5 Significant Steps to Seed Cleaning
Seed cleaning means removing the low-quality, debris, infected and infested seeds as well as weeds (which are different species seeds) from the sample seeds, as those are foreign elements. After seeds have been registered or harvested, they should be immediately cleaned. Machines are used to clean the extremely moist seeds, and they are dried within the fruits to within 12%-16% moisture content before cleaning them for preventing any kind of damage.
While handling seed cleaning tasks at their factory in Mid North, they are extremely careful to keep them protected least any damages are caused to the sample. In this process, the good seeds are prevented from wastage.
Here are the steps they follow to cater to the task as industrially instructed.
Step 1 – Examining Each Sample for Determining Provided Material’s State
1. Each accession is separately treated.
2. Each packet content is emptied into a large labelled tray so the material can spread out.
3. Whether the seeds are in dry fruits or in fleshy fruits, or are they already cleaned – are intensely checked.
Step 2 – Cleaning the Debris Coated Seeds
1. Whether the seeds are adequately dry for being cleaned is checked. The seeds should be without damage, since the moist seeds with 16% above moisture content, is likely to be damaged at the time of cleaning.
2. The very moist samples are given special treatment – the fruit-filled container is placed in the drying room, or else in a shady place for drying up.
3. The seeds are taken for safe cleaning when the moisture content of the seeds is predicted to be in the 12% – 16% range.
4. The seeds from the fruits are hand cleaned.
5. For some crops, small threshing machines are used, but the professionals are careful to prevent seeds damages. Threshing machines are cleaned between each session so the seeds are not mixed from different accessions. In multi-crop genebanks, mechanical cleaning holds less value.
6. By using graded sieves, debris is removed from the seeds.
7. Debris pieces of similar size and weight like the seeds are hand-removed.
8. Through winnowing, gentle blowing on seeds, and using a seed blower separates the dry lightweight materials from the seeds.
9. The cleaned seeds are returned to the tray for inspection.
Step 3 – Inspecting The Cleaned Seeds For Insect and Fungal Damages
1. The insect or fungi infected seeds are isolated from the sample. The infested seeds are dried in sealed containers with silica gel for preventing insect spread.
2. Drying seeds with low moisture content is a method of preventing further fungi growth and further reproductive insects cycle development. But herein, the insects will not be cleaned.
3. The adult insects are killed by storing at sub-zero temperatures, but fungi will not be killed. Killing larva and eggs are tougher.
4. When the seeds are to be stored above 0°C, then they are placed in a freezer for seven days for killing the insects before going ahead with normal packaging as well as stored procedures.
Step 4 – Examining The Cleaned Seeds For Empty Seeds and Physical Damages
1. The seeds are spread on a flat well lit contrasting colour surface, say an illuminated table.
2. The seeds are carefully examined for physical damages and empty seeds.
3. Any visually shrivelled, damaged or empty seeds are discarded.
4. The seeds are dissected or tested using special X-ray equipment for detecting empty seeds to determine the empty seeds' percentage.
5. Compared to the full ones, the empty seeds are lighter and a seed blower is used for separating them.
Step 5 – Destroying the Wasted Materials
1. Any waste materials are destroyed for preventing disease or insects spread to other materials.
Seed cleaning is done immediately after the seeds have been harvested or registered. The very moist seeds are dried within the fruits to within 12-16% moisture contents before cleaning using a machine, so the seeds are not damaged. Clean seeds are the chief need for farming since the finally grown crops must contain all the nutrients needed by people.