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We evaluated the effectiveness of soil and foliar applications of calcium chloride (CaCl2) on reducing pear susceptibility of brown spot (Stemphylium vesicarium). Two experiments were done using pear trees of the variety Abbé Fetel grafted on quince (Cydonia oblonga) rootstock. Potted trees were treated with soil and foliar application of CaCl2, while commercial trees were subjected only to soil application of 5.6 g CaCl2 L−1, and 11.2 g CaCl2 L−1. In a controlled environment, leaf and fruit brown spot incidence decreased with the increase of residual calcium (Ca) concentration in the tissue, according to a second degree function. In fruits from field experiment, disease symptoms were decreased by soil application of CaCl2 that increased Ca fruit concentration above 1000 mg kg−1 dw; however, no clear correlation between fruit Ca and brown spot incidence was found. Leaf water and osmotic potential were not related to brown spot incidence. [ABSTRACT FROM PUBLISHER]

The objective of this experiment was to evaluate in the long-term (9 years), the suitability of compost as a fertilizer in commercial peach orchard. The experiment was carried out on nectarine trees ( Prunus persica var . nectarina), Stark RedGold grafted on GF677 peach × almond ( P. amygdalus L.) hybrid. The treatments were: (1) unfertilized control; (2) mineral fertilization including phosphorus (P at 100 kg/ha) and potassium (K at 200 kg/ha) applied at planting and nitrogen (N at 70–130 kg/ha/yr) split in two applications at 40 days after full bloom (60%) and in September (40%); (3) cow manure supplied at planting [10 t dry weight (dw)/ha] and then, from the forth year at the rate of 5 t dw/ha/yr in spring; (4) compost supplied at planting (10 t dw/ha) and then, from the forth year at the rate of 5 t dw/ha/yr in spring; (5) compost supply at a rate of 5 t dw/ha/yr, and (6) 10 t dw/ha/yr, both treatment 5 and 6 split as described for treatment 2. Nitrate-N soil concentration was usually not affected by treatments. Soil microbial carbon, organic matter, total N, P, K were increased by application of organic fertilizers. SOM and total N were positively correlated to soil microbial biomass. Aggregate stability, humic and fulvic acid concentration were not affected by fertilization treatment. Only the application of compost at 10 t dw/ha/yr (6) increased fruit production. [ABSTRACT FROM AUTHOR]

An innovative teaching strategy focused on problem based approach rather than theorical aiming to facilitate the learning of the research methodology in advanced nursing student has been introduced. Through out a qualitative evaluation of the diary kept by the student nurses involved, advantages and disadvantages of this innovative approach have been evaluated. This paper reports a synthesis of the teaching strategy and its impact on the competences in the research methodology as it has been perceived by the students participants. [ABSTRACT FROM AUTHOR]

Background and Aims: Copper accumulation in soil may promote phytotoxicity in grapevines. Nutritional implications of potted vines to increasing concentrations of copper (Cu) in either clay loam soil or clay loam soil mixed with 85% sand were tested on Vitis vinifera (L.) cv Sangiovese and crop toxicity threshold and symptoms determined. Methods and Results: Soils were mixed at planting with Cu at the rates (mg Cu/kg) of 0 (control, native soil Cu only), 50, 100, 200, 400, 600, 800 and 1000, and non-bearing vines were grown in these for two seasons. Reduction of root growth was observed after addition of ≥400 mg Cu/kg to both soils; reduction of shoot growth, leaf number and chlorosis of leaf edges were detected only in sand-enriched soil. Root Cu concentration increased in response to soil Cu addition. Unlike that of leaf Cu and N, the amount of P and Fe (in both soils) and Mg and Ca (in sand-enriched soil only) were reduced by soil Cu. Conclusion: Vines grown in sand-enriched soil tolerated lower concentrations of Cu than in clay loam soil, probably because of the lower nutritional status and the higher root Cu concentration. Significance of the Study: Results provide information on the concentration of soil Cu that grapevine can tolerate and on the nutrients involved in the response to toxic levels of soil Cu in clay loam and sandy clay loam soils. [ABSTRACT FROM AUTHOR]

The effectiveness of spraying foliage with urea to provide nitrogen (N) to augment the seasonal internal cycling of N in young nectarine trees (Prunus persica (L.) Batsch var. nectarina (Ait. f. Maxim.), cv. Stark Red Gold) was studied. One-year-old trees were grown with contrasting N supplies during the summer and foliage was sprayed with a 2% urea solution labeled with 15N just before leaf senescence started. After leaf abscission had finished, the trees were repotted in sand and given no further N. Remobilization of both labeled and unlabeled N for leaf growth the following spring was quantified. [ABSTRACT FROM PUBLISHER]

Two-year old nectarine trees (Prunus persica, Batsch, var. nectarina, cv. Starkredgold on GF305 rootstock) planted in pots each received five applications of 1.0 g ^15N labeled urea either from mid May to mid July (early uptake) or from mid August to the beginning of October(late uptake). All trees were supplied with a corresponding amount of unlabelled urea when they did not receive the labeled N. In autumn,all abscised leaves were collected and during winter randomly selected trees were harvested and divided into main organs. The remaining trees were transplanted into similar pots filled with sand; they received no N fertilizer and were harvested in May to evaluate the remobilization of N. Total N and ^15N abundance were determined in each organ. Nectarine trees took up similar amounts of N in the 'early' and inthe 'late' period; however, more labeled nitrogen was recovered in the perennial organs during the winter when trees received the labeledN in the 'late' than in the 'early' period. Some 73-80% of the N present in the dormant trees was stored in the roots, which contained almost twice the amount of labeled N taken up 'late' than that absorbed'early'. Nitrogen for spring growth was remobilized predominantly from the roots and accounted for some 43-49% of the labeled N recoveredin the tree during winter. Results suggest that the nitrogen taken up 'late' in the season is preferentially stored in roots and used by peach trees to sustain new growth the following spring. [ABSTRACT FROM AUTHOR]

Both uptake of fertiliser N and remobilisation of stored N were quantified for the early growth of spur and shoot leaves, flowers and fruit development of pear trees. One-year old Abbi F. trees grafted on quince C rootstocks were fertilised with a generous N supply for one year and while dormant during the winter, transferred to sand cultures. Each tree received 3 g of labelled nitrate-N at the end of winter and in early spring. Leaves, flowers and fruit were sampled on 5 separate occasions and the recovery of labelled N used to distinguish the remobilisation of N and the root uptake of nitrate. Remobilisation ofstored N accounted for most of the N present in leaves and flowers during blossoming. Remobilisation of nitrogen stopped between petal fall and the beginning of fruit development. Root uptake of nitrate linearly increased over time and at the last sampling, 55 days after budburst, fertiliser N contributed approximately half of the total N recovered in both spur and shoot leaves, the remainder coming from remobilisation. Flowers and fruits based their N metabolism more on remobilisation as compared to the leaves. This pattern of internal cyclingof N is discussed in relation to fertilisation strategies for pear trees. [ABSTRACT FROM AUTHOR]