INFLUENCE OF CALCIUM AND MAGNESIUM UPON COMPOSITION OF BOSTON HEAD LETTUCE¹

COMPOSITION OF SQUASHES AFTER WINTER STORAGE1

“…The data regarding the amount of riboflavin, calcium, iron, magnesium, and phosphorus found in the 22 squashes examined a t the end of the winter storage period (Table 1) show this vegetable to be a valuable source of these essential food constituents. However, the squashes contained less calcium, iron, and magnesium but considerably more riboflavin and phosphorus than Holmes and Crowley' (1944) found in lettuce grown in this locality. Also Holmes, Crowley, and Euzmeski (1945) rtported that freshly picked kale grown in this area contained more calcium, iron, magnesium, and phosphorus than the squashes under consideration.…”

“…However, the squashes contained less calcium, iron, and magnesium but considerably more riboflavin and phosphorus than Holmes and Crowley' (1944) found in lettuce grown in this locality. Also Holmes, Crowley, and Euzmeski (1945) rtported that freshly picked kale grown in this area contained more calcium, iron, magnesium, and phosphorus than the squashes under consideration.…”

Aerated chicken, cow, and turkey manure extracts differentially affect lettuce and kale yield in hydroponics

“…The magnesium concentration in all manure extract solutions increased with increasing manure concentrations. Earlier studies have shown that the addition of magnesium fertilizer increases magnesium content in lettuce tissues (Holmes and Crowley 1944). Notably, the amount of magnesium in leaf tissue decreased in kale grown in both chicken and turkey extract solutions, as the manure concentration increased.…”

Chloroplast Pigments in Relation to Magnesium Deficiency

“…The study of Eisentnenger and Xucinski(12) concerning the relation of the order of plant development to the need of magnesium was based on observations made of plants grown on these plots. These plots were also used byHolmes and Crowley(17) and Holmes, Crowley and Xuzmeskl(16) in their study on the carotene, calcium, magnesium and phosphorus content of Boston head lettuce and kale.It should be noted that in the earlier studies of Jones(20) andBeaumont and Snell (2) dealing with these plots the same letters A, B, C, and D were used to designate them by starting at the north side with Plot A. In the later reports(16,17) they were designated by starting with Plot ▲ at ths south side.…”

“…These plots were also used byHolmes and Crowley(17) and Holmes, Crowley and Xuzmeskl(16) in their study on the carotene, calcium, magnesium and phosphorus content of Boston head lettuce and kale.It should be noted that in the earlier studies of Jones(20) andBeaumont and Snell (2) dealing with these plots the same letters A, B, C, and D were used to designate them by starting at the north side with Plot A. In the later reports(16,17) they were designated by starting with Plot ▲ at ths south side. Thus the placements of lime and magnesium have not changed in the twenty-seven years during which they have been used, but the letters ussd to designate the plots were changed.…”