If you notice that your rose plant does not have the vitality that characterizes it, its leaves, stems or flowers have spots, it is surely sick, this could be due to the attack of some insect or fungus, so in this article we present information about the different diseases of the rosebush, its causes and the preventive and corrective measures that must be applied, so we invite you to continue reading.
Frequent Rose Diseases
If there is a rose bush in a field, it is likely that those plants have been infected with diseases caused by fungi, viruses and bacteria. To avoid this contagion, there are practical guides to ensure the protection of this problem, the most frequent are those related to fungi. They reach 98% of the time. Rose bushes have generally been produced recently with great demand and despite their charm, they are not exempt from diseases and pests.
Since rose bushes are plants that can be altered in their life cycle due to the presence of unwanted organisms, it is recommended that special attention be paid to these flower crops to avoid possible slight or irreversible damage that ends with them. Just check the stems, shoots, and especially the leaves frequently, which are the part where symptoms appear when something is wrong. For all this, it is important that you know the following four diseases that can affect your rosebush:
Roya
It is a type of harmful fungus that seriously affects a rosebush. When they infect a plant they can be identified by dark-hued star spots on the tops of the leaves and can spread rapidly. As a result, the foliage falls much earlier to the point that the plant's leaves are completely uprooted in late summer. Rose stems can also be attacked. Diseased roses are not hardy and bloom less. Moisture favors the spread of rust. Pink rust has no other hosts, so it basically hibernates in the foliage of the affected plant.
Powdery mildew
This fungus appears as one of the diseases that mostly attacks rose bushes. They are identified as small light spots on the leaves and then spread to the rest of the leaves, buttons, terminal shoots and fruits. In rose bushes, blanquilla manifests itself in the discoloration of red tones. The main part of the fungus is found on the outside of the plant. Therefore, it is easy to clean the white film with a finger. The leaves curl up and then darken and fall off. Thus, severe infestation can lead to stem death, wilting of plant tissue, and inhibition of bud development.
Black spot or Marssonina
It is a disease that appears as round purple and blackish-brown spots on the leaves. A series of fibrils develop at points on the periphery, which expand and are surrounded by a yellow halo that eventually discolors the entire leaf. It can even attack discolored stems in the bark, creating dark blue and black spots that lead to sores. The black dots are circular with a perforated edge and reach a diameter of 14 mm. However, severely affected plants do not show a circular pattern because together they form a large black mass.
The black dots are a reaction of the plant to the attack of the mycelium of the fungus, which presents small pustules that are the fruiting bodies of the fungus, the acervuli. Each 5 to 10 millimeter spot can release up to 30.000 spores, the conidia. The attack continues to grow very rapidly and lasts for a week. The slightest splash (rain, irrigation) breaks the acervuli and causes the spread of Diplocarpon rosae. The usual treatment for the disease is to remove affected leaves and spray them with antifungal medication. Some rose stems can be left untreated and progressively weaken the rose.
Mildew
They are among the fungi that cause rose diseases, which appear during the months of April and August. It can be identified as red and purple markings. Also, it is known to create a dirty hairy coating on the underside of the leaves. It should be noted that this fungus enters the plant through the stomata on the back of the leaves, colonizing it with its mycelium that allows it to eliminate nutrients. A heavy infestation causes growth problems, leaf drop, shoot dryness, and shrinkage or loss of roses.
Rose Pests
After having mentioned the diseases of the rose bush, the time has come to be able to point out each of the pests that affect roses. As you may know, pests are a series of organisms that bring about the deterioration of the plant or any living being that can serve them as a source of energy. It can be found among spiders, aphids, some type of worm or even ants. However, in the following paragraphs of our article, we will explain which are the main invaders of rose bushes:
red spiders
It is a small insect that in its mature phase can grow up to half a millimeter, in addition, it usually obtains its nutrients from withered plants. However, it should be noted that although it is called a spider mite due to its ability to weave webs, this is not the case as it is a mite. They are usually found on the underside of leaves, as this is the most porous area (since this is where stomata and gas exchange are located) and accessibility for the mouthparts. On the other hand, the upper face of the leaf is completely sealed and therefore inaccessible to the spider mite.
Therefore, to monitor the possible presence of this individual that causes diseases in the rosebush, it will be necessary to be very careful to see the lower part of the leaf, to prevent and be able to stop this threat. Since, if left alone, it can weaken and finish off the rosebush very quickly, observing in the process how the tone of the plant turns yellowish, causing it to be exposed to all kinds of diseases, such as the ones we have previously mentioned and explained.
Rose Aphids
They are creatures that reach 3 millimeters in size, with a greenish tone, that usually attack the rose bushes attacking the tender buds and at the same time the flower buds, in addition, they have the particularity of feeding on the sap that the plant contains inside. With these actions, they produce diseases of the rosebush that weaken and deform it. Another important fact is that it does not appear alone, it is usually accompanied by the bold fungus, which is considered very harmful. The key to uncovering the pest will be the ants, as they are naturally attracted to the honeydew deposited by the aphid.
Green mosquitoes
Another of the pests that cause diseases of the rosebush is the green mosquito. This is identified as a parasite that affects different species of plants, including roses. It is easily distinguished by its appearance, since the adults are green in color and have an elongated shape. They are usually no larger than 4mm. and they move through the leaves by flying or jumping. The nymphs are very similar to the adults, although smaller and without developed wings.
The damage to plants caused by this pest is very characteristic, since it mainly affects the leaves, creating small whitish or reddish spots that start at the edges and gradually spread inwards. In some cases, when the infection is already in a very advanced stage, it can cause necrosis and spasm by rolling the lower part of the leaf. Therefore, to counteract this threat, it is best to use natural or chemical products and apply them at two times: when the number of nymphs increases and, conversely, when they lay eggs.
Care to avoid Rose Bush Diseases
Roses are very resistant plants, some bushes can live up to a hundred years, although it is almost certain that in the end they will produce very few roses. If you want your roses to give you flowers for many years, this is what you should keep in mind. First, the roses must be in a suitable place, with the hours of sun they need and the ideal soil, they are less vulnerable to diseases and pests than typical rose bushes. Second, the correct fertilizer will give us healthy and well-growing bushes, of course, it must be applied in the best way and at the right time.
Third, rose pruning has several functions. The first is to keep the bush in order, but also to prevent the appearance of some of the worst diseases of roses: fungi. Finally, you have to choose resistant and adapted varieties. As much as we love a rosebush, there are times when it is not recommended to have it in the garden. Not all roses grow well in all climate zones. Some are more resistant to cold and others to heat. Choose the shrub that best suits your climate and where you will place it in your garden.
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