Soil and plant selection for rain gardens along streets and roads in cold climates: Simulated cyclic flooding and real-scale studies of five herbaceous perennial species

This paper presents results from a container experiment and a real-scale study in road environments for evaluating the performance of soil mixtures and herbaceous perennials for use in rain gardens. The container experiment included 12 soil mixtures and 4 perennial species. The plants were exposed to three flooding events and one drought period, and their overall vitality was recorded after the floodings. The containers were stored outdoors the following winter and plant survival was observed in spring. Amsonia orientalis did not survive the winter after being exposed to flooding in the growing season and was replaced by Hosta ‘Francee’ in the real-scale study, which was established in Drammen (Norway) in a soil mixture based on optimisation of the best mixtures in the container experiment. Luzula sylvatica performed well in the container study and survived the winter; however, in the field study, individuals of this species that were located close to the road died due to de-icing salt. Eurybia divaricata showed some mortality in both studies, and total mortality occurred in individuals that were close to the road, due to de-icing salt. Hemerocallis cvv. performed well in both experiments and appeared to be useful in all rain garden positions in the cold climate road environment. H. ‘Francee’ developed well in the road environment, except when exposed to splashes of road water. The study highlights considerable differences between species’ adaption to roadside rain gardens in cold climates, and the need for further field investigations.     

Plant selection for rain gardens: Response to simulated cyclical flooding of 15 perennial species

Plant selection for rain gardens can be complicated, as cyclic flooding and a gradient of moisture level are expected in the depression structure of a rain garden. However, few studies to date have quantified how plant establishment is affected by rain garden moisture dynamics. This study investigated tolerance of 15 candidate perennial species, which experienced flooding cycles consisting of 1-day and 4-day inundation and draining phases. In this study, detection of species suitability using survival and growth measurements coupled with the stress indicator (i.e. chlorophyll fluorescence) provided a valid framework for wider use in plant selection for rain gardens. The methodology is also confident in predicting the possible placing in different plant moisture zones. All species survived the cyclic flooding treatments and grew to their maximum. Photosynthesis and physical growth in only a few candidate species (e.g. Amsonia tabernaemontana var. salicifolia, Gaura lindheimeri, Sanguisorba tenuifolia ‘Purpurea’ and Thalictrum aquilegifolium) tended to be inhibited by treatments adopting 4-day cyclic flooding, whilst tolerance to 1-day cyclic flooding was clearly demonstrated in most species. Analysis suggests that most species assumed to withstand infrequent to periodic inundation, such as Iris sibirica, Filipendula purpurea and Miscanthus sinensis, are resilient species and are sensible for use in a wider range of rain garden moisture conditions from damp depression bottom to dry margin. Species assumed to be intolerant of inundation such as Gaura lindheimeri may be successful in the rain garden environment, but they are recommended for the dryer zones.     

Hydrological behaviour of rain gardens and plant suitability: A study in the Veneto plain (north-eastern Italy) conditions

Since spring 2011 the roof of a building on the Agripolis Campus of the University of Padova (Italy) has been used as a drainage area for two rain gardens with a circular area of about 10% and 20% of the drainage area respectively. To improve soil infiltration, the topsoil was removed up to the depth of 1 m and filled with a mix of 50% sand, 25% compost and 25% of the existing topsoil. Herbaceous perennials were selected and planted to test their adaptability to different soil water conditions in the rain garden. To evaluate the capacity of each rain garden to manage stormwater runoff a simplified water balance was done, estimating actual evapotranspiration using the WUCOLS method. From autumn 2012 runoff volumes were collected just from one pitch of the roof, and directed only into the smaller rain garden that became equal to 15% of the new roof drainage area. We thus had the possibility to test the functionality of rain gardens with three different percentages of roof drainage area: 10, 15 and 20%, even if in different periods. Results are presented relating to a four-year experimental period. Regarding hydrological behaviour, the input water volumes caused a slight overflow only during a few rainfall events. Consequently, the results showed a high capacity to manage stormwater runoff and also in the smaller rain garden almost the total roof runoff volumes infiltrated into the soil. As regards plants, the results indicated that the growth is affected by their position in the rain garden, from the wettest condition in the centre to the driest at the perimeter, except for Hemerocallis hybrida that showed great adaptability in all positions. Aster novi-belgii, Echinacea purpurea, Iris pseudacorus, Molinia caerulea and Rudbeckia fulgida also showed good adaptation, even if not in all rain garden zones, with highly aesthetic results. Lythrum salicaria and Saponaria officinalis plants appeared to be unsuitable for rain gardens. The results of the experiment have shown that, in the Veneto plain environment, rain gardens with a size of 10–15% of the roof drainage area can ensure both the sustainable management of stormwater runoff and a high aesthetic functionality.     

