Nothing beats owning a fruit orchard but it does require work. While raising pears may seem to be a simple task and many people think the tree will take care of itself, it does take dedication to reduce plant disease problems. Below are a few of the common pear tree diseases that one may encounter but prior to seeing these issues, one must do their garden housekeeping to keep these diseases at bay. To learn these preventative measures, let’s take a walk down through the orchard together.
Pear Orchard Housekeeping
First, let’s take a look at things we cannot control. Weather of all types can be a friend or foe of a pear grower. The reason for this is the fact that certain plant diseases thrive in certain environmental conditions while others cause a decline. An unusual number of cloudy days can increase plant disease problem. Along with this are long periods of high temperatures and humidity, which can cause a rapid growth of plant diseases. Another fact is rain. While moisture is very important for fruit development, there is a fine line between enough rain and too much. Also the frequency of this rain can affect the abundance of pear tree diseases.
While there are things we cannot control, there are techniques that one can follow to deal with Mother Nature’s curveball. First, pick your pear trees wisely. There are many different types to choose from and if you know there is a problem in your area, select a tree that is known to be resistant to this issue. Second, when planting your tree take care and do it properly. Yes, I know you may be tempted to take a few shortcuts due to time, I caution you not to. A simple shortcut can cost you in the end when your tree develops a plant disease.
To proper plant your pear tree is simple and starts with the proper size hole. The hole will need to be the same depth of the root mass wile two to three times the width. If you have a lot of clay in your soil, once the hole has been dug scrape the side of the hole with a rake. This will prevent the sides from glazing over, which creates a barrier for the roots. Once the hole has been dug; test the tree in the hole. If the root mass is level with the hole, you are ready to plant. To prevent from damaging the roots of the tree, cut away the pot. After that is done, run your fingers around the roots to loosen them up and then place in the hole. Fill in the hole with a mixture of well-seasoned compost and removed soil. Water in and add additional soil as needed.
The last garden housekeeping task one will need to do is what is referred to as sanitation. What this means is to keep the orchard clean by removing dead and diseased branches, vegetation and/or fruit. Do not compost these items instead throw them in the trash.
Now that we know what we cannot control and proper orchard housekeeping techniques, let’s take a look at the diseases themselves and how to treat them.
Pear Tree Plant Diseases
FABRAEA LEAF SPOT
This pear tree disease is also known as leaf blight and black spot. It is caused by the fungus Fabraea maculata, which appears late in the growing season. This fungus attacks all parts of the tree, which includes the leaves, fruits, and/or twigs.
The symptoms of this pear tree disease start out as brown or black spots on leaves. As the infection progresses, the leaves turn yellow and drop off prematurely. If the leaf drop is severe or occurs for several seasons, the pear tree will be less vigorous, produce fewer pears and could eventually die.
This fungus can also set up house in fruit and will appear as lesions and as the fruit expands these lesions will turn into sunken places in the fruit.
Once this fungus appears in the orchard, it is hard to control. One reason is the fact that it will easily overwinter in fallen leaves and fruit. The other reason is the fact that it can be spread by wind and/or rain. While there are chemical treatments for this fungus, the best approach is to reduce the affect and/or prevent it all together. Keeping fallen leaves and fruit picked up and disposed of if diseased is one simple approach that will reduce the chances and possibly the stronghold of this fungus
This pear tree disease is caused by a bacterium called Erwinia amylovora. It is one of the worst plant diseases for pears and while it can take a few trees down, it is very possible that a whole orchard can be wiped out. This plant disease occurs in four stages, which includes canker blight, blossom blight, shoot blight and finally trauma blight.
Canker blight starts out in the spring and appears as oozing out of cankers. This oozing is a sweet substance that insects love. They land on this ooze and carry it to blossoms, which is where the name blossom blight comes from. This disease will continue to be spread by insects, wind and rain to other parts of the tree. In doing so, finishing off the other two stages, which include shoot blight and ending in trauma blight.
To reduce the chances of getting this plant disease, one must be on top of garden sanitation. This means cleaning and sterilizing all equipment that will be used on the trees. To do this one will either need to wipe down the equipment with a towel soaked in bleach water or submerge the item in bleach water. The latter is the best approach but due to the size of the equipment either approach will work.
As a preventative measure, make sure to dispose of the plant material in a way that is not near the orchard. If there is any question on the health of the plant material removed, throw it away in the trash.
Sooty Blotch is caused by Gloeodes pomigena. How do you know if you have this issue? Take a look at the fruit. If it has a black, sooty smudge on it then you have this pear tree disease. This plant disease is brought on by rainy weather and appears early in the spring and continues until late summer. While the fruit can just be wiped off, a better approach is to promote air circulation by thinning out the branches and keeping the grass mowed underneath the tree.
Pear scab is caused by a fungus called Venturia pirina. This fungus causes circular, olive-black spots that have a velvety texture. It can be found on the leaves, fruits, and sometimes even the twigs. The “scabs” appear the olive-black in color but as they age turn gray and cracked.
In the spring, spores that have lived in fallen leaves will be released when it rains. These primary spores will take up house anytime the weather is wet through June. After that a secondary type of spore will enter the environment. This spore is produced from the fungus activated earlier in the season. This infection is spread when water splash on leaves and fruit.
The best approach to preventing this plant disease is proper orchard sanitation. This includes removing any diseased fruit or leaves.