Pomegranate Cultivation: A Comprehensive Guide for Successful and Sustainable Practices

Pomegranates can withstand temperatures as low as -10°C in temperate climate zones, and their late flowering makes them resilient against spring frosts. However, late-maturing varieties may be affected by early autumn frosts.

In pomegranate cultivation, an average annual rainfall of 500 mm is sufficient, preferably falling during spring. This makes it a suitable fruit for our region in terms of climate. Summer rains negatively impact fruit quality, and rains near ripening can cause fruit skin cracking. Therefore, irrigation should be stopped during this period. Dry weather conditions during fruit formation enhance the quality of the fruit, increasing its market value. Pomegranate is a sun-loving plant, and attention should be paid to proper lighting conditions in orchard establishments.

Soil Requirements

Pomegranates are not very selective about soil types. They can be cultivated in various soil types such as siliceous, gravelly, sandy, calcareous, clayey, and heavy clayey soils. They can grow in alkaline and acidic soils and show moderate resistance to salinity. Unlike some fruits, pomegranates tolerate excessive soil moisture. Optimal growth is observed in deep, permeable, moist, and cool soils in response to dry and hot air conditions, especially during fruit formation.

CULTIVATION TECHNIQUE

Variety Selection

In pomegranate cultivation, variety selection is crucial. Varieties should be adapted to the region’s climate, resistant to diseases, productive, with fruits appealing to consumers’ taste and visual preferences, and durable for transportation. The decision to cultivate table or industrial varieties should be based on commercial goals. Additionally, selected varieties should meet the needs in terms of fruit size, skin color and thickness, seed color, soft-seededness, and juiciness.

Popular pomegranate varieties in Turkey are those with a slightly tart or sweet taste, seedless, and with large fruits. For export to Europe, varieties with red skin and slightly tart taste are preferred, while sweet varieties are chosen for export to Arab countries. Trials conducted by GAP/BKİB (Southeastern Anatolia Project / General Directorate of Agricultural Research and Policy) at the Şanlıurfa Koruklu Agricultural Research Station determined the most efficient varieties for the region as 0l N 03 Fellahyemez II (51.5 kg/tree), 2/3 Japanese pomegranate (40.4 kg/tree), 33 N 26 Seedless VI (37.0 kg/tree), 26/3 Seedless (36.7 kg/tree), 33 N 24 Bey pomegranate (30 kg/tree), Suruç (29.8 kg/tree), and 07 N 08 Hicaz pomegranate (28.1 kg/tree).

Studies by the Şanlıurfa Rural Services Research Institute also identified promising selections for the region, such as 07 N 08 (Hicaz pomegranate, Antalya), 07 N 14 (Mayhoş IV, Alanya), 33 N 16 (Silifke grafting, Silifke), and 33 N 24. Native varieties grown in the region, such as Nizip pomegranate, are large, sweet, and red, serving as export varieties.

Orchard Establishment

After determining the orchard location based on soil suitability, leveling should be performed. Soil preparation primarily involves breaking the plow base in the summer months. Deep plowing is then carried out in the fall, and planting holes of 40-60 cm depth and diameter are opened. The holes are filled with a mixture of topsoil and well-rotted farm manure, and weeds are removed. The soil is prepared for planting. Planting distances for pomegranates vary between 2 m and 6 m, with the most common spacing in closed orchards being 2.5 x 4 or 3 x 4 m. Rows should generally be oriented north-south to improve ventilation and sunlight exposure. Pomegranate orchards can be established with either steel or rooted seedlings. However, direct planting of steel into the orchard can lead to various maintenance difficulties and yield losses. It is more appropriate to root pomegranate cuttings in a nursery plot, take care of them there for a year, and then transplant them into the orchard after pruning.

Pomegranate saplings can be planted from autumn leaf fall through winter and early spring. In regions with mild winters, autumn planting is more beneficial. During planting, if there are any remaining nails on the cutting part of the sapling, they should be removed. Weak shoots should be pruned, and excessively long roots should be shortened. The shoot’s top is cut at 50-60 cm. If the shoot has not grown this much or is weak, it should be cut 2-3 eyes above the ground immediately after planting to promote the development of strong shoots for the next year. Then, a mixture of soil and manure previously filled in the hole is taken enough to cover the entire cutting part of the sapling. The sapling is placed here, and the same soil-manure mixture is filled again. The soil around the sapling is firmly pressed with the foot. A small basin is created around it to provide water, and in windy areas, two stakes are placed crosswise and tied to the sapling. A good pomegranate sapling should have a strong root system.

Finally, at least twenty liters of water should be given to the prepared basins, even if the soil is wet and it is raining. 3.3 Fertilization

Research on pomegranate fertilization has shown that organic fertilizers significantly impact growth, yield, and quality. Farmyard manure for pomegranates should be well-rotted and applied to cover the entire orchard at a rate of 2-3 tons per hectare during autumn-winter months. Green manuring with crops such as peas and beans is also beneficial for pomegranates. These plants are sown throughout the orchard, and the soil is tilled when they flower to incorporate them into the soil. This practice enriches the soil with nitrogen.

