Comment: Consumers should consider the economic, biological, climate and weather effects on produce before they contact the new Government-run Price Watch hotline, writes Dr Jacqueline Rowarth.

Roasted cauliflower and smashed avocado are at risk each time the supply chain can't keep up with consumer demand.

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Price goes up, and supermarkets receive complaints. Lately there have been accusations of price gouging, with the belief that "fat-cat" supermarkets are putting up prices so that people concerned about Covid-19 will pay more for the necessities of life, and profits will roll in.


But fact-checking reveals similar outrage in 2018 when cauliflowers hit $8.35 a kg.

The details are on the StatsNZ website. The reason for the price hike was drought on top of summer temperatures.

Cauliflowers are a cool season crop. Climate change is affecting temperatures and rainfall patterns to the extent that areas of production are changing, but increasing focus on environmental impact of production is restricting where horticultural crops can be grown.

Irrigation helps to maintain yields and reduce the variability in price to the consumer but is not available to all growers.

Despite the difficulties, growers try to keep consumers supplied with what has become a "MasterChef ingredient" – whether roasted or riced, cauliflower has moved from last century's boiled or steamed (with cheese sauce to give flavour on special occasions).

Cauliflowers are planted out every week in anticipation of demand approximately four months later.

Length of time required for growing depends on the season, and growth must be monitored carefully for pests and diseases.

Cauliflowers are a perishable crop and are a difficult to grow. Creamy white curds are a testament to grower skill, but browning can occur rapidly.


Anybody who has tried to grow them at home knows that sometimes they bolt before creating heads (heat and drought), that they attract butterflies and quickly become homes for caterpillars, that if it rains a lot fungus appears, if rain is absent watering is required and that deciding to postpone harvesting until the weekend could mean that the cauliflower head is lost.

The Reserve Bank Inflation Calculator (which currently stops at the end of 2019) indicates that since March 2018, food cost inflation has been 3 per cent, general inflation has been 3 per cent and wage inflation has been 6 per cent (including the Government-mandated increase in the minimum wage). Wages have increased more rapidly than food prices.

Of note is that the big supermarkets have indicated a 10 per cent increase in wages for staff working through the lockdown. Logic suggests that some, if not all, of that increase will be, or is being, passed on to the group that benefits – the consumer.

Consumers want supermarkets to stay open and have choice in buying or not buying.

That is another problem for the supermarkets and producers – will the cost of the cauliflower means demand reduces and wastage occurs? A proportion of the cost covers this and achieving the balance is far from easy.

Dr Jacqueline Rowarth. Photo / Supplied
Dr Jacqueline Rowarth. Photo / Supplied

Part of the reason that it appears to be cheaper to buy product "at the farm gate" is that the supply is simply what is suitable for harvest; the supply chain is short, but the number of products, (and hence choice), tends to be limited to what has been grown "on farm".

In contrast, supermarkets access from around the country and globe to source what they think consumers will want, and sometimes the cost of sourcing results in high prices.

Avocados provide another example of price fluctuations.

Smashed avocado is a brunch favourite, but, unlike cauliflowers, are not harvested all year round.

Listen to Jamie Mackay's interview with Dr Jacqueline Rowarth on The Country below:

September to April is the main picking time (for Hass, New Zealand's main cultivar) and storage allows avocado to be in the stores for most of the year. Storage adds cost.

The big price fluctuation is caused not only by season, but also by the fact that the crop tends to be biennial – a large crop of small avocados one year followed by a small crop of large avocados the next.

Avocado trees tend to be synchronised with each other because of a biological trigger such as frost.

In May last year, avocados reached $10 each, with reports of $12.50 at one Auckland store. Smashed avocado tended to be off the brunch menu in cafes … and once demand decreased and supply increased, prices came down.

Current awareness of prices could lead to a change in eating patterns in future.

Chefs have been urging the concept of "seasonal eating", as well as "local". However, New Zealand cannot grow sugar or chocolate and can't yet produce enough of some favourites to meet demand – bananas, pineapples, coffee, for instance.

Bread wheat production is approximately enough for South Island requirements, but for the North Island mostly comes in from Australia. Drought there means that prices are likely to increase. Supermarkets are influenced by what is happening in other countries as well as in New Zealand.

New Zealand is not in danger of running out of food, but the recent panic with "pantry-loading" has certainly created challenges with inventory management for supermarkets.

Before contacting the new Government-run Price Watch hotline, consider the interaction of economics, biology, climate and weather, nationally as well as globally.

Please note: Since publishing, StatsNZ reported on 15th April that fruit and vegetable prices were 1 per cent lower in March 2020 than March 2019.

- Dr Jacqueline Rowarth CNZM CRSNZ HFNZIAHS has been examining agri-environment and business information for several decades. The analysis and conclusions above are her own.