Barfoots Boost Chilli Yields with Orion FT Biostimulants
Grower Barfoots of Botley began growing chilli's in 2015 and after establishing two growing sites by 2018 chose to invest in a glasshouse which consolidated the growing space into 1.2 hectares at Waltons Farm in West Sussex. The move has challenged Operations Manager Warren Denbury to introduce new varieties and techniques to optimise production whilst managing pest and disease threats.
Three varieties were chosen to be the commercial crop. These were selected based on successful growing at the business’s Senegal operation and previous experience with one of the varieties, Serenade. The jalapeno variety was new to the grower and was selected to offer consistent size, flavour and colour.
“Having established the glass houses we developed a vertical growing system with the chillis grown on strings. The varieties we selected had been successful in Senegal where we have a similar growing operation, but on a larger scale,” says Mr Denbury.
He wanted vigorous varieties that had high yielding potential and could be vertically grown to maximise growing space in the glasshouse.
“The chillis are grown in peat free Coir from Sri Lanka which is a sustainable and forgiving growing medium because it has good water retention and aeration which helps if we have any problems with our irrigation system. It is also good for balancing pH and EC,” he says.
The grow bags were initially planted with three plants in each but this year he has trialled four to increase crop density.
“We have increased crop density by 9.2 percent by changing the 1m bags to 1.2m bags and growing four instead of three plants in each. There is no difference in crop height so in the next growing year we intend to trial four plants in the 1.1m bags to further increase the density of the crop,” he adds.
Starting afresh he had the opportunity to grow with fewer chemicals and devise a more sustainable growing system using biological products.
“I use biological parasites including Amblyseius cucmeris for thrip control, Aphidius Matricarae and Colemani for aphid control and Amblyseius Andersoni for red spider mite. We also use Aphidius aphidimyza throughout the summer to predate on aphids,” he says.
He suggests that the IPM strategy starts with staff and plant management to minimise any threats brought into the glasshouse. After this he has developed a mix of biological solutions that help to strengthen the plants against pests and disease.
“Working with Gerry Strydom from biostimulant specialist Orion FT I have developed a tank mix that includes fertilisers and a variety of biostimulants. We drip feed biostimulants Sirius, which contains silicon, and Pluton a PGPR. We also apply Rigel G, another silicon biostimulant, as a foliar spray,” he says.
Pluton, a liquid plant growth-promoting rhizobacteria (PGPR) contains the naturally occurring bacteria Bacillus velezensis. This enhances rooting, stimulates growth and nutrient mobility to increase yield and induce plant resistance mechanisms.
“We have changed our outlook so that instead of tackling pests and disease we are strengthening the plants to do it on its own. Following a year of this approach we have seen increased vigour in the plants and the yields have been our highest to date,” he says.
Sirius, which contains 21 percent bio available silicon, has been introduced to the tank mix at a concentration of 5 litres per hectare to improve growth, photosynthetic efficiency and yield. Pluton is added to a second tank at 2 litres per hectare to help with early root development. Both help increase leaf hair density which makes the plants less attractive to biting pests.
“We started with Pluton and Sirius early on in the growth development of the plants. Each tank mix lasts a week and after four weeks we moved to just using Sirius. This year the plants were in excess of a metre tall and we had not seen any aphid damage. This meant the plants were mature enough to stand up against potential aphid attacks,” he says.
For 16 weeks there were no signs of aphids, a first for Mr Denbury growing chillis. It meant he had no need to spray chemicals and as an experiment he lowered the biostimulant dose.
“We saw signs of aphids and immediately increased the dosage of Sirius which saw the aphids dissipate. We have the potential to spray Sirius too, but so far it has worked well as a drip feed,” he adds.
He has chosen to spray Rigel G, a 4 percent silicon product that also contains naturally derived plant extracts, to help with growth and vigour.
“We have only had to use it twice, but it has relieved the spider mite pressure on the Serenade variety each time. This year the growing conditions have been too hot at times to use foliar sprays because we risk leaf burn but I suspect we will have more use for Rigel G in normal growing conditions,” he says.
He suggests that every change made in the glasshouse influences the crop, pests and beneficial insects. Considering this he has been keen to minimise the use of chemicals that have the potential to upset the growing environment.
“Glasshouse growing never stops. Water, irrigation, fertiliser and climate are important every hour of the day. We have to be the grower, weather man and lots more. We have to adjust the glasshouse to the weather conditions outside, so we installed a state-of-the-art climate control system that has been calibrated to the crop since we moved in,” he says.
Despite all his efforts the threat of aphid, spider mite and mildew are all a constant challenge.
“The combination of biological parasites and the biostimulants has worked very well this year. However, the growing conditions have been unseasonably warm and dry which has no doubt helped. We do have a bio-fungicide product that we can resort to as well, before we need to look at using chemicals,” he says.
Inside the glasshouse is a captive bee population that is an important part of the IPM strategy and also helps with pollination.
“Bees are amazing creatures, and we value them for pollination. Having bees pollinate the chillis increases our yield because not every plant will self-pollinate,” he says.
Female bumble bees are supplied in cardboard hives with 150 bees per hive. These are replaced every 12 weeks depending on the weather.
“Watching them is fascinating. Each hive has a guard bee, or ‘bouncer bee’ as I like to call her. This bee will only let in bees from her hive and will fight off any interlopers.,” he says.
Keen to protect the bee population he has minimised the use of chemicals and should a chemical spray be needed he ensures the bees are in their hive beforehand.
“They are so intelligent. We put a red dot above the hive which they use as homing beacon to find their hive. Each bee flies around the hive, registers the dot and then will fly off,” he says.
Heating and venting the glass house has been a challenge in the hot weather. His aim is to not let the temperature fall below 18 degrees and to allow it to build at 0.5 degrees per hour to a maximum of 26 degrees at sunset.
“The curve in temperature optimises plant and fruit development. Too hot and the bees won’t work, and we need them for pollination. We open the vents in the morning to dry the flowers which become damp overnight. This helps the calyx to bend to create the typical chilli shape and makes the plant drier and more attractive to the bees which are less likely visit damp or wet plants,” he says.
By introducing the biostimulants, managing the biological parasites and protecting the bee population Mr Denbury has found a combination that has provided the best results seen in Barfoots of Botley UK chilli growing.
“It’s like a eureka moment. We have the right combination of measures in place, and we are not reliant on chemicals to grow a supermarket ready chilli. This is better for us because we are reducing our costs and it is a good message to our buyers and the consumer,” he concludes.
Contact Us
We have developed novel product formulations that stimulate natural plant defence mechanisms, with application across all sectors including agriculture, horticulture, ornamentals, amenity and forestry.
To speak to a member of the team to discuss your requirements, please Contact Us today.
Oct 2025 | Article
