II LITERATURE REVIEW 2.1 Definition of Seed
II LITERATURE REVIEW
2.1 Definition of Seed
Hatchery is one of the main factors that must be considered, because these factors also determine production. Rice seeds are grain produced in a special way and purpose to be planted into plantations. Seed quality itself will be determined in the process of seed development and maturity, harvesting and threshing, cleaning, drying, seed storage until the growth phase in the nursery (Canisius Agricultural Action, 1990).
Seed is one of the main components that play an important role in increasing the quantity and quality of rice production, therefore the use of high-quality (labeled) superior variety seeds is highly recommended. This is related to the characteristics possessed by superior varieties, among others: high yield, resistance to disease pests, and good taste of rice (fluffier). Source seeds to be used for planting seed production must be one class higher than the class of seeds to be produced. To produce base class seed for example, means the source seed is the seed class type, while to produce base class seed or purple label seed may use base class seed seed or seed type (Susilawati, 2010).
According to AAK 1990, to know the state of good seeds can be seen from:
- The physical state of the seed includes:
- Seed cleanliness of empty, half-empty grain, chunks of straw, gravel and soil, dirt and other objects, and warehouse pests.
- The grain color should match the original, which is bright and clean. It is possible there are different colors, for example green, black. This can happen to seeds that have non-uniform taste, environmental disturbances or different varieties. The occurrence of other colors can also be caused by planting falls in the rainy season.
- Seed purity.
Seed purity is related to genetic or hereditary traits that exist in the seed. But the purity of the seeds can be seen from the grain form.
Seed production is an effort that emphasizes quality, so that all stages of activities in the field of seeding are directed at the aspect of the quality of the results. If the quality of a seed cannot be guaranteed, then this product is not suitable to be marketed as seed. This seed improvement can be done through improved varieties with mutation breeding techniques or assembling existing superior varieties through crossing and biotechnology.
There are three aspects of seed quality namely physical quality, physiological quality, genetic quality, where each of the aspects of quality includes:
- The physical quality of a seed is closely related to the physical condition of the seed which includes: validity or physical deformity of the seed, normal size according to the conditions of description, the integrity of the seed, ie the seed does not break, crack, break or blister on vital parts of the seed: as well as the shape and the color is in accordance with the standard description. b. The physiological quality of a seed is closely related to the physiological condition of the seed which includes: growing ability, speed of growth, state of vigor, uniformity of growth and degree of abnormalities of sprouts.
- The genetic quality of a seed is closely related to the suitability of the description of the characteristics of its uniformity, its high purity (free from a mixture of other varieties or types of plants that deviate and its characteristics according to the class of seeds)
High quality seeds that have the ability to grow more than 90%, with the following conditions:
- Has a high viability or can maintain the continuity of its growth into a good plant or able to germinate to grow normally.
- Having purity means being free from impurities, free from other types of plants, free from other varieties and free from herbal seeds, pests and diseases.
In the context of agronomy, seeds are required to be of high quality because seeds must be able to produce plants that produce maximum with advanced technological means. Often farmers experience significant losses both in terms of cost and valuable time due to the use of low quality seeds. Therefore, although plant growth and production is greatly influenced by climatic conditions and farming methods, it must be kept in mind the importance of selecting seed quality to be used. (Sadjad, 1977)
2.2 Seed Processing Process
2.2.1 Acceptance of GKP (Ganen Dry Grain).
There are several activities carried out at the time of receipt of the GKP, namely document checking, weighing of unhusked rice (GKP) and sampling by the seed quality development (PMB) officer. Inspection of SPHP (Harvest Results Certificate) is carried out with the aim of ensuring the truth of the identity of the prospective seed. Sampling for laboratory testing includes testing the initial moisture content, green grains, and seed or mixture of impurities. The GKP standard determined by PMB is to have a moisture content of 25-27% (Ambiya, 2010).
2.2.2 Drying
In rice seed production techniques, drying the rice grain yields that will be used as seeds is a very important action to produce quality and durable rice seeds. Moisture content of rice harvested from rice fields is generally still quite high, around 20-23%. At this water level, rice is not safe to store because rice seeds can grow back into seeds. In order for rice to be safely stored, rice needs to be dried until it reaches a balanced water level of 12%. Therefore we need a drying process with an artificial heat source that can be regulated to achieve constant heat. Drying the seeds can be done by drying or by using a drying machine. The drying process is carried out to reduce the grain moisture content of the crop so that it reaches the ideal water content of rice seeds by 11 1212% (Nurwardani, 2008).
