Frequency and intensity of guttation events in different crops in Germany

Abstract

Background: In crops of economic relevance and some common weeds in Germany, several glasshouse and field trials were conducted at the JKI and cooperating research partners (DWD, IfZ, BDP and UFOP) from 2009 to 2011. Aim of the investigations was to analyze the guttation frequency of these crops, to document climatic conditions that trigger guttation and to describe the quality and quantity of guttation events (e.g. size/number of drops). Results: Guttation occurred in all crops mainly at young growth stages. Only maize, cucumber, oilseed rape and potato produced guttation droplets until emergence of inflorescence. The excreted amount of fluid was comparable for maize and oilseed rape but considerably lower for sugar beet and barley. In field situation guttation occurred frequently in more than one plant species in parallel when it was not dry or too windy or frosty.Conclusion: Monocotyledonous crops and weeds showed a higher guttation frequency than most dicotyledonous crops. Maize showed large guttation drops even under low relative air humidity, whereas guttation drops in sugar beets were much smaller and only observed under very high humidity conditions (>90%). Other dicotyledonous crops, such as oilseed rape and potato, showed a much higher guttation frequency than sugar beets.

Keywords

• guttation
• honey bees
• pesticides
• crops
• weeds