Open AccessTemporal Dynamics of Septoria Leaf Spot of Blueberry and its Relationship to Defoliation and Yield
Author(s) -
P. S. Ojiambo,
H. Scherm,
Phillip M. Brannen
Publication year - 2007
Publication title -
plant health progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.565
H-Index - 9
ISSN - 1535-1025
DOI - 10.1094/php-2007-0726-05-rs
Subject(s) - septoria , biology , abscission , shoot , growing season , horticulture , leaf spot , yield (engineering) , crop , agronomy , botany , materials science , metallurgy
In field trials on Premier rabbiteye blueberry in Georgia, onset of Septoria leaf spot (caused by Septoria albopunctata) occurred between late April and mid-June. Average disease severity increased sigmoidally until late September, after which it declined due to the abscission of severely affected leaves. Disease severity was highest on early-emerging leaves and on those located on shoots closer to the ground. Pycnidiospore inoculum was present throughout the season, and leaves became infected by S. albopunctata season-long. Disease severity, defoliation, flower bud set, and next season's yield were interrelated; severely affected leaves abscised earlier in the fall than those with low disease severity, and shoots with severely diseased leaves and/or high levels of defoliation had reduced flower bud set. Furthermore, such shoots consistently had low yields the following year. The results form the basis for identifying disease levels that can be tolerated during specific periods of crop development without negatively impacting flower bud set and yield. Accepted for publication 15 March 2007. Published 26 July 2007.