Technical regulations for macadamia nut cultivation in Yunnan Hot cropping Institute

Macadamia nut orchard

(3) soil management

1. Maintenance of planting belt

In the annual dry season, the planting belt should be maintained in combination with weeding to ensure that the 2-meter-wide belt is flat and introverted, so as to cultivate soil and fill in depressions. In the steep slope area where the width of the belt surface is difficult to guarantee, the inner wall of the planting hole should be expanded to make the width of the planting hole more than 1.5 meters, which is not only beneficial to field management, but also prevent the inner wall from collapsing and harming the plant.

2. Weeding

It is required that there are no weeds within 30 cm outside the crown drip line, the planting belt should be weeded frequently, and the weed height between the two weeds should not exceed 10 cm; weeds in the protective belt should be prevented from extending to the planting belt, and sparse tall weeds and small weeds should be cut down at any time. Special care must be taken when using herbicides to avoid spraying or drifting onto macadamia nut trees.

3. Press the green

Starting from the biennial tree, pressing the green and improving the soil was carried out from July to August every year when the plant growth was relatively slow. Dig a green pit with a length of 1 meter, a width of 0.4 meters and a depth of 0.6 meters under the crown dripping line. The pit is carried out in turn in four directions of the plant, in order to see the root, to avoid a large number of root damage, and then fill it with green manure and mature fertilizer, so that the root system of macadamia nut tree can be developed.

4. Rhizosphere cover

Cover the planting belt with weeds from the planting belt or protective belt from November to December every year. It is strictly forbidden for the mulch material to come into contact with the stem (keep a distance of about 15 cm apart to prevent termites from harming the stem of macadamia nut trees). The thickness of the mulch should be up to 15-20 cm.

(4) protecting flowers and fruits

Macadamia nuts have a large number of flowers. according to statistics, a 15-year-old macadamia nut tree produces about 10,000 inflorescences per florescence, each inflorescence is about 300 florets, but at first only 6-35% of flowers set fruit, and finally only 0.3-0.4% of flowers can develop into mature fruit. Macadamia nut young fruit drop seriously, usually 3-8 weeks after anthesis, more than 80% of the initial fruit will fall off on its own. All the producing areas in the world are carrying out extensive research work on the serious problem of macadamia nut drop, looking for countermeasures, and achieved certain results.

According to nutrition determination, before the lowest value of nutrition in the plant, nutrients should be supplemented in advance, and attention should be paid to avoid excessive vegetative growth in the fruiting period, prevent serious nutritional competition between vegetative growth and fruit development, and play an effective role in fruit preservation. Macadamia nuts actually grew the most rapidly before June, and the fruit size was basically fixed, and then there was a process of oil accumulation, so it is more important to strengthen fruit protection measures at the stage of young fruit development. Studies have shown that the use of 1ppm-NAA alone can increase the fruit setting rate of young macadamia nuts by about 35%, but the effect of ring cutting alone is not significant, and the topping measure has no effect. Spraying 0.02% borax and using PP333 and B9 have been reported to increase production. Peak release is used to increase pollination rate in orchards in Hawaii and Australia, which has a good effect on increasing yield. Although there are many researches in this area, a set of perfect methods for field production and application have not been formed so far.

VII. Harvesting, storage and processing

(1) pre-harvest preparation

1. One or two weeks before fruit ripening and falling off (about the first ten days of August), the weeds, litter and other obstacles in the orchard must be removed to level the ground under the canopy.

2. the method of determining the harvest time.

The harvest period of macadamia nuts is longer, from mid-late August to mid-October, and the ripening time is related to variety and climate. The endocarp of the immature fruit is white or light brown. When the fruit is fully ripe, the endocarp is dark brown and the shell is brown and hard.

(2) harvesting and sorting

Macadamia nuts fall off to the ground after ripening and are usually picked up by hand or mechanically. In orchards with uneven or small slopes, macadamia nuts are generally harvested by hand, while larger flat orchards can be picked by machinery.

The harvest interval should be comprehensively considered according to the specific conditions of weather, diseases and insect pests, rodent pests and labor force. Generally, the harvest interval should be harvested every 1-2 weeks. In orchards with serious diseases and insect pests or in wet weather, the harvest interval should be shortened as far as possible to ensure the quality of nuts; in dry season, if there are fewer diseases, pests and rodents, the harvest interval can be appropriately extended.

(3) desquamation and drying

1. Desquamation: manual peeling is often used at present. Fix the fresh fruit and separate the pericarp with wooden hammers and bricks. You should grasp the strength when striking to avoid breaking the shell. This method is only used in small-scale plantations. With the development of macadamia nut industry, a large number of fresh fruits are peeled mechanically. After peeling, move the peel to a place far away from the processing equipment and shed for composting, remove all imperfect shelled fruits and burn them regularly.

2. Screening: peeled fruits with shells must remove impurities, peel fragments, diseases and insect pests, germinated fruits, cracked fruits (except those with small cracks) as soon as possible. In addition, in order to ensure the kernel production rate, the fruits with smaller fruit shape and lower kernel yield must be screened out.

3, dry storage: after peeling nuts, if a large number of hoarding, high temperature and high humidity will lead to fruit mildew, and then make nuts rancidity, resulting in heavy losses, so it must be dried as soon as possible. For small orchards, there are not many nuts, and the simple drying method is to spread the fruit on a steel wire rack in a shaded and well-ventilated place, with a thickness of 10-25 cm, raking once a week, and it takes about 6 weeks to complete the drying. this natural air drying method has a minimum water content of 10%, and when the water content reaches 10%, nearly half of the nuts will be shaken with a "rattling" sound. Artificial drying is generally used in large-scale nut production.

It is worth noting that the shell fruit is strictly forbidden to be exposed to the sun, otherwise the shell fruit will crack, which can easily cause kernel rancidity, resulting in a rapid decline in kernel quality and loss of utilization value.

(4) grading

The fruit with shell is dried at low temperature until the water content is about 1.5%, the kernel and shell are separated by manual or mechanical method, and then the kernel is graded further. The classification generally adopts the water flotation method, and the nuts are separated by water with a density of 1.000 kg / L. the first-class nuts floating on the water surface are the first-class nuts with an oil content of 72%, the nuts are plump, light-colored, the base is smooth, and the roasted kernels are bright brown and crisp with a soft nutty flavor. The nuts sunk in water are then put into salt water with a density of 1.025 kg / L, and the floating kernels are secondary nuts with an oil content of 66-72%. The nuts are slightly contracted and slightly black, the processing quality is unstable, there is a tendency to lose taste, and the texture is soft. The rest are third-grade nuts, which are of little value. Nuts after water should be dried and stored as soon as possible to maintain the flavor of nuts. (contributed by Provincial Hot works Institute)