Edit: A bit quick with this one.
Responding to a 29 November, 1952 article in The Economist putting forward "rather pessimistic predictions" about the future of the Basin after the departure of English managers, writing in a letter published in the 30 April 1955 issue, P. X. Levandis, the Greek Agricultural Minister was pleased to refute those predictions by citing high production per hectare. I missed this letter because I don't do the end-of-month issues of The Economist unless I've screwed up my withdrawal requests, which never happens, practically. Well, hardly ever.
I did not miss, and mentioned in the postblogging, the response of the Liquidator of the Lake Copais Corporation, F, W. Willis. Willis refutes the claim of increased productivity of wheat and cotton by showing that Levandis is using misleading figures, specifically only those of the freeholding farmers. When land held by the company, or now the Greek government, and run as largescale farms are included, there is no trend line. Without going back three years to find out just how pessimistic The Economist was being, consider it not refuted. On the other hand, there's evidently a whole history here of the people who actually farmed the land, and something of an elephant in the room in terms of what was farmed. Wheat and cotton are cash crops, and in particular the great cash crops of third-quarter Nineteenth Century agricultural expansion that gave us bonanza farms in the Americas and Australia and more complicated booms in the Old World. (For example, the "salinisation crisis due to irrigation/irrigation failure due to rampaging Mongols" story about Iraqi agriculture derives from abandoning barley for wheat in this period.)
Wheat and cotton are, as these things go, extensive crops, not traditionally the ones you grow on expensively reclaimed land. The Greeks eat rice and make linen, right? Given the emphasis on the landholders, one wonders exactly how much consultation there was with the locals who might have been using the Lake for traditional purposes like retting flax for weaving prior to the beginning of excavation and pumping.