Almond Cultivation: Climate Requirements, Soil Needs, and Variety Selection

Almond, one of the oldest fruit species in Anatolia, is not given the necessary importance in our country and is generally grown as a border tree along field edges. There are very few almond orchards (orchards established only with almonds) in our country, and maintenance work is generally not carried out on existing trees.

Due to the insufficient almond demand met domestically, almonds are imported. In recent times, almond production areas have been rapidly increasing worldwide. The leading countries in almond production are the United States, Spain, Iran, and Morocco.

Botanical Characteristics

Almonds are divided pomologically into two types:

1. Bitter Almonds
2. Sweet Almonds

Bitter Almonds: They are bitter as they contain cyanidric acid and can be poisonous when consumed in excess. They are used to extract almond oil.

Sweet Almonds: They are divided into four groups: soft-shelled, hard-shelled, kernel, and stone almonds. The thickness of the shell decreases as it thickens.

Climate Requirements

Almond is a plant of warm temperate climates. It thrives in the Mediterranean climate, which has mild and rainy winters and hot and dry summers. If winter temperatures drop below -25 ºC, the plant is damaged, and if it drops below -18 ºC, the buds are harmed. Almonds require chilling below -7.2 ºC for about 300–500 hours.

Late spring frosts are crucial in almond cultivation, as almonds bloom before many fruit trees, making their flowers vulnerable to frost. Therefore, almond orchards should not be established in areas where spring frosts are common. Additionally, as a precaution, orchards should be established on sloping terrain to allow cold air to flow when frost occurs. Almonds require high temperatures to ripen their fruits.

Soil

Almonds prefer sandy, moderately loamy, and lime-rich well-draining soils. Especially in arid regions, soils with light clay at the lower levels and light sandy soils in the upper layers are suitable for almonds.

Pollination Biology

Most commercial almond varieties are self-sterile, so it is necessary to use pollinator varieties. Insufficient pollination and fertilization are the main reasons for low fruit setting in almonds. Therefore, orchards should be established with at least 2–3 almond varieties that have overlapping flowering times, mutual compatibility of pollen grains, and attention to the placement of varieties within the orchard.

Production Technique

Closed orchards should be established in two ways:

1. Direct Seeding in the Field: Applied mainly in places with limited irrigation opportunities, involving grafting on site.
2. Planting with Grafted Seedlings: Grafted seedlings should be used in areas with suitable soil and irrigation conditions.

For seedling production, the “dormant bud grafting” method is used.

Rootstocks

As rootstocks for almonds, almond, peach, almond x peach hybrids, and plum can be used.

1. Almond Rootstock: Suitable for lime-rich, dry, and non-irrigated lands. It has good compatibility with varieties. Grafted trees are long-lived and vigorous, but the root rot method is sensitive to root cancer and Armillaria.
2. Peach Rootstock: Suitable for irrigated lands with water retention and nematode problems. Peach rootstocks are not well-compatible with almonds, and trees start to decline in yield from the age of 10–12. Therefore, almond x peach hybrids are used.
3. Almond x Peach or Peach x Almond Hybrids: Generally adaptable to different soil conditions. GF 557 and GF 677 are suitable for vegetative propagation.
4. Plum Rootstocks: Used in soils with water retention and root rot problems. Plum rootstocks generally do not match well with almonds, resulting in low yield and quality.

Protection and Transportation of Seedlings until Planting

Almonds are very sensitive to relocation. Care should be taken during uprooting to prevent roots from staying in the soil or getting damaged. After uprooting, the roots should be kept moist, and they should not be exposed to wind.

Seedlings should be protected from wind in a sheltered place until planting to prevent damage. If planting is not possible, trenching should be done in cold areas, or seedlings should be kept in cold storage.

Some Local Varieties

1. 101/13: Spreading, densely branched, late bloomer, 27% kernel yield, stone almond group.
2. 101-23: Upright, densely branched, late bloomer, 35% kernel yield, stone almond group.
3. 104-1: Upright, spreading, densely branched, late bloomer, 45% kernel yield, hard-shelled almond group.
4. 300-1: Spreading, moderately branched, midseason bloomer, 43% kernel yield, dual purpose almond.
5. 120-1: Upright, spreading, vigorous, sparse branches, midseason bloomer, 30% kernel yield, hard-shelled almond.

Some Foreign Varieties

1. Nonpareil: Spreading, vigorous, moderately branched, midseason bloomer, 60–70% kernel yield, soft-shelled almond.
2. Texas: Upright, few branches, late bloomer, 45–50% kernel yield, hard-shelled almond.
3. Ne Plus Ultra: Moderate vigor, midseason bloomer, 50–60% kernel yield, soft-shelled almond.
4. A.I.: Spreading, highly branched, late bloomer, 40–45% kernel yield, soft-shelled almond.
5. Avola: Spreading, early bloomer, 22% kernel yield, soft-shelled almond.
6. Cristomorto: Upright and spreading, very late bloomer, 28% kernel yield, soft-shelled almond.
7. Ferragnes: Sparse branches, late bloomer, 39% kernel yield, hard-shelled almond.
8. Ferraduel: Very spreading, very late bloomer, 28% kernel yield, hard-shelled almond.
9. Marcona: Spreading, midseason bloomer, 25–28% kernel yield, hard-shelled almond.
10. Tuono: Spreading, very late bloomer, 40% kernel yield, very large kernel, self-pollinating.

Annual Maintenance Tasks in Almond Orchards

A. Soil Cultivation: Deep soil cultivation is done in the fall to retain winter rains in the soil and incorporate applied fertilizers into the soil. Spring and summer tillage should be done superficially to kill weeds and reduce soil water loss.

B. Fertilization: Soil analysis must be done before fertilization, and fertilization should be planned according to the results. Chemical fertilizers should be applied in a way that does not allow them to come into contact with the tree’s canopy. Farmyard manure must be used.

C. Irrigation: Irrigations starting from April-May will accelerate shoot development, promote healthy and sufficient flower bud formation, and ensure the fullness of fruits.

D. Pruning: The modified leader training system is generally applied for shaping pruning in almonds. Pruning should be done regularly every year for product pruning purposes. However, severe pruning should be avoided. In productive trees, annual cuts to 1 to 3-year-old branches, along with irrigation and other maintenance measures, promote growth and increased yield.

E. Harvesting: Harvest begins when the outer green shell of the fruit cracks, and it partially changes color. Harvesting should not start until the green shell of the fruits in the inner parts of the tree opens. Suitable harvesting should be done by shaking the branches, and tools that can damage the tree, such as poles, should never be used.

Almonds that do not separate from the outer shell after harvest should be hulled as soon as possible. Usually, this hulling process is done manually.