How and Why Plant Stress increases production costs while at the same time is reducing the quality and the quantity of the production.
The maximum yield of plants is determined by their genetic potential, is rarely achieved because factors such as insufficient water or nutrients, adverse climatic conditions, plant diseases, and insect damage will limit growth at some stage. Plants subjected to these biotic and abiotic constraints are said to be stressed.(1) Furthermore, physiological and anatomical changes occur in plants as a result of biotic - abiotic stress. If transpiration of leaves stomata is restricted from a vascular disease (e.g., plant diseases) leaf temperatures will increase.(1)
Pinter et al(2) used a thermal-infrared radiometer to measure leaf temperatures of sugar beets infected with Pythium aphanidermatum, since the disease could not be visually ascertained without examining the roots. They found that leaf temperatures of diseased plants averaged 2.6 - 3.6°C warmer than the leaves of healthy plants. Furthermore, temperatures of diseased plants remained higher than those of healthy plants, even under conditions of water stress.(1)
Some vineyard diseases causing biotic stress and are not pathognomonic at the early stage, are trunk diseases (e.g. esca), Grapevine Leafroll Disease and Pierce disease.
Trunk diseases in France are costing €1 billion annually in wine production loss. More than 100.000 hectares lost in 2014, while there was a 10 - 15% loss of production in 2015.(3)
California has economic losses of $260 million per year due to trunk diseases. Furthermore, esca contribute to a loss of about $2,000-3,000 per hectare per year to Californian viticulturist.(3)
Furthermore, Californian grape growers suffered a total cost of $56.1 million due to the cost production loss and vine replacement from Pierce disease.(4)
Last, Grapevine Leafroll Disease is affecting up to 50% of the global vineyards. It can have devastating impacts on a vineyard, dramatically reducing fruit quality and yield. With no cure, infected vines must be removed and replanted to prevent the spread of disease, a hard cost of up to $200,000 per hectare, with little yield for almost three years.(5)
Sources:
(1) Jackson, R. D. Remote Sensing of Biotic and Abiotic Plant Stress. Annu. Rev. Phytopathol. 1986, 24, 265–287.
(2) Pinter, P. J.; Stanghellini, M. E.; Reginato, R. J.; Idso, S. B.; Jenkins, A. D.; Jackson, R. D. Remote Detection of Biological Stresses in Plants with Infrared Thermometry. Science 1979, 205 (4406), 585–587.
(3) Grapevine Trunk Diseases. A Review. International Organisation Of Vine And Wine May 2016.
(4) Tumber, K. P.; Alston, J. M.; Fuller, K. B. Pierce’s Disease Costs California $104 Million per Year. Calif. Agric. 2014, 68 (1), 20–29.
(5) Almeida, R.; Daane, K.; Bell, V.; Blaisdell, G. K.; Cooper, M.; Herrbach, E.; Pietersen, G. Ecology and Management of Grapevine Leafroll Disease. Front. Microbiol. 2013, 4.
The maximum yield of plants is determined by their genetic potential, is rarely achieved because factors such as insufficient water or nutrients, adverse climatic conditions, plant diseases, and insect damage will limit growth at some stage. Plants subjected to these biotic and abiotic constraints are said to be stressed.(1)