In the coming weeks – as glasshouse pepper crops enter the final phase of fruit setting – it is important to ensure plants are in the best of health to maximise final harvests, reports Biobest.
Towards the end of the year, depending on light levels and temperatures, fruit set to harvest takes around 7-8 weeks for coloured varieties. Maximising photosynthesis is key to getting good fruit set. As fruits swell and develop seeds they become strong ‘sinks’, pulling in energy (carbohydrates) produced in photosynthesising leaves. If demand is greater than the supply of energy, newly formed flowers will abort.
The head of the plant is where it is all happening. Photosynthesis in these younger leaves is important to provide the carbohydrates needed to fuel fruit development. This is also where new flowers open.
Late surges in aphids are also often concentrated in this soft new growth at the plant apex. Keeping the top of plants pest-free helps maximise photosynthesis and flower development – optimising production of good-sized, high quality fruits at the end of the season. It is therefore advisable to closely monitor and scout the crop using sprays such as Spyro® or Protac SF® to keep the heads aphid-free.
Although pepper flowers can self-fertile, heavier fruits are associated with cross-pollination. Low temperatures (<18°C) and low fruit load can lead to slightly deformed flowers. This phenomenon is likely to be linked to an over-supply of photo-assimilates (carbohydrates) to the flower bud. The reproductive structures in these poorly formed flowers may not enable self-pollination and fruit may be deformed and have few, or no, seeds.
Deploying bumblebees, to move pollen between the flowers of different plants, can reduce the risk of abnormal fruit development. To achieve the best pollination in the crop’s final fruit sets, Biobest recommends introducing 1-2 Standard Hives per hectare at the end of August.