Physiological Disorders in Tomato – Naveen Chandra
Physiological Disorders Blog | UCBMSH – Agriculture Degree courses college in Dehradun ( Doon ) , Uttarakhand , India .
- Blossom end rot: it is more serious, ground discoloration starts. In blossom end of the fruit. Black spot develops to encompass ½ to 2/3 rd portion of the fruit. Later the tissues shrink and skin becomes dark grey to black. It may lead to secondary infection by fungus and unfit for consumption.
Causes: use of Ammonium sulphate, imbalance of Mg & K; deficiency of calcium
Remedies: cultural practices that concern soil moisture and maintain uniform moisture supply. Transplanting in early April instead of early June. Foliar spray of 0.5% CaCl2. Apply Nitrogen in the form of Urea.
- Fruit cracking: occurs for middle of the May. Reduced transpiration has increased cell turgidity and contributed to tomato fruit cracking. Reduced transpiration occurs even in summer when fruit are grown in green house. Cracking also occurs in rainy season when rains fall in long dry spell. Presence of water on the surface of fruit is more conducive in cracking than high soil moisture. Boron deficiency in the soil also causes fruit cracking. They are two types of cracking.
- radial cracking: occurs mostly at ripe stage.
- Concentric cracking: it is common in mature green stage.
Remedies: use of resistant cultivars like Sioux, Punjab chuhara. Picking of the fruit before the full ripe stage. Soil application of Borax @ 10 – 15 kg per ha. Regulation of soil moisture. Misting (spray of cool water).
- Puffiness: commonly known as hallowness. Tomato puffs, puffy tomatoes, puffs and pockets. As the fruit reaches about 2/3rd normal site outer wall continues to develop normally but remaining internal tissue growth is retarded. Fruit become lighter in weight and partially filled. Very high or vary low temperature and low soil moisture conditions will lead to puffiness.
- Cat facing: a large scar is formed at the blossom end portion of the fruit. Such fruits have ridges and furrows and blotches at blossom end.
Reasons: low temperature, faulty pollination, application of nitrogen during transition from vegetative to reproductive phase.
Remedies: balanced fertilizer application; regulation of temperature.
- Sunscald: when fruits and leaves are exposed to the sun, there is appearance of yellow, white patches on green and ripen fruits. These patches may have secondary infection of fungus and start rotting varieties with sparse foliage will suffer more sunscald especially in the month of May and June.
Remedies: prefer the varieties having more foliage and follow appropriate cultural practices.
- Flower and fruit drop: higher incidence of flower and fruit drop is resulted because of fluctuations in temperature poor water management and soil moisture.
Remedies: good package of practices should be followed. Moisture stress should be avoided. Spraying of planofix or NAA @ 1 ml in 4.5 lt of water. Control of fluctuations in temperature.
- Blotchy ripening: greenish yellow; maintain balance between Nitrogen and Potassic fertilizers.
- Bronzing or internal browning: also known as grey wall. Characterized by death of tissues within the fruits associated by vascular browning variety EL 235673 is found resistant to this disorder.
- Green back: stem and portion of the fruit turns green. At high temperature ripening is inhibited and green band is expected. Reduce temperature by artificial means.