Physiological disorders in Banana
Qura-Tul-Ain, Kinza Noor, Amir Aziz, (Department of Soil & Environmental Sciences), University College of agriculture, University of Sargodha.
Introduction
The Physiological disorders in different fruit crops results from change in environmental variables including sunlight, aeration, temperature and nutritional imbalance. These disorders result in decrease in fruit quality and quantity. In fruit crops the disorders associated with micronutrient deficiencies are more common than that of macronutrients. Due to less use of organic manures, imbalanced NPK fertilizers and high intensity crop plantation the disorders resulting from nutritional imbalance have become more common. The micronutrient deficiency should take in account prior to the appearance of visual symptoms for achieving maximum yield and good quality fruits.
Physiological disorders in Banana
Physiological disorders of Banana include:
- Choke throat
- Chilling injury
- Kottai vazhai
- Finger drop
- Peel splitting
- Choke throat
Symptoms
This disorder results from low temperature. Due to low temperature yellowing of leaves occurs and under severe conditions the leaves become necrotic. The low temperature at the time of flowering effects the bunch formation. Under normal conditions the bunch emerges from pseudo stem but when temperature is low it do not emerge properly from pseudo stem.
The maturity time of bunch is extended up to 5-6 months than 3.5-4 months. This order is called choke throat because in the inflorescence distal part comes out but the basal part becomes tapered at the throat.
Management
The management of choke throat includes the use of varieties that tolerate low temperature and the use of eucalyptus as a shelter belt check the effect of cold wind.
- Chilling injury
Symptoms
The chilling of banana occurs or results when the pre-or post-harvest temperature falls below 14oC.The symptoms include uneven ripening, watery dark patches on skin, dull yellow to smoky yellow color of the ripening fingers. Brown streaks are also observed on the vascular bundle of the sub epidermal layer. These are resulting from enzymatic oxidation of dihydroxy phenyl alanine.
Management
Avoid to store the fruits at temperature below 13oC (55oF). This disorder can be easily circumvented in Mussa cultivars by storing at a temperature above threshold level.
- Kottai vazhai
Symptoms
This disorder seriously effects the Pooran variety of banana and results in 10-25% reduction in yield. This disorder is characterized by the presence of sharp, tapered and ill filled fruits that have seedy structure in their central core. That makes the fruits inedible. The symptoms of this disorder do not appear at the earlier stages.
Management
It can be managed by spraying 20ppm (1g in 50L of water) 2, 4-D. by applying this the seediness of the fruits can be completely controlled and make the fruits good in quality.
4.Finger drop
Symptoms
It is a disorder in which the pedicle become soft and weak. The individual fruits can be dissociated from the bunch very easily during ripening.
Management
Provide ventilation and temperature of 18oC to the fruits for ripening. Use ethylene (1ml/L) for the ripening of fruits for 24-48hours at on temperature of 14-18oC and 90-95% relative humidity. Use carton for the packing of the fruit bunches.
5.Peel splitting
Symptoms
In this disorder the peel of the fruit is splitted into bisects and consequently the pulp is exposed as the cracks widens.
Management
Provide ventilation and temperature of 18oc to the fruits for ripening. Use ethylene (1ml/L) for the ripening of fruits for 24-48 hours at on temperature of 14-18oC and 90-95% relative humidity. Use carton for the packing of the fruit bunches.
