Comparison of the performance of leaf wetness duration models for rainfed jujube ( Ziziphus jujuba Mill.) plantations in the loess hilly region of China using machine learning

Ecohydrology ◽  
2020 ◽  
Vol 13 (7) ◽  
Author(s):  
Zhiyong Gao ◽  
Wenjuan Shi ◽  
Xing Wang ◽  
Bing Cao ◽  
Youke Wang
Author(s):  
Jianpeng Ma ◽  
Xing Wang ◽  
Xining Zhao ◽  
Wenfei Zhang ◽  
Youke Wang

Abstract In order to study whether jujube trees can grow normally under rain-fed conditions in loess hilly areas, we planted jujube trees (Ziziphus jujuba Mill.) 4 years after felling a 23-year-old apple orchard. The growth process of the jujube trees and the variation in soil water content (SWC) were monitored for three consecutive years following planting in order to study the effects of the water-saving pruning (WSP) technique. Results showed that: (1) The soil at a depth of 0–1,000 cm had been desiccated when the area was an apple orchard. (2) Under rain-fed condition, the jujube trees with WSP technique were always able to maintain normal growth while the jujube trees with conventional pruning method had a normal growth stage of only 4 years. And the water use efficiency of the jujube trees with WSP technique was much higher than that of the jujube trees with conventional pruning. We recommend WSP in jujube orchard management, because the jujube trees with WSP could maintain normal growth in deep dried soils of the loess hilly region, as WSP can reduce the water consumption of the jujube trees and may has positive effect on soil moisture restoration.


2020 ◽  
Vol 12 (18) ◽  
pp. 3076
Author(s):  
Ju-Young Shin ◽  
Bu-Yo Kim ◽  
Junsang Park ◽  
Kyu Rang Kim ◽  
Joo Wan Cha

Leaf wetness duration (LWD) and plant diseases are strongly associated with each other. Therefore, LWD is a critical ecological variable for plant disease risk assessment. However, LWD is rarely used in the analysis of plant disease epidemiology and risk assessment because it is a non-standard meteorological variable. The application of satellite observations may facilitate the prediction of LWD as they may represent important related parameters and are particularly useful for meteorologically ungauged locations. In this study, the applicability of geostationary satellite observations for LWD prediction was investigated. GEO-KOMPSAT-2A satellite observations were used as inputs and six machine learning (ML) algorithms were employed to arrive at hourly LW predictions. The performances of these models were compared with that of a physical model through systematic evaluation. Results indicated that the LWD could be predicted using satellite observations and ML. A random forest model exhibited larger accuracy (0.82) than that of the physical model (0.79) in leaf wetness prediction. The performance of the proposed approach was comparable to that of the physical model in predicting LWD. Overall, the artificial intelligence (AI) models exhibited good performances in predicting LWD in South Korea.


Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 29
Author(s):  
Martín Solís ◽  
Vanessa Rojas-Herrera

The prediction of leaf wetness duration (LWD) is an issue of interest for disease prevention in coffee plantations, forests, and other crops. This study analyzed different LWD prediction approaches using machine learning and meteorological and temporal variables as the models’ input. The information was collected through meteorological stations placed in coffee plantations in six different regions of Costa Rica, and the leaf wetness duration was measured by sensors installed in the same regions. The best prediction models had a mean absolute error of around 60 min per day. Our results demonstrate that for LWD modeling, it is not convenient to aggregate records at a daily level. The model performance was better when the records were collected at intervals of 15 min instead of 30 min.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1878 ◽  
Author(s):  
Junsang Park ◽  
Ju-Young Shin ◽  
Kyu Rang Kim ◽  
Jong-Chul Ha

Leaf wetness duration (LWD) models have been proposed as an alternative to in situ LWD measurement, as they can predict leaf wetness using physical mechanism and empirical relationship with meteorological conditions. Applications of advanced machine learning (ML) algorithms in the development of empirical LWD model can lead to improvements in the LWD prediction. The current study developed LWD model using extreme learning machine, random forest method, and a deep neural network. Additionally, performances of these ML-based LWD models are evaluated and compared with existing models. Observed LWD and meteorological variable data are obtained from nine farms in South Korea. Temporal and geographical information were also used. Additionally, the priorities of the employed variables in the development of the ML-based LWD models were analyzed. As a result, the ML-based LWD models outperformed the existing models; the random forest led to the best performance for LWD prediction among the tested LWD models. Strengths of associations between input variables and leaf wetness were relative humidity, short wave radiation, air temperature, hour, latitude, longitude, and wind speed in descending order. Uses of the geographical and time information in development of LWD model can improve the performance of LWD model.


2016 ◽  
Vol 60 (11) ◽  
pp. 1761-1774 ◽  
Author(s):  
Verona O. Montone ◽  
Clyde W. Fraisse ◽  
Natalia A. Peres ◽  
Paulo C. Sentelhas ◽  
Mark Gleason ◽  
...  

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