Enhancing the profitability of rhubarb using spectral modifications

There has been little innovation in forced rhubarb production in recent years, despite increasing consumer demand for this valuable product. While the UK produces a high quality crop, our current rhubarb forcing methods are costly and labour-intensive. With a great scope for the expansion of this industry, the proposed trial will examine a hybridised method of production; a novel system of field forcing that could lead to the production of a field crop comparable in quality to that of the traditionally forced product. An increase in crop quality via more resource efficient production would maximise the sector’s profitability. This project will examine the efficacy of field forcing under photoselective films, building on past studies that have shown the photobiologic manipulation of rhubarb to be an effective method of producing rhubarb petioles with the desired marketable characteristics. The initial phase of the project will see the development of a range of polytunnel films, allowing the transmission of specific wavelengths of light to stimulate stem pigmentation, etiolation and sugar accumulation prior to commercial-phase testing. The development and commercial trialling of prototype photoselective film polytunnels would include a comprehensive assessment of the effects on yield and crop quality, pest and disease control, and collateral effects such as the reduced requirement for forcing conditions (cost of heating, dedicated forcing sheds) to produce a crop of high market value. A successful project would result in the production of guidelines for growers looking to implement similar systems, with practical information and a breakdown of economic feasibility to support rapid uptake by the industry of an innovative growing approach.

Aim: To develop an economic production system that will maximise the quality of field-grown rhubarb.

Objectives:

1. To develop and trial a functional prototype photoselective film polytunnel for effective rhubarb field forcing.
2. To compare different forcing strategies for their effect in crop yield and post-harvest crown condition, and their economic efficiency.
3. To quantify the effect of rhubarb field film-forcing in marketable stem characteristics, e.g. colour, texture, sugars.
4. To assess the effectiveness of photoselective protection in controlling rhubarb pests and disease.
5. To generate grower guidelines for future implementation of developed technology.