Nguyen Huu Huan, Vice Director General
Plant Protection Department, Ho Chi Minh City, Vietnam
In the Mekong Delta the rice crops between 2005 and 2007 suffered heavy infestations of planthoppers and virus diseases. It was estimated that about 1.0 million tons of paddy were lost. The Australian Centre for International Agricultural Research (ACIAR) commissioned a scoping study to identify the key issues. In trying to handle the problem the Government of Vietnam spent about US$ 6.6 million and 55% of this was used for pesticide distribution and subsidies. Only 7% was spent on extension and training activities (Final Report). Scientists at the consultation workshop identified the “Escape Strategy” as a robust way to improve the use of ecological basis for management, the use of biological control services through increasing habitat biodiversity (now known as ecological engineering) and the need to use standard protocols to monitor insecticide resistance development.
Five years later the Plant Protection Department (PPD) convened a review of the progress made since the scoping project workshop on January 8, 2008. At the review meeting held on 9 March 2012 in Vung Tau, reports from the various scientists, both regional and provincial, had endorsed success in managing the planthopper and virus disease outbreaks in the Mekong. Rice yields had increased from 4.83 tons/ha in 2006 to 5.51 tons/ha in 2011 (by 14%). Rice fields heavily infested by planthoppers had declined from 87,349 ha in 2008 to 15,142 ha in 2011 (> 80% decrease). Fields destroyed by planthopper-borne viruses dropped from 25,220 ha in 2006 to zero in 2010 and 2011. Today planthopper outbreaks occur only in small spots, usually in areas where high seed rates, excessive fertilizers and pesticides are used. This is in contrast to what is happening in Thailand where more than 200,000 tons of paddy has been lost in the first 2 months of 2012, after the floods.
The success in managing the planthopper problems in the Mekong has been attributed to the widespread adoption of “Three Reductions, Three Gains” and the “Escape Strategy”. Using the incremental approach, 3 reductions had been extended into 5 reductions 1 must do. These methods together with recently introduced “Ecological Engineering” are aimed at curbing insecticide misuse, the primary cause of planthopper outbreaks. In Northern Vietnam, PPD is advocating the use of SRI (System of Rice Intensification) to increase plant spacing and decrease pesticides as a strategy to prevent hopper outbreaks. The efforts implemented by PPD are well in line with the IRRI Action Plan to prevent rice planthopper outbreaks.
In the Vung Tau review meeting, Professor Nguyen Tho, vice president of the Vietnam Plant Protection Association (VPPA), warned of the strong roles that the pesticide industry play in influencing misuse. This caution was given by Dr K.L. Heong of IRRI in his speech and the vice minister Dr Bui Ba Bong also voiced his concerns in his closing remarks. He further emphasized that future rice pest management will need to develop ecological based preventive systems and ways to tightly control pesticide misuse. To curb pesticide misuse, Vietnam has developed Circular # 18, a set of new regulations for marketing and distribution of pesticides to be implemented in 2012. An administrative order was issued by the Director General of Plant Protection, Dr Nguyen Xuan Hong in November 2011 to control pesticide promotion campaigns to prevent pesticides being sold as FMCG (fast moving consumer goods). Recently another administrative order regarding pesticide advertising (310/BVTV-TTra dated 4 March 2012) was issued. Such efforts to control insecticide misuse at the policy level and active implementation of ecological engineering will help restore biodiversity and resilience in the rice landscapes that will continue to prevent planthopper outbreaks.