Introduction to Main Almond Varieties and Key Cultivation Techniques

I. Introduction to Excellent New Almond Varieties

Almonds are classified by shell thickness into:

1. Thin-shelled almonds: shell as thin as paper, thickness 0.06-0.10 cm, easily cracked with one hand, kernel yield above 50%.

2. Soft-shelled almonds: shell thickness 0.1l-0.15 cm, kernel yield 40%-50%. The shell structure has spongy tissue and a beautiful appearance; although the shell is thicker, it can be cracked by squeezing with both hands.

3. Standard-shelled almonds: shell thickness 0.26-0.25 cm, kernel yield 32%-40%, can be cracked by pinching with pliers or tapping lightly with a hammer.

4. Hard-shelled almonds: shell thickness above 0.26 cm, kernel yield 17%-30%, can only be cracked with a heavy hammer, and cracking tends to produce large amounts of broken kernels, with poor marketability; used only as rootstock or breeding material.

Nonpareil: the main cultivar grown in California, USA; kernels medium to large, kernel weight 1.0-1.3 g, shell as thin as paper, not tightly closed, splitting open along one suture line, high kernel yield, suitable for kernel production; characterized by early bearing, stable yield, high yield, large and uniform fruit, and good flavor. Kernel yield 60-70%, matures from late August to early September; the tree is large, trunk and branches upright, branches spreading, vigorous growth.

Napras: this cultivar is an excellent pollinizer for the main California cultivars, with early bearing, high yield, large kernels, soft shells, tight closure, and good flavor. Blooming 5 days earlier than Nonpareil, harvest about 2 weeks later.

Mission: one of the cultivars more widely grown in California, USA. Early bearing, high and stable yield, plump fruit, good flavor, good marketability; kernels small and plump, average kernel weight 1.0 g, shell very hard, kernel yield 40%-45%. Blooms late, 6 days later than Nonpareil, easily avoiding late frost damage, harvest about 1 month later than Nonpareil. Combined with the early-blooming Napras, it pollinizes Nonpareil and is a good pollination combination. The tree is large, young trees vigorous, strongly upright, easy to train and prune.

Shaan 86-1: selected by the Fruit Tree Research Institute of Northwest A&F University from a 'Nonpareil' cultivar orchard introduced from the USA. Kernels long oblate, uniform in size, kernel surface smooth, good appearance, kernel color light brown. Shell very thin, extremely easy to remove, kernel yield higher than the 'Nonpareil' cultivar, reaching 70%, nuts mature 20 days earlier; in the Weibei area of Shaanxi, full bloom begins in late March, fruit matures in late July to early August. Early bearing, good productivity.

Shaan 86-3: selected by the Fruit Tree Research Institute of Northwest A&F University from seedlings grown from seeds introduced from Israel; average single kernel weight ].1 g, double-kernel fruit weight 1.7 g, kernels brown, shell thick, kernel yield 49.4%. In the Weibei area, it blooms and fruit matures in mid-August. Early bearing, good productivity, tree growth robust; the drawback is a high rate of double kernels.

Shaan 86-4: selected by the Fruit Tree Research Institute of Northwest A&F University from materials introduced from the USA; kernels oblate, plump, single weight 1.26 g, kernel yield 45.1%. Blooming slightly later than Shaan 86-1, fruit matures in mid-September. Tree upright, growth vigorous, good productivity, strong adaptability; also a good pollinizer for Shaan 86-1.

II. Current Production Status and Development Prospects of Almonds

Almond, also known as Badam apricot, is a precious dried fruit and one of the main woody oil tree species. It belongs to the genus Prunus in the subfamily Prunoideae of the Rosaceae. It originated in the mountains of West Asia and Central Asia. It has now become a worldwide fruit tree, cultivated on all five continents. Almond cultivation in China dates back before the Tang Dynasty; currently it is mainly concentrated in the northwest and southwest regions, especially with more cultivation in Aksu, Kashgar, and Hotan south of the **Tianshan Mountains. Based on analysis of national meteorological data and the indicators for dividing China's fruit tree zones, at latitudes 30-40 degrees N, including the Liaodong Peninsula, Hexi Corridor, and the provinces along the Yellow River basin, trial planting is possible; currently the Xi'an Botanical Garden in Shaanxi Province, many counties in Hebei Province, Beijing, Tai'an in Shandong and other provinces and cities have successful trial planting examples, indicating that almond cultivation in the lower reaches of the Yellow River has great promise and development prospects.

