METRIC ASSOCIATIONS AND PATH ANALYSIS IN SWEET POTATO ( Ipomoea batatas (L.) Lam.) IN JOS-PLATEAU NIGERIA

Résumé

A study was carried out on the metric associations and path analysis in sweet potato (Ipomoea batatas (L.) Lam.) in Jos – Plateau. Fourteen (14) clones namely, E2, E6, E8, E10, CIPMAT 3, CIPMAT 31, CIPMAT 32, TIS 8441, TIS 86/0356, TIS 87/0087, TIS 2532.OP.1.13, EX-IGBARIAM, WAGABOLIGE and 440168 were laid out in a randomized complete block design (RCBD) in three replications. The results showed that, mean tuber weight, tuber length, tuber girth, petiole length, mean number of tubers per plant, leaf area and leaf area index were positively and significantly correlated with total tuber yield. Relative growth rate was highly correlated with vine length, tuber length, tuber girth, mean number of tubers per plant, leaf area and leaf area index. Total tuber yield, relative growth rate, tuber length, tuber girth and mean number of tubers per plant were negatively, but non- significantly correlated with dry matter content. Path coefficient analysis showed that mean tuber weight and tuber length exerted a high direct positive influence on total tuber yield
while vine length exerted the highest indirect positive effect via tuber length on total tuber yield. The results show that leaf area index, mean number of tubers per plant, petiole length, tuber girth, tuber length and mean tuber weight are important yield indices that are useful in the selection of sweet potato clones for improved tuber yield