The effect of application of copper fungicides on photosynthesis parameters and level of elementary copper in hops
2012
Krofta K.,, Chmelarsky Inst., Zatec (Czech Republic) | Pokorny, J., Ceska Zemedelska Univ., Prague (Czech Republic) | Kudrna, T., Chmelarsky Inst., Zatec (Czech Republic) | Jezek, J., Chmelarsky Inst., Zatec (Czech Republic) | Pulkrabek, J., Ceska Zemedelska Univ., Prague (Czech Republic) | Krivanek, J., Chmelarsky Inst., Zatec (Czech Republic) | Becka, D., Chmelarsky Inst., Zatec (Czech Republic)
Photosynthesis and transpiration rates in the interval of 30 min before and 30 min after copper fungicide application show an increase from the level of 5.0 to 7.0 micromol CO2/square m/s and 0.75 to 1.00 mmol H20/square m/s. Long-term measurements show that the increase of photosynthesis rate after Cu application is temporal and fades away after 10-14 days. No stress response was induced after the application of Cu fungicides. Cu concentrations in hop cones are up to 500 mg/kg if total amount of applied Cu does not exceed 15 kg/ha. Cu levels on leaves are 2-5 times higher at the same application dose. Application of 5 kg Cu per one hectare of vigorous growth of Agnus variety increases Cu concentration on hop leaves by 1,000 mg/kg at least. The same amount of Cu increases its concentration in hop cones by 300 mg/kg at the ripening period. Tight correlation between the amount of Cu applied and its level in hops does not exist. Elementary Cu from leaves is brought into harvested hops in the form of biological admixtures. Cu concentration in hop cones shows a decreasing trend, which is given by gradual increase of cones size at the ripening period. Similar trend on hop leaves shows that washing off and dissolving of Cu compounds by atmospheric water can participate in this process as well. Common Cu level in untreated hop cones and leaves is up to 20-25 mg/kg.
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