Persimmon diseases and measures to combat them
Lamziri Beradze - Academic Doctor of Biological Sciences
Ioseb Basilia - Agricultural Science. doctor,
Rusudan Takidze - Science of Agriculture. Acad. Dr
Nika Guntadze - Master's student
Ltd. Anaseuli soil and food diagnostic center named after Adam Beridze
Key words: persimmon, fungus, disease, conidium, conidia bearer, conidiophore, mushroom fertility, sclerotium, stain, archia, exudate.
Abstract: the following diseases are noteworthy for their harm to the persimmon plant: persimmon gray rot - Botrytis diospyri Borg., persimmon cancer (phomopsis) - Phomopsis diospyri Rob., persimmon blight - Ragnildiana Levieri Vass., persimmon anthracnose - Colletotrichum Kaki Maffei, persimmon verticillium wilt - Verticillium diospyri Kleb.,
Measures to fight against diseases are given in the work.
Introduction: Persimmon culture has been known to man for a long time. Its homeland is China, from where it was later introduced to Japan as one of the main fruit-bearing crops. It spread from Japan to the coastal countries of the Mediterranean Sea.
    In 1892, Tbilisi Botanical Garden received several persimmon varieties from Italy. In 1895, agronomist Klingen and professor A. Different varieties of persimmons were imported from Japan by Krasnov. According to some researchers, persimmon culture was known earlier in Georgia.
    Along with the development of agriculture in our country, persimmon has found a significant spread among subtropical fruit plants. Persimmon fruit is characterized by a very good nutritional value.It contains a large amount of sugars, mineral salts, fats and vitamins. In addition, persimmons are less demanding on soil conditions. Among the positive features of the persimmon, it is worth noting that it is one of the most frost-resistant plants among subtropical fruit trees. There are more than 100 varieties of subtropical persimmons in our country.
    The yield of subtropical persimmons is significantly reduced by various fungal diseases.
The main part: in 2006-2008, persimmon planting in the humid subtropical zone of Western Georgia was investigated. As a result of research, more than 30 different species of mushrooms were identified. Among them, the following are noteworthy for their harmfulness and negative economic value for persimmon culture: Botrytis diospyri Borg., Phomopsis diospyri Rob., Verticillium diospyri Klel., Ragnildiana Lavieri (Magn.) Vass., Colletotrichum Kaki Mahhei, Pestalotiopsis diospyri Sud., Fusarium sambuci num Fuck. ., Fusarium gibosum App. et. Wr. Emend Bilai., Trichothecium zoseum Link., Alternaria alternata (Fr) Keisl., Cladosporium herbarum (Pers.) Link., Scllerozium Rolfsii sacc. (1)
Gray rot of persimmon - Botrytis diospyri Borg. It infects persimmon leaves, young shoots, flowers, buds and fruits. The disease is mostly detected in spring - April and May.
In spring, the disease is first observed on the tips of green shoots, the diseased shoots turn green. Then the disease spreads to the one-year branches and appears in the form of brown spots. The spot gradually enlarges, surrounds the branch, after which the upper part of the branch dries up.The conidial fertility of the fungus is observed on the branches in the form of gray snowflakes.
  The spots on the leaves are light green. The spots eventually turn brown. At high relative humidity, the spots are covered with bluish snowflakes, the diseased leaves fall prematurely.
    The damage caused by this fungus is very harmful to flowers and newly grown fruits. Diseased shoots and fruits fall. The disease of mature fruit is especially harmful. At first, there are small black spots on the fruit, which then penetrate deep into the fruit, the pulp of the fruit rots and falls off. The fallen fruit turns brown from the side of the stalk and is covered with bluish snowflakes. It is also well characterized by the stalk of the fruit left on the tree (2,3).
    The bluish snowflakes formed on diseased organs represent the reproductive organs of the fungus - conidial fertility. It consists of conidiophores and conidia developed on them.
    According to our research, in 2006, fruit disease reached 25-28%, in 2007, the disease was determined by 15-20%. In 2008, the development of the disease reached 30-35%. Fungus Botrytis diospyri Borg during ripening of persimmon fruits in 2006-2008. Conditions were favorable for development and spread, both in terms of relative humidity (80-90%) and air temperature, and therefore the percentage of disease was quite high.