Comparative growth analysis of Russet Burbank potatoes at two Idaho locations

Detailed growth analyses were conducted with Russet Burbank potato to provide validation and parameterization data for a computer growth model being developed cooperatively at the University of Idaho and University of California, Davis. At each of two locations (Aberdeen and Kimberly, Idaho) plants were sampled seven times at about two-week intervals. Plants were separated into individual leaf blades, petioles, internodes, tubers, and roots. Leaf area indices and leaf elevation angles were determined in 20 cm strata. Plants at Kimberly emerged approximately 10 days prior to those at Aberdeen. At both locations, the increase in total dry weight was curvilinear for 30–40 days after emergence and then was linear until the end of the study. The maximum top weight per hill was slightly higher at Aberdeen, but near-maximum values occurred for much longer at Kimberly. Total leaf area at Aberdeen reached a maximum of approximately 4.0, while the maximum at Kimberly was 5.5. Root dry weight reached a maximum much earlier at Kimberly and the change in root dry weight paralleled that of tops in both places. Tuber initiation occurred approximately 19 June at both locations. Following an initial increase, tuber number/hill decreased for several weeks. Final tuber numbers per hill were approximately six at Aberdeen and 12 at Kimberly. Dry weight per tuber showed a curvilinear increase for 20–30 days and then was constant at 0.68 and 0.37 g/tuber.day at Aberdeen and Kimberly, respectively. Bulking rates were 17 and 21 g/m².day. Final yields were 39 T/ha at Aberdeen and 49 T/ha at Kimberly. The higher final tuber yield at Kimberly was the result of a higher rate of bulking and a longer leaf area duration.