In Italy’s Val di Non region, hundreds of hectares of apple orchards were damaged by a violent hailstorm that hit Trentino on July 22，2021.
In various parts of the region, around 500-600 hectares of apple trees were damaged by the unusually timed storm.
Hail nets come to mind during this time. Hail nets are an effective means of protecting our orchards.
However, when it comes to using hail nets, you may have some concerns of one kind or another. One of the biggest worries may be whether these nets will have an effect on the colour of the apples. This is because once the colour of the apples is not bright enough, the price of these apples will be affected.
What ingredients affect the colouring of apples?
The anthocyanin content of apples affects their colouring. And anthocyanins need light to be synthesised.
The use of hail netting reduces the amount of light available to the apples and this reduction in light results in fewer anthocyanins being produced. The reduction in anthocyanins causes a reduction in apple colouring. Of course, if the type of apple grown is green it will not be affected.
What can be done to prevent the colouring of apples from being affected?
Use Transparent Hail Netting
When choosing a net, ensure that it has the least impact on the light. It has been proven that the shading rate of transparent anti-hail nets is only 7%, so it is possible to minimise the shading rate. By reducing the loss of light, the colour effect on apple appearance can be minimized.
Use Reflective Ground Mulch
To a lesser or greater degree, hail nets can block sunlight, which can affect the colouration of apples. How can this effect be avoided?
One effective and well-researched method is the use of reflective ground mulch, which reflects the light that hits the ground back onto the apple tree.
Saskia Weber’s research has shown that 1.6 to 3.9 times more light is reflected when the ground cover is used. The increased light utilisation resulted in improved skin colour, particularly on the shady side of the apple fruit and on fruit in the lower inner part of the canopy.
Similar results were found in Tobias’ study. With the use of black hail nets, the proportion of well-coloured Class I fruit was on average 9% higher in apple orchards where reflective mulch was used than in those without.
Kerstin Funke’s trials have confirmed that reflective mulch is effective in improving fruit colour and maintaining good fruit quality if it is laid on the bushes of the late-maturing bicolour variety Braeburn in mid-September, four weeks before harvest.
The use of hail nets can potentially have an effect on the colouring of apples. But only if certain measures are taken. When choosing the colour of the net, choose a colour that has little effect on light. And use a reflective mulch to increase the effective light intensity. This will protect your apple orchard from hail storms and also ensure the quality of your apples and increase their yield.
EyouAgro strives to be the customer’s top choice for unique and innovative crop protection solutions, which is why we provide premium polymer netting for controlling microclimates to make plants healthier and stronger. With UV protection and durability against rips and tears, our products support sustainable agriculture and horticulture growing. Get in touch with us at [email protected] for more information about our selection of crop covers and other horticulture solutions, or for recommendations regarding your specific project.