31 October 2014 04:28 am Views - 3317
Drought conditions have in the past affected tea and rubber production adversely and coconut output during these periods and few months after the drought also had been very low, due to residual effect. A significant decrease in hydropower generation due to low levels of water in the reservoirs would increase import expenditure on oil.Also, these adverse developments will affect national output, decrease exports, increase imports, strain public finances, increase the cost of living and worsen livelihoods, especially of the rural poor. For these reasons, management of drought conditions is crucial for the economy.
PREPAREDNESS
Although, we have been experiencing heavy rains and floods in some parts of the country in the recent past, yet we need to be prepared for such calamities. We will not be able to avoid such occurrences, but the impact of the adverse effects can be minimized.
ELNINO
More severe expression of drought/ flooding, referred to as EL Nino, is also of frequent occurrences in the plantation areas.The global El Niño weather phenomenon, whose i mpacts cause global famines, floods – and even wars – now has a 90 percent chance of striking in 2014/2015, according to the latest forecast. El Niño begins as a giant pool of warm water swelling in the eastern tropical Pacific Ocean, that sets off a chain reaction of weather events around the world – some devastating and some beneficial.Asia is expected to be the first to suffer, with weaker monsoon rains undermining the nation’s fragile agriculture, followed by further scorching droughts in Australia and collapsing fisheries off South America. But some regions could benefit, in particular the US, where El Niño is seen as the “great wet hope” whose rains could break the searing drought in the West.
WHAT IS ELNIÑO?
The knock-on effects can have impacts even more widely, from cutting global gold prices to making England’s World Cup footballers sweat a little more.
The latest El Niño prediction comes from the European Centre for Medium-range Weather Forecasts (ECMWF), which is considered one the most reliable of the 15 or so prediction centres around the world. “It is very much odds-on for an event,” said Tim Stockdale, principal scientist at ECMWF, who said 90 percent of their scenarios now deliver an El Niño. “The amount of warm water in the Pacific is now significant, perhaps the biggest since the 1997-98 event.” That El Niño was the biggest in a century, producing the hottest year on record at the time and major global impacts, including a mass die-off of corals.
But what is very much unknowable at this stage is whether this years 2014/2015 El Niño will be a small event, a moderate event – that’s most likely – or a really major event. The picture will become clearer in next month or two. It is which way the winds blow that determines what happens next and there is always a random element to the winds.
The movement of hot, rain-bringing water to the eastern Pacific, ramps up the risk of downpours in the nations flanking that side of the great ocean, while the normally damp western flank dries out. Governments, commodity traders, insurers and aid groups like the Red Cross and World Food Programme all monitor developments closely and water conservation and food stockpiling is already underway in some countries.It has been reported that a major El Niño is more likely than not, because of the specific pattern of winds and warm water being seen in the Pacific. “In the past, such alignments have always triggered strong El Niño events,” it has been said .El Niño events occur every five years or so and peak in December, but the first, and potentially greatest, human impacts are felt in Asia. The reliance of its several billion-strong population on the monsoon, which usually sweeps up over the southern tip of the sub-continent around 1 June, has led its monitoring to be dubbed “the most important weather forecast in the world”. This year, it is has already got off to a delayed start, with the first week’s rains 40 percent below average.
El Niño could be quite devastating for agriculture/ plantations and the water supply. Two-thirds of Asian farmland lacks irrigation and is reliant solely on rainfall, meaning even current official prediction of a 5 percent reduction in monsoon rains would have a major impact: a 10 percent fall is an official drought. Even if the 2014/2015 El Niño turns out not to be a very hot one, it can still have a major effect on the monsoon because it is the specific location of the warm Pacific water which is the critical factor.The moderate El Niños of 2002 and 2009 impacted the monsoon in Asia much more greatly then the major 1997 event, it has been said, adding that the biggest cut in rainfall is not usually felt until latter part of the year.
