Limited Availability Of Herbicides For Brassica Crops

In the USA, a collaborative project was established in 1963, known as the IR-4 Project (Inter-regional Research Project Number Four). Collaboration has been established between state agricultural research stations, the US Department of Agriculture-Cooperative States Research Service (USDA-CSRS), chemical manufacturers and growers organizations to identify and register herbicides for use with speciality crops such as the brassicas (Hopen, 1995; Baron et al., 2002). This initiative was driven by the lack of suitable chemicals being placed on the market by the chemical industry for these small area crops. The project (IR-4), with headquarters at Rutgers University, New Jersey, aimed to assist in gaining registration and label recommendations of agrochemicals for use on highly intensive vegetable crops (Baron et al., 2004). Labels are of national, regional, state need and state emergency categories. The programme succeeded in expanding the availability of herbicides for Brassica crops. In particular, the participants attempted to find molecules that were safe and effective for use as selective herbicides applied to established crops.

Weeds such as hairy galinsoga (Galinsoga ciliata), wild proso millet (Panicum miliaceum), velvet leaf (Abutilon theophrasti) and yellow nutsedge (Cyperus esculentus) are difficult to control in standing crops and cause considerable loss of yield and quality. Comparable schemes are under development in Canada and Australia.

A project with similar aims is established in the UK, operated by the Horticultural Development Council (HDC) and known as the Specific Off-label Approval Scheme (SOLA). The HDC assembles a dossier of information for a particular chemical that might be valuable for growers and submits this for consideration for SOLA approval to the Pesticide Safety Directorate (PSD). Regrettably, the agrochemical industry in Europe is not prepared to contribute financially towards the success of the SOLA programme. Similar types of scheme are emerging in many countries to support vegetable growers. The European Union (EU) is currently considering the use of a scheme similar to SOLA across the Community. At the same time, opportunities for the use of chemicals in vegetable crop production are being severely limited by national governments and international organizations such as the EU. The latter, for example, is undertaking a re-registration process for herbicides and other crop protection chemicals, as is the American Environmental Protection Agency (EPA). Agrochemical companies are being required to re-submit applications for older chemicals with data brought up to current standards. Frequently, the companies are reluctant to do this for crops grown on limited areas of land because the expense involved is not justified by the income gained from sales. In consequence, many of the vegetable and especially Brassica crops are now devoid of herbicides for specific and specialized aspects of weed, pest and pathogen control. Although a few herbicides have been used in Brassica production for many years, these are exceptional. New molecules with apparent potential value for these crops are frequently suggested, but few achieve regulatory acceptance and even if this happens they may disappear from the market very quickly for a range of commercial reasons. Because of this transient situation which applies to all agrochemicals (herbicides, insecticides, fungicides and growth regulators), no lists of chemicals are included in this book, but these are available in Anon (2006).

0 0

Post a comment