The drying process is carried out to reduce the grain moisture content of the crop so that it reaches the ideal water content of rice seeds by 11 – 12%. Drying method conducted at PT. Sang Hyang Seri uses a natural drying system and drying with a box dryer.
- Natural drying.
Drying is done by drying in this way it is recommended to use a drying floor made of cement, covered with tarpaulin so that it is not too hot and the grain is not scattered, the drying floor is clean from the rest of the grain. Drying is done until the water content of the seeds reaches 11-12%. Harvested rice must be dried immediately by drying in the sun. Drying is enough for 2-3 days, every day for 3-4 hours. During drying, it needs to be turned over twice so that it is evenly dry.
The purpose of drying is:
- Reducing grain moisture content, at harvest time 23-27% grain moisture content, after drying the water content is 11-12% with that water content, the grain can last a long time in storage.
- Relieve transportation with the weight of grain reduced transport costs can be minimized.
- Avoid pests and diseases.
- Artificial drying.
Dryer with Box Dryer is a room as a drying place to reduce water content. Grain will fall into the dryer due to gravity, then the grain will be blown by hot air produced by the “burner” and “blower” so that there is a decrease in water content. The maximum temperature for seed drying is 42ºC, but the temperature rise is adjusted so that it does not cause the seed to drop (Husas, 2011).
2.2.3 Cleaning (Cleaner) Cleaning grain by using “Air Screen Cleaner”. Grain can be transported via silos or directly from temporary storage after drying using a conveyor to the cleaning tool. Cleaning the seeds is very necessary due to physical differences and properties that can obscure the purity of the seed. Cleaning is done to remove or separate the dry grain from dirt or foreign matter. Materials that can be separated with “Air Seed Cleaner” include plant residues (stems, twigs, leaves), gravel and hollow seeds (Ambiya, 2010).
2.2.4 Storage
Saving seeds is an important part of maintaining seed quality before planting in the field. Seed after going through the stages of processing (seed processing) is usually packaged for further marketed and stored in a warehouse as a backup to anticipate the needs of seeds in the next planting period. As long as the seeds are in the marketing stage or stored in a warehouse, there is a risk of deterioration and can not be separated from the risk of damage due to pest attacks, which will both cause a decrease in quality. Therefore knowledge of the techniques in storing seeds is an important (Fahrudin, 2013).
In the save period there is a difference between strong seeds and weak seeds. Because the save period is a function of time, the difference between strong and weak seeds lies in their ability to eat time. Like other life, seeds also have age (age range) meaning that one day the seeds will also die. Thus it is very important to know how long the seeds can be stored before use. Often the age of seeds is related to the storability of seeds (Kuswanto, 2006).
2.2.5 Seed Quality Testing
Seed testing is carried out in a laboratory to determine both the physical and physiological quality of a type or group of seeds. Testing of the physical quality of seeds includes seed sampling activities, testing of seed purity, seed moisture content. Whereas testing on the physiological quality of seeds includes germination testing activities. The seed test aims to assess and determine the value of each seed sample that needs to be tested in harmony with seed quality factors. However, the number of species or varieties of plants that are diverse, there is a tendency for seeds to be mixed with one another. To ensure the use of seeds that are truly pure, clean and not mixed with other ingredients, one of which is to conduct seed purity testing (Sutopo, 2004).
Pure seeds, which are one component in seed testing, are very important in producing high quality seeds. In germination testing, the tested seed is taken from pure seed lots. Thus the results of testing the purity of seeds and seed germination affect the value of seeds for planting purposes. Purity testing is used to determine the composition of working samples, purity, and identity which will reflect the composition of the seed lot based on the weight of the seed testing component (Sutopo, 2004).
2.2.5 Packaging
According to Yuniarti (2015) packaging seeds for storage used containers that are not impervious to water vapor and gas but sufficient to maintain moisture, such as cotton bags, burlap sacks, paper bags, hollow plastic bags, cardboard boxes and wooden boxes. Mixing material as a storage medium can be used in storage such as moist sawdust, moist coconut coir powder, perlite stones and other materials. Therefore it is important to study the methods and methods of packaging seeds that are good and right.