Editing Physiological plant disorder (section)

==Diagnosis of disorders==
Diagnosis of the cause of a physiological disorder (or disease) can be difficult, but there are many web-based guides that may assist with this. Examples are: ''Abiotic plant disorders: Symptoms, signs and solutions'';<ref name=Schutzki2007 /> ''Georgia Corn Diagnostic Guide'';<ref name=Lee2012>{{cite web|last1=Lee|first1=R.D.|title=Georgia Corn Diagnostic Guide|url=http://extension.uga.edu/publications/detail.cfm?number=B1221|website=extension.uga.edu|publisher=University of Georgia Cooperative Extension|accessdate=10 April 2015|date=2012}}</ref> ''Diagnosing Plant Problems'' (Kentucky);<ref>{{cite web|last1=Green|first1=J.L.|last2=Maloy|first2=O.|last3=Capizzi|first3=J.|last4=Hartman|first4=J.|last5=Townsend|first5=L.|title=Diagnosing Plant Problems: Kentucky Master Gardener Manual Chapter 7|url=http://www2.ca.uky.edu/agc/pubs/id/id194/id194.pdf|website=www2.ca.uky.edu|publisher=Kentucky Cooperative Extension|accessdate=10 April 2015|date=2011}}</ref> and ''Diagnosing Plant Problems'' (Virginia).<ref>{{cite web|last1=Niemiera|first1=A.X.|title=Diagnosing Plant Problems|url=http://pubs.ext.vt.edu/426/426-714/426-714.html|website=pubs.ext.vt.edu|publisher=Virginia Cooperative Extension|accessdate=10 April 2015|date=2009}}</ref>

[[File:Apple sunburn1.jpg|thumbnail|Sunburn on apple.]]
Some general tips to diagnosing plant disorders:
*Examine where symptoms first appear on a plant—on new [[leaves]], old leaves or all over?
*Note the pattern of any discolouration or yellowing—is it all over, between the [[vein]]s or around the edges? If only the veins are yellow, deficiency is probably not involved.
*Note general patterns rather than looking at individual plants—are the symptoms distributed throughout a group of plants of the same type growing together? In the case of a deficiency all of the plants should be similarly effected, although distribution will depend on past treatments applied to the soil.
*Soil analysis, such as determining [[Soil pH|pH]], can help to confirm the presence of physiological disorders. 
*Considering recent conditions, such as heavy rains, dry spells, frosts, etc., may also help to determine the cause of plant disorders.