Nitrogen is crucial for pomegranates, and the use of nitrogen fertilizers is necessary for shoot development and fruit growth. In the first years, 50-100 grams of pure nitrogen (ammonium sulfate) per tree (250-500 grams) provide beneficial results. After reaching full productivity, this amount should be increased to 200-300 grams per tree (ammonium sulfate) (1-1.5 kg). Nitrogen fertilizers are applied twice, in early spring and summer, with 2/3 of the specified amount in March and 1/3 in June-July. After fertilization, the tree should be irrigated immediately or, if irrigation is not possible, the soil should be mixed with a hoe.

Phosphorus fertilizers are related to flowering, fruit set, and root development in pomegranates. The phosphorus requirement for pomegranates at full productivity is determined to be approximately 100-200 grams of pure phosphorus (triple superphosphate) per tree (250-500 grams). Phosphorus fertilizers are applied in winter by opening 4-6 holes around the tree, 20-30 cm deep, in areas where the branches reach.

In the application of both organic and commercial fertilizers, the physical and chemical structure of the soil, the condition of the tree, and soil and leaf analysis should be carefully observed, and fertilizer application should be done after considering these factors.

Irrigation

Pomegranates generally require moist and cool soil conditions. Therefore, irrigation is necessary during periods when rainfall is insufficient. It is advisable to irrigate less but frequently. It is essential to maintain soil moisture continuously from the emergence of buds in February-March to the formation of fruit in September-October.

Particularly during three periods, namely shoot emergence, flower bud observation, and fruit development, sufficient soil moisture must be ensured. Depending on the soil structure of the orchard, a specific irrigation interval (7-10 days) should be determined, and irrigation should be done at these intervals. However, the frequency and amount of irrigation can be increased during the summer months.

Irrigation should be stopped 10-15 days before the final ripening period of the fruits, or else significant problems, such as skin cracking, may occur. Pomegranate orchards are generally irrigated using the basin method. If possible, modern irrigation systems such as drip irrigation, subsurface irrigation, and leakage irrigation should be applied. Although the initial investment costs of these systems are high, they provide significant benefits such as long-term labor savings and economic water use.

Pomegranate Tree Care

Soil Cultivation

In young pomegranate orchards, deep tillage tools are used for two-way plowing in the first few years. In subsequent years, narrow orchard tractors, disc harrows, rototillers, and harrows that work the soil shallowly can be used. If necessary, tree bases can be hoed with hand tools, and herbicides can be used for weed control if desired.

Pruning

Formative pruning is done in the first 2-3 years before trees come into production. After planting, 3-4 strong shoots emerging from the base are selected as the main trunk, and their tops are cut at 50-60 cm to achieve low branching. In the first and second branches originating from the main trunk, topping is done in the 2nd-3rd years to complete crown formation.

Productive Pruning: Pomegranates generally start bearing fruit from the 2nd and 3rd years. After pomegranates bear fruit, no topping should be done on shoots that will bear fruit. During this period, continuous cleaning of shoots emerging outside of the selected 3-4 trunks is essential. Additionally, if there are excessive branches in the crown, thinning should be done to ensure sunlight exposure and ventilation. This thinning process should prioritize the removal of weak, dried, and diseased branches.

Developmental Pruning: Pomegranates, depending on various conditions, typically experience a decrease in productivity around 20-30 years old. However, with new shoots emerging from the root collar, pomegranates can maintain productivity for over 100 years. In this case, old trunks are pruned from the base to encourage the formation of new shoots. New shoots are then used to create new trunks following the same methods. If desired, the rejuvenation process can be carried out gradually by cutting 1-2 trunks from each tree every year. This way, continuous harvesting can be maintained from the orchard without interruption.

Diseases, Pests, and Control

The most significant disease affecting pomegranates is caused by certain fungi leading to fruit rot. Cultural practices can largely prevent these diseases. Fungicide applications made close to maturity can prevent long-term rotting of stored fruits. The most significant pests in pomegranates are rodents, especially damaging sweet pomegranates and those near maturity. Other common pests include aphids, pomegranate whiteflies, powdery mildew, scale insects, red spiders, Mediterranean fruit flies, pomegranate worm, and underground pests. Effective control measures are essential for managing pests in pomegranates.

Harvest, Packaging, and Storage

Harvest

Pomegranate harvest generally begins in late August and continues until mid-November, varying depending on varieties and regions. Due to the long flowering period of pomegranates, ripening occurs at different times, requiring harvesting to be carried out in 2-3 stages. Harvesting should be completed before early autumn frosts and rains, leaving 1-2 mm long stems on the fruits when cutting them with scissors. Particularly during harvest, preventing fruits from falling to the ground and protecting them from impacts enhances quality and prevents fruit rot. Moreover, no more than two rows of fruits should be stacked in crates.

Packaging

The packaging of pomegranates is crucial for marketing. The selection, sizing, and packaging of fruits are especially important for export. Manual selection and sizing of fruits are more suitable, and care should be taken not to pack fruits that touch each other.

Storage

Due to the special structure of pomegranate skin, pomegranates can be stored for 4-6 months under various conditions. Modern cold storage facilities are the most secure and least loss-prone for pomegranate storage, despite additional expenses. These storage facilities allow the adjustment of temperature and relative humidity, and fruits can be stored at 1-2°C with 85-90% relative humidity. Pomegranates are well-suited for storage, and due to the significant increase in prices during winter, they represent a profitable and sound investment.

In conclusion, pomegranate cultivation involves various stages, from orchard establishment to maintenance, fertilization, irrigation, pest control, and finally, harvesting, packaging, and storage. Proper practices at each stage contribute to successful and sustainable pomegranate cultivation.