Site Specific Weed Management

Weeds, the non-desired species, have been recognised for hundreds of year as a major factor in hindering yields of field-based crops. They are notoriously competitive for nutrients, water, light and space and create an undesirable canopy for modern day food production. They’re well-recognised for their ability to shed seed at a prolific rate. They also have no value from a nutritional or medicinal point of view.

Over the past century many different control techniques have been used with varying success. Most recently, chemical herbicides have become the dominant control method for mainstream agriculture (estimated 96% of European agriculture). The reliance on herbicides became prominent and now, as they begin to fail, controlling weed burdens is again a focus for modern producers in order to remain profitable. Organic systems offer much insight into cultural techniques but some would question sustainability long-term.

The objective of my study was to examine selective techniques, chemical and non-chemical, available and in development, with emphasis on moving away from the “blanket” approach used today. It was also important to try to access some of the financial elements concerned with each technique.

My research focused on three areas;

• Remote Sensing (passive and active)
• Inter Row Management
• Robotics

I visited two continents, looking at research facilities both commercial and educational, choosing countries with ability economically to invest in the technologies whilst being in the forefront of modern grain production:

Canada and United States of America

Australia

Each country had its own set of constraints which were led by several factors. It was important to bear some of these in mind as the outlook of each individual, company or country would be slightly different as a result. Examples included:

• Legislation
• Climate
• Markets
• Soils
• Profitability

I found that it is possible that these technologies, both commercially and environmentally, will be viable in the future. Each could often be complementary to another with a high level of precision being required. However, more developments are essential to achieve ’market readiness'. It was encouraging that there is enough incentive from both commercial and government organisations to sponsor this technology forward. There was an obvious level of investment in certain locations but it wasn’t always driven by the need to become more ‘sensitive’ with herbicide applications. The Australian farmers, I concluded, were the best in the world with their business knowledge, open-eyed and also holistic approach to every aspect of site specific weed management.