PATTERNS OF STORAGE AND FIBROUS ROOT DEVELOPMENT IN SEVERAL SWEETPOTATO CULTIVARS AND THEIR PROGENIES
In 1991 leafless stem cuttings 7 nodes long from 4 maternal parents (`Carver', Carver ii', `TU-1892' and `Georgia-Jet') and their progenies (MP/P) were planted 3 nodes deep in greenhouse benches filled with Jiffy-Mix to determine if any similarity in storage (SR) or fibrous root (FR) patterns could be used to identify high yielding cultivars in a breeding program. The experiment was planted in a complete randomized block design with 7 replications for each treatment and the total number of SR and FR data were collected over a 9 wk period with weekly sampling. The results indicated that SR initiation was a continuos process and took from 5-9 wk before reaching a maximum level for some MP/P. There was a significant inverse relationship between SR and FR numbers, as SR increased FR decreased. SR for most MP/P were initiated at the underground node closest to the soil surface and FR at the lower two nodes. When regression equations were used on the greenhouse data to predict total number of SR that would be produced in a field trial, no significant differences were found between the number of SR initiated in the greenhouse and field trial 80 days after transplanting by some of these MP/P. However, cultivars with the highest number of storage roots in the field trial did not have the highest number of marketable roots or yield and this was probably due to differences among MP/P in the rate of root enlargement.