NEW TRENDS IN LEUCAENA PSYLLID RESISTANCE

The psyllid is a Latin American parasite which defoliates Leucaena, causing widespread damage in established plantings throughout Asia. During 1987 the Nitrogen Fixing Tree Association (NFTA) established a Leucaena Psyllid Research Trial with cooperators at 12 international locations, including the Waimanalo Research Station, Hawaii. The trial evaluated psyllid resistance and fodder yields of 13 Leucaena varieties and hybrids. Trials were evaluated monthly for psyllid adults, nymphs, eggs and damage based on a 1-9 rating system. Fodder cuttings were taken from a 5 m row of trees spaced 25 cm apart at 6,9, and 12 months. Although the first year's measurements haven't been completed, initial results from psyllid-resistant tree strains have already been received from international trials.

A complete study summary will be published in Leucaena Research Reports Volume 9.

Cebu, Philippines

Elevation: 300m. Precipitation: 1628 mm. Soil pH 4.8-5.2. Best growth and psyllid resistance was observed with Lucaena strain KX1 followed by K785, KX2, K376 and K784, which is nearly the same order as observed in Hawaii.

Nueva Ecija, Philippines

Elevation: 236 m. Precipitation 1850 mm. Soil pH 4.4. Very low soil fertility, long hot dry season. Heavy psyllid damage with Mealy Bug infestation on L. pallida and L. diversifolia (K156). Best performers were K785, K743, KX1, KX2 and K636.

Bob Wheeler NFTA News, Number 6, May 1988. P.O. Box 680, Waimanalo HI 96795, U.S.A.