Thermal imaging for assessment of maize water stress and yield prediction under drought conditions
Issued Date
2023-02-01
Resource Type
ISSN
09312250
eISSN
1439037X
Scopus ID
2-s2.0-85124573929
Journal Title
Journal of Agronomy and Crop Science
Volume
209
Issue
1
Start Page
56
End Page
70
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Agronomy and Crop Science Vol.209 No.1 (2023) , 56-70
Suggested Citation
Pradawet C., Khongdee N., Pansak W., Spreer W., Hilger T., Cadisch G. Thermal imaging for assessment of maize water stress and yield prediction under drought conditions. Journal of Agronomy and Crop Science Vol.209 No.1 (2023) , 56-70. 70. doi:10.1111/jac.12582 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81465
Title
Thermal imaging for assessment of maize water stress and yield prediction under drought conditions
Author(s)
Other Contributor(s)
Abstract
Maize production in Thailand is increasingly suffering from drought periods along the cropping season. This creates the need for rapid and accurate methods to detect crop water stress to prevent yield loss. The study was, therefore, conducted to improve the efficacy of thermal imaging for assessing maize water stress and yield prediction. The experiment was carried out under controlled and field conditions in Phitsanulok, Thailand. Five treatments were applied, including (T1) fully irrigated treatment with 100% of crop water requirement (CWR) as control; (T2) early stress with 50% of CWR from 20 days after sowing (DAS) until anthesis and subsequent rewatering; (T3) sustained deficit at 50% of CWR from 20 DAS until harvest; (T4) late stress with 100% of CWR until anthesis and 50% of CWR after anthesis until harvest; (T5) late stress with 100% of CWR until anthesis and no irrigation after anthesis. Canopy temperature (FLIR), crop growth and soil moisture were measured at 5-day-intervals. Under controlled conditions, early water stress significantly reduced maize growth and yield. Water deficit after anthesis had no significant effect. A new combination of wet/dry sponge type reference surfaces was used for the determination of the Crop Water Stress Index (CWSI). There was a strong relationship between CWSI and stomatal conductance (R² = 0.90), with a CWSI of 0.35 being correlated to a 64%-yield loss. Assessing CWSI at 55 DAS, that is, at tasseling, under greenhouse conditions corresponded best to the final maize yield. This linear regression model validated well in both maize lowland (R² = 0.94) and maize upland fields (R² = 0.97) under the prevailing variety, soil and climate conditions. The results demonstrate that, using improved standardized references and data acquisition protocols, thermal imaging CWSI monitoring according to critical phenological stages enables yield prediction under drought stress.