Template-Type: ReDIF-Article 1.0 Author-Name: J. Blažek Author-Workplace-Name: Research and Breeding Institute of Pomology, Holovousy, Czech Republic Author-Name: R. Vávra Author-Workplace-Name: Research and Breeding Institute of Pomology, Holovousy, Czech Republic Author-Name: J. Kučerová Author-Workplace-Name: Research and Breeding Institute of Pomology, Holovousy, Czech Republic Title: Analysis concerning the rapid spread of apple proliferation phytoplasmas in a breeding orchard of apple seedlings Abstract: The spread of apple proliferation (AP) phytoplasmas was monitored for 6 years in a breeding orchard in which nearly 16 thousand apple seedlings were planted. Out of this number 1,888 trees were identified as AP infected till the end of the growing season 2004, which corresponded to the proportion of 11.9%. The epidemic started in 1999 when the first 18 trees were diagnosed as contaminated by AP. Since that time the number of AP infected trees in the whole orchard increased exponentially yearly up to 877 specimens in 2004. The decisive factor that influenced this spread of AP in this study was the use of fungicides for pest control in three different parts of this orchard. Some other factors - rootstock, age of trees or top-working were identified as influencing this AP spread in different ways. Their role in this spread is discussed in more detail. Trees of the age 10 years were the most frequently infected on average. Top-working significantly increased numbers of infected trees in the year of the treatment application in comparison with trees from adjoining rows without this treatment. The early removal of all AP infected trees from the orchard did not considerably reduce the rates of AP infection. Keywords: apple proliferation, phytoplasmas, apple, spread, vectors, breeding, insecticides Journal: Horticultural Science Pages: 43-49 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3764-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3764-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0001.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3764-HORTSCI Template-Type: ReDIF-Article 1.0 Author-Name: A. Kurunc Author-Workplace-Name: Department of Farm Structures and Irrigation, Faculty of Agriculture, Gaziosmanpaşa University, Tokat, Turkey Author-Name: C. Cekic Author-Workplace-Name: Department of Horticulture, Faculty of Agriculture, Gaziosmanpaşa University, Tokat, Turkey Title: Response of three strawberry cultivars (Fragaria × ananassa Duch.) to different salinity levels in irrigation water Abstract: Irrigation with saline waters is an agricultural practice that becomes increasingly common as competition for fresh water increases. In this study, three strawberry cultivars (Fragaria × ananassa Duch.) were tested for their salt tolerance. For this purpose, five salinity levels in water with electrical conductivities (ECi) of 1.1, 1.6, 2.1, 2.5, 2.9 dS/m and river water as control (0.5 dS/m) were used in a randomised design with four replications. Percent leaf damage at two dates and accumulation of salts in soil were determined for each cultivar. Considering the results, Maraline is the most tolerant to salinity. Severe effects of salt on Muir and Tudla growth were observed even at ECi 1.1 dS/m. The higher the level of ECi of irrigation water, the higher the soil ECe produced. In general, the highest soil ECe's were produced by Muir followed by Tudla experiment. Keywords: irrigation, saline water, strawberry, salt tolerance, electrical conductivity Journal: Horticultural Science Pages: 50-55 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3765-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3765-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0002.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3765-HORTSCI Template-Type: ReDIF-Article 1.0 Author-Name: K. Hamouz Author-Workplace-Name: Faculty of Agrobiology, Food and Natural Resources, Czech University of Agriculture in Prague, Prague, Czech Republic Author-Name: P. Dvořák Author-Workplace-Name: Faculty of Agrobiology, Food and Natural Resources, Czech University of Agriculture in Prague, Prague, Czech Republic Author-Name: J. Čepl Author-Workplace-Name: Potato Research Institute, Havlíčkův Brod, Czech Republic Author-Name: J. Pivec Author-Workplace-Name: Faculty of Agrobiology, Food and Natural Resources, Czech University of Agriculture in Prague, Prague, Czech Republic Title: The effect of polypropylene fleece covering on the yield of early potatoes Abstract: In 2000-2003 the effect of white fleece Pegas-agro 17 UV on the dynamics of yield formation in irrigated early potatoes (Adora and Impala varieties) was investigated in an early potato production region of the Czech Republic. The fleece was placed over the crops for 49 days (2000), 35 days (2001), 37 days (2002) or 45 days (2003) after the planting. The fleece significantly increased the yield of commercial tubers at early harvest (31. 5. 2000 to 121.3%, 7. 6. 2001 to 133.7% and 31. 5. 2002 to 134.5% in comparison with the control and on average of both varieties). Differences between the control variant and the fleece variant were insignificant during harvest at the end of June. In later sequential harvests differences between the fleece variant and the control variant diminished and at the end of June they were already insignificant. Between the varieties a greater yield effect was found in Impala variety in comparison with Adora variety. Favourable effects of the fleece on soil temperatures were demonstrated. Keywords: early potatoes, fleece, yield, variety, soil temperature Journal: Horticultural Science Pages: 56-59 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3766-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3766-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0003.