So, the problem can be solved if the sowing is preponed and the Heading is reached in early March or late Feb,
- But if you prepone and sow in October, heading occurs within 70 days affecting the yield. If sown in early November, premature flowering occurs.
- This is because the crops cannot bloom at very low temperatures if sown early. So the solution is to reduce their blooming temperature!
- Hence the solution is the HD-3385, which will come to heading within 100 days and therefore shall be sown early. Also, the new variety accumulates biomass along with grain weight.
- ICAR scientists breed new climate-smart varieties-Know more about the same
- ICAR’s New Delhi-based Indian Agricultural Research Institute (IARI). Scientists have bred wheat varieties with what is termed “mild vernalisation requirement” or the need for a certain minimum period of low winter temperatures for initiation of flowering.
- In this case, the crop, when sown in October 20-25, will come to heading only in 100-110 days. Adding another 4-5 days for pollination, it leaves a long window from mid-February for grain formation and filling.
- Maximum temperatures should ideally be in the early-30 degrees range during the 30-40 days when the kernels are formed, take in nutrients from the stems and leaves, and ripen after hardening and drying.
- The early-sown IARI varieties not only have a longer window for grain development, but also for vegetative stage growth between germination and flowering.
- By not heading early despite early sowing, the new varieties are able to accumulate more biomass along with grain weight and they can beat the heat.
- The IARI scientists have developed three varieties, all of them incorporating genes that are responsible for the mild vernalisation requirement preventing premature flowering and early heading.
- The first, HDCSW-18, was released and officially notified in 2016. Although having a potential wheat yield of over 7 tonnes per hectare – as against 6-6.5 tonnes for existing popular varieties such HD-2967 and HD-3086 – its plants grew to 105-110 cm. Being tall, compared to 90-95 cm for normal high-yielding varieties, made them prone to lodging or bending over when their earheads were heavy with well-filled grains.
- The second variety HD-3410, released in 2022, has higher yield potential (7.5 tonnes/hectare) with lower plant height (100-105 cm).
- But it’s the third one, HD-3385, which looks most promising. With the same yields as HD-3410, plant height of just 95 cm and strong stems, it is least lodging-prone and most amenable for early sowing. This variety, sown this time at IARI’s trial fields on October 22, has reached pollination stage – while the emergence of the earheads is yet to start for the wheat that was planted in the normal time.
- IARI has registered HD-3385 with the Protection of Plant Varieties and Farmers’ Rights Authority (PPVFRA). It has also licensed the variety to the DCM Shriram Ltd-owned Bioseed for undertaking multi-location trials and seed multiplication. “This is the first ever such PPP experiment. By registering the variety with PPVFRA, they are ensuring full protection of our intellectual property rights.
- Involving the private sector in commercialisation of publicly-bred crop varieties will benefit farmers through faster adoption and diffusion of technology.
- It is also beneficial for ICAR because the institutes will earn royalty on every kg of seed sold by the licensee, which they can plough back into research. And the country gains through higher production from climate-smart varieties.
- How has the weather over North India been in 2023?
- North India Witnessed summer-like temperatures as Mercury levels reach 5-10°C above normal
- February usually serves as a transitionary period between the winter's biting cold and the summer's blistering heat. However, the mercury reaching levels usually reserved for March has people from many parts of the country lamenting about the hot weather already.
- A "very early and strong anti-cyclonic circulation" is driving the heat wave in Gujarat and Konkan, while the Northwestern states are bearing the brunt of the insufficient winter precipitation.
- Meteorologists say that the dry weather is due to the absence of stronger western disturbances (WD) — storm systems originate from the Caspian Sea and move across the Afghanistan-Pakistan region to bring rains across Northwest India. While a couple of WDs did visit north India last week, their intensity remained very low.
- What is the reason behind an early temperature rise in North India?
- It is still February, technically a winter month, and temperatures in some parts of the country are touching 40 degrees Celsius- Why has there been a sudden rise in temperatures?
- The western disturbance plays an important role in weather in different parts of the country. The lack of strong western disturbances is the primary reason for the early heat in the city and other parts of northwest India.
