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• Efficacy of ethrel (2-chloroethyl phosphonic acid) as a chemical hybridizing agent in red pepper (Capsicum annuum L. var. Pusa jwala)

  41-44

  D. K. Agnihotri

  S. V. S. Chauhan

  Views:

  317

  A field experiment was conducted during 2003-2004 and 2004-2005 to study the effect of foliar sprays of ethrel or ethephon (2- chloroethyl phosphonic acid) on pollen sterility and yield parameters in Capsicum annuum var. Pusa jwala. Effect of treatments was also studied in F1 hybrids raised from treated male sterile plants crossed with the control plants. Plants sprayed with 0.1, 0.2 and 0.3% (v/v) ethrel exhibited 93.1-100% pollen sterility. This was associated with significant reduction in yield parameters (number of flowers, fruits/plant, fruit size, number of seeds/fruit and total yield/plant). However, the plants sprayed only once with 0.1% ethrel at pre-meiotic stage showed 93.1% pollen sterility without any significant reduction in yield parameter. The F₁ hybrids obtained by crossing the 100% male sterile treated plants with the pollen of untreated (control) plants exhibited only insignificant reduction in the number of flowers/ plant, fruits/plant, fruit size, number of seeds/fruit and total yield/plant. However, these parameters in F₁ hybrids were significantly higher over the treated plants.

• Impact of foliar fungi on dogroses

  23-30.

  C. S. Schwer

  U. Carlson-Nilsson

  Uggla M.

  G. Werlemark

  H. Nybom

  Views:

  334

  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:

  347

  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.

• The effect of climatic anomalies on the nutrient supply of fruit plantations (Minireview)

  111-116.

  P. T. Nagy

  M. Sipos

  Z. Szabó

  M. Soltész

  J. Nyéki

  Views:

  12784

  Climatic conditions play an important role in agricultural production. It has a profound influence on the growth, development and yields of a crop, incidence of pests and diseases, water needs and fertilizer requirements in terms of differences in nutrient mobilization due to water stresses. Nowadays, we have to know the dark side of the weather events because it is causing more and more problems and significant hazards to many horticultural regions in Hungary. The aim of this study is to explore the problems of nutrient uptake following climatic anomalies and response. These problems are: (i) water supply problems (water-stress); (ii) drought and frost as temperature­ strees. Reviewing the effects and nutrient disorders caused by climatic anomalies, the following statements can be taken:

  • Nutrient demand of trees can be supplied only under even worse conditions.
  • The most effective weapon against damage of climatic anomalies is preventative action.
  • When developing a fruit orchard, three factors should be taken into consideration: "Location, Location, Location".
  • Moreover, proper choice of cultivars, species and cultivation should provide further possibilities to avoid and moderate the effects of climatic anomalies.
  • Fruit growing technologies especially nutrition should be corrected and adjusted to the climatic events as modifier factors.
  • Urgent task of the near future is to correct and adjust the tested technologies of fruit growing according to these climatic events as modifier factors.

  Optimal nutrient supply of trees decreases the sensitivity for unexpected climatic events. To solve these problems supplementary, foliar fertilization is recommended, which adjusted to phonological phases of trees.

  Another solving is groundcover of soil means a potential opportunity to temper or even avoid climatic anomalies.