月季新品种‘天香’、‘天山白雪’、‘天山桃园’、‘天山之光’与‘天山之星’

利用弯刺蔷薇（Rosa beggeriana L.）与现代月季品种进行远缘杂交,育成5个灌丛月季品种。其中‘天香’花深粉红色,重瓣,浓香;‘天山白雪’花白色,半重瓣;‘天山桃园’花粉色,半重瓣;‘天山之光’花白色,重瓣;‘天山之星’花粉红色,半重瓣,浓香,花径小,仅5 ~ 6 cm。5个品种均表现为植株高大,生长势旺盛,抗寒性极强,是庭园绿篱、绿地景观或道路绿化的理想材料。     

The physiology of hyacinth bulbs. XV. The effect of gibberellic acid and silver nitrate on dormancy release and growth

The effect of gibberellic acid (GA₃), supplied to dormant hyacinth bulbs of cultivars ‘Lady Derby’ and ‘L'Innocence’ by vacuum infiltration, on growth and flowering was investigated. Results showed that GA₃ in all applied concentrations (50, 500, 1000 and 5000 mg/l) accelerated growth and flowering in both cultivars, after chilling for 42 days in a garden frame in natural conditions or chilled dry in cold storage at 5°C. Bulb infiltration with 10 mg/l AgNO₃ resulted in the acceleration of flowering only in ‘L'Innocence’, but stimulated the growth of the inflorescence stalk and leaves in both cultivars regardless of the mode of chilling.The infiltration method was confirmed to be very promising.     

The physiology of hyacinth bulbs. XI. The effect of gibberellic acid on the growth and flowering of variously chilled bulbs

The effect of gibberellic acid, GA₃, on the growth and flowering of hyacinth cultivars ‘Pink Pearl’, ‘Delft Blue’ and ‘Carnegie’, chilled in a cold room at 5°C or a garden frame for 28, 42 or 81 days, and either rooted or dry, unrooted, was investigated. GA, was applied to the basal plates of the bulbs in a lanolin paste on 10 October 1975.The growth of the inflorescence and leaves of plants originating from dry-chilled bulbs was generally the same as that of those grown from rooted plants. A similar response to GA₃ treatment was observed in all cultivars. Treatment of bulbs with GA₃ decreased the number of days to flowering, stimulated the growth of inflorescences and leaves, and its effect was most pronounced in the plants chilled for shorter periods.     

The domestic garden – Its contribution to urban green infrastructure

Domestic gardens provide a significant component of urban green infrastructure but their relative contribution to eco-system service provision remains largely un-quantified. ‘Green infrastructure’ itself is often ill-defined, posing problems for planners to ascertain what types of green infrastructure provide greatest benefit and under what circumstances. Within this context the relative merits of gardens are unclear; however, at a time of greater urbanization where private gardens are increasingly seen as a ‘luxury’, it is important to define their role precisely. Hence, the nature of this review is to interpret existing information pertaining to gardens/gardening per se, identify where they may have a unique role to play and to highlight where further research is warranted. The review suggests that there are significant differences in both form and management of domestic gardens which radically influence the benefits. Nevertheless, gardens can play a strong role in improving the environmental impact of the domestic curtilage, e.g. by insulating houses against temperature extremes they can reduce domestic energy use. Gardens also improve localized air cooling, help mitigate flooding and provide a haven for wildlife. Less favourable aspects include contributions of gardens and gardening to greenhouse gas emissions, misuse of fertilizers and pesticides, and introduction of alien plant species. Due to the close proximity to the home and hence accessibility for many, possibly the greatest benefit of the domestic garden is on human health and well-being, but further work is required to define this clearly within the wider context of green infrastructure.     

