Horticultural Science, 2005 (vol. 32), issue 2
Analysis concerning the rapid spread of apple proliferation phytoplasmas in a breeding orchard of apple seedlings
J. Blažek, R. Vávra, J. Kučerová
Hort. Sci. (Prague), 2005, 32(2):43-49 | DOI: 10.17221/3764-HORTSCI 
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...
Response of three strawberry cultivars (Fragaria × ananassa Duch.) to different salinity levels in irrigation water
A. Kurunc, C. Cekic
Hort. Sci. (Prague), 2005, 32(2):50-55 | DOI: 10.17221/3765-HORTSCI
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...
The effect of polypropylene fleece covering on the yield of early potatoes
K. Hamouz, P. Dvořák, J. Čepl, J. Pivec
Hort. Sci. (Prague), 2005, 32(2):56-59 | DOI: 10.17221/3766-HORTSCI
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...
Estimates of genetic variability in vegetable amaranth (A. tricolor) over different cuttings
S. Shukla, A. Bhargava, A. Chatterjee, A. Srivastava, S. P. Singh
Hort. Sci. (Prague), 2005, 32(2):60-67 | DOI: 10.17221/3767-HORTSCI
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...
Effect of CO2 treatment on dormancy duration, sprout growth and sugar content in two potato cultivars: Short communication
R. Ezekiel, B. Singh
Hort. Sci. (Prague), 2005, 32(2):68-73 | DOI: 10.17221/3768-HORTSCI
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...
Prospects of classical cross protection technique against Citrus tristeza closterovirus in Pakistan: A review
M. Abbas, M. M. Khan, S. M. Mughal, I. A. Khan
Hort. Sci. (Prague), 2005, 32(2):74-83 | DOI: 10.17221/3769-HORTSCI
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...