Sustainable Agriculture
Biologicals Demystified

This article appeared in HARVEST SA

Biological solutions have a critical role to play in IPM programs. Biologicals contribute to reducing, managing and minimising crop loss due to pest damage, and are also increasingly being applied to enhance soil, root and plant health. With the new growing season in full swing, more and more growers are looking for innovative, effective solutions which can be added into their existing programs.

Biologicals have the great advantage of low to no residue levels. As market access regulations continue to be tightened on Maximum Residue Levels (MRL’s), particularly on export crops, growers are recognising the value of incorporating biologicals into IPM programs sooner, rather than later.

“Biopesticides are no longer being seen or regarded as a ‘soft option’. They offer highly effective pest control options that are safe for the environment, filling the gaps created by banned chemical pesticides and contributing to reduced chemical residues,” says Michelle

Lesur, Managing Director of Madumbi Sustainable Agriculture, the Hilton-based company that is spearheading biomanagement and biostimulant crop solutions.

Biological at a glance

Biological products are derived from living organisms and fall into four categories:

• Biostimulants – Natural plant growth stimulants impacting plant growth, e.g., kelp, fulvic acid.
• Semiochemicals – Natural insect pheromones used as attractants for mating disruption.
• Microbials – Micro-organisms with pest or disease control qualities i.e. fungi, bacteria, Viruses.
• Macrobials – Nature’s predators that can reduce crop pests e.g. ladybirds feeding on aphids.

Microbial products used to reduce pests or diseases are more commonly known as Biopesticides. Biopesticides require the same stringent tests as chemical solutions and must be registered by the Department of Agriculture, Land Reform and Rural Development (DALRRD) before they may legally be sold or used.

Biologicals on farm

Biologicals are used on a wide range of crops both globally and in South Africa, including fruit, vegetables, tree-nuts, row and field crops. Biologicals add great value to conventional IPM crop programs as well as to organically grown crops.

Farmers can apply biologicals with the same equipment used for chemical applications, directly onto plants, into the soil or as a seed treatment. Due to biologicals containing living organisms, they may be impacted by age, temperature, UV exposure, pH etc.

Correct handling and application are critical to efficacy. Compatibility tests should always be conducted prior to tank mixing biologicals and chemicals together. Depending on the chemistry and biology involved, this may or may not be possible. Growers should always read the label and follow manufacturer recommendations.

The key benefits of biologicals

The main difference is that biologicals are living organisms. As such, they degrade rapidly and do not linger in the environment.

Biologicals are often exempt from MRL’s, a critical market barrier on export and local crops.