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• Impact of foliar fungi on dogroses

  23-30.

  C. S. Schwer

  U. Carlson-Nilsson

  Uggla M.

  G. Werlemark

  H. Nybom

  Views:

  185

  Wild roses of the section Caninae, commonly known as dogroses, have been described as more disease tolerant than ornamental roses and could therefore become valuable for breeding improved rose cultivars. Two fields with dogroses, one with plants obtained by open pollination in wild populations, and one with plants obtained from intra- and interspecific crosses, were evaluated for blackspot, powdery mildew, rust and leafspots in the autumn of 2005. Symptoms of the different fungi on different dogrose species were carefully evaluated in a microscope and documented by photography. Interestingly, almost no symptoms of powdery mildew were found in either field, although the fungus infected wild roses of a different section in a field closeby. Surprisingly few symptoms were found also of blackspot, and they differed considerably from those found on ornamental cultivars, indicating a lower susceptibility in dogroses. The most important fungal disease in 2005 was rust, followed by leafspot symptoms. The latter were apparently caused by Sphaceloma rosarum and Septoria rosae which can be properly discriminated only in a microscope. The investigated dogrose species and their progeny groups varied significantly in disease susceptibility and in the appearance of encountered symptoms but there was no evidence of major resistance genes, except possibly in Rosa rubiginosa which did not show any symptoms of Septoria. In 2006, a subset of the plant material in Field 1 was evaluated to check for consistency between the years. Leafspots had overtaken rust as the most important disease but results were otherwise very similar to those of 2005.

• Response of alternate bearing of “Badamy sefid” Pistachio cultivar to foliar application of some macro and micro elements

  109-112.

  G. Davarynejad

  E. Davarynejad

  Views:

  210

  Response of “Badamy sefid” Pistachio trees to spraying of fertilizer was studied over two years (2006–2007). The boron and zinc fertilizer were used just on swelling time of female flower bud in compare to no fertilization (control). Also nutritional solution combined of nitrogen (400 ppm), phosphorus (P2O5) (380 ppm), potasium (K2O) (520 ppm), Fe (5 ppm), Cu (2 ppm), Zn (2 ppm), Mn (2 ppm) in 1000 liter water per hectare sprayed at first week of May, third week of June and July). The concentration of some macro and micro elements in flower bud and in leaves, also productivity (g/shoot sectional area) mean nut weight, fresh weight of nut per cm2 branch cross sectional area, blanks nuts %, non-split nut %, new shoot growth length after cessation of growth and remained flower bud (%) at the next spring were recorded for the different treatments. The results showed that boron and zinc concentration increased in the bud of sprayed trees in compare to control. Application of nutritional solution decreased the flower bud abscission, also resulted in increased vegetative growth, nut weight, and productivity of trees. In conclusion, spraying of fertilizers in the suitable time to the pistachio trees might be a useful method in decreasing flower bud abscission and mitigating the alternate bearing.