A comparison between yields calculated from the grain-straw ratio and those calculated from small cut-out areas

Yields obtained on three types of harvesting methods were secured from a series of oat plats. In the first method the entire plat was cut and threshed; in the second, yields were calculated from small areas cut-out with a hand sickle; while in the third, yields were obtained from the grain-straw ratio in a portion of the plat and the bundle weight of the entire plat. Higher values for "r" and "Z" were obtained when actual plat yields were compared to yields calculated from weight relationships than from area relationships. The regression lines obtained from the weight relationships compared more closely in all cases to the line Y = X than did the regression lines obtained from the area methods of calculating yields. The standard errors of estimate and the errors of estimate from the line Y = X varied significantly between all area methods and the method in which the weight relationship of five bundles to the total grain and straw weight of the entire plat was used. The errors for the yields based on one bundle were significantly greater than the errors for yields based on five bundles. The magnitude of the errors in every case was considerably lower when yields were calculated from weight relationships than from the area methods. The calculated yields varied progressively from the actual plat yield with the decrease in the number of bundles weighed and with the number of areas cut, but the yields from one bundle were closer to the actual plat yields than when yields were based on six areas. From the data presented, it would appear that three bundles weighed from a plat of this particular size would give a very accurate estimate of the plat yields and would be the recommended number to use in yield estimation. A harvested area as small as 1,000 square feet has been satisfactorily taken care of by this method. When compared to the method of cutting out small areas, the grain-straw ratio method of harvest has the advantage of being more accurate and more efficient in the use of labor. An experiment consisting of 108 plats of oats was harvested in 4 1/2 hours. Four men were required to do the work, two of the men were required to run the binder since the tractor did not have a power take-off. The amount of hand labor involved is materially lessened since the grain is cut with the binder.