Holzhäcksel- und Miscanthusmulch erhalten die Bodenfeuchte und fördern die biologische Bodenaktivität sowie vegetatives und generatives Wachstum junger Apfelbäume

Tree rows of a two-year-old apple (cv. ‘Topaz’) orchard in Klein-Altendorf near Bonn, Germany, were mulched with either a) shredded broadleaf tree trunks (5?cm; 29?t dm/ha) in January 2005, b) high (6?cm; 17?t?dm/ha), or c) low (3?cm, 7?t dm/ha) shredded stems of Miscanthus in July 2004 to conserve resources and achieve closed systems; uncovered soil served as control. The following results were obtained in this MSc thesis during the 2005 growing season:

1. Soil covered with any of the three mulches mineralised 7–14?kg less nitrogen per hectare throughout the growing season resulting in a more balanced nitrogen mineralisation. The reduction in nitrogen supply prevented late vegetative growth and contributed to good fruit colouration.
2. The largest soil respiration was recorded with wooden chips as mulch with a peak of 1.6?CO₂?m^–2?h^{– 1} in June/July, followed by Miscanthus mulch and the uncovered control, which indicates enhanced microbial activity in the summer as a result of medium C/N ratio, warming and better aeration of the wood chips.
3. The organic mulches preserved soil moisture with values of less than 53 centibars and with less fluctuation than in the control.
4. The organic mulches reflected ca. 10% of incident PAR 1?m above ground, i.e. more light than uncovered soil, all without affecting fruit colouration.
5. The two thicker (5?cm and 6?cm) organic mulches suppressed weed population by 63–67% relative to the control.
6. The two thicker (5–6?cm) organic mulches improved potassium uptake by the apple leaves with 1.5 % K relative to 1.3 % K in the control on a leaf dry matter basis, but reduced their calcium and magnesium content.
7. Wood chips as mulch improved vegetative growth of the apple trees during the growing season, measured as trunk diameter, of 4?mm, followed by 3.6?mm of the high Miscanthus and 2.8?mm in both the low Miscanthus mulch and the control.
8. The organic mulches enlarged apple fruit diameter from 78?mm in the control to 80?mm with a concomitant increase in fruit weight from 180?g in the control to 185–188?g.

     

Variation of physical and chemical characters within an elite sea buckthorn (Hippophae rhamnoides L.) breeding population

Physicochemical characteristics of 44 elite sea buckthorn bushes were determined over 2 years. The bushes can be divided into five groups on the basis of their origins. Significant group differences were detected among most studied traits. Finnish origins (subsp. rhamnoides) were characterized by low vitamin C (VC) concentration, low total sugar (TS) concentration and high titratable acidity (TA), while Chinese origins (subsp. sinensis) showed high VC, TS and TA. Progenies from crosses between Finnish and Danish individuals showed no significant difference from their parents for the traits concerned. Hybrids between Chinese (subsp. turkestanica) and Finnish individuals were intermediate. However, hybrids between Siberian and Finnish individuals had a relatively high sugar:acid ratio (SAR), which is a desirable property for fresh fruit production. Large fluctuations in physicochemical characteristics between the two years show that the results of one year are not sufficient to reveal the phenotypic potential of a particular genotype. However, strong rank-order correlations for VC, TA, pH, TS, SAR and berry shape between the two years suggest that one can compare different genotypes on the basis of 1 year’s data. The negative correlation between seed weight and TS suggests that seed weight could usefully and cheaply predict sugar concentration of sea buckthorn berries in a preliminary screening. Climatic conditions and variable periods between ripening and harvesting appear to have considerable effects on the studied traits.     