Effect of native habitat on the cooling ability of six nursery-grown tree species and cultivars for future roadside plantings

Vegetation in urban areas provides benefits to people, which are increasingly assessed and valued as ecosystem services (ESS). The regulation of the urban microclimate is one of these services, since trees have the potential to reduce urban heat loads by evapotranspiration and shading. Simultaneously, it has been suggested that trees from dry habitats should be used to cope with the increasing risks of drought under climate change in Central Europe. The underlying properties that enable those trees to reduce dependence on the environment, however, are assumed to come at the expense of biomass production and water loss. In the potentially conflicted area between drought tolerance and ESS we compared water consumption, water-use efficiency (WUE), crown structure and growth of six roadside species/cultivars, which are assumed to vary in drought tolerance, due to differing resource supplies in their native habitats. Acer platanoides, Carpinus betulus ‘Fastigiata’, and Tilia cordata ‘Greenspire’ were compared with Acer campestre, Ostrya carpinifolia, and Tilia tomentosa ‘Brabant’, the latter presumably being less water-demanding. Measurements took place in the municipal nursery of Munich during summer 2016.Surprisingly, the less water-demanding species/cultivars exhibited on average 1.24 times higher values of maximum daily sap flux density and up to seven times higher growth rates, both contributing to higher WUE. Scaled to leaf level, however, their mean daily transpiration rates were on average lower (0.21 and 0.31 kg H₂O m⁻² d⁻¹, respectively). They also showed higher flexibility in response to changing weather with increased growth and transpiration under favorable conditions in early summer, but a more conservative water use in dry late summer. The results suggest that these species/cultivars tend to regulate their water use stronger under increasing dryness, whereas canopy size and leaf amount are still the main important determinants of species and cultivar differences in water use.     

Video evaluation of ethylene sensitivity after anthesis in carnation (Dianthus caryophyllus L.) flowers

Differences in ethylene sensitivity among carnation (Dianthus caryophyllus L.) cultivars were evaluated using a time-lapse video recording system. Measurement of time to petal inrolling of ‘White Sim’, ‘Nora’, ‘Chinera’, and line 64-54 flowers subjected to a range of 1–20 μl l⁻¹ ethylene showed that 10 μl l⁻¹ was the optimum concentration for sensitivity evaluation with our video system. With this system we found clear differences in ethylene sensitivity among 10 cultivars and one line. ‘Candy’, ‘Pallas’, ‘Chinera’, and line 64-54 had lower ethylene sensitivities than the other seven cultivars. Line 64-54 had the longest ethylene response time (20.6 h to start of petal inrolling). Video monitoring is a simple and accurate way of evaluating ethylene sensitivity. We have also used the system to study changes in the ethylene sensitivity of carnation flowers after anthesis. We were able to detect a shift in responsiveness to ethylene that was impossible to detect by previous methods. In the Sim-type carnation cultivars tested (‘White Sim’, ‘Scania’, ‘U Conn Sim’, and ‘Nora’), ethylene sensitivity after anthesis decreased significantly with age in both early-cut and late-cut flowers. These results clearly showed that decline of ethylene sensitivity is caused by the increasing physiological age of flowers. Ethylene sensitivity after anthesis decreased with age in normal Sim-type carnations in the same way as in long-vase-life variants such as ‘Sandrosa’.     

