Use of an Empirical Model to Estimate Leaf Wetness Duration for Operation of a Disease Warning System Under a Shade in a Ginseng Field
| Autor: | S.-H. Lee, Je Yong Kang, Dong Yun Lee, Kwangsoo Kim, Kyu Jong Lee, Byun-Woo Lee, Soo Won Jang |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Fuzzy logic system 010504 meteorology & atmospheric sciences Mean squared error Warning system Fuzzy model Plant Science Biology 01 natural sciences Ginseng Statistics Dew Duration (project management) Agronomy and Crop Science Leaf wetness 010606 plant biology & botany 0105 earth and related environmental sciences |
| Zdroj: | Plant disease. 100(1) |
| ISSN: | 0191-2917 |
| Popis: | Ginseng foliar diseases are typically controlled by spray application using periodic schedules. Few disease warning systems have been used for effective control of ginseng foliar diseases because ginseng is grown under shade nettings, which makes it difficult to obtain weather data for operation of the disease warning system. Using weather data measured outside the shade as inputs to an empirical leaf wetness duration (LWD) model, LWD was estimated to examine if operation of a disease warning system would be feasible for control of ginseng foliar diseases. An empirical model based on a fuzzy logic system (fuzzy model) was used to estimate LWD at two commercial ginseng fields located in Gochang-gun and Jeongeup-si, Korea, in 2011 and 2012. Accuracy of LWD estimates was assessed in terms of mean error (ME) and mean absolute error (MAE). The fuzzy model tended to overestimate LWD during dew eligible days whereas it tended to underestimate LWD during rainfall eligible days. Still, daily disease risk ratings of the TOM-CAST disease warning system, which are derived from estimates of wetness duration and temperature, had a tendency to coincide with that derived from measurements of weather variables. As a result, spray advisory dates for the TOM-CAST disease warning system were predicted within ±3 days for about 78% of time windows during which the action threshold for spray application was reached. This result suggested that estimates of LWD using an empirical model would be helpful in control of a foliar disease in a ginseng field. It was also found that a spray application time model using meteorological observations may prove successful without the requirement of leaf wetness sensors within the field. Development of empirical correction schemes to the fuzzy model and a physical model for LWD estimation in a ginseng field could improve accuracy of LWD estimates and, as a result, spray advisory date prediction, which merits further studies. |
| Databáze: | OpenAIRE |
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