Crop protection

A look at the key factors to consider when dealing with weeds, pests and diseases.

The problem with weeds, pests and diseases on a nursery is that they can result in poor quality, even unsaleable, plants. And that can mean a reduction in already slim profit margins. At their worst they can ruin entire crops, result in an expensive clean-up job and put your business in jeopardy.
Clearly, it is important to keep an eye open for weeds, pests and diseases, and to tackle them as early as possible — before they have a chance to build into serious infestations. But it is also important not to panic at the first sign of trouble. Plan the battle carefully and, in the long run, you could save time, money and effort.

Know the problem – identification
Before doing anything, you need to know exactly what it is that you are looking at. Correct identification is paramount and may involve calling in the services of a diagnostic laboratory — especially in the case of diseases where symptoms may be similar to those arising from nutritional disorders or poor growing conditions.

Assess the extent – evaluation
The level of the infestation should be determined as well as thought given to the likely effects in terms of disruption to production cycles as well as economics. Has this problem been spotted on the nursery before? How was it treated (or not treated) then and what were the consequences? Look back at your spray records to determine what chemicals have been used against this problem in the past — but remember that products used years ago may no longer be legal.

Plan the attack – best option
It is a waste of money to use herbicides and pesticides unnecessarily. More importantly it also puts the sprayer operator, public, wildlife and other plants at needless risk. And it can contribute to the build-up of resistance, making product selection more difficult in the future. Misuse and abuse of products threatens the availability of chemicals in the future. So, whatever the problem, it is essential to stop and think through all the options for controlling it. Chemicals should not be thought of as the first line of attack. They should be viewed as the last resort.
There are many options for weed control. Hand weeding, hoeing, hot water treatment and flame guns are some of the things you need to consider before electing to grab the sprayer and dose the unwanted vegetation with herbicide. In the long term, the practicalities of weed prevention using mulch materials should be considered and the costs evaluated.
Equally, the pest or disease you spotted on your crop walk might be very limited and may be controllable simply by picking or by the introduction of biological control agents. Again there may be long-term solutions, such as the use of insect netting or cladding containing spectral filters to deter certain pests and diseases.

Which product? Selection
Where it is deemed necessary to use a herbicide, pesticide or fungicide, it is important to choose the product that poses the least risk to humans, animals and the environment. At the same time, the product must have a good record of controlling the weed, pest or disease in question. It is vital the product is for use against the problem identified and is approved for use in that situation.
As the list of approvals is forever changing, it is sensible to seek up-to-date information by checking the Pesticides Monitor website ( and checking details on the Pesticide Safety Directorate website ( or consulting a BASIS-certificate holder.

Make sure you understand the recommended rates and have appropriate equipment for applying the product. That equipment should be in good working order and the sprayer operator must be qualified and competent. The correct personal protective equipment, in good condition, must be worn as required. Remember it is a requirement of the regulations that the pesticide label is read and the instructions followed. Keep your spray records up-to-date — they may be useful if the problem strikes again.

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Sign up now
Already registered?
Sign in

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

IoG Saltex 2017 - Kit showcase

IoG Saltex 2017 - Kit showcase

Mowers, turf care, battery equipment, seeds, arboriculture kit and weed control will all see a wide range of new releases at Saltex, Sally Drury reports.

Get set for Saltex 2017

Get set for Saltex 2017

This year's Saltex show at the NEC in Birmingham offers something for everyone, says Sally Drury.

Horticulture education update - staying on course

Horticulture education update - staying on course

Raised levels of investment in horticulture education and increased student take-up is welcome news for the industry, says Rachel Anderson.

Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +
Horticulture Jobs
More Horticulture Jobs

IOG Saltex

Get set for IoG Saltex 2017 with our comprehensive show guide and exhibitor info.

Jeremy Barrell On...

Jeremy Barrell

Tree consultant Jeremy Barrell reflects on the big issues in arboriculture.

Products & Kit Resources