Abstract
Some farmers mechanically screen farmer stock (FS) peanuts after combining to remove undesired materials for value and quality improvement. Screening is accomplished with low capacity, portable screens at the field after combining or with high capacity cleaners or screens at buying points. An alternative method for FS peanut screening has been developed cooperatively by Amadas Industries and USDA-ARS, National Peanut Research Laboratory utilizing an experimental combine screening attachment. The attachment is a hydraulically driven, rotating cylindrical screen (trommel) with an axis inclined less than 10° from horizontal during operation. Peanuts are screened with the trommel prior to entering the combine basket, and smaller, unwanted materials are returned to the soil. Thirty-eight lots of FS peanuts averaging 3.27 t/lot were combined throughout all U.S. peanut-producing regions to examine performance. Foreign materials for the screened lots averaged 2.15% less than the unscreened lots (P = 0.05). Hulls were 0.62% less in the screened lots (P = 0.05). None of the other grade factors or market values per hectare were significantly different for runner peanuts. Foreign materials for screened virginia peanuts were 2.44% less than in unscreened (P = 0.01). Loose shelled kernels were 0.44% higher (P = 0.05), hulls 0.67% lower (P = 0.10), and damage 0.56% higher in screened peanuts than in unscreened. None of the other grade factors or market values per hectare were significantly different for Virginia peanuts. Although most grade factors and values per hectare were not significantly different for screened and unscreened peanuts tested, foreign materials were reduced significantly providing needed quality improvement. Possible cleaning costs also could be reduced with the attachment.
