Investigations on yield in the cereals. I

Abstract

Itis unlikely that as a formulated problem any consideration of settled crop-husbandry is of greater antiquity than the cereal yield problem. In its broad form it embraces all the possible means of increasing the output of grain per unit area. The earliest civilizations of Mesopotamia and Egypt must have been compelled to explore these means as soon as they began to encounter the limitations to cultivable area which dwelling in fixed communities imposed. Wheat and barley were their principal food stuffs so that the cereal yield problem, the most comprehensive concern of present-day agriculture, goes back to the remotest antiquity. It must have evoked incessant effort along divers lines and the cumulative result is appreciable from a comparison of the best cereal races of to-day and the forms which likeHordeum spontaneumandTriticum dicoccum dicoccoideshave been regarded as the progenitor types. Unfortunately it is not possible to trace back very far the sequence of the solution of the problem as constituted by improvements in husbandry and the utilization of better cereal forms. Fragments of information may be culled from the writings of various periods but they are of doubtful value. The author's reliability is often in question, the unit of measure uncertain, and even the identity of the crop a matter of doubt. Herodotus' well-known story, passed on from another, of increases of 200 and even 300 fold yielded by barley in Mesopotamia in 500B.c.is possibly the oldest fragment. It is difficult to interpret but it gains colour from the further statement that the leaves of the plant were of the width of four fingers. Concerning progress in England, while reasonably precise information goes back no further than forty years, there are widely separated records of sufficient worth to indicate the historical trend. It has been deduced from the Manorial Records that at the time when that system had become established there was a flat rate of about ten bushels per acre for wheat. Much later, when Sir Charles Davenant compiledAn Essay upon the Probable Methods of making a People Gainers in the Ballance of Trade(published 1699), he computed the “neat produce” of eight million acres of arable land to be 79 million bushels of grain.