- The weak western disturbances led to below normal rainfall especially in the hilly region.
- What exactly is IMD saying about the situation?
- The IMD scientists have warned that the temperatures may go up to 40 degrees Celsius in one or two meteorological subdivisions of northwest India in the first half of March.
- The lack of rainfall due to absence of effective western disturbances over north India has led to unusual heat.
- La Nina phenomenon, North-South low-pressure pattern over India in winters and Heat Waves-Connect the dots
- What is the La Nina phenomenon?
El Nino – Low pressure in the tropical Central and Eastern Pacific and High pressure in the tropical western Pacific.
La Nina – High Pressure in the tropical Central and Eastern Pacific and Low pressure in the tropical Western Pacific.
- These two phases relate to Walker Circulation.
- Walker Circulation is caused by the pressure gradient force that results from a high pressure area over the eastern pacific and a low pressure area over Indonesia.
- Weakening or reversal of the Walker Circulation decreases or eliminates the upwelling of deep cold water at Eastern Pacific thus creating El Nino.
- A strong Walker Circulation causes La Nina.
Walker Circulation – Along the equator trade winds (blowing from east to west in the Pacific) cause the ocean currents in the Eastern Pacific to draw water from the deeper ocean to the surface, thus cooling the ocean surface.
- Under the influence of the equatorial trade winds, the cold water flows westwards along the equator where it is heated by the Sun.
- So the sea surface temperature in the Western Pacific is generally warmer by 8 – 10o C than the Eastern Pacific.
- The warmer areas of the ocean in the Western Pacific is a source of convection and cloudiness.
During El Nino years the cold water weakens or disappears, as the water in the Central & Eastern Pacific becomes as warm as the Western Pacific.
- During non – El Nino conditions, the Walker circulation is seen as trade winds that move warm water towards the west. This creates ocean upwelling off the coasts of Peru and Ecuador and brings nutrient rich cold water to the surface increasing fish stock.
- The Western side of the Pacific is characterized by warm and wet low pressure weather and high precipitation.
- The ocean is 60 cm higher in the Western Pacific as the result of this motion.
- So during normal conditions trade winds blow from east to west, push warm surface waters and pile it up in the Western Pacific.
- But in some years the trade winds weaken and upwelling of cold water is reduced off the coast of South America. Climatologists call it El Nino.
But eventually the trade winds pickup again and sometimes become stronger than normal.
When that happens, they push the warm water back to the Western Pacific and restart the upwelling of cool water towards the surface in the Eastern Pacific. This is La Nina.
ENSO – El Nino, La Nina and the Neutral Phase.
Neutral Phase – If the temperature variation is within 0.5o C. It is the transition between the warm and cold phases.
Southern Oscillation –
- It is the atmospheric component of ENSO.
- It is the oscillation in surface air pressure between the tropical Western and Eastern Pacific regions.
The strength of the Southern Oscillation is measured by the Southern Oscillation Index (SOI).
SOI is calculated from the fluctuations in the surface air pressure difference between Tahiti & Darwin, Australia.
- El Nino – Negative SOI – Low pressure over Tahiti & High pressure over Darwin.
- La Nina – Positive SOI – High pressure over Tahiti & Low pressure over Darwin.
• Do You Know- El Nino and La Nina are climate patterns in the Pacific Ocean that can affect weather worldwide. Episodes of El Nino and La Nina typically last 9-12 months, but can sometimes last for years. El Nino and La Nina events occur every two to seven years, on average, but they don’t occur on a regular schedule, say experts. Generally, El Nino occurs more frequently than La Nina. According to the latest forecast by the National Oceanic and Atmospheric Administration (NOAA), a transition from La Niña to ENSO-neutral will occur mostly during the February-April 2023 season. Climate models are predicting a potential return to El Niño by May-July, which coincides with the summer monsoon that spans from June- September. The occurrence of three consecutive La Niña in the Northern Hemisphere is a relatively rare phenomenon and is known as the ‘triple dip’ La Niña. The latest triple dip La Nina occurred between 2021-23.
Also Read: https://www.jatinverma.org/ipcc-special-report-el-nino-and-la-nina