Abstract only

Depending on the purpose and grade, grain is sorted out as seed, food grain or feed grain during its cleaning and screening after harvest. The system of the grain after-harvest processing usually includes seed drying, cleaning and sorting. In International Maize and Wheat Improvement Center (CIMMYT, Mexico) additional operations are introduced in seed processing: washing of seed and its treatment by fungicides. Faculty of agricultural mechanics of the Mexican Agrarian University in Chapingo together with CIMMYT (Mexico) and with financial support of National Committee on the Science and Techniques (CONACYT) has developed a number of special machines for after harvest processing of grain. Among them are a special dryer, the amalgamator of seeds with preservatives and a cleaner of seeds. To simplify drying and to get it rid of influence from the weather conditions, a dryer has been developed that can dry simultaneously grain of 30 various varieties without mixing, which is very important for breeding programs. The dryer consists of three cases with racks, which can contain up to 3 kg of seeds of one variety and a fan with automatic maintenance of temperature of forced air in the range of 25-70°C. Output of the dryer is as high as 100 kg per hour of seed, which is dried to 10-11 %- moisture content. The following parameters of drying were determined using an experimental dryer: decrease of moisture content of seeds, temperatures, and forced air speed and amount. Germination test of the seed samples has confirmed that use of the dryer does not reduce viability of seeds. After the final adjustments, three dryers have been constructed and established in CIMMYT (Mexico) where they function now. To exclude cases of disease transfer, CIMMYT introduced washing wheat and barley seed and its processing in a special solution. After drying, seed is packed into packages, mixed with fungicides (dust) and send to approximately 90 countries of the world. CIMMYT prepares for sending almost 500,000 packages in a year. Each package contains 5 g of seed of various wheat lines and 0.2-0.5 g of fungicide dust. In the earlier years, seed was treated manually, which created many problems associated with safety of work, even application of the fungicide and number of the workers. A decision was made to develop a machine for automation of seed treatment and packaging. The designed and constructed machine allows to produce 25 packages in a minute with accuracy of 0.05 g in applying the fungicide, thus reducing number of the workers and improving safety of the work. To screen small amounts of grain a special machine was developed containing a fan that can be driven by an electric or gasoline engine, the cylinder, sieve and a pneumo-cyclone for preliminary, intermediate and final cleaning. The machine allows clearing up to 50 kg of grain per hour.

English

0409|AGRIS 0401|AL-Wheat Program|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Publications Collection