Stages of Sunflower Development (A1145, Reviewed July 2019)
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Description of sunflower growth stages
The total time required for development of a sunflower plant and the time between the various stages of development depends on the genetic background of the plant and the growing environment. When determining the growth stage of a sunflower field, the average development of a large number of plants should be considered. This staging method also can be used for individual plants. The same system can be used for classifying a single head or branched sunflower. In the case of branched sunflower, make determinations using only the main branch or head. In stages R7 through R9, use healthy, disease-free heads to determine plant development if possible because some diseases can cause head discoloration.
V-E
V-2
V-4
V-12
True leaf — 4 cm
R-1
R-2
R-2 Less than 2 cm
R-3
R-3 More than 2 cm
R-3 Top View
R-4 Top View
R-5.1
R-5.5
R-5.9
R-6
R-7
R-8
R-9