Seasonal changes in CO2 assimilation in leaves of five major Greek olive cultivars

Leaf CO₂ assimilation rate, stomatal conductance (g_s), internal CO₂ concentration (C_i), chlorophyll (a + b) content, specific leaf weight (SLW) and stomatal density were measured during the season, under field conditions, for five major Greek olive cultivars, ‘Koroneiki’, ‘Megaritiki’, ‘Konservolia’, ‘Lianolia Kerkiras’, and ‘Kalamon’, with different morphological and agronomic characteristics and diverse genetic background. Measurements were taken from current-season and 1-year-old leaves, and from fruiting and vegetative shoots, throughout the season, from March to November in years 2001 and 2002. CO₂ assimilation rates showed a substantial seasonal variation, similar in all cultivars, with higher values during spring and autumn and lower values during summer and late autumn. Stomatal conductance (g_s) followed similar trends to leaf CO₂ assimilation rates, increasing from March to July, following by a decrease during August and increasing again in autumn. ‘Koroneiki’ had the highest leaf CO₂ assimilation rate and g_s values (21 μmol m⁻² s⁻¹ and 0.45 mol m⁻² s⁻¹, respectively) while ‘Lianolia Kerkiras’ and ‘Kalamon’ showed the lowest leaf CO₂ assimilation rate and g_s values (13–14 μmol m⁻² s⁻¹ and 0.22 mol m⁻² s⁻¹, respectively). One-year-old leaves had significantly higher leaf CO₂ assimilation rate than current-season leaves from April to June, for all cultivars. From August and then, leaf CO₂ assimilation rate in current-season leaves was higher than in 1-year-old leaves. There were no significant differences in leaf CO₂ assimilation rate between fruiting and vegetative shoots. Total chlorophyll (a + b) content increased with leaf age in current-season leaves. In 1-year-old leaves chlorophyll content increased in spring, then started to decrease and increased slightly again late in the season. Chlorophyll content was higher in 1-year-old leaves than in current-season leaves throughout the season. Total specific leaf weight (SLW) increased throughout the season for all cultivars. Stomatal density in lower leaf surface was lowest for ‘Koroneiki’ (399 mm⁻²) and highest for ‘Megaritiki’ (550 mm⁻²). Our results showed differences in leaf CO₂ assimilation rate among the five different olive cultivars, with a diverse genetic background, ranging from 12 to 21 μmol m⁻² s⁻¹. From the five cultivars examined, ‘Koroneiki’, a drought resistant cultivar, performed better and was able to maintain higher leaf CO₂ assimilation rate, even under high air vapor pressure deficit. All cultivars had a pronounced seasonal variation in leaf CO₂ assimilation rate, affected by date of the year, depending on ambient conditions. The high temperatures and high air vapor pressure deficit occurring during summer caused a reduction in leaf CO₂ assimilation rate in all cultivars. Leaf CO₂ assimilation rate was also affected by leaf age for all cultivars, with old leaves having significantly higher leaf CO₂ assimilation rate than young leaves early in the season.     

Defect-disorder and risk assessment of heritage trees in urban Hong Kong

Heritage trees in a city, echoing factors conducive to outstanding performance, deserve special care and conservation. To understand their structural and health conditions in urban Hong Kong, 30 defect-disorder (DD) symptoms (physical and physiological) subsumed under four tree-position groups (soil-root, trunk, branching, and crown-foliage) and tree hazard rating were evaluated. The surveyed 352 trees included 70 species; 14 species with 233 trees were native. More trees had medium height (10–15 m), medium DBH (1–1.5 m) and large crown (>15 m). In ten habitats, public park and garden (PPG) accommodated the most trees, and roadside traffic island (RTI) and public housing estate (PH) had the least. Tree dimensions and tree habitats were significantly associated. The associations between the 2831 DD and tree-position groups, tree habitats and tree hazard rating were analyzed. Fourteen trees from Ficus microcarpa, Ficus virens and Gleditsia fera had high hazard rating, 179 trees from 22 species moderate rating, and 159 trees from 55 species low rating. RTI, roadside tree strip (RTS), roadside tree pit (RTP), roadside planter (RP) and stone wall (SW) had more moderate hazard rating, and PPG, roadside slope (RS) and government, institutional and community land (GIC) more low rating. Redundancy analysis showed that DD were positively correlated with RTS, RTP, RP and SW, but negatively correlated with PPG, RS and GIC (p < 0.05). The DD significantly increased tree hazard rating and failure potential. Future management implications for heritage-tree conservation and enhancement focusing squarely on critical tree defect-disorder in urban Hong Kong were explored, with application to other compact cities.     