Stolon Development and Cultural Production Practices of Winter-Grown Strawberries

ABSTRACT

The four experiments described here are part of a 5-year program focused on determining whether day-neutral and short-day strawberries would be suitable for commercial off-season/winter (temperate climate) production in greenhouses. All research was performed using container-grown plants fertigated through a capillary mat production system with heat supplied under the benches. The first experiment focused on stolon development. The second experiment investigated the influence of stolon removal on berry production and included the removal of flowers for the first three weeks. The third and fourth experiments were conducted as a comparison of university research (experiment 3) versus a commercial operation (experiment 4). In experiment one, of 13 cultivars, ‘AC Wendy’ plants produced significantly more stolons than the other cultivars. In experiment two, stolon production peaked at weeks 12 and 13, with ‘Chandler’ plants producing significantly more stolons (starting at week 9) than the other cultivars. At week 13, ‘Seascape’ plants produced more total berry weight than the other cultivars. The influence of stolon removal on total berry weight varied, with ‘Evie-2+’ plants (large crowns) producing higher total berry weight with the stolons on as compared to ‘Evie-2’ plants, which produced higher total berry weight with the stolons removed. In experiment 2, fruit production was low and was probably a result of deflowering for three weeks. Consequently, it may not be advisable to deflower during the ‘off-season’ for greenhouse-grown strawberries. In the final two experiments, which involved a commercial cooperator as well as the university greenhouse, it was found that of the five cultivars trialed, the same cultivars at both sites produced the maximum total berry weight. Stolon production differed at the two locations, but the optimal time for stolon removal was similar. Thus, it is recommended that for winter greenhouse production, stolons be removed initially at week 8 and then at weeks 11–12 of the production cycle.     

Soil pH effects on yield and fruit size of two rabbiteye blueberry cultivars

The effects of soil pH on yield and average berry weight of rabbiteye blueberry cvs Delite and Tifblue were investigated. Over a three year period, the higher soil pH decreased from 6.5 to 5.9, but the total yield of both cultivars decreased more than 60% as soil pH increased from 4.5 to 6.5 in the first two years and to 5.9 during the last year. Percent marketable yield was less influenced by the change in soil pH than was total yield. ‘Tifblue’ produced more fruit and had higher marketable yields, but the fruit size determined by average berry weight was smaller than ‘Delite’. When the soil pH was at a more desirable range for maximum yield (4.5 to 5.3), ripening was more uniform for both cultivars. This study illustrated that: (a) two rabbiteye blueberry cultivars differed in tolerance to alkaline growing conditions, (b) the response of the two cultivars to the change in soil pH varied from year to year, and (c) total yield of both cultivars was maximized when soil pH was below 5.0.     

Identification and genetic relationship based on ISSR analysis in a germplasm collection of sea buckthorn (Hippophae L.) from China and other countries

Sea buckthorn (Hippophae L.) is a woody, outcrossing dioecious pioneer plant, being widely planted as a new berry crop with rich nutritional and medicinal compounds, as well as a means of prevention of soil erosion. Inter simple sequence repeat (ISSR) markers were generated in 219 plants of 40 cultivars from China and other countries, representing two species of Hippophae salicifolia and Hippophae rhamnoides that includes two subspecies (ssp. mongolica and ssp. rhamnoides) and intraspecific hybrids between ssp. mongolica and ssp. sinensis. Fifteen selected ISSR primers generated 385 bands with an average of 25.6 bands per primer. Thirty hundred and eighty-five bands were used to generate a Dice's coefficient matrix of pairwise comparisons between individual ISSR profiles. Cluster analysis based on this matrix showed clustering of plants into groups which was in good agreement with their taxonomic classification. The results also revealed the presence of different cultivars with the same name, identical cultivars but with a different name and the genetic relationship of cultivars with unknown parentage to those with known parentage. Our data will be helpful in collection and conservation of sea buckthorn germplasm and potential hybrid strategy for breeding.     

Combining Plant Growth with Nutrient Content Measurements as a Method to Compare Nutrient Use by Different Raspberry Cultivars

