Abstract
Chasmothecia of Erysiphe necator form in one
season, survive winter and discharge ascospores that cause
primary infections and trigger powdery mildew epidemics
in the next season. A strategy for powdery mildew control
was developed based on (i) the reduction in overwintering
chasmothecia and on (ii) spring fungicide applications to
control ascosporic infections timed based on estimate risk
(two to five sprays per season). Several fungicides, the
hyperparasite Ampelomyces quisqualis, and a mineral oil
product were first tested as separate applications in a
greenhouse and in vineyards. In the greenhouse, A. quisqualis
suppressed chasmothecia formation by 41 %; fungicides
and mineral oil suppressed chasmothecia
formation by 63 % and ascospore viability by 71 %. In
vineyards, application of boscalid + kresoxim-methyl or
meptyldinocap once after harvest, as well as application of
A. quisqualis pre- and post-harvest, delayed disease onset
and epidemic development in the following season by 1 to
3 weeks and lowered disease severity (up to the pea-sized
berry stage) by 56 to 63 %. Risk-based applications of
sulphur and of synthetic fungicides provided the same
control as the grower spray program but required fewer
applications (average reduction of 47 %). Sanitation strategies
were then tested by combining products and application
times (late-season, and/or pre-bud break, and/or
spring). Adequate disease control with a reduced number
of sprays was achieved with the following combination:
two applications of A. quisqualis (pre- and post-harvest),
one application of mineral oil before bud break, and
model-based applications of sulphur fungicides between
bud break and fruit set.
Lingua originale | English |
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pagine (da-a) | 817-829 |
Numero di pagine | 13 |
Rivista | European Journal of Plant Pathology |
Volume | 135 |
DOI | |
Stato di pubblicazione | Pubblicato - 2013 |
Keywords
- Ascosporic infection
- Biocontrol
- Chasmothecia
- Fungicide scheduling
- Overwintering