Chlorosis
In
The word chlorosis is derived from the Greek khloros meaning "greenish-yellow", "pale green", "pale", "pallid", or "fresh".
In
Burgundy. In these soils the grapevine often struggles to pull sufficient levels of iron which is a needed component in the production of chlorophyll.[2]
Causes
Chlorosis is typically caused when leaves do not have enough nutrients to synthesise all the chlorophyll they need. It can be brought about by a combination of factors including:
- a specific mineral deficiency in the soil, such as iron,[3] magnesium or zinc[4]
- deficient nitrogen and/or proteins[4]
- a soil pH at which minerals become unavailable for absorption by the roots[5]
- poor drainage (waterlogged roots)[5]
- damaged and/or compacted roots[5]
- pesticides and particularly herbicides may cause chlorosis, both to target weeds and occasionally to the crop being treated.[6]
- exposure to sulphur dioxide[7]
- ozone injury to sensitive plants [2]
- presence of any number of bacterial pathogens, for instance Pseudomonas syringae pv. tagetis that causes complete chlorosis on Asteraceae[8]
- fungal infection, e.g. Bakanae.
However, the exact conditions vary from plant type to plant type. For example, Azaleas grow best in acidic soil and rice is unharmed by waterlogged soil.
In grape vines
Like many other plants,
The Great French Wine Blight, when European Vitis vinifera were affected by Phylloxera, chlorosis became a greater problem in viticulture. To deal with the Phylloxera blight, V. vinifera was grafted onto rootstock based on American species of the genus Vitis, such as Vitis riparia, Vitis rupestris, and Vitis berlandieri. However, many of these were less adapted to the lime-rich soils that were common in France's vineyards, in particular many of those that produced wines of top quality. Many grafted vines in lime-rich vineyards therefore showed signs of iron deficiency, and in France this specific form of chlorosis was termed chlorose calcaire. The problem was largely overcome by the selection of lime-resistant American vines as basis for hybrid vines used for rootstock material. However, since such rootstocks may be less than optimal in other respects, it is necessary for the viticulturalist to balance the need for chlorosis resistance against other viticultural needs. This is illustrated by one of the most common lime-resistant rootstocks, 41 B, which is a hybrid between V. vinifera cultivar Chasselas and V. berlandieri, which generally has a sufficient, but not extremely high, Phylloxera resistance.[9][10]
Treatments
Specific
chelate or sulphate, magnesium or nitrogen compounds in various combinations. If the soil is too acidic, applying lime can raise the pH to the proper range, making more nutrients available to the plant. Likewise, sulfur can be used to lower soil pH if it is too alkaline.[11]
See also
Wikimedia Commons has media related to Chlorosis.
- Forest pathology
- Phytopathology
- Virescence
References
- PMID 15273297.
- ISBN 9781905819157
- ^ Koenig, Rich and Kuhns, Mike: Control of Iron Chlorosis in Ornamental and Crop Plants. (Utah State University, Salt Lake City, August 1996) p.3
- ^ a b Botany for Gardeners, p. 178, 3rd edition, Brian Capon, Timber Press 2010
- ^ a b c Schuster, James. "Focus on Plant Problems - Chlorosis". University of Illinois. Retrieved 2008-12-22.
- ^ Pests of Landscaped Trees and Shrubs: An Integrated Pest Management Guide By Steve H. Dreistadt, Jack Kelly Clark, p. 284, Regents of the University of California Division of Agriculture and Natural Resources, 2004
- ^ [1] Trees for Problem Landscape Sites -- Air Pollution, Virginia Tech May 2009
- . Retrieved 8 November 2022.
- ISBN 978-0-19-860990-2.
- ISBN 978-0-19-860990-2.
- ^ Gardner, Eva. "Chlorosis in Plants: Causes, Symptoms, Best Treatment". www.helpfulhomeadvice.com. Retrieved 2023-05-26.