Pomegranates bloom all year long in a tropical climate. There are three separate flowering seasons in subtropical central and western India, however, yield and quality are not as good as all crop harvests. It is critical to identify crop flowering and fruiting habits, as well as the manner in which bahar will produce a productive crop when all the elements associated with that bahar are taken into account.
Objectives of crop regulation
The main purpose of crop regulation is to force the tree to rest and produce prolific blossoms and fruits during any one or two flushes. Besides, some objectives are as under:
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To obtain a suitable crop at a desired season
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To regulate a uniform and good quality of the fruits
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To maximize the production as well as profit to the grower.
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To reduce the cost of cultivation because uninterrupted continuous blossom will produce light crops over the entire year and require a high cost for the monitoring and marketing.
Ambebahar (spring season flowering), mrigbahar (June-July flowering), and hastabahar (August-September flowering) are the three main flowering and fruiting seasons of the pomegranate (October-November flowering). Plants may continue to bear blooms and small crops irregularly at different times of the year under such conditions, which may not be commercially viable. Only one harvest each year is desirable for commercial production. Bahar selection is influenced by location as well as certain current production constraints such as irrigation water availability, fruit quality, market prices, and disease and pest infestations. Water supply is a major challenge for pomegranate growers in arid and semi-arid regions throughout the summer season. They constantly avoid picking ambebahar crops and limit harvesting to the winter months. Some farmers prefer Hastabahar because it has less water.
Principles of flower regulation
Crop regulation’s main premise is to alter the pomegranate plant’s natural flowering to a desired season to maximize fruit yield, quality, and profitability. It is beneficial for the most efficient and long-term use of resources, as well as high production of high-quality fruits. Environmental and genetic factors influence the onset of flowering and the regulation of flowering. Pomegranates bloom intermittently in the arid and semi-arid regions from February to October. To avoid this, pomegranate crop regulation is done by a set of mechanisms at certain periods. All commercially grown varieties in the country are extremely susceptible to diseases and pests, especially Bacterial Leaf Blight, Scorching, Nematode, Termite, and Mite, among others. Therefore, availability of irrigation water, climate, pest and disease infestation, and market demand are major issues for flower regulation in pomegranates. Indian varieties mostly produce flowers throughout the year.
Methods of crop regulation in pomegranate
Many factors influence flowering, including irrigation withholding, defoliants, plant growth hormones, nutrient status, and canopy management (training and pruning), among others. Irrigation is stopped for one to two months before the required bahar in the pomegranate is obtained. After that, minor pruning and then foliar spraying of ethrels are defoliant to get rid of the leaves. The tree around the topsoil was dug up to a depth of 30 cm, equal to the leaf canopy. Manure and fertilizers are spread on the soil, which is subsequently leveled. Following the administration of the necessary dose of manure and fertilizers, light watering is performed. The better flowering, better floral sex ratio, higher fruit setting and eventually higher quality yields may result in fruits being taken in a year by these treatments. There must be good growth and development of pomegranate plants up to the first two years. Bahar treatment must begin from the third year onwards for better quality fruit production. Bahar treatment is done in the following ways in pomegranate.
Flowering due to the stress of water scarcity
The main principle of holding with irrigation is to provide rest to the plant. It results in an increase in the number of flowers and accumulation of large quantities of food in the growing season. In light sandy soils, irrigation is withheld for one month, while in loamy soils, it is withheld for one and a half months. When pomegranate plants have the desired leaf fall, this is the optimal condition for crop regulation (50 to 70%). Plants generate ostein, proline, and arginine protein in response to water stress. Proteogenic amino acids, such as prolines, accumulate as a beneficial solute in plants under stress and non-stress conditions, providing a high capacity for stress tolerance. These amino acids also aid in stimulation of flowering plants under water stress conditions. As a result, plants produce more flowers, have a better sex ratio, and produce more fruits.
Use of chemicals for flowering
In recent times, the foliar spray of ethrel (1-2 ml per liter) is widely practiced for crop regulation in pomegranate crops. Ehtrel stimulates the hormone enzymes ie cellulase and polygalacteronase for cell smelting. This condition is considered good for achieving more flowering, better sex ratio and higher yield.
Flower regulation by cultural practices
Higher flowering% and quality fruit pomegranates in fruit production are best achieved through canopy management strategies such as training, trimming, and fertilizer control (carbon nitrogen ratio). Pomegranate trees can be trained to be multi-stemmed or single-stemmed. To avoid stem borer damage, 3 to 4 stems are usually kept, while the remaining shoots are cut, giving the tree a bushy appearance. Pomegranate plants are often trained in using an open center technique in their early years. After withholding watering for 15 to 20 days before starting a new bahar, light pruning is done. To prevent fungal infestation, 10% Bordeaux paste is applied to trimmed plant portions.
Mrigbahar is regulated in dry areas to ensure high-quality crop production. For regulating crop in dry areas, withholding of irrigation is done in April-May. Subsequently light pruning and spraying followed the mixer of 1000-2000 ppm ethrel and 0.5 per cent diammonium phosphate. Flowering takes place in June – July. It gives good quality fruits in November- December. For getting good quality yields 60 to 80 fruits should be retained on a single plant.
Insect-pests and diseases management
Crop regulation is an effective method of controlling insect pests and diseases. Depending on the dose of defoliant used for crop management, leaf falls range from 50 to 100 percent. Insect pests and diseases should be eradicated to some part by collecting and burning fallen leaves. As a result, it will prevent aids in insect pests and diseases, as well as reduce insecticide use.
Author
Lokesh Kumar, Dr. RL Bhardwaj
Department of Horticulture, Agriculture University, Jodhpur