ABSTRACT

Monthly above-ground destructive sampling and partitioning of the plant into distinct component parts for growth and nutrient element (N, P, K, Ca, Mg, Na, B, Cu, Zn, Fe and Mn) analyses were used to compare elemental compositions in two red raspberry (Rubus idaeus L.) cultivars (‘Willamette’ and ‘Haida’) grown in a uniformly managed field plot. Quantitative measurements showed that the two cultivars had different growth patterns. ‘Haida’ yielded greater fresh berry weight and dry matter content than ‘Willamette’ on a per floricane basis, but, because of fewer ‘Haida’ than ‘Willamette’ floricanes in the plot after standard commercial pruning practices, fresh berry yield was similar for both cultivars on a unit area basis. ‘Haida’ berries ripened slightly earlier than ‘Willamette’. Stem, lateral and leaf growth differed between the two cultivars. Although only whole above-ground accumulation (kg ha-1) of one (Ca) of the ten elements measured was different in the two cultivars, the amounts and patterns of all nutrients in the various plant components of floricanes and primocanes differed in significant ways. In some cases, element concentrations in a specific plant component differed between cultivars while dry matter accumulation differed in the opposite way resulting in the same total accumulation in the cane involved. In other cases, there was greater accumulation in one cane type (primocane vs. floricane) than the other such that there was similar accumulation of that element in the whole plant. For Ca, accumulation in primocanes was greater for ‘Willamette’ than ‘Haida’ whereas there was no difference of accumulation in floricanes which resulted in greater accumulation of Ca in the whole above-ground plant in ‘Willamette’. Maximum accumulation of the elements in floricanes occurred generally earlier in the growing season (July to September) than in primocanes (September to October), and these maxima were frequently at different times for the two cultivars, making comparisons of nutrient compositions in the two cultivars complex. Detailed sampling periodically over the growing season in combination with element analysis of these raspberry plant components as done in this study provided a better basis for comparing nutrients in raspberry cultivars than examining element concentrations of a specific plant component (e.g., leaves) sampled once during the growing season because patterns of nutrients over time in the cultivars differed.     

Annual dry-matter production by three apple cultivars at four within-row spacings in New Zealand

Summary

Annual dry-matter production was estimated from eight year old apple trees of ‘Fuji’, ‘Braeburn’ and ‘Royal Gala’ on rootstock M.9, trained as slender spindles, in a spacing trial with trees spaced at 1.3, 1.5, 1.9 and 2.4 m within the row with tree rows 3.5 m apart. Light interception was recorded at intervals during the season. Both fresh weight yield and total dry-matter production were linear functions of light interception, with a higher slope recorded for the two late season cultivars compared with the early maturing ‘Royal Gala’. Comparison of the relationship between mid-season light interception and apple yields with published values from elsewhere, reveals that the slope of the relationship is enhanced under New Zealand conditions. The relationship suggests an upper limit of yield of 169 t ha^–1 at 90% light interception, slightly higher than the maximum yield recorded of 163 t ha^–1. Energy conversion of intercepted light over the growing season into dry-matter production was similar to that observed in the United Kingdom, suggesting that the major climatic advantage in New Zealand over the United Kingdom is the higher growing season radiation integral. Dry matter was allocated in the order fruit>woody tissue>leaves, with partitioning to the fruit of 74, 72 and 63% for ‘Braeburn’, ‘Fuji’ and ‘Royal Gala’, respectively. Under New Zealand conditions, sustainable 70% harvest index values may be achievable for mature apple trees on dwarfing rootstock with late maturing cultivars.     

Einfluss von Unterlagen im Vergleich zu selbstbewurzelten Birnenbäumen auf vegetative und generative Parameter unter biologischen Anbaubedingungen in Ostösterreich

In spring 2006, in the research center of the University of Natural Resources and Life Sciences in Vienna, the pear cultivars ‘Bosc’s’, ‘Williams’ Christ’ and ‘Uta’ were planted on the rootstocks Kirchensaller Mostbirne (Seedling), Pyrodwarf, Farold 69, Quince Adams (with intercropping ‘Conference’) and own-rooted from in vitro culture, trained as spindles and tested for eight years under organic production rules. The own-rooted ‘Williams’- and ‘Bosc’s’-trees had many tree losses in the first year, they grew medium and started with fruiting later than the grafted trees. The trees on rootstock Quince Adams were growing very weakly in the high lime containing soil at the site, with the consequence of chlorosis, tree losses and small fruits, but also a higher brix-, vitamin C- and apple acid-content in the fruits. ‘Bosc’s’ showed low yields on all rootstocks in the observing period. ‘Williams’ on Farold 69 and Seedling had good yield and fruit quality, while the weakly growing cultivar ‘Uta’ showed low tree losses and high yields on Seedling. Pyrodwarf had very few tree losses and was similar in growth and yield compared to Farold 69 and Seedling, however the fruits of ‘Williams’ and ‘Bosc’s’ were smaller.     

