02671nam a2200265 a 450000100080000000500110000800800410001910000210006024500720008126000520015330000100020550000820021552019750029765300130227265300120228565300140229765300130231165300150232465300090233965300120234865300090236065300090236965300120237865300150239010069272015-07-20       1977    bl uuuu  m   00u1 u    #d1 aLESQUEVES, E. C.  aRemoval of soil peds from soybean (Glycine max (L.) Merrill) seeds.  aMississipi : Mississippi State Universityc1977  a50 f.  aThesis (Master of Science) - Mississippi State University, Mississippi State.  aOne of the major threats to soybean production in the United States is the soybean cyst nematode. One method of its spread is its introduction into uninfested fields by planting seed lots contaminated with soil peds containing nematode cysts. A study was designed to estimate the amount of peds in combine-run soybeans and to evaluate the effectiveness of the air-screen cleaner, spiral separator and gravity table in the removal of soil peds from soybean seed lots. Samples of combine-run soybeans were collected at grain elevators and in filds and their soil ped content determined. It was found that 95% of the seed lots contained some peds and 46% of the lots contained peds within the size range of the seeds. Four seed lots contaminated with soil peds within the range of 3.175 mm to 8.731 mm diameter were processed by the air-screen cleaner alone or in combination with the spiral separator and/or gravity table. The air-screen cleaner removed the majority of the peds, but the most effective separation was made by the air-screen - spiral separator - gravity table combination. Complete separation was not accomplished by any combination used. As ped removal effectiveness increased, seed loss increased. The following conclusions were reached: 1. Practically all combine-run lots of soybean seeds contain soil peds. 2. The air-screen cleaner alone can adequately remove peds from about 54% of all lots. 3. The greater the ped removal efficiency of a treatment, the greater will be the seed loss. 4. Complete removal of peds is not likely concentional equipment. 5. The air-screen cleaner-gravity table is better than the air-screen cleaner-spiral separator in soil peds removal from soybean seeds and is approximately equal to the air-scfreen cleaner-spiral separator-gravity table combination. 6. Since complete removal of peds is not likely, there remains a possibility of spread of the pest when seeds from an infested area are planted in uninfested fields.  aColheita  aLimpeza  aNematodeo  aProducao  aProduction  aSeed  aSemente  aSoil  aSoja  aSoybean  aTratamento