The edible part of almond is the almond kernel (i.e., American almond), which in recent years has become a hot commodity on the international market, with annual trade volume in Europe and America reaching about 150,000 tons, and very good economic returns. The main producing countries are the USA, Italy, Spain and others. These countries mostly develop in conjunction with the ecological environment and ecological benefits; for example: California in the USA has annual rainfall of only 480 mm, and the vast majority of rainfall is concentrated from November to March, with the growing season from May to September being the dry season, yet it has 6,000 almond growers operating 220,000 hectares of almond orchards, with annual almond production of X.7 million tons and direct economic benefits reaching 830 million USD. The state's Blue Diamond Almond Company is responsible for purchasing almonds and then processing them into various high-end products, sold to 92 countries and regions worldwide, with @#@136@#@ amounting to 200 million USD.

Almonds have become California's second largest pillar industry. China has not yet exported Badam apricots, and the domestic market quantity is also small. In supermarkets across the country, mostly imported Badam apricots are sold, at relatively high prices. According to the market situation in the place of origin of China's Badam apricot **, the price per kilogram is 30-35 yuan; calculated at a yield of 100 kilograms, the output value per mu can reach 3,000-3,500 yuan. Therefore, developing almonds can bring considerable economic benefits. The varieties developed should mainly be the Nonpareil, Nonpareil, Mission and the selected Nonpareil 86-1 introduced from the USA.

III. Key Almond Cultivation Techniques

(I) Orchard Establishment

1. Site selection. Almond can withstand low temperatures of -20 to -26 degrees C during dormancy. During the flowering and young fruit stages, it can endure brief low temperatures of 4 degrees C and 0.5 degrees C. Almond has the characteristics of a short dormancy period and early flowering; its flowering period is basically the same as that of apricot, so it is prone to late frost damage. This is a problem requiring special attention when selecting a site; the orchard should be established on the middle slopes or open valleys where late frost is unlikely to occur, and at the same time not on the windward side directly facing the prevailing wind. Almond has strong light requirements, so the site should preferably be chosen on sunny south-facing slopes. It has strong drought tolerance and is not strict about soil, but from the perspective of producing high-quality, high-yield almond products, well-aerated, fertile sandy loam or loam is most suitable.

2. Arranging pollinizer trees. Most almonds are self-unfruitful; even if a few varieties are self-fruitful, the fruit set rate is very low, so pollinizer trees must be arranged when planting. Generally, planting 3-4 cultivars in the same orchard is more appropriate. Almond pollination requires high temperatures; under conditions of high air humidity and temperatures of 9-12 degrees C, the anthers do not dehisce and pollen cannot be released, resulting in poor fertilization and reduced yield.

3. Planting density. Almond likes light and should not be planted too densely; generally 3-4 m x 5-6 m; on dry land and poor hilly land, somewhat denser; in fertile, irrigated areas, somewhat sparser.

(II) Training and Pruning Techniques

Almond begins bearing relatively early. Grafted seedlings generally begin bearing in 2-3 years, with strong growth vigor, high bud-break rate and branching rate, large annual growth, and the characteristic of two growth flushes per year. Latent buds have strong sprouting ability and can sprout shoots once stimulated, and easily form flower buds, bearing early and easily achieving high yield, but after heavy bearing the tree vigor tends to decline. Therefore, after planting, starting from the second year, rational training and pruning must be carried out. The following tree forms are mainly used:

(1) Natural open-center form: trunk height 40-60 cm, with 3-4 main branches borne on the trunk, base angle 40-50 degrees, main branch spacing 20-40 cm, extending outward centrifugally. Each main branch is furnished with 3-4 side branches, and the side branches are furnished with fruiting branch groups.

(2) Double-main-branch "V" shape: trunk height 40-50 cm, on which 2 large main branches are trained left and right; on the main branches, 4-5 side branches are then selected and arranged; this tree form grows robustly, has good light exposure, and high yield.

(3) Modified central leader form: trunk height 50-70 cm, with a central leader; on the central leader, main branches are arranged spirally and alternately every 15-30 cm, base angle 45-50 degrees; on the main branches, several side branches are then selected and arranged; the side branches are furnished with fruiting branch groups.

(III) Pest and Disease Control Techniques

The main pests and diseases of almond are the following:

(1) Dieback (gummosis): strengthen soil, fertilizer and water management to enhance tree vigor; whitewash the trunk to prevent sunscald; remove sources of inoculum in winter; use 4-5 " lime-sulfur mixture to brush the disease scars, 60% sodium arsenite or 1% concentration of Shuangxiaoling and other agents to smear the disease scars.

(2) Powdery mildew: prune out diseased branches and leaves, clean the orchard after autumn. Use thiophanate-methyl, diniconazole, Tuzet, etc., either one or two used alternately, spraying once every 10-15 days, for a total of 2-3 times.

(3) Gummosis: strengthen tree management, prevent pest damage; starting from April, spray a fungicide once every half month, for a total of 3-4 times. Use fenitrothion, methamidophos, isocarbophos, imidacloprid, clofentezine, etc. to spray and kill aphids, red spider mites, and other pests.