Increase In Total Phosphorus Research Articles

Vineyard Response to Phosphate-Zinc Foliar Sprays

Five replicated vineyard trials were conducted during a two-year period to test the response of commercial 9Thompson Seedless9 raisin vineyards to foliar sprays of two proprietary nutrient spray materials. Nutra-Phos 24 and Zinc Nutra Spray 50 were applied three times in 1962 and twice in 1963 at equal concentrations of zinc content. Two-inch shoot tip samples were collected throughout the season from before bloom until early harvest stage, and these were analyzed for zinc and phosphorus. Shoots were tagged for growth rates, fruit samples were collected at three dates for quality measurements, and total crop as raisin yield was compared with that from unsprayed controls. Zinc content of tips was increased two- to-threefold by both materials, especially by the prebloom sprays. Increase of total phosphorus was not detectable by either of two analytical methods with precision of ± 100 ppm P. Visual symptoms of zinc deficiency did not develop, and the content of phosphorus in the tissue was about average for the area. There was no measurable benefit from phosphorus <i>per se</i>. In all five trials Zinc Nutra Spray 50 increased raisin yields 3 to 7%, but only one, at plus 6%, was statistically significant; and it was associated with a statistically reduced °Balling of the fruit.

The respiration rate and loss of dry matter from stored bran

1. Experiments were made on the respiration of bran at different moisture levels using a continuous absorption apparatus in which the humidity of the air-stream was adjusted to be at equilibrium with the respiring bran. The rate of respiration was accelerated with increasing moisture content and was very rapid deterioration due to the high respiration rate and microbiological damage.2. Experiments were made on the storage of bran at known moisture contents in closed tins in the laboratory and also in sacks kept under farm conditions. The total nitrogen content of the bran stored in the tins appeared to increase during storage. From similar increases in total phosphorus, it is clear that the increase in total nitrogen was caused by a loss of dry matter from the stored feeding stuff, a fact which was further demonstrated by the loss in dry weight of the sacks of bran with attributed to two causes: (1) the respiration of the plant cells still active in the bran itself, and (2) the respiration of developing micro-organisms. It is evident from these experiments that fresh bran, free from insect infestation and stored at a moisture content of less than 13%, will have a very low respiration rate and will, therefore, not be liable to heating. Bran of 15–19% moisture content respires at a much faster rate and the time for which such material can be stored with freedom from heating or other types of deterioration will be limited.

On Phosphorus Metabolism in Embryonic Life

ABSTRACT An investigation was made of the phosphorus metabolism of several marine invertebrate eggs (two echinoderms, one gephyrean annelid, and two Crustacea). The distribution of phosphorus-containing compounds was measured before and after development had taken, place. Data are given for the total and lipoid phosphorus, the total water-soluble and stable organic water-soluble phosphorus, the inorganic ortho-and pyro-phosphate, the phosphoprotein and the nucleoprotein. During the development of the sand-crab (Emerita analoga) water is absorbed from the environment, as in the well-known cases of the frog, the trout, and various cladocerans. The egg shell of the brine-shrimp (Artemia salina) contain both calcium and haematin, offering thus a parallel with the shell of avian eggs. During the development of the sanddollar egg (Dendraster excentricus) there is an increase in total phosphorus per unit weight of dry solid. It is pointed out that this absorption of an element from the sea water by the embryo must be taken into account in considering the penetration of marine organisms into fresh water, if, as seems probable, the phosphorus concentration in an aqueous environment may act as a limiting factor. The spicules of the sanddollar pluteus probably contain inorganic phosphate, in quantity roughly corresponding to the amount taken in by the developing egg from the sea water. In all cases so far studied the extent to which lipoid phosphorus is transformed into other forms of phosphorus during embryonic life is proportional to the amount of lipoid phosphorus present at the time of fertilisation. Included in the large stores found in certain eggs there is a fundamental quota which no egg can do without, though this may be, reckoned in absolute values, very small. A computation shows that the contribution of one echinoderm spermatozoon to one egg is of the order of a ten-thousandth part of the phosphorus which is there already. The analyses reported in this paper indicate that, in spite of the large increase of visible nuclear matter during echinoderm development, there is no corresponding synthesis of nuclein. The formation of the chromatin of the nuclei must therefore consist in an organisation of preformed nucleic acids into structural arrangement and not in a manufacture of these compounds by chemical means from other raw materials. Nuclein synthesis, however, certainly occurs in some eggs, and study of the relevant investigations of other workers leads to the conclusion that it is associated with uricotelic metabolism, terrestrial development, and the properties of cleidoic embryos. Wherever the purine ring is synthesised by embryonic cells for nitrogen excretion, there a notable synthesis of the purine ring for cell-nuclei is also found : whatever this is not so, there the eggs are provided by the parent organism with sufficient nuclein for the needs of the embryos.