A survey conducted by Terre Innovia (interprofessionnel technical center for oleaginous, proteaginous and hemp products) revealed the increasing impact of bird damage on sunflower fields. It is therefore necessary to act and protect the crop prior to sowing since birds will be quick to damage it, especially close to hedges and towns. Harvest losses associated with this bird damage can be significant, particularly since the control methods available are limited. Are there any methods available to limit the damage caused by these feathered pests?
The damage caused by birds on sunflower fields takes several forms. Regularly spaced, visible holes of a few centimetres show that the birds have been looking for the seeds following the seed lines. They eat the seed that they dig up from the soil. The softest seeds then present an empty shell. The leaves located under the flower head are often soiled by the droppings of these birds. Damage to the flower heads and cotyledons is also observed. In this case, the cotyledons are often pulled off or split by the birds trying to get to the seeds.
In this context, Terres Innovia has conducted various surveys in a number of regions to review the sunflower crop situation. Two such surveys were carried out in 2012 and 2014. Result? A steady increase in bird damage can be observed nationally: 77% of farmers estimate that bird attacks have increased over the past 5 years. 80% of their sunflower fields have suffered damage (source CETIOM 2012).
Bird attacks on sunflower crops occur from the sowing stage up to the 4-leaves stage (around 3/4 of cases). Sometimes they occur later - in around a quarter of cases - affecting the flower head. Attacks can be very frequent and cause substantial damage to the sunflower crop.
The great majority of cases involve pigeons (91%): wood pigeons and town pigeons, as well as corvidae, such as rooks and crows are reported in 62% of cases.
A field’s vulnerability is more related to its position, with some areas being at greater risk, than to the effectiveness of protective systems. Despite the presence of protective systems - primarily bird scarer devices - half of all sunflower fields have been attacked by birds and thus resown. Proximity to a town or hedge makes attacks more likely. These locations are ideal for the development of nests and pigeon populations.
The damage caused by attacks depends on their scale. Often, the main target is not the sunflower seed but, instead, the young seedling, which is fragile and soft. Thus the birds eat the cotyledons but do not damage the stem. However, a lesion on the stalk can cause the plant to die.
Sunflowers are very susceptible to birds. So susceptible, in fact, that bird damage can lead to the entire crop being destroyed and abandoned. Visual or acoustic bird-scaring methods, such as bangers, scarecrows, balloons, kites, etc. or repellents are not effective enough to limit bird damage. However, it is possible to fortify young sunflower plants during their starting period in order to limit the impact of this bird damage. This reinforcement involves optimising the plant’s mineral and water absorption and making the cell walls thicker in order to create an environment unfavourable to bird pests
Don’t wait until birds are already established in your sunflower fields; act fast, as soon as they are planted. It is possible to fortify young sunflower plants during their starting period in order to limit the impact of this bird damage. Contact our experts for more information!