Prevention of fireblight in fruit trees
Introduction
Fireblight is a highly invasive and destructive fungal disease that affects the fruit trees. If this disease is not treated on time, it can affect the fruit trees seriously to the extent of killing them. Fireblight is a sporadic disease that can survive very cold winters as dormant spores in dead plants that are around the base of fruit trees. The fierblight disease mostly affects the young fruit trees that are prone to infections. Fire blight is caused by a bacterias known as erwinia amylovora. This bacteria is spread by splashing river water, insects and improperly washed pruning tools.
Step 1
Choose tolerant varieties
Some fruit trees are very susceptible to fireblight. It is important to know the different types that are highly and less susceptible to the fire blight infection. Always go for the less prone trees to prevent damage and loss. The susceptible apple trees are Fuji, gala, golden delicious, granny smith, graven-stein, jonathan, mustu, pink-lady and yellownewton. The pear fruit trees that are susceptible include the Asian pears and red pears. The less susceptible pear trees are brad-ford, capitol and red-spire.
Step 2
Remove diseased wood
Complete and successful removal of fireblight is done during winter or summer when the infection is not spreading. If the fireblight infection occurred on the trunk or major limb, scraping off the bark down to the cambium layer in the infected ares would be the best thing to do so as to save the wood. When scrapping look for long narrow fireblight infections that can spread beyond the canker margin. Remove all the infected tissue and 5-8 inches more beyond the infection point to ensure complete removal of the fireblight infection. If the limb is girdled, then it has to be removed in whole.
Step 3
Chemical control
The only available home remedy for fireblight is copper products that are not 100% effective even after multiple applications. A mild mixture of Bordeaux or other copper products can reduce new infections when applied severally but cannot eliminate the fireblight infection totally. The mixture should be applied to open blossoms and should be used depending on the bloom period length. Make the first application when blossom begins. During periods of high humidity, apply on intervals of four to five days.
Step 4
Cultural practices
Cultural practices include site selection, proper pruning and fertilizing. Proper cultural practices can help to prevent and minimize the effect of fire blight. Avoid heavy pruning when the trees are young as it stimulates growth that in turns attracts fire blight infections. Use a balanced fertilizer when the temperatures are cooler and less conducive for fire blight infections. Plant new trees on the best and proper sites that have not had the fire blight infection before to minimize the chances of infections.
Step 5
Proper irrigation
Over irrigation provides the best breeding site for fire blight. Therefore irrigation should be done when necessary and at set periods of time. Before irrigating, keep the ground clear of the dead plant materials that suffered the fire blight infection as they start new bacterial infections.
Signs of fire blight infection
The signs of fire blight infection are evident during the trees blossoms and spurs development.
- The infected blossoms turn brown and wilt.
- The twigs and branches darken as they develop a water soaked appearance, they turn black and their twigs curl into the shepherds crook.
- A yellowish tan ooze at affected areas base.
- Trunks and limbs develop cankers.
- The bark appears sunken.
- Cankers surround the limb and kill it.
