Effects of three soil types and three rootstocks on the performance of Valencia orange trees as measured by root distribution, leaf composition and yield were studied. The majority of roots were concentrated in the top 60 cm of soil. Trees on Murray sand had twice as many roots as on Barmera sand 'shallow phase', or as on Moorook sandy loam below 90 cm. Chlorophyll and iron levels were lowest in new 3-month-old leaves and increased with age. Levels of zinc, manganese, magnesium, calcium and chloride showed similar trends. Trees on Moorook sandy loam were not chlorotic in spite of the low chlorophyll in their leaves and the lowest production.

A simple and rapid method for ultimate particle size analysis of soils has been developed which replaces the methods first introduced by Piper. The method relies on the removal of organic matter by sodium hypochlorite and a dispersion in an ultrasonic bath. This method has now been used nearly 2 years in our laboratories, and has resulted in a substantially greater throughput of samples with the same staffing component. The method is recommended for all service laboratories.

Lemnos loam, a red-brown earth used for fruit production in the Goulburn Valley, Victoria, has degrees of friability in the subsoil as assessed in the field. Forty-one samples from three subsoil depths were obtained from 25 sites near Kyabram. Aggregate stability, as measured in the laboratory was found to be related to field assessments of friability. Exchangeable cations, pH, silt, clay and clay minerals were determined on the samples. By relating some of these measurements to aggregate stability it has been shown that exchangeable Ca++ contributes to a strongly aggregated soil (friable) ; and silt, exchangeable Na+ and exchangeable Mg++ to a weakly aggregated soil (less friable). The effect of silt and exchangeable Na+ is greater than that of exchangeable Ca++ and exchangeable Mg++. A multiple regression equation describing the effect of these four significant factors on stability percentage is presented. This equation accounts for 85.5 per cent of the variation in stability percentage. There is a strong relationship between field assessment of friability and exchangeable Ca++/Mg++ ratio; the higher the ratio, the more friable is the soil.

Lemnos loam, a widespread red-brown earth soil type in the Goulburn Valley, Victoria, has been re-surveyed in an area of approximately 6,880 hectares near Kyabram. Three degrees of subsoil friability have been recognised and mapped. The root distribution, butt circumference and height of ten year old peach trees (Golden Queen and Cornish varieties) have been studied In relationship to these degrees of friability. The results obtained show that the greater the friability of the subsoil, the better is tree performance as measured by butt circumference and tree height. Furthermore, the greater the friabihty of the subsoil, the deeper is the penetration of roots into the subsoil layers and the higher is the root concentration in the deeper horizons of the soil. A regression equation, with a coefficient of determination of 89.7 per cent, has been obtained for the relationship between total root length in the subsoil and butt circumference.

This investigation was carried out during 2012 and 2013 seasons on 6 year old olive trees cv. Kalamata . Selected trees were planted at 6 x 4 meters apart in a sandy soil; subjected to drip irrigation; uniform in shape and size as much as possible and received regularly the recommended horticultural practices according to the recommendations of the Horticulture Research Institute. Kalamata olive trees were foliar sprayed with calcium chloride at 1 or 2%; potassium chloride at 2 or 4%, and urea at 2 % each alone or in combination at full bloom. Obtained data indicated that all tested treatments increased fruit set, the number of fruits per tree, yield (kilogram per tree) and improved fruit quality (fruit weight, fruit dimensions flesh/pit ratio and oil content) while, decreased both June and pre-harvest drop in comparison with the control. In addition to improve NPK status of Kalamata olive leaves.The most effective treatments on tree fruiting were the combinations of 2 and 4 % potassium chloride with 2 % urea. Regarding, fruit quality, the two concentrations of calcium chloride or potassium chloride alone or supplemented with 2% urea, improved fruit quality. Besides, 2 or 4% potassium chloride induced the highest values of fruit oil percentage as fruit fresh weight, while as dry weight, the treatment of 1% calcium chloride associated with 2% urea induced the highest values. Regarding leaf NPK content, the treatment of 2% calcium chloride increased leaf nitrogen content in the first season, while, treatment of 2% potassium chloride + 2 %urea was the most effective treatment in the second season. Either 2 % or 4 % potassium chloride treatments increased leaf P content during 2012 & 2013 seasons, whereas leaf K content was not affected with the tested treatments in the first season, while in second season the treatment of 1 % calcium chloride was the most effective treatment. This study recommended that spraying olive trees cv. Kalamata with 1 % or 2 % calcium chloride; 2 or 4 % potassium chloride and 2 % urea, each alone or in combination, at full bloom increased tree fruiting; improved fruit quality and increased fruit oil content.