Improving knowledge and experience of micronutrient management in cucurbit production in Wales

Cucurbits include a number of important crops such as courgette, marrow, pumpkin and squash. These crops are robust and can be grown in a variety of field conditions, and can offer increased variety to farm shop style businesses. As field crops, they can also be integrated into a mixed cropping system, or offer an accessible diversification crop for arable farms. Pumpkins can potentially offer high-value returns from pick your own local Halloween markets, however there has been continued growth of pumpkin as an edible crop with a number of prominent eating varieties now available to growers.

A common problem within this crop group is the development of rots such as blossom end rot (BER) which can render the fruit unmarketable. BER can lead to significant crop loses and it is one of the primary sources of wastage in this sector. A limited range of fungal plant protection products are available, but as these are generic fungicides their use in an open field setting may be unsuitable.

An evolving body of evidence suggests that the development of BER is likely to be linked with crop nutritional status and it is believed that management of the crop’s calcium and boron nutritional status may provide a method of its control. As it is a difficult and relatively slow process to control the crop’s nutrition through the soil, applying calcium and boron directly to the plant through foliar feeding may be a more effective method. In this approach, nutrients are applied to the leaf and fruit of the plant as a fine mist which is then absorbed by the plant. 

Two relatively small scale horticultural units based in Brecon, who are members of the Tyfu Cymru network, will be working together in this two year project to gain more knowledge on whether foliar feeding calcium and boron can reduce the incidence of BER in their pumpkin crops.


The project plan

  • At least five different commercially available calcium and boron foliar feed products will be trailed over two growing seasons at each site.
  • The products will be trailed on three replicate blocks consisting of 10 m length and 4 rows of a single pumpkin variety (Harvest Moon), with a density of 1 pumpkin per m2.
  • The foliar spray products will be applied every 10 – 14 days from the onset of flowering (c. 4 – 6 weeks from planting), and will be continued until the onset of leaf senescence. There will also be an untreated plot to act as a comparison.
  • Field observations of crop condition will be made (canopy density, leaf chlorophyll and vigor) throughout the season alongside the incidence and severity of visible BER symptoms (e.g. rot incidence).
  • At harvest, the quantity of fruit from each plot will be recorded and will be assessed for quality (size, color, fruit firmness, commercial grading). Some pumpkins from each plot will also be shelf life tested for up to 28 days.

Hopefully this project will provide guidance to small scale growers on how it is possible to reduce BER incidence within their crop by utilising micronutrient foliar feeding. This could then lead to increased product quality and sales, and could also reduce crop wastage and fungicide applications.