The effects of mulching on establishment of Syagrus romanzoffiana (Cham.) Becc., Washingtonia robusta H. Wendl. and Archontophoenix cunninghamiana (H. Wendl.) H. Wendl. & Drude in the landscape

Three palm species common to southern California landscapes were grown and established under mulch treatments. Turfgrass clippings and Eucalyptus sideroxylon mulches increased the growth of king and queen palms and increased survival of king palms. Although palms growing under fresh eucalyptus mulches did not display nutrient deficiency symptoms, Mexican fan palm and queen palm were not significantly benefited by mulch treatments. Mexican fan palm was not adversely affected by turfgrass growing around it. However, turfgrass significantly reduced queen and king palm growth and increased mortality of king palms during establishment. Turfgrass increased drought effects and decreased stomatal conductance of palms. Soils under turfgrass were significantly drier than mulched or unmulched soils.     

沙棘中糖、酸、维生素C和SOD的动态变化

对中国沙棘、俄罗斯沙棘和蒙古国沙棘果实的总糖和可溶性固形物、总酸、维生素C和SOD以及叶中维生素C在年生长周期中的变化规律进行了比较研究。结果表明,果实着色前含糖量和可溶性固形物的变化一直下降,着色后呈上升趋势;有机酸含量在果实发育前期至中期一直呈增加趋势,至果实着色期后迅速下降,但中国沙棘在着色期后有机酸含量变化不大,成熟前才迅速下降;维生素C含量变化是中国沙棘在成熟时达到最大,成熟后迅速下降,俄蒙沙棘叶中维生素C则高于中国沙棘;SOD是先升后降,在成熟前达到最大值,成熟时下降。     

Cell wall development in the berries of two grapevines

The cell wall content of the berries of grape cultivars ‘Barbera’ and ‘Freisa’ was examined and analyzed during their growth and ripening from July to October.The build-up of cell wall material was much faster in ‘Barbera’ than in ‘Freisa’, and ended 2 weeks before completion of commercial maturity, while in ‘Freisa’ it progressed at a lower rate, but continued up to picking-time. The two most important groups of cell wall polysaccharides were insoluble pectins and hemicellulose. Their behaviour appeared to be always complementary.Cell number per berry apparently decreased steadily in both cultivars, more rapidly in ‘Freisa’ than in ‘Barbera’. The reason for this is not certain, but appears to be due either to cell fusion or to cell squeezing. The average number of cells per berry in both cultivars was of the same order of magnitude, and in agreement with the findings of other authors.     

Root zone temperature,plant growth and yield of broccoli [Brassica oleracea (Plenck) var. italica] as affected by plastic film mulches

Plastic film mulches are often associated with increases in plant growth and yield of vegetable crops. Few studies, however, report on the effect of plastic film mulches on root zone temperature on broccoli. The objectives of this study were to determine the effects of colored plastic mulches on root zone temperature and broccoli plant growth and yield Broccoli (‘Packman’) plants were grown using plastic film mulch and drip irrigation. The treatments consisted of plastic film mulch (black, blue, gray on black, red, silver on black, and white on black mulches) and bare soil. Colored plastic film mulches affected root zone temperature and the accumulation of soil degree-days. Mean daily RZT, maximal daily RZT and degree day accumulation in the soil were highest in dark-colored mulches (blue, black, red, and gray) and lowest in light-colored mulches (silver and white), while minimal daily RZT was highest in silver mulch and lowest in white mulch. Silver mulch showed the smallest diurnal fluctuations in RZT among plastic mulches, with the highest RZT during the night and among the lowest in the afternoon. Colored plastic mulches also affected broccoli plant growth and yield, although the effect of mulches was more dramatic in the spring than in the fall seasons. Broccoli yield was linearly related to both the vegetative top dry weight and root dry weight of mature plants. Broccoli yield was little affected at mean RZT of <21 °C but increased with increasing mean RZTs above 21 °C up to 25 °C. Thus, broccoli plant growth and yield responded more favorably to dark-colored mulches than to light-colored mulches, suggesting that broccoli benefited from increased soil warming. No high RZT stress effects on broccoli plant growth or yield were observed in this study. Thus, this study suggests that plastic film mulches, particularly the dark-colored mulches, may be an option for spring broccoli production in areas with cool conditions early in the spring.     

