Physiological disorders are abnormalities in vegetable economic parts that are abiotic in origin. Physiological disorders are distinguished from deficiencies of a single nutrient and physical chemical or herbicide injury.
1. FRUIT CRACKING
Symptoms
Cracking on the surface of the fruit at the stem end is common occurrence .It is develop mostly in full ripe fruit then in mature green or breaker stage .Sudden water availability cause to rapid fruit expansion lead to fruit cracking.
Causes
1. High temperature and high light intensity
2. Excessively rapid fruit growth cracking.
3. Some cultivars crack more than other because of genotypic differences.
4. boron deficiency (especially calcareous soil)
5. Fruit exposed to sunlight lead to more concentric cracking.
Management:-
1. Soil application Borax @ 15-20 kg/ha.
2. Spraying of borax 0.25% 2-3 times fruiting stage to ripening stage.
3. Maintaining plants at low to medium soil moisture so preferable to grow in
the greenhouse.
2. Blossom end rot (BER)
Symptoms
The water soaked area at the blossom end of the fruit. The area usually develops rapidly eventually resulting in a blackened, dry, sunken leathery spot.BER affects the blossom end of the placenta and adjacent locular contents as well as outer wall .It can most easily be identified by a discoloured ,sunken spot at the blossom end of the fruit.
Causes
BER is not caused by any single factor but a combination of one or more factors intensifying the effect it includes high salinity high MgSO4 ,NH4 and/ or K concentration .Accelerated growth rate, unfavourable moisture relationships.
Management
- Cultural practices, such as us of polyethylene mulch maintain adequate soil moisture, and avoiding varieties that are most susceptible to BER will help reduce the incidence.
- Misting or fogging inside the greenhouse reduces the incidence.
- Foliar spray of CaCl2 solution 0.5%@time of fruit developed was effective control.
- PUFFINESS
Symptoms
Puffiness refers to the existence of open cavities between the outer walls and the locular content in one or more locules and is also known as hollowness or boxiness.
Causes
Non fertilization of ovules Embryo abortion after normal fertilization High temperature and high soil moisture are predisposing factors.
Management
Maintenance of normal temperature
Spraying of Borax or Solubor 10-15 ppm at at the peak flowering time
- SUNSCALD OR SUNBURN
Symptoms
Green fruits exposed to direct sunlight ripen unevently so that yellow patches appear on the side of the tomato fruit when it ripens. Symptoms are most likely to appear at the mature green to breaker stage of development. The lesions are infected by secondry infection of fungus which shows black dark spots making tomatoes units for consumption.
Causes
High fruit pericarp temperature 40.C In bright sunlight surface temperature may be more then10 c highest then the air temperature.
Management
The best protection against sunscald is to be utilize cultivars with enough foliage to cover the fruit and to provide enough water and pest protection to maintain the healthy foliage Crop are planted at higher densities are less susceptible Cultivation of indeterminate /semi determinate varieties without staking
- BLOTCHY RIPENING
Symptoms
This disorder also known as gray wall is recognized as grayish appearance caused by partial collapse of the wall tissue hence the term gray wall
The affected area remain green or yellow are usually found nearly at the stem end of the tomato fruit
Causes K deficiency
Management:-
Use of balanced fertilizer dose (after soil testing) in the crop prevents the occurrence of
blotchy ripening
Adjust planting date to achieve favourable light intensity for good fruit development.
6 CAT FACE
Symptoms
Cat face is a disorder characterized by gross deformity of tomato fruit , which usually renders them unmarketable . The defect is usually located on the blossom end of the fruit cat face is a commonly observed in first harvest.
Causes
In the field air temperature of 17/10c for a weak are sufficient to induce abnormal flower development Low temperature during the sensitive period increase the no. of locules in the fruit .The time of greatest sensitivity for an individual flower is well before anthesis.
Control
Maintenance of sufficient soil moisture balance
Recommended cultural practices should be adopted
6 GOLD FLECK OR GOLD SPECK
Symptoms
Gold speck or flecks are often observed around the calyx and should of mature fruit Particularly in summer season . In green fruit the speak are white and less abundant The specks decrease the attractiveness of the fruit and significantly shorten its self life .Cells containing a granular mass of tiny calcium salt crystals , probably calcium oxalate appears as golden colour .
Causes:-
These speaks are considered to be symptoms of excess calcium in the fruit. Increasing the P level increased also increased calcium uptake rate and increased speckling. As temperature increase during the growing season the incidence of gold spot also increase. Particularly when average temperatures were higher then usual
Control:-
Cultivars resistant to BER tend to be more susceptible to goldspots Increasing the electrical conductivity of the nutrient solution reduced gold speckincidence
Author;
Lalit Kumar Verma , B.S. Asat ,Hemant Kumar , Okesh Chandrakar ,Summit Visvas, Sonu Diwakar, Department of Vegetable Science Pandit Kishori Lal Sukla College of Hortculture &
Research Staton Rajnandgaon, C.C.G. Author for corresponding: [email protected]
