High-density mechanical harvesting - the future of lettuce production?

High-density mechanical harvesting - the future of lettuce production?
High-density mechanical harvesting - the future of lettuce production?

With the demand for healthy, leafy greens on the rise and consumers becoming more health conscious, growing short-cycle crops such as speciality lettuce can become challenging.

This is especially so considering disease pressure, input cost and the demand for pest and disease control all on the rise, while consumers want fewer chemicals on their produce. The rise of labour costs and availability of skilled labour in certain parts of the world also challenges lettuce growers.

That is why, understandably, especially in European countries and the US, there is rising demand for growers to maximise the productivity of the space they have available, minimise crop protection product application and meet the large demand of a more health-conscious consumer group.

In South Africa we do not have the same labour shortages as other countries, but South African leafy green growers are also pressured by rising labour and other input costs, growing demand for higher productivity of available space, healthier produce for more health-conscious consumers and rising disease pressure.

Therefore, practices such as high-density mechanical harvesting (HDMH) of lettuce is a popular topic now. We already see high-density production becoming popular in South Africa, with the use of hydroponic systems to increase plant populations and shorten growth periods to harvest. We also see a rise in the production of leafy greens under protection and growers making use of controlled-environment agriculture principles, where certain growth parameters such as lighting, CO2 concentration, temperature and humidity can be controlled while pathogens and pathogen causing vectors can be minimised.

In other parts of the world, there is a strong movement to add mechanical harvesting to these systems. This allows growers to reduce open walkways and workspace within their greenhouses, allowing more space to plant crops at higher densities than normal maximising productivity.

Examples of these HDMH systems can be seen in Europe and the US, where entire nutrient film technique gutters are mechanically moved on to a conveyor belt and harvested in an automated production line. Growers in the US have managed to grow lettuce from seedling to harvest without human hands ever touching the produce; the consumer is the first person to touch the leaf, when they open the packet at home. This creates a whole new level of food safety for consumers.

Seed companies such as Starke Ayres must adapt to the new requirements to enable growers to pursue and implement these new growing techniques successfully, and produce the quality and quantity of lettuce required. That is why Starke Ayres sources and develops varieties from market-leading breeding programmes that are focused on meeting the needs of HDMH plantings.

High-density plantings require varieties that can produce a high-yielding, uniform crop in limited space. These varieties also need to be fast-maturing, and need stronger disease resistance to assist farmers to manage fungal diseases and other threats.

Our baby leaf varieties, such as Wahoo, are ideal for high-density plantings and offer excellent quality and yields in these conditions. Starke Ayres is also in the process of launching several new speciality lettuce varieties to cater for different segments, including new red and green multi-butter varieties. We are excited to evolve with our growers, and help provide our consumers with healthier, optimal-quality lettuce.