24/10/19: Olive trees are tolerant, hardy, resilient and can survive throughout prolonged drought periods and weather extremes. Olive Growing all over the world are suffering adverse effects of climatic factors including water scarcity, prolonged higher temperatures, and high irradiance. Production losses due to drought stress are felt by today’s olive producer especially in these times of the current widespread drought in Australia.
Sufficient, reliable and sustainable water availability is a primary resource mandatory in achieving a commercially viable olive crop and has a negative impact on the capacity and volume of production of Australian olive oil and table olives. The accepted industry threshold of additional water resources needed is from 3ML up to 12ML/ha per annum to achieve commercially viable cropping in olives.
Efficient measures are needed in response to the mechanisms to drought stress or drought intolerance including but not limited to varietal performance, photosynthetic performance impairment, oxidative stress and imbalances in plant nutrition. Although the olive tree has several mechanisms that allow for good acclimation to drought, they are activated at the expense of carbon reserves and may be detrimental with the increased duration and intensity of the stress.
The Australian Olive Industry encompasses over 10 million olive trees planted in commercial orchards with an estimated 25% of these trees deemed unproductive during these difficult times of scarce water availability (the estimate of trees affected could be much higher than expected).
Understanding the main effects and the response mechanisms adopted by the olive tree to cope with drought is crucial to improving crop management strategies and designing sustainable and productive crop systems and saving water resources.
Increasing consciousness regarding the nutritional value of olive oil has enhanced the demand for this product and, consequently, the expansion of olive tree cultivation. Although it is considered a highly resilient and tolerant crop to several abiotic stresses, olive growing areas are usually affected by adverse environmental factors, namely, water scarcity, heat, and high irradiance, and are especially vulnerable to climate change. In this context, it is imperative to improve agronomic strategies to offset the loss of productivity and possible changes in fruit and oil quality. To develop more efficient and precise measures, it is important to look for new insights concerning response mechanisms to drought stress. In this review, we provided an overview of the global status of olive tree ecology and relevance, as well as the influence of environmental abiotic stresses in olive cultivation. Finally, we explored and analysed the deleterious effects caused by drought (e.g., water status and photosynthetic performance impairment, oxidative stress and imbalance in plant nutrition), the most critical stressor to agricultural crops in the Mediterranean region, and the main olive tree responses to withstand this stressor.
Figure 2 (above). Strategies adopted by the olive tree to improve drought adaptability (i.e. drought avoidance, tolerance and recovery capacity).
Authors: Cátia Brito, Lia-Tânia Dinis, José Moutinho-Pereira and Carlos M. Correia . CITAB—Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
Read the full study at MDPI