Highbush Blueberry Cultivar Trial in Ontario,Canada

ABSTRACT

A replicated trial of eleven cultivars was planted at Simcoe, Ontario in 1991. Plants were first harvested in 1994. After eight harvest seasons, ‘Bluegold’ was the highest yielding cultivar, averaging 6.8 t/ha, and ‘Toro’ had the largest berries, averaging 1.81 g per berry. ‘Bluetta’ was the earliest cultivar with on average 50% of its yield picked by 16 July and ‘Elliott’ the latest, with on average 50% of its yield picked by 27 August. Overall, ‘Duke’ proved to have the best combination of characteristics of the early cultivars, and ‘Nelson’ was the most impressive late cultivar.     

Wie viele Nährstoffe werden mit dem Mulchen der Fahrgassen in den Baumstreifen einer Obstanlage verfrachtet?

The objective of this PhD project was to investigate the nutrient translocation associated with the mulch from the grass alley to the tree strip. Therefore, a historical, approved 40-year fertiliser trial with apple cv. ‘Gloster’ on M9 rootstock at a spacing of 4 m?×?1.5?m was employed at Klein-Altendorf Research Centre, University of Bonn, Germany, which comprised mineral nutrition (1?t/ha??CaO? $ + $ ?NPK), an organic plot (10?t??FM/ha pig manure) and an unfertilised plot as control. Grass alleys were mowed 5?× in 1995 and 3?× in 1996 as commonly practised in fruit orchards; foil was spread on the tree strips to capture the biomass transferred with the mulching. Overall, ca.??60% of the grass mulch dry matter (mowed at 2?cm height) remained in the grass alleyway, while ca.??40% was translocated to the tree strips, which amounted to 550?kg??DM (Dry Matter) in the unfertilised plot and 800?kg??DM/ha/year in both fertilised plots with the five mulches in the wet year 1995. Grass mulch contained 2–3%??N and 2.2–2.9%??K in the unfertilised control plot or 2.1–3.9%??N and 2.7–4.1%??K on per leaf dry matter in both the inorganic NPK and organically fertilised plot; the nitrogen content of the grass mulch increased during the growing season in the wet year 1995, but remained low and constant at 2.5%??N in the dry year 1996. By contrast, calcium was decreased from 0.5–0.7%??Ca in the unfertilised plot to 0.3–0.6%??Ca in the organic plot. Overall, 25–50% of the grass mulch was translocated from the grass alleys (ca. 4,000 m²) into the tree strips, representing an organic fertilisation of 10–25?kg??N, 2–4?kg??P, 15–25?kg??K, 3–5?kg??Ca and 1–2?kg??Mg per hectare and year. This would theoretically be equivalent to ca 50% supply of??N,??P and??K and??10% of calcium as required nutrients by fruit trees depending on rate of nutrient availability. Its subsequent partial availability reported of 54%??N within??90 days after mulching and large nutrient content are discussed with respect to the low nutrient content in leaves dropped from the fruit trees in the autumn, where the nutrients had been previously translocated into the woody perennial parts of the tree. This nutrient cycling should be integrated in environmental-friendly sustainable fertilisation strategies for fruit orchards.     

Influence of sprayable mulch colour on yield of eggplant (Solanum melongena L. cv. Millionaire)

Planting beds were treated with sprayable, synthetic latex film (BASF, Charlotte, NC, USA) and oversprayed with black, white, red, blue, yellow or silver oil-based paint to study the effect of coloured spray mulches on yield of eggplant (Solanum melongena L. cv. Millionaire). Nonpainted mulch base and bare ground plots served as control treatments. Individual experimental units consisted of three rows, 102 cm wide × 7.3 m long, transplanted with 8 plants per row. Treatments were replicated in four blocks each at two separate locations near Fresno, CA. Plants grown on silver-painted beds produced significantly greater numbers (42–221%) of fruit and total fruit weight (42–237%) than all other treatments at both locations after eight harvests. Silver-painted mulch stimulated significantly greater flowering and fruit set numbers prior to the first harvest at one site. Apart from silver, only blue- and white-coloured mulches provided increased numbers and/or fresh weight yields at one site only. Mulched plots painted with other colours did not produce yields different from either the bare ground or nonpainted mulch base controls at either site.     

