Declining production and inferior quality are the twin problems now plaguing tea plantations in south India which, along with the eastern state of west Bengal and north eastern state of Assam, produce most of India's tea.

The main reasons are shortage of labor, old tea bushes, failure of owners to modernize their plantations and the erratic climate condition in tea-producing parts of India.

Tea production from South India decreased from 246.9 million kg in 2008 to 240.88 million kg in 2011. In 2009, tea production was recorded at 244.13 million kg and in 2010 it was down to 243.37 million kg.

However, in the same period, tea production from North India increased from 733.93 million kg in 2008 to 747.45 million kg in 2011.

Unlike other land crops, tea is not very sensitive to rainfall variations but over the last several years, changes in the weather pattern have eventually affected the quantity and quality of tea produced in the southern part of India. "The weather has been unpredictable during the past few years. Rainfall is less and the dry periods are getting longer. Production is likely to decline in the coming years in south mainly due to erratic weather condition and the old age of the tea plants."Harrisons Malayalam executive director N. Dharmaraj said.

Dharmaraj said most of the plantations in south India have tea bushes that are past their prime."The average age of tea bushes would be around 70 years. There are new and better quality clones available but replanting has been slow in the south,"he said.

According to the M.S. Swaminathan Commission, which was appointed to study farm crisis in parts of south India, environmental factors have changed dramatically and could threaten the livelihood of millions of Indian tea farmers.

The commission studied rain and temperature data for the past few decades and found that the number of rainy days has declined both during the southwest and northeast monsoons.

The temperature data for the region also revealed that maximum temperature was rising over the years, while minimum temperature was decreasing. The rate of decrease in the minimum temperature is slightly lower, but very significant.

Chacko P. Thomas, managing director of Kanan Devan Hills Plantations,the largest tea plantation in south India, said"We feel it is going to be a difficult time for the tea industry in the southern plantations. In the last four to five years, weather has become completely unpredictable. We have lost a large area to frost due to cold and dry conditions. The maximum temperature has increased over the years by almost 1.5C, while the minimum has fallen by the same level."

United Planters Association of South India (UPASI) Tea Research Foundation joint director P. Mohan Kumar said that a combination of factors, including erratic weather, were to be blamed for the declining production.

Kumar said that in Valaparai, where the UPASI is located, the maximum temperature has increased to 34C in the last 10 years from around 30C. Similarly, the minimum temperature has also fallen.

What compounded the problem, Kumar said, is that some large estates were unable to harvest their crops completely due to shortage of labor."Machine harvesting is an option but the quality of tea suffers when compared to manual harvesting," Kumar said.

In some cases, the tea bushes are very old resulting in declining yield every year. "In south India, for example, more than 50 percent of the tea bushes are above their prime productive age," Kumar said.

The shortage of labor for tea plantations was due to the migration of workers to other thriving industries like hosiery in Tirupur in India's southern state of Tamil Nadu.

Available data from the UPASI shows that India consumes about 25 percent of the world's tea production and over 75 to 80 percent of its own output. Domestic tea consumption has grown by 3 to 3.5 percent per annum over the last decade.

This indicates that because of economic growth, the demand for tea will increase and the industry will benefit. But to meet local demand, India will have to import tea.