WATER IN PLANTS
Water is a major constituent of protoplasm; Is the solvent in which mineral nutrients enter a plant from the soil solution.Also, water is the solvent in which mineral nutrients are transported from one part of a cell to another and from cell to cell, tissue to tissue, and organ to organ ; Is the medium in which many metabolic reactions occur; Is a reactant in a number of metabolic reactions; In photosynthesis the hydrogen atom in the water molecule is incorporated into organic compounds and oxygen atoms are released as oxygen.Water imparts turgidity to growing cells and thus maintains their form and structure. In fact water can be regarded as a material that provides mechanical support and rigidity to no lignified plant cells.
Gain or loss of water from cells and tissues is responsible for a variety of movements of plant parts. The elongation phase of cell growth depends on absorption of water. Water is a metabolic end product of respiration and More water is absorbed by plants and greater amounts of water are lost as water vaporby plants than any other substance.
DROUGHT MANAGEMENT IN TEA
Young tea and mature tea in the final year of the cycle, are mostly affected by drought. Removal of leaves, by stripping or pruning, enables the bush to survive severe drought. Adequate levels of leaf nitrogen and potassium also helps to mitigate the effects of drought. Therefore, spraying of K2SO4 together with urea, just prior to drought and also, foliar application various chemical antitranspirants will help. Maintaining adequate root starch reserves by resting the bush prior to drought is also beneficial.VP teas are, however, vulnerable to adverse impacts of climate change. The new improved seedling tea introduced by TRI is an effective adaptation measure that minimise this risk.
Seedling tea is better drought resistant due to tap root and hard nature of its roots and therefore is a best option for tea plantations in the Uva region which is most vulnerable to the drought. TRI has introduced the technology but cannot commercially supply seedling tea plants to meet the huge demand. Therefore, RPCs should establish their own Seed gardens. These should be maintained in isolation, in rubber estates, to avoid pollination. In the development of high yield seeds TRI used VP series as parental plants. Different combinations were used to incorporate different characters and there are biclonal and policlonal seed varieties developed at several seed gardens in different climatic zones.
ISSUES
The problems of environmental degradation and ecological imbalances have assumed critical proportions and demand urgent and committed action. The sad part of the story is that global climatic changes and the El Nino and La Nina effect; have created havoc in plantation areas resulting in unprecedented drought or floods in most Plantation areas. The rainfall has almost declined to half causing high temperatures which in turn affect the MACRO and MICRO climate resulting in low productivity.
The truth is that there is no scarcity of water really. The problem is how to harness water from rains and floods and recycle it back into plantations. Conserving and directing rain water into definite predetermined paths for immediate or later use is nothing new .This has been known and practiced over many years in the past, mainly in the Asian and African regions
RUBBER
Adverse impact in rubber plantations could be in the form of a reduction in growth and yield and decline in stand per unit area.The effect of the drought would depend on the duration of the drought period. Even in the wet zone, dry spells of 1-2 months had been common in some years but, the rubber plantations generally withstand these dry seasons without any significant adverse effects on growth or yield.
However, prolonged drought periods also occur in some regions with distinct dry spells and these lead to soil moisture stress of different magnitude, adversely affecting the growth which results in longer immature period and sometimes death of very young rubber plants.Effects will also depend on the maturity of the clearing. For instance, fully grown mature rubber plantations are somewhat identical to a natural forest system. Under such conditions the impact of El - Nino is considered to be minimal compared to other agricultural crops. However, there could be noticeable effect on rubber yield as the drought is expected to be really severe. The impact of drought on young rubber plantations would be very much severe compared to mature trees. The young plants may initially show signs of retarded growth and could end up with high mortality rates. This would result in low stand per land area. Maintaining a healthy rubber stand throughout the lifespan is considered is important.
MANAGEMENT PRACTICES
The impact of drought on young rubber plants may not be much severe if appropriate agronomic practices have already been adopted.
Rubber is usually grown in association with a leguminous ground cover, which persists during the immature phase and perishes when the canopy of rubber trees closes. The moisture retention is higher under a good cover compared to other situations mainly due to increase water holding capacity by the mulch of decomposing organic matter and humus formed by the cover crop.
CONCLUSION
There are no universally accepted successful systems for averting drought. The uncertainty that characterizes plantation agriculture - much of it due to climate variability- is among the greatest challenges facing growers and others in the plantation agriculture value chain. Any research information that reduces the uncertainty about future production or prices has immense value to them.