Effect of the Time of Application of Fertilizer Nitrogen on the Growth,Flowering and Fruiting of Maiden Apple Trees Grown in Sand Culture

Mailing II rootstocks were grown throughout 1960 in sand on nutrient culture solutions containing 1, 4 or 10 mg. equivalents of nitrogen as nitrate (referred to as N₄, N₁₀ rootstocks) and during that summer each rootstock was budded with the variety Lord Lamboume. The growth, flowering and fruiting performance of the resultant maiden shoots were recorded from bud break 1961 to fruit set 1962. Throughout this second period each tree was given only a minimum of nitrogen (N_x) except during a certain period of one or two months’ duration, when it received a simulated fertilizer application (N₁₀).

The greatest amount of primary extension growth in 1961 took place on the maidens given supplementary nitrogen in June on the N₁ and N₄ rootstocks and in July on the N₁₀. Secondary extension growth in 1961 was apparently induced by supplementary nitrogen given to the maidens on the N4 stocks in July and to those on the N_x in August.

The highest number of fruit buds and blossoms in 1962 resulted from the June 1961 high-nitrogen supplement to the maidens on the N_r and N₄ stocks and from the July supplement to the N₁₀.

After open pollination, the maidens grown on the NIO stocks set fruit better than on those that were more nitrogen-deficient. Among the N₁₀ and N₊ maidens, those receiving the September nitrogen supplement gave the highest yield.

These results are discussed especially in relation to apparent differences in quantity and quality of blossoms. It is suggested that the quantity of blossoms is related to the amount of primary extension growth, while the quality is determined by the extent to which reserves of carbohydrate and nitrogen have been accumulated during the previous autumn.     

The Pollination of Strawberries by Honey-Bees

Pollination of strawberries by honey-bees increased the percentage of flowers that set fruit, the weight of the berries, and the percentage of well-formed berries.     

Growth Regulator Effects on Quality and Pre-Harvest Drop of Worcester Pearmain Apples

The application of 2-chloroethylphosphonic acid (CEPA) at 750 or 1500 ppm improved the colour of early harvested Worcester Pearmain apples but greatly increased pre-harvest drop. The drop-promoting effect of CEPA could be overcome by applying succinic acid 2,2-dimethyl hydrazide (aminozide) at 2000 ppm or a-(2,4,5-trichlorophenoxy)-propionic acid (2,4,5-TP) at 20 ppm. The combination of CEPA 750 ppm+2,4,5-TP 20 ppm appeared to be particularly promising for improving the attractiveness, flavour and texture of Worcester Pearmain picked on 1st September and 7th September. No damage was seen on the trees either in the year of application or the following year.     

Improved seed development and germination of stenospermic grapes by plant growth regulators

Plant growth regulators were applied to the foliage and immature fruit clusters of the stenospermic grape selection ‘C35-33’ at various periods before bloom to stimulate viable seed development. In the 1987 season five different plant growth regulators were used, but in 1988 the growth retardants Cycocel and XE-1019 were used exclusively. Chemical treatments applied 35 days after bud break increased significantly germination percentage. Experimental results indicate that the use of certain plant growth regulators may aid in increasing the efficiency of seedless grape breeding by providing an alternative to in-ovulo embryo culture.     

Modifications of wheat flour proteins during in vitro digestion of bread dough, crumb, and crust: an electrophoretic and immunological study

The proteins of wheat flour have several biological activities that can affect human health and physiology when wheat-based foods are consumed. The modifications of bread crumb and crust proteins during an in vitro peptic/pancreatic digestion process were studied by electrophoresis and immunoblotting with polyclonal antibodies specific for single proteins or groups of homologous proteins of the wheat flour, and the results were compared to those obtained for an unheated dough sample. The results show that baking affects the extent of proteolysis and the immunological and physicochemical features of the digestion products in relation to the level of the heat treatment. Therefore, the results concerning the digestion of the unheated wheat flour or dough are not representative of what happens when baked products enter the human digestive tract.     

The effect of phosphorus supplementation to common carp diets on fish growth

The effect of supplementation of fish diets with phosphorus was studied both in tank and pond experiments. In the tank experiments phosphorus (6.5% di-calcium or mono-calcium phosphates) was added to three diets: two containing fish meal as the main protein ingredient and the third containing algal meal to replace it. Feeding common carp in tanks with these diets significantly increased fish growth rate (P < 0.05) over fish fed the same diets without phosphorus supplementation. In the pond experiments phosphorus was added to a fish meal diet in two different compounds: mono- and di-calcium phosphates (at 1% of the feed). The diets were fed to fish in a polyculture system for two consecutive culture cycles. Due to supplementation with phosphate, growth rate of tilapia (Sarotherodon aureus) increased in both culture cycles. The growth rate of common carp fed phosphorus-supplemented diets increased over the control only in the first cycle, when fish were large and the standing crop of carp exceeded 1.8 ton/ha. At lower standing crops the natural food seems to supply adequate amounts of phosphorus. Silver carp were not affected by phosphorus supplementation, probably because they consume very little supplementary feed. Total yield for the entire season (kg/ha) was significantly higher in ponds where fish were fed a phosphorus-supplemented diet. Di-calcium phosphate, which is soluble only in weak acids, seems to be more efficient than the water-soluble mono-calcium phosphate in affecting the growth of common carp even though this fish lacks a gastric acid secretion.