Injury symptoms on young oil palms induced by topical and basal application of herbicides.

5 ref.

On 14 month-old nursery oil palm, 1 litre of diluted herbicide solution was poured on the soil around the collar of the palms. Symptoms of injury were observed on palms treated with glyphosate + dicamba, glyphosate + fluroxypyr, imazapyr, paraquat+ diuron, metsulfuron-methyl and glyphosate + 2,4-D isopropylamine. Glyphosate alone did not result in any injury symptom. Palms with basal treatment by metsulfuron-methyl, glyphosate + 2,4-D isopropylamine and glyphosate + metsulfuron-methyl recovered after 150 days. Partial recovery was observed on palms treated with paraquat + diuron. Topical (direct) spraying of 150 ml per palm was done using a knapsack sprayer fitted with a fan nozzle (5/64 in). Results showed that injury was induced by 2,4-D sodium salt + DSMA + diuron, glyphosate, paraquat + diuron, glufosinate-ammonium, glyphosate + dicamba, glyphosate + fluroxypyr, triclopyr, glyphosate + 2,4-D isopropylamine, imazapyr, glyphosate + metsulfuron-methyl and paraquat + metsulfuron-methyl. No visual phytotoxicity was observed when cinosulfuron or metsulfuron-methyl were sprayed topically. The implications of these research findings are discussed.