Fifty years ago, a ground-breaking book credited with helping launch the modern environmentalist movement was published.
Rachel Carson's Silent Spring provided an insightful look at the development and use of crop protection products and the unintended impacts of first generation pesticides.
Carson's research is today recognised by the manufacturers of agrichemicals as an important book for the crop protection industry, consumer wellbeing and environmental safety.
Silent Spring was primarily about the impact of the insecticide DDT on bird life. The book's thesis was that pesticide use harmed not only animals and birds, but also humans.
Silent Spring was a catalyst for change and had a huge impact. Sue Kedgley's view on these pages this month that few people listened to Carson does not recognise the biologist's enormous contribution to the nascent Green movement.
President John F. Kennedy launched an investigation into Carson's claims which ultimately led to the formation of the United States Environmental Protection Agency (EPA) to regulate the crop protection industry.
Product registration, training and pest management strategies were all outcomes of this one book.
In 1972, DDT was banned in the US. Stricter controls were placed on its use in New Zealand before it was deregistered in 1989.
A more modern and risk-averse approach to crop protection has undisputedly benefited people and the environment.
After DDT was banned, along with other changes, the bald eagle's population rebounded and the species was removed from the US federal government's list of endangered species in 1995.
A lot can happen in half a century, including a sea change in the public's expectations on health and safety.
Another area which has undergone much improvement is transport. Today, we have many rules and regulations which curb speeding and unsafe driving, and encourage safety. But in 1962 you could legally drive or be a passenger in a car with bald tyres and no seat belts. You could also presumably drive drunk, because there were no breath and alcohol tests until 1969.
The progress in car safety, rules and driver behaviour has been mirrored in the agrichemicals industry too.
Pesticide development and testing by the crop protection industry, and EPA registration, take an average of nine years. It costs pesticide manufacturers about US$200 million ($256 million) for each crop protection product introduced to market.
On average, only one in 139,000 potential pesticide products successfully makes it through the regulatory process to the farmer's field.
Today in New Zealand, all crop protection products undergo a rigorous approval and registration process under the auspices of the main environmental regulator, the EPA. All applications for agrichemicals and other hazardous substances and new organisms are evaluated by a decision-making committee of the EPA.
Health, economic, social and cultural wellbeing of all people, communities and iwi must be taken into account by the committee. Public submissions may be invited and a public hearing may be held before the application is approved or declined.
The decision includes special conditions or controls on the substance or organism to manage its environmental effects and risks. All users must comply with these conditions.
The Ministry for Primary Industries (MPI) is also a regulator of crop protection products. MPI's responsibilities include a rigorous process for assessing a crop protection product, and ensuring any tiny trace chemical residues in food meet internationally acceptable levels for healthy food.
Ms Kedgley is correct that crop protection products used improperly will affect non-target species. This is why it's so important that users of the products read and follow the label and other safety information, and undergo training courses through the industry-supported GROWSAFE programme.
Her claims that bee numbers are plummeting due to pesticides coating seeds do not stand up to scrutiny in New Zealand. Neonicotinoid pesticides have since 1992 protected seeds and seedlings from being eaten by any number of pests such as aphids and grass grubs.
Bee numbers plummeted after the arrival of varroa in 2000, with feral non-native bees particularly hard hit. The number of managed hives fell to 300,000.
Due in part to pesticides introduced to control varroa, the number of managed hives has been increasing since 2005. Latest estimates suggest there are 450,000 managed hives. Bee prices and the number of beekeepers are rising - the exact opposite of an industry in steep decline.
Ms Kedgley's conclusion that there needs to be better data on the quantities and use of agrichemicals has merit. It would show that farmers and growers are using less of the older and more toxic chemicals, in favour of softer and more targeted products designed to control the pest, and leave friendly insects alone.
Graeme Peters is the chief executive of Agcarm, the industry association for companies which make and sell crop protection products.