Sultan Qaboos University is exploring ways to rejuvenate lime cultivation in Oman

However, in the past two years, there has been a significant reduction in the production of lime in the Sultanate. The area cultivated with lime trees is now only 50 per cent of the land that was used for lime cultivation in 1990, mainly due to a disease known as Witches' Broom Disease of Lime (WBDL). This disease is caused by phytoplasma, an organism that resembles both bacteria and viruses.

Dr Rashid Al Yahayi, an assistant professor in the Crop Sciences Department at Sultan Qaboos University and his colleagues are engaged in a research project on rejuvenating lime production in Oman. The project is funded by the strategic research grant of His Majesty. According to Al Yahayi, WBDL is a disease that originated in the Sultanate, and has the potential to devastate lime production throughout the entire regions of western Asia and North Africa.

"These problems have been worsened by the increasingly stressful conditions caused by drought, salinity and soil infertility which ultimately led to the decline of fruit production in the country", said Dr Rashid. Loss in lime production has resulted in a decline of tree fruit acreage and profitability, reducing income from largely traditional farming systems.

The unsustainable tree fruit production has eventually led to the abandonment of many farms, to conversion of fruit farms into forage farms, or to converting the land for some other commercial projects. While the causal agent of WBDL has long been identified, practical solutions to thwart the disease have not been found.

Through national and international collaboration, methodological experimentation in the laboratory and field testing of efficient management strategies, the ongoing research at SQUSQU will tackle solution-oriented aspects of WBDL in Oman.