Einfluss von blattappliziertem Bor auf Boraufnahme und Fruchteigenschaften von Kulturheidelbeeren (Vaccinium corymbosum)

In 2003, highbush blueberry (Vaccinium corymbosum) cultivars ‘Brigitta Blue’ and ‘Nelson’ were treated with a foliar boron-containing, ascofol spray (Wuxal^®). After blossoming, the plants were sprayed three times with 0.5% ascofol solution. Control plants were sprayed with tap water. Fruit harvest of each cultivar was on July 19 and 30, respectively. Leaf samples were taken on June 4 and August 7. The boron content of fruits and leaves was analyzed along with fruit yield and single berry weight. The potential absorption rate of applied boron (boron increase in leaves and fruits) was calculated. Foliarly applied boron was readily taken up by the leaves of both cultivars and translocated to the fruits. A potential boron absorption rate of 2.4% was calculated for ‘Nelson’. Foliar application of boron did not increase fruit yield in either cultivar. However, ‘Nelson’ showed a slight increase of berry weight in the second harvest, associated with the boron treatments.     

Effects of grafting height of MM106 rootstock on growth,lateral shoot formation and yield in apple trees

Summary

Between 2004 and 2008, the effects of different grafting heights on sylleptic shoots were tested in the apple (Malus domestica Borkh.) cultivars ‘Granny Smith’ and ‘Gloster’, and cumulative fruit yields were evaluated. MM106 apple rootstocks were grafted 10, 20, 40, or 60 cm above soil level in August 2004. The results showed that an increased grafting height significantly decreased tree height in both cultivars. The tallest and shortest trees were observed at grafting heights of 10 cm (153.0 and 170.0 cm) and 60 cm (141.3 and 143.5 cm) in ‘Granny Smith’ and ‘Gloster’, respectively.Among the various grafting heights tested, 60 cm in ‘Granny Smith’ and 20 cm in ‘Gloster’ gave the largest stem diameters (17.6 mm and 16.8 mm, respectively). The number of lateral shoots increased significantly with increased grafting height in both cultivars. The largest numbers of lateral shoots in ‘Granny Smith’ (10.75) and ‘Gloster’ (2.00) were obtained from a grafting height of 60 cm, while 2.55 and zero lateral shoots occurred at 10 cm grafting height in ‘Granny Smith’ and ‘Gloster’, respectively. Shoot lengths decreased significantly by increasing the grafting height. Grafting heights of 10 cm and 60 cm resulted in the tallest and shortest shoots in both cultivars. Cumulative fruit yields were significantly affected by grafting height in both cultivars. The highest yield was found for a 60 cm grafting height in both ‘Granny Smith’ (11.295 kg tree^–1) and ‘Gloster’ (4.818 kg tree^–1).The results of this study suggest that grafting heights of 40 cm and 60 cm have the potential to promote branching and early bearing for apple fruit production in sustainable and organic agricultural systems.     

葡萄果实采后衰老及其相关基因表达的分析

对8 个葡萄品种果实采后衰老情况以及相关基因的表达进行了分析,发现欧美杂交种葡萄‘藤稔’、‘夕阳红’和‘信侬乐’VvNCED1、VvACO1、VvPG 基因表达水平高,葡萄果实耐压力、耐拉力下降明显,落粒数增加,其耐贮性较低;欧亚杂交种葡萄‘红地球’、‘黄意大利’和‘美人指’VvPOD2、VvMnSOD 基因表达水平高,果实的耐压力、耐拉力相对下降较慢,落粒数较低,其耐贮性也较高。表明葡萄贮藏过程中衰老相关基因的表达量能够反映出葡萄的耐贮性好坏。     

鲜食葡萄新品种‘学苑红’

‘学苑红’葡萄是从以匈牙利品种‘罗萨卡’为母本、‘艾多米尼克’为父本的杂交后代中选育出的新品种。成龄叶片很大，果穗中等。果粒着生紧密，椭圆形，极大，平均质量12.9 g。果皮红色，薄，涩。果实无特殊香气，通常有2粒种子。有一定的耐挂性，耐贮运。在北京地区3月下旬开始萌芽，5月中旬开花，7月中下旬开始成熟，8月中上旬充分成熟。