common tomato diseases
physiological diseases of tomatoes
that are not caused by fungi, bacteria or insects, but are meant to be diseases that appear as a result of inappropriate weather conditions such as low temperatures or high temperatures.
It also produces physiological diseases as a result of error in fertilization, as well as irregular irrigation and lack of good drainage, as well as high soil salinity (EC), as well as high or low soil PH.
These causes result in the so-called physiological diseases, and by knowing the cause of the disease, it can be overcome, as the varieties differ among themselves with regard to their sensitivity or resistance to these diseases. Examples of this are.
1- Flower tip rot disease:
The most important symptom of apical flower tip rot is a spot of the crust that is brown in color, as well as soft tissues and skin in the terminal part.
The direct cause of this is the lack of calcium in the fruits, which results from the exposure of plants to unnatural conditions such as.
* Lack of soil moisture.
* Increased soil salinity in the root zone.
* High soil PH, which helps to stabilize calcium.
* Increased soil moisture, which leads to poor ventilation.
These conditions can be avoided as soon as the symptoms of the disease appear, and in general, if this infection appears, it is possible to spray with one of the compounds that contain calcium in order to prevent the emergence of this disease in new fruits, and it is preferable to avoid this spraying from the beginning with any compound containing calcium from the beginning of the decade and repeat spraying several times in a row.
2- Tomato fruit cracking disease.
Cracking of tomato fruits often occurs in ripe fruits, and it may start several days before coloring and continue until the red color is complete.
It should be noted here that the sensitivity of the fruits to cracking is a genetic trait linked to the same variety, and the emergence of cracking disease also helps with high temperatures with a sudden drop in ground moisture.
Also, when suddenly irrigated after the plants are starved for a long time, the tissues being filled with water puts pressure on the cells and causes them to crack.
To treat this phenomenon, the most resistant varieties must be selected and planted, while avoiding the high temperature of the fruits by covering them when temperatures rise with rice straw, while maintaining the soil moisture in a state of balance. And that when plants are exposed to extreme thirst, irrigation should be done gradually (i.e. not to over-irrigate) so that the plant adapts and is not surprised by the abundant irrigation.
3- Discoloration of tomato.
When this disease appears, the fruits appear in irregular colors, where the color of the fruits is light green, or sometimes some areas on the fruits are not colored.
This phenomenon is associated with irregular lighting intensity, as well as sudden cold with high soil moisture, and increased nitrogen fertilization (nitrogen) with potassium deficiency (imbalance of fertilization).
In general, this phenomenon is the result of the imbalance of fertilizer elements with low or high temperatures in the phase of coloring the fruits, which affects the level of lycopene pigment (the pigment responsible for the coloration of fruits in tomatoes).
4- Sun blotch and orange color appearing on tomato fruits:
Sun blight and orange color appear on the fruits of tomatoes with high temperature or increased intensity of lighting and the fruits are not covered under these conditions.
Any leaves that can protect the fruits from direct sunlight should be avoided during the spring and summer months when the fruits are exposed for long periods of direct sunlight.
As for the orange-colored fruits, the reason could be a deficiency in the lycopene pigment, which causes the red color when the temperature rises. As for the carotene pigment, which causes the yellow-orange color, it is not affected by high or low temperatures.
As for the continuation of the green shoulders color with the development and growth of the fruits, it can be considered a genetic trait linked to the variety, and to avoid these problems, the fruits should not be exposed to direct sunlight.
It is also possible to plant tomato varieties with abundant vegetation, which protects plants from sunburn, and shading can be done to reduce the intensity of lighting.
First, the stinking soft mold.
The fungus that causes rotten fruit:
Symptoms of rotten rot in fruits
One of the main symptoms of this disease is fat spots
With white growth resembling butter in the cracked areas
Occurs in fruits with a fetid odor; And that
As a result of secondary bacterial infection.
Er-winia carotovora P.V crotovora .
Second: black mold.
The fungus that causes black rot in tomato fruits:
Symptoms of black rot in tomato fruits:
One of the most important symptoms of the disease is the presence of intussusception
Superficial brown to black sunken spots
It extends even inside the fruits. It may be spots
V-shaped often formed at the scars
Which are related to the fruits through the stem.
Third: soil rot disease.
Soil rot is one of the diseases that affect
The fungi that cause soil rot disease are:
Soil rot symptoms:
Where the symptoms appear in the areas where the fruits touch the surface of the soil and appear in the form of solid, sunken brown spots; with centered rings
The color is light brown and dark brown alternately.
Phoma rot disease in tomato fruits.
Phoma rot is one of the diseases that affect
The fungus that causes Foma rot:
Symptoms of Foma rot on tomato fruits:
Symptoms appear as small sunken spots
at the edges of the scar the connection of the fruit with the stem; and grow up
These spots turn into round spots on the skin
Black with faded edges.
Resistance to the above-mentioned molds.
1- Follow the agricultural methods that preserve the fruits
from contact with the soil surface.
2- Cultivation of tomato varieties that produce fruits
3- Preventive spraying at the beginning of the contract is repeated
When the fruits grow and the beginning of their maturity.
4- The following fungicides are sprayed:
Rovral fungicide, at a rate of 100 gm
Per 100 liters of water
Or Ronilan fungicide at a rate of 150 g per
100 liters of water
Or a fungicide Topsin at a rate of 150 g per
100 liters of water.
Or use a specialized fungicide for molds
Fruits such as Eubarben, at a rate of 250 g per
100 liters of water.