Pests and diseases have long plagued farmers in the Middle East, with agriculturalists in ancient Mesopotamia having had to take action against them as far back as 4,500 years ago.
In the first known use of pesticides, Sumerians applied sulphur compounds to protect plants from insects and mites.
Back then, the world population was in the tens of millions, while today, with billions of mouths to feed, protecting crops from pests and diseases is more important than ever.
Date palms are vulnerable to fungal diseases and more than 50 insects and mites worldwide, but in the UAE significant efforts are made to protect the trees.
Caught in a trap
As reported in The National, the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA) has used pheromone and light traps to protect more than two million date palms from harmful insects like the red palm weevil and the stem borer this year.
Farms across Abu Dhabi host more than 21,000 light traps and over 125,000 pheromone traps, according to the official news agency, Wam.
Prof Synan AbuQamar, a plant molecular geneticist at UAE University in Al Ain, told The National that the red palm weevil was “the most destructive pest for date palms”.
Originally from tropical Asia, it has spread to the Middle East, North Africa and parts of Europe.
“This pest causes internal damage as larvae feed on palm tissue, often leading to the death of the tree if left uncontrolled,” Prof AbuQamar said.
Various measures are used to combat the pest, including the application of chemical pesticides early on in an infestation.
Pheromone traps like those deployed by ADAFSA can target adults, while good orchard management and care of the offshoots can also reduce the impact of the red palm weevil and other pests and diseases.
Biological control, the use of organisms that are predators or parasites of the pest, is also being explored. Tiny worms called nematodes are “being studied for their effectiveness against the red palm weevil”, Prof AbuQamar said.
When it comes to controlling pests and diseases, a broader strategy called integrated pest management is seen as optimal. Combining biological control with insecticides, this minimises pesticide use and reduces the environmental risks.
Other pests include the dubas bug, which weakens date palms by sucking sap from the leaves. It also promotes mould growth, which reduces photosynthesis and yield. Diseases, particularly fungal infections, also affect date palms.
For example, sudden decline syndrome (SDS) results in wilting and rot, posing “a serious threat to date palm cultivation”, Prof AbuQamar said.
Research by Prof AbuQamar and his colleague Khaled El Tarabily, a professor of applied and environmental microbiology at UAEU, has explored the use of Streptomyces violaceoruber UAE1, a type of actinobacteria, to prevent SDS.
“Given the widespread nature of fungal diseases in the UAE, there is significant potential for expanding the use of actinobacteria as a biological control agent,” Prof AbuQamar said.
“These micro-organisms not only protect against fungal pathogens but also improve overall plant health and soil quality.
“Wider application of actinobacteria, through bio-inoculants, could provide an eco-friendly, sustainable method to manage fungal diseases in date palms, reducing reliance on chemical fungicides while supporting long-term agricultural sustainability.”
Traditional plant breeding has long been used to improve the resistance of crops to pests and diseases, but genetic engineering offers a more precise method to achieve this by introducing genes from plants or other organisms that cannot naturally be crossed with the crop.
Genetic engineering offers a more precise way to do this, and enables genes to be introduced from plants or other organisms that the original crop cannot be crossed with.
Growing resistance
Dr Sarah Garland, founder and executive director of the Triple Helix Institute for Agriculture, Climate and Society, described genetic engineering as “one of the most exciting” ways of improving crop resistance.
“Depending on the type of disease or pest – viral, fungal, bacterial, insect – different genetic engineering strategies can be used to protect the plant,” she said.
A successful example is the Rainbow papaya in Hawaii, which was genetically modified to resist the papaya ringspot virus. The insertion of viral genetic material into the Rainbow papaya’s genome conferred this resistance.
“If you visit the Big Island of Hawaii today, it’s nearly impossible to find a papaya tree with this disease, even including trees that are not genetically engineered, because the intervention worked so well,” Dr Garland said.
New methods to combat pests and diseases in crops are becoming increasingly important, because climate change is expected to exacerbate the threats posed in the UAE and elsewhere.
Rising temperatures and altered rainfall patterns will likely lead to more frequent and severe infestations and will weaken date palms and other crops, making them more vulnerable, Prof AbuQamar said.
For example, the red palm weevil is expected to thrive in warmer conditions, while warmer winters mean that pests and disease-causing microorganisms are more likely to remain active year-round.
Global temperature rises may also cause some pests and pathogens to spread to new geographic regions.
“In summary, climate change is expected to amplify the impact of pests and diseases on date palms and other crops in the UAE,” Prof AbuQamar said.
“This highlights the need for resilient agricultural practices, including integrated pest management and the use of biological control agents like actinobacteria, and the development of climate-smart crop varieties.
“Sustainable approaches will be critical for adapting to climate change and ensuring food security in the region.”
