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Crops > Vegetables > Watercress > Plutella (DBM), Pacific approaches

Crops VegetablesWatercress Plutella (DBM), Pacific approaches

Diamond back moth

January 2006. Comments were provided on IPM approaches to Diamond back moth in the Pacific Islands, now that work is being undertaken once more, this time with the support of ACIAR (an article on the project appeared in Islands Business, 5 January, 2006. The concerns can be summarised thus:

  • Previous programs, such as that developed in conjunction with the GTZ (German) plant protection project, are unlikely to be successful as there is a complex of pests and diseases, rather than one – Plutella – affecting crucifers.
  • Farmers have apparently never adopted the program, and the first thing to do would be to find out why.
  • The new project seems to be repeating past approaches by not giving sufficient importance to other pests and diseases. For instance, in Samoa, both Alternaria brassicicola and Albugo candida can require regular (5-7 day interval) spraying with fungicides to control them. What will be the impact of these fungicides on the insect pest predators and parasites?
  • The sustainability of farmers’ interest once the project has finished can be an issue, even though farmer participatory approaches are used, such as those in CABI projects in the Philippines, China, etc. The empowerment of the farmers is crucial to success.

In reply, it was pointed out that a short popular article on one aspect of a large ACIAR project on the integrated management of Brassica pests in Fiji and Samoa could not give more than a brief introduction to the project. The concerns on PestNet do not accurately summarize the aims, objectives and focus of the entire project. As PestNet has a significant readership in the Pacific region it is important to correct these misconceptions and resolve any confusion that may have been caused by this misleading posting.

Integrated approaches to the management of insect pests of Brassica crops have been extremely successful in many regions of the world, including regions where the crop is attacked by a suite of insect pests (including Plutella xylostella and Crocidolomia pavonana). However, previous initiatives in Samoa and Fiji (and elsewhere in the Pacific region) have not been effective. There are many possible reasons for these earlier failures, but the lack of effective communication with Brassica crop growers has undoubtedly played a major role. A major focus of the ACIAR project will be to improve communication with farmers by the establishment of farmer field schools (FFS). Through the activities of a FFS, a group of farmers is encouraged to experiment to determine courses of action that are most appropriate for the crop, decisions are not made based on one component of the complex agro-ecosystem alone. Such strategies have proved extremely effective in a wide range of crops (including Brassica crops) in Asia.

Plutella xylostella is a key insect pest of Brassica crops in Fiji and Samoa and, as such, is an important component of the research initiatives of the project. However, it is not the only serious insect pest of Brassica crops in the region and effective management of Crocidolomia pavonana, and other pests, will also be a major focus of research.

This project is a collaborative effort between staff at SPC, MASLR (Fiji), MAF (Samoa) and the University of Queensland (Australia). It is hoped that this short overview may go some way towards addressing the most obvious misinterpretations of the project that appeared in the earlier posting. It is not expected to have all the answers at the end of the project, but to make some progress.