The Effect of Irrigation, Nitrogen Level and Season on the Composition of Cabbage.

The use of irrigation in the production of vegetables in the eastern part of the United States has shown a very rapid increase in the past 4 or 5 years. Irrigation not only increases the total yield, but also in many cases, the quality of the crop produced is improved as well. Physiologists are interested in learning if such differences in quality are largely of a physical nature or if there are also some chemical differences between poor and good quality vegetables. The author in a previous publication (5) presented data on the composition of beans grown with several rates of irrigation. The main difference was one of moisture content-beans growing without irrigation having a higher per cent. dry weight than those which were irrigated. On a dry weight basis, there were small differences in carbohydrate, organic nitrogen and potassium content. It is characteristic of fruits to be rather uniform in composition regardless of the conditions under which they are grown. It was felt that a crop which consists largely of leaf tissue would show more marked variations in composition associated with a difference in growth than do fruits. This study was made to determine the effect that (1) soil moisture (as influenced by irrigation), (2) nitrogen level and (3) season had on the composition of cabbage and also if there was any relation between quality and chemical nature of the crop. Quality is used here to mean appearance, succulence and similar factors which made for high consumer acceptance.