New Zealand's ability to react to new pests may be limited by proposed changes to the use of 29 insecticides containing organophosphate and carbamate active ingredients.

While the review by the Environmental Protection Authority has general support from horticultural and farming sectors, there are concerns that revoking or phasing out some chemicals, diazinon in particular, could make this country vulnerable to new pests.

'We need to find ways to survive if a biosecurity incursion happens, and we have no suitable crop protection to get us through a critical pest or disease risk,” says HortNZ communications manager Leigh Catley.

Elizabeth Dixon – DairyNZ policy manager agrees. 'It is difficult to predict what might be needed to effectively respond to an incursion of a pest that is new to New Zealand. One substance we will be paying particular attention to is diazinon, given its use for controlling pests in certain conditions.

'Having appropriate tools to respond in a biosecurity crisis is important to primary industries and we are looking at the proposals in this light.”

Organophosphate and carbamate-based insecticides are used on a variety of agricultural and horticultural crops in New Zealand, including vegetables and fruit as well as in grain silos. They are also used for biosecurity plant protection including the treatment of imported root stocks and for the control of pest species new to New Zealand.
However, there is concern both in New Zealand and overseas about the harmful effects these substances can have on human health and the environment. These concerns have led some overseas regulatory authorities to ban or restrict the use of some of these insecticides and led the EPA to establish that there were sufficient grounds to reassess their approvals.

Dr William Rolleston, Federated Farmers Vice-President and spokesperson on food production sciences also has concerns about the proposals around diazinon. 'Those products which control grass grub seem to be the most concerning. At the moment diazinon appears to be the most important agrichemical for this use. However, we are aware that alternatives many not be as effective and may be more expensive. If we cannot find effective ways of preventing pests, there will be an impact on both employment and the GDP.”

Leigh says at least eight different groups, representing fruit and vegetable growers of more than 60 different products, are working on submissions showing how wide ranging the effect of the proposal may be and how many growers will be concerned with the outcome.

'Until a final decision is made by the EPA panel it is hard to say which sector may be most affected. There are some products which have been proposed for a very short phase-out (18 months- three years) which could have significant impacts for growers of crops such as carrot, parsnip, strawberry and kumara.

'Chlorpyrifos, pirimicarb, diazinon and dichlorvos are used by the widest range of growers, and of these, diazinon and dichlorvos are proposed for phase out so their removal will have the widest effect.”

Elizabeth says it is important that regulation of substances like organophosphates and carbamates is driven by science and evidence-based policy making.

'Alternative ways of managing grass grub would be required to help offset pasture loss and potential production losses. To a certain extent, pasture pests can be managed through non-chemical means. Research currently underway might give more options, including more resilient pasture species or bio-controls.”

William says where the risks of using various products outweigh the benefit to the whole country of using them, then it is time to consider where to from here. 'However, the industry needs time to come up with alternatives, or to bring in safer methods of using the product where necessary. One size will not fit all.”

Leigh says the driver for the EPA review is protecting the New Zealand environment and our own families and workers. 'The EPA does a good job of listening to everyone and trying to work out what's best for us all. Sometimes that means tough calls for horticulture.
'Many overseas countries still retain the use of some organophosphate and carbamate compounds and recognize that their broad spectrum activity is beneficial for crop production.”

Removing or restricting the use of some products may threaten growers' economic viability but Leigh says growers can be put out of business for lots of reasons. 'Reducing access to crop protection products is likely to be a significant factor for those who are already finding times are tough. This is why we work so hard to get reasonable phase-out times for these reassessed agchem products, because in some cases growers need as much time as they can get to adjust to running their business without the assistance of sometimes irreplaceable crop protection.”

Public submissions of the EPA review close on January 22, 2013. To make a submission go to: www.epa.govt.nz/publications-resources/topics/Pages/Organophosphates-and-carbamates.aspx