The use of native turf mixtures to approach sustainable lawn in urban landscapes

Native grasses are excellent candidate species for manipulation to produce dwarf and turf type varieties as well as for producing cultivars with higher attractiveness and requiring less maintenance to be used as a turf grass in arid and semi-arid regions of the world. This investigation was conducted to explore visual qualities of native grasses and their mixtures compared to commercial turf. The field experiment was set out in a split-plot in time based on a randomized experimental design with three replications. We used two native monoculture accessions, perennial ryegrass (Lolium perenne L. ‘Yarand’) and (Lolium perenne L. ‘Shadegan’), Native low-variety Mixture (NM1): consisting of 50% Lolium multiflorum ‘Shadegan’? 50% Festuca spp. ‘Shadegan’, Native high-variety Mixture (NM2): consisting of 55% Lolium perenne L. ‘Yarand’? 35% Lolium perenne L. ‘Shadegan’? 5% L. multiflorum ‘Shadegan’ and 5% Festuca spp. ‘Shadegan’ and compared this with one commercial turf mixture that is commonly used in landscaping. Results indicated the effects of seasons and turf grass types and their interaction had significant effects on most variables including quality, season color, leaf texture, density, quality after clipping (p < 0.01). The visual quality measurements indicated the superiority of L. perenne ‘Shadegan’ over other native monoculture and polyculture and its ablility to compete with the commercial turf. The native turf mixture of NM2 showed several good characteristics. L. perenne ‘Yarand’ had statistically the lowest score for visual appeal as compared with the other turf types. This research suggests that the use of native grass species of L. perenne ‘Shadegan’ is worth investigating for better performance of the native landscape.     

Bud opening of cut liatris flowers

The possibility of bud opening of cut liatris flowers (Liatris spicata L.) harvested at a tight bud stage was examined. Of the different solutions tested, 5% sucrose together with 0.2% TOG germicide solution gave the best results as evaluated by vase-life and inflorescence development. The subsequent quality of the treated flowers was superior to that of non-treated flowers harvested at a commercial stage.When flowers were exposed to simulated air-shipment after treatment, the superiority of treated bud-stage flowers over commercially harvested ones was even greater.     

Interspecific hybridization in Lonicera caerulea and Lonicera gracilipes: The occurrence of green/albino plants by reciprocal crossing

Lonicera caerulea L. var. emphyllocalyx (Maxim.) Nakai is a berry crop cultivated in cold regions. So far, commercial cultivars have been mainly introduced from selection of wild plants. Therefore, fruit traits and other agricultural characteristics have been limited. In this study, interspecific crosses between L. caerulea var. emphyllocalyx and Lonicera gracilipes var. glabra Miquel were examined to increase genetic variability of L. caerulea var. emphyllocalyx. Seedlings were obtained from reciprocal crosses between L. caerulea var. emphyllocalyx and L. gracilipes var. glabra. The hybrid nature of seedlings was confirmed with random amplified polymorphic DNA analysis. Viable green plants were obtained efficiently from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx. In contrast, all plants produced from L. caerulea var. emphyllocalyx × L. gracilipes var. glabra were albino. These albino plants were very weak and only survived in culture condition. The chlorophyll deficiency was unilaterally observed, suggesting the occurrence of nuclear–cytoplasmic incompatibility. Viable F₁ hybrids obtained from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx are amphidiploid (2n = 4x = 36) as showing same to both parents. The hybrid plants are expected to increase the variability of fruit traits, and may have heat tolerance from L. gracilipes var. glabra.     

Phenolic Compounds,Antioxidant Activity,Fatty Acids and Volatile Profiles of 18 Different Walnut (Juglans regia L.) Cultivars and Genotypes

