Producing peppers or capsicum when temperatures exceed 30C (86F) can be challenging in conventional houses especially when outdoor humidity levels are high since plants tend to stop producing fruit and the produce becomes soft. We have proven that it can be quite easy to harvest peppers for 7-8 months in warm and hot climates even when outside temperatures exceed 39C (102F). An independent shelf life test was done on the fruit from the retractable roof compared to a conventional nethouse proved that fruit from the retractable roof had:
- 13-21% increase in fruit wall thickness (more kg/box)
- 40% increase in fruit firmness (longer shelf life)
- 35% less dehydration after 15 days of post-harvest storage (longer shelf life)
- Greater fruit color intensity (higher quality)
The optimal retractable roof design will depend on whether summer humidity levels are high or low and whether insects pose a major problem. If insects are a challenge or summer humidity levels are low, then it will be an advantage to install insect net below the retractable roof.
The insect net under the roof helps provides a stable microclimate that is free of insects helping to reduce losses from the pepper weevil. For some locations, retracting the net can be helpful during the winter to help to increase production by increasing light levels as well as plant and soil temperatures.
The retractable roof being installed above the insect net helps optimize leaf temperatures and humidity levels inside helping to prevent the foliar diseases. The roof will be used to help cool by blocking sunlight midday helping to prevent the heat from entering below the insect net. The retractable roof will also be used to protect from rain, cold and dew.
Crunchy bell peppers in the Cravo demonstration house, April 24, 2015
Cucumbers and peppers growing in 39C without cooling pads, fog or fans, Culiacan Mexico
Harvest season for peppers is limited in a nethouse due to lack of flowering and soft fruit
16 years experience growing peppers and cucumbers in a Cravo retractable roof house
Discussion with Carlos Ruiz on vegetable development in the Cravo Demonstration Greenhouse, May 3, 2016
Young plants performing well at 45C in the Cravo Education and Training Center, October 25, 2014