Bad date: Global warming, pests and pestilence threaten date palms
Along with changing rainfall patterns and local conditions for date palms, climate change may also encourage the growth of new date palm parasites, according to Dr S Mohan Jain of the University of Helsinki's Department of Agricultural Studies, who presented at the Fifth International Date Palm Conference in Abu Dhabi this month.
“The most influential factors that might impact the future distribution of date palms is the sharp variation in rainfall, global warming, gas pollution and decline of water resources,” Jain said.
His paper listed some of the threats: “Sustainable date palm production faces new challenges – industrialisation, loss of gene pool, and climate change. There are several climate-change factors including abiotic and biotic stress, increase in UV-B radiation level, global warming etc. Global warming may hamper overall agriculture production due to the appearance of new insect pests and diseases and some existing ones may disappear.”
The main pest to threaten date palms remains the Red Palm Weevil, but Jain also highlighted Bayoud disease, a fungal infection, along with phytoplasma diseases such as Al-Wijjam and lethal yellowing.
“Utmost attention is needed in developing date palm varieties harbouring resistance to these biotic agents, tolerant to drought, salinity, and high temperature and the development of multiple cropping systems in date palm oasis,” said Jain in his paper.
There are major international efforts to stem the spread of the Red Palm Weevil, which has migrated west from Asia to Europe in recent decades. Its larvae burrow into the trees, creating holes up to a metre long which weaken the palms, eventually killing them.
Last year researchers at the University of Cordoba in Spain announced the development of a pesticide which can deter the beetles. Currently the use of pheromone traps is the leading method of preventing the spread of the Red Palm Weevil.
New breeding techniques
Along with better pest control, Jain's solution is to invest more time and effort in breeding programmes for date palms, along with creating more hybrid varieties through cross-breeding and genetic engineering. Jain also suggested date palms could become a more viable crop if they were used as energy sources, as well as food sources.
“Date palm could become a major source of producing bio-ethanol, since its fruits have a high percentage of carbohydrates (total sugars 44-88%). Millions of date palm trees are grown in the Middle East, North Africa, and South Asia, and they provide food and nutrition to millions of people, and could also become a major source of bio-energy,” his paper stated.