8th International Sulfur Workshop, Creswick, November 22-27, 2010. Historical flashback. William Forsyth (1802) discovered the fungicidal effect of elemental ...
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Sulfur and biotic interactions
Ewald Schnug Silvia Haneklaus Elke Bloem Institute for Crop and Soil Science Julius Kühn-Institut (JKI) Braunschweig, Germany
www.jki.bund.de
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Historical flashback
William Forsyth (1802) discovered the fungicidal effect of elemental sulfur.
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Up to date elemental S is the only effective fungicide against powdery mildew of grape vine!
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Influence of foliar S0 application and inoculation with F. culmorum on infection rate (%) of winter barley with Fusarium head blight three and four weeks after inoculation and yield parameters.
Weekly S0 application1
Inoculation with F.
culmorum
Infection Rate (%)
BBCH 73 BBCH 77 without without 35 48 without with 34 58 with without 28 37 with with 19 38 1 first S0 application one week before inoculation Source: Haneklaus et al. (2007)
Grain yield (dt ha-1)
Straw yield (dt ha-1)
72.9 65.2 76.6 74.6
43.4 36.4 43.4 47.2
Only recently it was shown that elemental S reduced significantly the infection rate by Fusarium spp. and mycotoxin content in grain.
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Elemental S reduced the alkaline phosphatase activity in soils by 40% irrespective of a thiobacilli addition which suggests a direct inhibitory effect.
Influence of S form and thiobacillus amendment on the relative alkaline phosphatase activity in a sterilized soil inoculated with R. solani. (100% alkaline phosphatase activity = 340, 556, 471, 345 µg NP g-1 h-1 0, 2, 4 and 6 days after inoculation)
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Sulfur and insects
Interactions between performance of Brassica crops and gradation of pests in relation to anthropogenic and environmental factors (Defense metabolites: -N = N-free; +N and +S = N and S-containing compounds).
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Influence of fertilization on infestation of plants with pests by influencing the plant nutritional status and plant nutrient ratios, and morphological changes due to changes in growth rates; enhanced/delayed maturity; size of plant parts; thickness and hardness of epicuticle.
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Interactions between plant nutritional status of crops and infestation by insect pests
Plant stress hypothesis
Vigor hypothesis
(Dosdall et al 2004)
(Dosdall et al 2004)
Carbon nutrient balance theory
Homeostasis
(Bryant et al. 1983)
(Lynds and Baldwin 1998)
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Glucosinolates Specialist herbivore
Generalist herbivore
- oligophagous
- polyphagous
- adaptation to GSL/myrosinase system
- no adaptation to GSLs
- GSLs increase activity, feeding
- GSLs decrease activity,
and reproduction - Insect-specific adaptations: Brevicoryne brassicae – produces myrosinase; sequesters plant GSLs
Pieris rapae – intestinal protein converts GSLs into less toxic nitriles
Plutella xylostella – converts GSLs into non-toxic desulfo-GSLs
feeding and reproduction
8th International Sulfur Workshop, Creswick, November 22-27, 2010
Influence of S and N fertilization on occurrence of D. platura imagines in oilseed rape with in dependence on the growth stage (statistically significant differences at p