The study was carried out to determine phenolic compounds, antioxidant activity, total lipids, saturated fatty acids, unsaturated fatty acids, and volatile organic compounds (VOCs) of 18 different walnut (Juglans regia L.) cultivars and genotypes grown in Usak province, Turkey. The biochemical compounds were identified for each cultivar and genotype and a comparative evaluation was carried out. The results showed that most of the biochemical compounds are significantly varying among each other (p?<?0.05). The existence and abundance of the biochemical compounds in the cultivars and genotypes have not only found to be a cause of differentiation, but they have been important parameters for the similarities among the cultivars and genotypes. Total phenolic content and antioxidant activity ranged from 750.67 to 1245.64?mg GAE ml^?1 and from 42.46 to 56.50% in kernels, respectively. The highest contents of the phenolic compounds were noted from gallic acid (11991?mg kg^?1), ellagic acid (1057.16?mg kg^?1), catechin (425.4?mg kg^?1), and rutin (216.6?mg kg^?1), as an average of all cultivars and genotypes. The highest lipid contents were noted from ‘Franquette’ and ‘Fernette’ as 64.28% and 63.26%, respectively, while the lowest content was noted from ‘Oguzlar 77’ (52.52%). A total of 42 VOCs were described from the 18 different walnut cultivars and genotypes. Overall, results showed that the phenolic profiles, fatty acids composition, and VOCs play an important role in similarities and diversities among the cultivars. According to the results, 7 different clusters were developed from the 18 cultivars and genotypes. Herein, ‘Fernor’, ‘Maras 18’, ‘Arslan Local Type’ and ‘Cisco’ cultivars were found to have the lowest biochemical compositions. The superior cultivars or genotypes, in terms of the abundance of the biochemical composition, were found to be ‘Gulizar Hanim Type’, ‘Lara’, ‘Pedro’, ‘Tulane’, ‘Fernette’, ‘Balkan’ and ‘Franquetta’, where they were found to develop 3 clusters by 1:3:3, respectively.

     

Study on Fruitset and Pollen-Compatibility Status in Sweet Cherry (Prunus avuim L.) Cultivars

Prunus avium L. is one of the most important temperate zone fruits in the world. Most of the cherry cultivars always have difficulties of fertilization and fruit set due to self-incompatibility, so they need suitable and compatible pollinizers for commercial fruit production. In this experiment, pollination compatibility of cherry cultivars of ‘Napoleon’, ‘Burlat’, ‘Zhan’, and ‘Lambert’ was studied as both pollen recipients and donors. To determine the compatibility or incompatibility of pollinizers, percent of fruit set was calculated. This research was carried out as a factorial experiment in a randomized complete block design. The final average fruit set in studied cultivars was different under self or cross-pollination. The results showed that ‘Napoleon’, ‘Zhan’ and ‘Lambert’ cultivars are the suitable pollinizers for ‘Burlat’. Also, ‘Burlat’ is a cultivar which produced many fruits under self-pollination. Therefore, ‘Burlat’ can be used as monoculture for orchard establishment. Results showed that cultivar ‘Napoleon’ was cross-incompatible with ‘Lambert’. ‘Zhan’, ‘Napoleon’ and ‘Lambert’ cultivars are founded self-incompatible and require cross-pollinations to obtain fruits.

     

A hypothesis to explain the relationship between low-temperature treatment,gibberellin activity,curd initiation and maturity of cauliflower

The effects of cold-treating young cauliflower plants (Brassica oleracea var. botrytis L.) of the cultivars ‘Lero’, ‘Lawyna’, ‘Novo’ and ‘Janavon’, on gibberellin activity and the spreads of curd initiation and maturity are described and discussed in relation to other similar work.Exposure of plants to 0°C for 15 days increased gibberellin activity in the apices of ‘Lero’ and ‘Lawyna’ plants. The spreads of curd initiation and maturity of ‘Lawyna’ were significantly reduced by cold-treatment at 0°C, but ‘Lero’ was not affected, possibly because plants had initiated too many leaves and were thus beyond the stage receptive to low-temperature treatment. This treatment had no effect on gibberellin activity nor on the spreads of curd initiation and maturity of ‘Novo’ or ‘Janavon’, probably because plants had not reached the sensitive stage when cold-treated.It is postulated that the phase of growth during which the curd-initiation period can be shortened by cold treatment is specific for each cultivar, and other data were used to confirm this. It seems likely that the receptive phase occurs at higher leaf-numbers with cultivars which take longer to initiate curds.     

