4.0: Seed Production
4.0 Soybean Seed Production and Certification
Only released and approved varieties that have gone through the Seed Certification procedure will be done by Seed Services Unit (SSU). The seed crop has to be registered, inspected in the field and tested in the laboratory.
4.1 Classes of Seed
In seed production there are three classes of seed that are used. Breeders’ seed: This is a generation which is handled by breeders and usually is in small quantities. The breeder tries to ensure that the genetic make up is maintained in order to have the purity at the recommended standard. Basic seed is produced from breeder seed with more quantities and is given to farmers with appreciable experience so that the seed is not wasted because this is meant for further production. Certified seeds which is marketed for production of grain is produced from basic seed.
4.2 Registration of Seed Producers
Registration can be done in all the seed services offices in the research centers as follows: Bvumbwe in the Southern region, Chitedze and Lifuwu in the Central region and Lunyangwa in the North upon payment of a prescribed fee. The importance of registration is to record all necessary details about farmer including location of the field. Registration is only done once.
4.3 Site Selection
Characteristics of a good site: Soybean seed can only be produced on a piece of land where previously no soybean was grown. This is important because it takes care of disease incidents and issues of admixtures. For basic seed it requires 2 years before any soybean seed can be planted on that land and for certified seed it requires one year before any soybean seed can be planted on that land. If the land was planted to tobacco then soybean seed cannot be planted on that piece of land for two years.
4.4 Isolation Distance
Soybean is a self-pollinator. However isolation distance is applied because of the possible physical admixtures from one field to the other. For basic seed it requires 10m while certified seed requires 5m of isolation distance.
4.5 Source of Seed
Only the approved source by Seed Services Unit will be accepted for registration. This means that the unit is aware of the class of seed, when and where it was grown through previous registrations and field inspections.
4.6 Crop and Field Management
Land preparation, Planting (seed rate and plant spacing), inoculant application, and weeding are the same as for production of grain. But for fertilizer it is recommended that the farmer applies 50kg of 23:21:0 + 4S per ha. Control of Common Pests and Diseases is very crucial.
4.7 Rogueing
General good crop management is recommended to allow the seed crop to show all its growth characteristics. This helps in identifying off-types at vegetative, flowering and harvesting stages. The seed crop which is true to type should display same hair colours, branching, same flowers and leaves throughout the vegetative growth up to the time of harvest. A farmer is advised to remove all off types and diseased plants (rogueing). The seed field should be free from weeds all the time. Disease and pest control is important in order to achieve quality seed (see figure 15)
4.8 Post-Harvest Handling: Harvesting, Processing,
Grading & Packaging
After harvesting the Seed Services Unit expects the farmer to process the seed according to the required standards, so the sampling and testing results of that seed do not require the farmer to rehandle or regrade the seed. Soybeans require harvesting as soon as the crop is dry preferably around morning hours when the temperatures are low to avoid splitting. Slow drying helps the soybean seed to complete its drying process and maintain the viability. Use a tiny stick to process the crop because this will reduce any breakages that can affect the physical purity and germination test. Ensure that all the broken, weevilled, shriveled, rotten, termite damaged and other variety seed are removed during grading. Pack in good clean sacks ready for sampling and label.
Transportation of Harvested Seed: When transporting seed from the farm or any location to the processing facility a farmer is supposed to seek permission on the movement of the seed. This is important so that the seed can be traced back and no other variety seed is added in the process.
4.9 Labelling
All the bags should be labeled for identity as follows: Crop, variety, lot number, quantity, name and address of the producer. This helps to identify the seed lot among so many others from different farmers.
4.10 Seed Sampling and Testing
A representative sample of the seed lot is collected by the samplers for for various quality tests like physical purity, defects, moisture content and germination. The recommended sample size is submitted to the seed testing laboratory for the analysis. A certificate or analysis of results is issued based on the findings.
4.11 Storage of Seed
In seed production the demand for seed comes later in the season so the farmer is supposed to keep the seed in well ventilated, cool and dry conditions. The containers should be well labelled. Pallets are recommended for stacking but the farmer can also use ordinary poles so that the seed is kept raised from the ground. Seed is a living material. Therefore any remaining seed after sales should be re-sampled for re-testing
4.11 Marketing of Seed
Marketing of seed depends on the class of seed but also market forces. The advantage of seed over grain is that the prices are significantly higher than those of grain.
