This publication might be termed “a progress report,” since two previous publications by the author2 3 reported the results obtained on effect of spacing and length of harvesting period,2 on yields of asparagus. In the first publication it was concluded that plants harvested until July 15 in 1929, 1930 and 1931 showed a reduction in yield in 1931 compared to plants harvested until July 1 each year. It was also concluded that, “after harvesting plants to July 1 for 3 years the increase over the plants harvested a shorter period of time, though significant, is not highly so, and future records may disclose that July 1 is entirely too late to harvest.”
The second publication by the author3 contained results for the following 3 years, 1932, 1933 and 1934. Those results on effect of length of cutting season may be summarized as follows: “Harvesting until July 15 materially shortened the profitable life of the planting. The quality of spears as indicated by weight and diameter was so poor that it rendered the planting unprofitable after 5 years of harvesting to this date. Cutting until July 1 was profitable for 6 years, but indications point to a reduction in weight and diameter of spear in the sixth year, and future trends appear to be downward. Harvesting until May 1, May 15 or June 1 was not as profitable as harvesting until June 15, although the market quality of spears was better in these three treatments than any of the others. The total yield was not sufficient, however, to justify discontinuing harvesting at these dates.”
Haber, E. S.
"Effect of spacing and length of harvesting on yields of asparagus,"
Bulletin P: Vol. 1
, Article 1.
Available at: http://lib.dr.iastate.edu/bulletinp/vol1/iss6/1