A pear rootstock trial in Israel

The pear cultivars ‘Spadona Estiva’, ‘Coscia’, ‘Beurré Superfin’ and a ‘Bartlett’ clone of South African origin (termed ‘Bartlett Sport’) were tested on 5 quince rootstock types, 5 Pyrus species and on 5 or 30 cm long interstocks of the pear cultivars ‘Bergamotte Esperen’ and ‘Spadona Estiva’ on quince MA, while ‘Dr. Jules Guyot’ was used as an interstock on ‘Bartlett’ seedlings.At the age of 10 years only ‘Spadona Estiva’ showed no signs of decline on quince rootstocks, ‘Coscia’ showed moderate decline, while the remaining cultivars had already declined severely. When the trunk circumference of ‘Beurré Superfin’ trees on the various quince clones was taken as an indicator for the degree of graft incompatibility, a negative correlation was found between this parameter and cyanogenic glycoside content in the stem bark of ungrafted quince plants belonging to the same clones. Pear interstocks on quince MA rootstocks did in some cases increase crops compared to the same quince alone, but did not prevent the decline of ‘Beurré Superfin’ and Bartlett Sport' on quince.The most vigorous and most prolific rootstock was Pyrus betulaefolia. However, with ‘Spadona Estiva’ differences in vigor between the rootstocks were only small and crops on the Israeli quince CI 7 were similar to those on Pyrus betulaefolia, but fruit size was larger on quince. Cropping of this cultivar at the age of 4 years was closely related to the intensity of flowering, whereas with ‘Coscia’ this relation was much less evident.Leaf fall in autumn and the opening of the vegetative buds of ‘Beurré Superfin’ in spring were earlier on quince than on Pyrus rootstocks.     

Antioxidant capacity is correlated with susceptibility to leaf spot caused by a rapid temperature drop in Saintpaulia (African violet)

The relationship between the susceptibility to rapid temperature drop induced leaf injury, i.e. “leaf spot”, and the antioxidant capacities of several Saintpaulia (African violet) cultivars was examined. Cultivars ‘Ritali’ and ‘Tamiko’, that are more susceptible to leaf spot caused by a rapid drop in leaf temperature from 30 to 15°C than are cultivars ‘Maui’ and ‘New Jersey’. The susceptible cultivars were also more susceptible to oxidative stress caused by H₂O₂ and active chlorine than the tolerant cultivars. Reduction of available chlorine, considered to be accelerated by antioxidants of leaf tissue, was rapid in ‘Maui’ and ‘New Jersey’. Activity of the antioxidant enzymes superoxide dismutase and catalase were higher in the leaves of ‘Maui’ and ‘New Jersey’ than in the susceptible cultivars. These findings show a correlation between leaf spot injury and antioxidant capacity in Saintpaulia leaves.     

The Pillnitz Re-Series of Apple Cultivars – Do They Hold Promise? – 80 Years of Professional German Fruit Breeding 2008

The aim of the Pillnitz apple breeding is to combine improvements in fruit quality + yield + resistance to different pathogens in new cultivars. Early-, mid- and late-season apple cultivars were selected in two series, Pi- and Re-cultivars?. The Re-cultivars? guarantee a high degree of resistance. Triple and multiple resistant cultivars were selected with resistance to scab, mildew and fire blight: ‘Remo^®’, ‘Regia^®’, ‘Rewena^®’ and ‘Rebella^®’. ‘Rebella^®’ was found to have resistance also to bacterial canker, red spider mite and abiotic damages. The cultivars are the base for a new growing management in integrated and organic cultivation. Doubtless, the Pillnitz resistance breeding conception is a success, even if some problems remain to solved in the future. Various degrees of scab infection on Vf-resistant cultivars had been observed since 1984 in Central Europe. No infections were found in cultivars with other genes like V _f such as ‘Reglindis^®’ (V _A), ‘Reka’ (V _r), or ‘Regia^®’ (V _r). New sources are necessary for resistance breeding, especially for pyramiding of resistance genes. However, if the V _f-gene is overcome, new resistance sources and cultivars with two or more different sources of resistance to stabilize healthiness in the field will be required in the future. More explanation and advertisement about the value of resistant cultivars to promote the cultivation in commercial orchards is needed.