Tropical Grasslands (1994) Volume 28, 182190
Seedling vigour of some Leucaena spp. and their hybrids
C.T. SORENSSON1, H.M. SHELTON2 and M.T. AUSTIN1
1Department of Horticulture, University of Hawaii, Honolulu, USA
The seedling vigour of 19 leucaena lines comprising principally the species Leucaena leucocephala, L. pallida, L. diversifolia and their hybrids was studied in glasshouse and field experiments in Hawaii between April and July 1991. Seedling vigour assessment was based on plant heights and plant weights during 84 days of growth. L. pallida and its hybrids with L. leucocephala gave more than twice the early growth of L. leucocephala cv. Cunningham or the common, weedy Hawaiian type, which were not significantly different. The early growth of the arboreal line, L. leucocephala K636, was greater than that of Cunningham, and its hybrids with L. pallida were outstanding. In the first 6 weeks of growth, L. diversifolia genotypes were less vigorous than L. pallida and, with the exception of CPI46568, were less vigorous than Cunningham. Days to emergence and growth at 16 days in the glasshouse were good indicators of subsequent growth potential both in the glasshouse and in the field. The implications of the results for breeding psyllid-resistant leucaena are discussed.