Developing tools for precision horticulture: Manipulating growth rates at the plant scale to reduce in-field leafy salad and vegetable crop variability, increase production efficiency and reduce waste.

Summary: Uniform growth and maturity is the ultimate aim for many field vegetable crops, such as lettuces and brassicas, with growers looking to harvest plants of the same size and weight in a single pass (lettuce) or minimal number of passes (brassica). Variation in individual plant growth is affected by environmental variation at both the transplant raising stage and field stage.  The cause of the variability in the transplant stage is not fully understood, but a number of factors are likely to be involved such as water availability and light levels.  Plant growth in the field after transplanting can also vary.  A small number of studies have correlated general soil factors such as organic matter content with plant growth in leafy crops. The options open to growers to manipulate factors such as organic matter at a commercial scale are limited.   An alternative approach is to control plant growth through agronomic applications but until recently, growers have had no option but to irrigate and feed at one rate across a field/block, without considering the variation that’s inevitably present across this area. With the emerging precision agriculture technology, it is now possible to monitor crop development at the individual plant level and apply treatments to a local area or individual plants.  This project will develop understanding and commercial treatments to reduce variation in transplant size at planting and manipulate the growth of plants in the field post-transplanting to increase crop uniformity.  Of equal importance, this project will develop an applied scientist who would be well suited to working in the UK industry across a range of crops.