Control of fungal diseases in winter wheat with appropriate dose rates and weather‐based decision support systems ¹

Abstract

Fungicide inputs in cereals have to be reduced, in order to sustain gross margins and reduce environmental side effects. This can be achieved by using fungicide programmes in which doses and timing of fungicides are influenced by detailed knowledge on inherent properties of the fungicides, cultivar resistance and epidemic development of diseases in relation to crop stage and weather conditions. In 1994 and 1995, field trials were carried out in winter wheat in which strategies using full and reduced rates at fixed growth stages were compared with the computerized weather‐based decision support systems PC Plant Protection and PRO_PLANT. A further strategy was included in which timing and dosage of fungicides was based on expert judgement of the interactions of growth stage, disease pressure, weather conditions and cultivar resistance. Effective control of septoria diseases, brown rust and powdery mildew was achieved by all programmes. There was no programme that always resulted in the highest yield and gross margin.

Temporal and spatial dynamics of wheat powdery mildew in Sichuan Province, China

“…Powdery mildew exhibits an extended logistic period in extremely susceptible plant varieties (Wang and Zhang, 1998) and the occurrence and severity of this disease are determined by weather factors (Te Beest et al, 2008). The spatial epidemiology of wheat powdery mildew was affected mainly by wind and airflow, and the temporal dynamics were affected primarily by temperature and humidity (Bruggmann et al, 2005;Chen et al, 2007;Johnson et al, 1994;Last, 1953;Moschini and P erez, 1999;Schepers et al, 1996;Te Beest et al, 2008). The relationship between weather and disease epidemics was examined by Johnson et al (1994) using linear discriminant and logistic regression analyses.…”

Computer aids for plant protection, historical perspective and future developments*

“…Another example of collaborations were the comparison trials with cereal disease DSSs in Denmark, Germany and the Netherlands (Schepers et al ., 1996; Johnen et al ., 1998).…”

Evaluation of an action threshold‐based IPM wheat model in Rheinland (Germany) in 1999/2001*

“…(1991), a pathogen‐specific action threshold‐based model, the IPM wheat model, has been developed and progressively modified, and is now being used successfully in Bayern and Schleswig‐Holstein (Verreet, 1995; Klink, 1997). In contrast to models mainly based on weather data (Schepers et al ., 1996), the application of plant protection measures using the action threshold‐based IPM wheat model is determined by the epidemiology of the pathogens or pathogen complex in the field. The objective of this model is to restrict pathogen development to levels causing no economic losses, while at the same time reducing negative fungicide side‐effects on the environment to a minimum.…”