Increased biodiversity in cherry polytunnels positively influences the presence of pollinators

06 Nov 2024
1942

Open polytunnels are widely used in the commercial cultivation of cherries in temperate regions, including the UK. These tunnels protect the fruit from adverse environmental factors, such as rainfall.

Cherry trees are typically covered during the flowering and fruit development phases, but they are left uncovered in winter to allow for the chilling requirements of the buds to be fulfilled.

Polytunnels offer several advantages, as they protect flowers and fruit, which in turn improves fruit quality, consistency of marketable production, and overall yields. Additionally, the flowering and harvesting period of cherries becomes more predictable.

The persistence of plant protection products (such as insecticides like lambda-cyhalothrin and cyantraniliprole) is prolonged under polytunnels, thus reducing the need for additional chemical applications.

However, there are also some negative aspects associated with polytunnels, including increased risk of pests and diseases, potential for excessive heat, and occasionally reduced fruit formation and quality.

Immagine 1. Suddivisione delle file in quattro sezioni e 12 sottosezioni (ss), compreso il buffer (non valutato). Modificato da Mateos-Fierro et al. (2021).

Moreover, the presence of insects can be affected by the specific types of plastics used in polytunnels, which may influence beneficial insects, including both pollinators and natural enemies of pests.

Despite the fact that natural enemies are generally not deterred by polytunnel covers, it remains uncertain how beneficial insects (both pollinators and natural enemies of pests) are impacted.

Field studies have revealed that beneficial insects are more commonly found on the outer part of the field, with their presence decreasing towards the center of the plot.

In this UK study, the effect of perennial flowering areas in the inter-row was examined to understand its role in mitigating the potential "edge effect."

The main objective was to determine whether edge effects influenced the density, , and behavior of natural enemies and flower visitors, along with their respective ecosystem services, such as pest regulation and pollination in ten commercial cherry orchards grown under polytunnels.

A conventional control strip (CS) was compared to a standard wildflower strip (single cut at the end of the season) and an actively managed wildflower strip (routinely cut at a height of 20 cm).

Natural enemies were observed in the inter-row and on the plants after the flowering period, and flower visitors were observed at various distances from the orchard boundary both during and after flowering.

In 2019, a trap system for predatory insects on trees was implemented to assess pest regulation services. The study found a 33% reduction in pest control toward the center of the orchard when the inter-row was managed conventionally (CS).

Immagine 2. Predicted density (mean number of individuals) of the natural enemy taxa which were significantly affected by distance from the orchard edge in at least one alleyway treatment including (A) Neuroptera in 2018, Hemiptera in (B) 2017 and (C) 2018, (D) Opiliones in 2018 and parasitoid wasps in (E) 2017 and (F) 2018 from surveys in alleyways according to alleyway treatment and distance (m) from the orchard edge towards the orchard centre. Regression lines fitted on GLMER.NB with 95% confidence intervals (shadows). CS (Control Strips), SWS (Standard Wildflower Strips), AMWS (Actively Managed Wildflower Strips). Note differences in y-axes.

The diversity and density of flower visitors also decreased with distance from the edge, showing a 34% reduction in individuals.

These findings indicate that wildflower strips are an effective method to mitigate edge effects on pest control, even if their impact on pollination is limited.

Wildflower strips, regardless of their management style, have proven to be a beneficial intervention in reducing the edge effect within cherry orchards by supporting natural enemies.

The even distribution of flower visitors along the rows was promoted by wildflower areas, which also helped to partially mitigate the negative impact of the edge effect on fruit formation and quality.

As a result, establishing wildflowers in the inter-row of cherry orchards is a beneficial practice for growers, offering many advantages with minimal risk.

Images: Matteos Ferros et al.; SL Fruit Service

Source: Wildflower strips in polytunnel cherry orchard alleyways support pest regulation services but do not counteract edge effects on pollination services - Zeus Mateos-Fierro, Michael P. D. Garratt, Michelle T. Fountain, Kate Ashbrook, Duncan B. Westbury - Frontiers in Sustainable Food Systems

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

A sustainable approach to valorise sour cherry by-products: extracting antioxidant compounds

Processed

19 Feb 2024

When several extraction methods are combined, the purity and yield of the extract are improved. The pulsed electric field technique is a fast and effective method to break the cell membrane with electricity, thus facilitating the extraction of bioactive compounds.

The role of supercooling in sweet cherry flower buds to avoid frost damage

Tech management

17 Oct 2024

Experiments were conducted on sweet cherry flower buds using differential thermal analysis (DTA), a technique that monitors the release of heat due to ice melting. Researchers observed the formation of ice within the bud structure, identifying barriers that prevent its spread.

In evidenza

Strigolactones against gray mold: a new promising strategy to protect cherries during postharvest

Crop protection

04 Sep 2026

Strigolactones strengthen postharvest defenses in sweet cherries against Botrytis cinerea. Research on the Xianfeng cultivar shows that 0.1 μM reduces gray mold, lesion development and fungal biomass by activating phenylpropanoids, flavonoids and defense proteins.

How to prevent or minimise cold damage to cherry trees. Advice from an expert

Tech management

04 Sep 2026

Managing frost damage in cherry trees requires action from dormancy breaking through vegetative growth. Preventing ice nucleation, protecting cell membranes, and controlling Pseudomonas and bacterial canker can help preserve orchard health, resilience, and productivity.

Tag Popolari