The Heat Stress Window: Protecting Greenhouse Crops When Temperatures Peak
Summer brings its own particular challenges to commercial greenhouse and glasshouse operations. When temperatures climb and remain high for extended periods, crops come under physiological stress, affecting growth, quality and yield. Managing that stress effectively requires prompt action, and the way the product is delivered during these critical windows matters as much as what is being applied.
What is heat stress in greenhouse crops?
Heat stress occurs when sustained high temperatures push crops beyond their comfortable operating range. The effects vary by species but commonly include reduced photosynthesis, poor fruit set, leaf scorch, accelerated water loss and increased susceptibility to secondary problems such as tip burn in leafy crops or blossom end rot in tomatoes and peppers.
The challenge for greenhouse managers is that heat stress often develops quickly. A run of sunny days in July can push internal temperatures well beyond what even well-ventilated structures can manage, and by the time visible symptoms appear, the crop has already been under pressure for some time.
How can foliar application help protect greenhouse crops from heat stress?
Targeted foliar applications of calcium, biostimulants and amino acid products can support the crop's resilience during high-temperature periods. Calcium in particular plays a critical role in cell wall integrity; maintaining adequate calcium levels in the leaf tissue helps the plant manage the physiological demands that heat places on it.
Biostimulants containing seaweed extracts or amino acids are increasingly used as part of heat stress management programmes in commercial horticulture, helping to support root function and overall plant vigour during periods when the crop is working hardest. These products are well suited to aerial delivery via the XAG P100 Pro agricultural drone, which can apply them quickly and uniformly across large glasshouse structures.
Why is drone application particularly useful in commercial glasshouses during summer?
Working inside a large glasshouse or polytunnel during peak summer temperatures is genuinely demanding. Temperatures inside structures can significantly exceed those outside, and carrying out manual spray operations in those conditions places real demands on staff. In larger commercial operations, the sheer scale of the structure makes thorough manual coverage time-consuming even in cooler conditions.
The drone addresses both issues. It works quickly, covering large areas in a fraction of the time it would take manual application, and it keeps the team out of the hottest, most uncomfortable parts of the working day. Operators monitor progress from outside or from a cooler part of the structure rather than working directly in the spray environment.
What is the difference between drone application and rover application in a greenhouse?
The XAG P100 Pro drone is the right platform for foliar nutrition and biostimulant applications that support heat stress management. For chemical crop protection treatments, including fungicides needed to address the secondary disease pressure that often follows a period of heat stress, the XAG R100 agricultural rover is the appropriate ground-based option. The rover navigates the rows autonomously, keeping operators away from the spray zone and delivering consistent coverage at canopy level.
Used together, the two platforms cover the full range of applications a commercial greenhouse operation is likely to need through the summer months.
Which greenhouse crops are most vulnerable to summer heat stress?
Tomatoes, cucumbers, peppers and aubergines are among the most sensitive to sustained high temperatures, particularly during flowering and fruit set. Leafy crops,, including lettuce and herbs,, can suffer from tip burn and bolting under heat-stress conditions. Ornamental and bedding plant production is equally affected, with quality and shelf life both impacted when growing temperatures exceed optimal ranges.
For commercial nurseries and large-scale protected cropping operations across Lincolnshire, the Fens, Kent and the South West, summer temperature management is an ongoing concern rather than an occasional one, and having a fast, effective application method available makes a genuine difference to how well the crop comes through the hottest periods.
How do I set up a foliar programme to manage heat stress in my greenhouse?
The starting point is identifying which products are appropriate for your crop and your specific situation, which is a conversation for your agronomist or crop adviser. Once the programme is in place, the QuadRotor team can advise on integrating drone delivery into it and on the logistics of a treatment visit for your site. Get in touch to start that conversation.