Head lettuce growth and nutrient absorption studies indicate need for re-evaluation of fertilizer practices
AuthorsF. W. Zink
Authors AffiliationsF. W. Zink is Specialist in the Experiment Station, Department of Vegetable Crops; M. Yamaguchi is Associate Olericulturist in the Experiment Station, Department of Vegetable Crops, University of California, Davis.
Hilgardia 17(6):13-14. DOI:10.3733/ca.v017n06p13. June 1963.
In Salinas Valley trials, Great Lakes lettuce produced more than 70% of its fresh weight during the 21 days before first harvest—and absorbed over 70% of the total nutrient uptake of the crop during the same period. These results indicate that the practice of some growers using a preplant application of from one-half to two-thirds of the total amount of nitrogen to produce the crop is questionable. Since lettuce absorbs little nitrogen in the early phase of growth, a more realistic program would include preplant applications of only one-fourth the amount of total nitrogen to be used and two side-dressings to apply the balance—one after thinning and a second a month before the predicted first harvest.
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