Farmers' knowledge, perceptions and practices in mango pest management in the Mekong Delta, Vietnam

A survey of mango farmers' knowledge, perceptions and practices in pest management was conducted during the dry season of 1998 in the Mekong Delta, Vietnam. identification and control of pests was often based on damage symptoms, rather than on recording of causal agents. Damage caused by the seed-borer Deanolis albizonalis (Hampson) was often wrongly attributed to the fruit flies Bactrocera dorsalis Hendel. Nearly all farmers applied calendar sprays of insecticides (97%) and fungicides (79%) from pre-flowering until harvest, with on average 13.4 and 11.6 applications per year, respectively. Pyrethroids were most popular (57%), followed by organophosphates (25%) and carbamates (15%). Around 20% of the insecticides used belonged to WHO Toxicity Class I, while the rest nearly all belonged to Class II. Half of all the target sprays were done with three pyrethroid products only. Farmers' estimated yield loss due to insect pests was strongly correlated to estimated pest severity. Due to pesticide sellers' recommendations, farmer's sprayload significantly increased from 26 to 37 sprays per year, whereas the number of insecticide products used per farmer increased from 2.6 to 3.9 with advice from extension staff and media. Expenditure for pesticides was correlated with that of fertilizers. There was no relationship between the amount of pesticides sprayed and yield. On-farm research is needed to evaluate whether significant savings can be obtained given a more judicious use of pesticides. Only 10% of the 93 participating farmers knew about natural enemies, all of which were predators.