Soybean integrated pest management implementation in Argentina

Several insect and animal pests represent a serious thread to soybean production in the large geographical area where this crop is cultivated in Argentina from southern Buenos Aires to the northern subtropical provinces. Major soybean pest in the Central Provinces (Buenos Aires, Cordoba, Santa Fe and Entre Rios) where most of the soybean is cultivated (12 mill. Ha. in 2003) are several defoliators worms mainly Rachiplusia nu and Anticarsia gemmatalis (Lepidoptera: Noctuidae), a bud borer, Epinotia aporema (Lepidoptera: Tortricidae) and a stink bugs complex : the green stink bug, Nezara viridula and the alfalfa stink bug, Piezodorus guildinii (Hemiptera: Pentatomidae). In 1979 the National Institute of Agricultural Technology (INTA) implemented a Soybean Research and Extension Program in order to improve crop management. Working with universities and private organizations growers gradually adopted better insect management as action thresholds and replaced highly toxic fosfate insecticides by synthetic pyrethroids. Field evaluation studies showed a great diversity of efficient natural enemies of soybean pests. As a result of an improved crop management yields and quality gradually increase while insecticide use was reduced. No-till soybean, widely adopted since the early 1990's., favored an increase of soil related damaging pests as cutworms, grasshoppers, crickets, pillbugs and slugs. In the northern provinces two introduced pest, the stem beetles, Sternechus pinguis and Promecops carinicolis, develop heavy infestation to unprotected soybean fields. In this subtropical region soybean have more risk of pests attacks than the central provinces and several insectcides treatments usually are needed. In the last years a significant adoption of early maturing soybean group and early planting in the central producing provinces permited growers to reduce insectide application. Average soybean insecticide cost estimate at national level (approx. 12 mill. ha in 2002) since 1999 ranged 2,20-3 U$A per hectare and treatment number in pilot soybean IPM fields in eastern Cordoba ranged 0.2-0.4 per field in the last 8 years. Favourable environment condition for crop development and an effective biological control reduce pest negative impact on soybean.