Detection of crop water status using UAV mounted sensor

Brown, PH ORCiD: 0000-0001-6272-5507 0000-0002-4033-6719; Koech, RK ORCiD: 0000-0002-0563-6687Advances in precision agriculture technologies allow crop management targeting specific needs of individual plants or regions within a crop at specific times rather than at the whole of crop level used in traditional crop production systems. Irrigation is one of the most important inputs in horticultural production systems, but current management practices typically do not allow precise delivery of irrigation inputs where and when they are required within a crop. Multispectral and thermal imagery has the potential to directly assess crop water status at a spatial scale not possible with the current soil sensor probe systems, and thus contribute to improved irrigation decision making. Relationships between thermal imagery data, gathered using a UAV system, and crop water status was determined in a vegetable system (chilli) 'Cayenne' Capsicum annuum 'acuminatum'. Areas within a crop where water stress led to reduced transpiration could be detected in advance of any visible signs of water stress, and patterns of variability detected by the aerial thermal sensor within a crop were also linked to patterns of variability detected by ground-based sensors within the same crop at approximately the same time of day. © 2020 International Society for Horticultural Science. All rights reserved