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Increased productivity and better quality of greenhouse grown organic vegetables

Activity summary

Tasty and healthy foods are becoming a key issue for Canadian consumers and a marketing tool for growers and retailers. Compared to conventional food, organic products are generally considered to be safer, tastier and richer in nutritive and healthy bioactive components. Yet, the evidence that organic fruits and vegetables have a higher gustatory and nutritional value and higher beneficial health effects than conventional products is not unequivocal.

The aim of this study is to improve the gustatory and nutraceutical quality attributes of greenhouse cucumbers, peppers and tomatoes by a judicious use of organic nutrients and biofertilizers, and by implementing an intra-canopy light emitting diode (LED) lighting system. Experiments will be performed in a commercial greenhouse (Les Serres Lefort Inc., QC) to determine the effects of cover crop/green manure, nitrogen forms (mineral vs. organic), rootstocks and biofertilizers on the taste, nutritional value and shelf life of organic greenhouse produce. Furthermore, the effects of a 3-D intra-canopy LED lighting system (with specific light spectrum) on crop morpho-physiology and fruit quality will be examined at the greenhouse research facility of Université Laval. Different light spectra will be applied at different positions within the plant canopy to determine their influence on the sensory and nutritional value of fruits. In addition, the 3-D LED light systems will be modulated during the day to stimulate specific physiological responses (leaf photosynthesis, fruit ripening, synthesis of secondary metabolites). These experiments will be also validated at the commercial level.

Based on the study results (i.e. the relationships among all studied parameters at Université Laval and at the commercial site), clear guidelines will be established for the industry in terms of the best environmental and agronomical practices to adopt to increase the sensory and nutritional value of greenhouse vegetables without an adverse effect on productivity. An environmental assessment (life cycle analysis) will also be performed to evaluate the sustainability of the proposed growing system in comparison to existing commercially used organic systems, and to further identify efficient, innovative solutions to research needs. The main barrier for growers to convert from conventional to organic farming is a lack of knowledge with regard to the release of soil nutrients and ion balance to fulfill, in real time, plant requirements and ensure a high yield of tasty and nutritious fruits.

By combining optimized organic farming with the greatest advancement in horticulture lighting, the Canadian organic food industry will successfully grow and sell greenhouse products with an added plus value, on a year-round basis. Hence, this activity is essential to the development of scientific and technical knowledge that will contribute to defining clear guidelines for the industry regarding the use of LED lighting and the impact of the growing conditions on taste, nutraceutical attributes and post-harvest shelf life.

Materials and Results to Date

• • Acta Hort (2016) 1137: 19-26
    
• • Acta Hort (2014) 1041:239-246
• • Acta Hort (2016) 1137: 27-32
• [PDF - 6.4 MB]
  
  • Presented at the 2nd Canadian Organic Science Conference. 2016
    

• Searching for the best fertilization and lighting for the production of greenhouse vegetables: Lefort Greenhouses

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Activity researchers

Contributing partners

• Les Serres Lefort Inc.