Seed harvesting methods in medicinal plants
Dry seed harvesting methods are usually done by manual and mechanized methods.
Manual harvest:
Hand picking is used for valuable seeds on a small scale. In most medicinal plants, a large part of the plant with seed clusters is cut by hand with a knife, sickle, etc. The seed is ready do The process of separating the seeds from the branches is done by manual methods, including rolling, banging the material against the wall or the ground, or with a mechanical threshing machine. Usually, the seeds that have been threshed by hand are still mixed with plant remains, and further separation is done by fanning (threshing) and sieving. The shearing blade places the cut organs in rows. The machine features a fabric belt in addition to the shearing blade, and the cut plant organs are carried under the machine and on The harvested crop rows are placed. The harvested crop row can also be returned to the rows or in its original place for drying based on the density of the materials and the amount of them. It will be dried in the field. Usually, the harvest of grains is used for harvesting medicinal plants. It depends on the type of threshing machine and the cleaning parts of the combine. For example, in the case of the cumin medicinal plant, the characteristics of the harvester of this plant are similar to grains, but the problem in harvesting the cumin is that it is not uniform. or in harvesting coriander seeds, due to the weak connection of the seed to the cluster, it should be done before it is fully ripened, and at this time also because the stems are green, the resulting straw and stubble should be moist. It may cause the cylinder to seize.
Separation
When the seeds are harvested, they are not pure and may contain a large amount of non-plant materials (soil, stones, etc.), plant residues, weed seeds, insects, materials with high humidity, and broken and wrinkled seeds be If such seed shipments are stored under such conditions, their storage will not be done well. Seed treatment is the process of removing these substances from the seed and increasing the purity and quality of the seed. Cleaning the seed depends on several factors, including the size, specific weight and shape of the seed compared to the waste and foreign materials that accompany the original seed. During irrigation, seed quality is improved in the following two ways:
1- Separating seeds from other plants, weeds and foreign materials
2- Removal of low quality, rotten, infested, damaged seeds, etc.
Steps
Generally, cleaning the harvested seeds from impurities is done in the following two steps:
1- Preliminary Bojari Operations:
Usually the seeds that are brought to the place of cultivation have a high percentage of green stems, stubble, plant remains and insects. These materials slow down the movement of the seeds on the elevators and reduce the efficiency of the cleaning and watering devices once or twice. In such conditions, the preliminary probability is needed, which increases the efficiency of seeding and the accuracy of separation and prevents the loss of seeds in different stages of seeding. This operation is done with special devices such as a peeling machine and a de-shaving machine. In the conditions where the amount of seed is small, it is possible to air the seed in the open air for initial irrigation.
Bojari is done with the following goals:
1- Facilitates the movement of the seed cargo in the sprinkler machines and as a result minimizes the stoppage during the sprinkler operation.
2- During the initial irrigation operation, the green material with high humidity is removed, and as a result, the time and cost of artificial drying of the seed cargo is reduced.
3- Preliminary irrigation increases the efficiency of the irrigation machines and as a result, seed losses are reduced.
2- Bojari's main operation:
If the seeds differ in terms of some physical properties, they can be separated mechanically and through some electrical or mechanical processes. Therefore, using the difference in physical properties, the Bojari machine separates plant seeds from weed seeds and foreign materials, and separates foreign materials such as stones and makes stubble. The roots and stems of plants are simple, but separating the seeds of other plants and weeds is very difficult, and this problem is intensified when the external characteristics and size of these seeds are similar. Size, length, width, thickness, shape, weight, texture, color, etc. are among the physical characteristics. which are used in the separation of seeds. In the simplest form of bujari, the seed is first sieved and then the small particles are separated by blowing.
The most important bojar -seeded cars
1- Air Bojari Cars:
These machines combine air and sieve ( sieves) are made, the principle of operation of these machines is that the air (suction) system is based on the weight of grain and particles separates, while sieves separate based on size (width and thickness).
2- Greater separators:
These machines separate seeds from each other based on weight or density. It separates unwanted seeds and foreign materials that are very similar to the plant in question in terms of size, shape and characteristics of the shell and cannot be separated from the original seed in any other way. These machines are used after initial payment.
3- Roller or sauce machines:
The device is able to separate the misshapen, broken, cracked, unripe seeds, those with fine texture and foreign materials inside the smooth seeds from the seeds of medicinal plants.
4- Magnetic Separate:
These machines act like roller separators by using differences in seed levels and separate the seeds from each other. In this method, the seeds are combined with a small amount of water containing fine iron particles. The iron filings absorb the uneven surface of the badly shaped seeds and the seeds are attracted and separated by the magnet.
5) Spiral separators:
This device is used to separate non-spherical or irregularly shaped seeds from round seed types.
6) Color separators:
These separators only separate impurities or seeds that are slightly different in color from quality seeds. Therefore, this machine should be used only after the seeds have been cleaned by other machines.
7. Chlorophyll Florents:
This machine works similar to color separators and separates based on the amount of chlorophyll in the seed. In general, the amount of chlorophyll is correlated with the maturity of the seed and as the seeds reach the final stage of their maturity. The amount of chlorophyll is less.
8) Electrostatic machines:
Electrostatic separators separate the seeds from each other according to their differences in the natural electrical characteristics of the seeds themselves or the characteristics induced to them.
_9 Shake Separate:
These separators have a covered vibrating plate on which the seeds are poured. The separation of seeds in this device depends on the reaction of the seeds to the vibration and the type of plate coating.
Seed drying
The obtained raw seed often has a lot of moisture. The amount of water in the seed is expressed as the amount of moisture. The amount of seed moisture is one of the factors affecting the life span, viability of seeds, storability and trade of seeds. In the storage and transportation of seeds, when the amount of moisture is high, the possibility of the growth of storage fungi increases, which can decrease the quality of the seeds. High humidity is often seen in plants whose seeds are hard and fall before reaching the ground. In such conditions, there are seeds that can be stored if their water content is below the determined limit. The heating of the immature product is caused by the respiration of the seed or the respiration of bacteria and fungi that multiply on the moist seed product. In this case, the vitality of the seed and also the breakdown of materials by micro-organisms are lost to a great extent and harm the power of the plant. Therefore, the danger of heating the seeds should be avoided in any case. During seed drying, excess moisture is taken from the seed. This process is done in the field by means of natural factors (such as wind and sunlight) or by using thermal dryers with continuous air flow, rotary dryers, strip dryers, etc.