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3766-HORTSCI Template-Type: ReDIF-Article 1.0 Author-Name: S. Shukla Author-Workplace-Name: Division of Genetics and Plant Breeding, National Botanical Research Institute, Rana Pratap Marg, Lucknow, India Author-Name: A. Bhargava Author-Workplace-Name: Division of Genetics and Plant Breeding, National Botanical Research Institute, Rana Pratap Marg, Lucknow, India Author-Name: A. Chatterjee Author-Workplace-Name: Division of Genetics and Plant Breeding, National Botanical Research Institute, Rana Pratap Marg, Lucknow, India Author-Name: A. Srivastava Author-Workplace-Name: Division of Genetics and Plant Breeding, National Botanical Research Institute, Rana Pratap Marg, Lucknow, India Author-Name: S. P. Singh Author-Workplace-Name: Division of Genetics and Plant Breeding, National Botanical Research Institute, Rana Pratap Marg, Lucknow, India Title: Estimates of genetic variability in vegetable amaranth (A. tricolor) over different cuttings Abstract: The present investigation was carried out to study different selection parameters for foliage yield and its important yield contributing traits in 29 strains of vegetable amaranth (A. tricolor). The data were recorded for plant height (cm), stem diameter (cm), branches/plant, leaves/plant, leaf size (cm2), and protein content (mg/100 mg) in each cutting separately. Foliage yield (kg) was recorded on plot basis comprising 4 cuttings. The highest foliage yield per plot was recorded for strain AV-38, followed by AV-23 and AV-31. In general, protein content was high in the 2nd cutting in all strains. The heritability estimates were in general high for all the characters in all the cuttings and ranged from 74.87% to 93.33%. Genetic advance was maximum for foliage yield (42.50%), followed by leaf size (31.02%) and stem diameter (21.13%). It was concluded that foliage yield could be increased substantially in vegetable amaranth through indirect selection based on the characters leaf size and stem diameter. Keywords: A. tricolor, foliage yield, heritability, genetic advance, selection Journal: Horticultural Science Pages: 60-67 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3767-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3767-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0004.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3767-HORTSCI Template-Type: ReDIF-Article 1.0 Author-Name: R. Ezekiel Author-Workplace-Name: Division of Crop Physiology and Post Harvest Technology, Central Potato Research Institute, Shimla, India Author-Name: B. Singh Author-Workplace-Name: Division of Crop Physiology and Post Harvest Technology, Central Potato Research Institute, Shimla, India Title: Effect of CO2 treatment on dormancy duration, sprout growth and sugar content in two potato cultivars: Short communication Abstract: Dormant tubers of two potato cultivars Kufri Jyoti and Kufri Chandramukhi were treated for 7 days with 5, 10, 15 and 20% CO2 concentrations at 18 ± 1ºC and 90-95% RH, and compared with GA treated tubers and with untreated tubers serving as control. During subsequent storage at the same temperature and RH, dormancy duration was reduced by 20 days with CO2 treatment and by 35 days with GA treatment. In Kufri Jyoti, GA treatment caused 2.6 fold increase in the concentration of reducing sugars and 0.8 fold increase in total sugars in the apical half of the tubers leading to early release of dormancy in apical buds but this increase in sugar content was not observed in the basal half where the buds remained dormant. Keywords: potatoes, dormancy breaking, CO2 concentration, sprout length, weight loss, reducing sugars, total sugars Journal: Horticultural Science Pages: 68-73 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3768-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3768-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0005.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3768-HORTSCI Template-Type: ReDIF-Article 1.0 Author-Name: M. Abbas Author-Workplace-Name: Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan Author-Name: M. M. Khan Author-Workplace-Name: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom Author-Name: S. M. Mughal Author-Workplace-Name: Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan Author-Name: I. A. Khan Author-Workplace-Name: College of Agriculture, Sultan Qaboos University, Sultanate of Oman Title: Prospects of classical cross protection technique against Citrus tristeza closterovirus in Pakistan: A review Abstract: In Pakistan citrus groves in general are facing a serious problem of decline that is attributed to different causes. The major cause, however, is the prevalence of citrus virus and virus-like diseases; Citrus tristeza virus (CTV) is of utmost concern. Although CTV has been identified and characterized on the basis of serological and physical properties, no information is available on the strains of CTV in Pakistan. The identification of CTV strains will be helpful in developing strategies to control the decline of citrus trees to a great extent. Many citrus growing countries have successfully used the technique of cross protection to minimize the drastic effect of severe CTV strains. By pre-immunization of the citrus tree with mild strains, the decline can be controlled to increase the life span of the citrus tree. In this study we focus on the possibility of establishing a cross protection technique in Pakistan against the CTV strains. Keywords: Citrus tristeza virus, cross protection Journal: Horticultural Science Pages: 74-83 Volume: 32 Issue: 2 Year: 2005 DOI: 10.17221/3769-HORTSCI File-URL: http://hortsci.agriculturejournals.cz/doi/10.17221/3769-HORTSCI.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/hor-200502-0006.txt Handle: RePEc:caa:jnlhor:v:32:y:2005:i:2:id:3769-HORTSCI