End Of Bloom Research Articles

Assessing inorganic nitrogen transport in marine phytoplankton assemblages through the 15N-tracer technique and metatranscriptomics

The availability of inorganic nitrogen is considered one of the limiting factors for primary production in the ocean. However, different phytoplankton possess unique strategies to take up and assimilate nitrate and ammonium to cope with environmental changes. To investigate the nitrogen uptake characteristics of different size-fractionated phytoplankton in natural assemblages, 3 research cruises were conducted in the southern East China Sea in 2018 and 2019. The nitrogen uptake characteristics of 2 size-fractionated natural assemblages, microphytoplankton (20-200 µm) and pico-nanophytoplankton (<20 µm), were measured using the 15N-tracer technique. At most of the stations, significantly higher potential maximum uptake rates of ammonium than of nitrate were detected in the pico-nanophytoplankton, indicating that small phytoplankton possess a relatively superior capacity to take up ammonium. By contrast, comparing the potential maximum uptake rate for nitrate between microphytoplankton and pico-nanophytoplankton showed that microphytoplankton exhibit a higher capacity for nitrate uptake as a nitrogen source compared to pico-nanophytoplankton. However, repressed uptake rates of ammonium and nitrate in microphytoplankton were sometimes found at the coastal station even when ambient nitrate concentrations remained high. Metatranscriptomic analysis of nitrogen transporter genes in microphytoplankton suggests that most diatoms utilize regenerated ammonium before nitrate to maintain their populations at the end of blooms. Metatranscriptomic approaches identify the transcriptional responses of dominant diatoms to explain how diatoms regulate their nitrogen transporter genes to cope with environmental changes in natural assemblages.

Differential Response in Chlorophyll-a Concentration to Seasonal Forcings along the West Coast of India

The chlorophyll-a (Chl-a) concentration, an indicator of biomass that is a conduit for fixation of atmospheric carbon dioxide, is analyzed using Ocean Colour Climate Change Initiative (OC-CCI) 4-km eight-day resolution data along the west coast of India. A peak of Chl-a blooms during the southwest monsoon (SWM) along the west coast of India and during northeast monsoon (NEM) in northern regions is observed. The blooms start as early as the end of April in southern regions and spread northward. The Fourier transformation and wavelet analysis explicitly reveals the annual and seasonal variability of these blooms and aids in grouping the regions into three zones. The blooms are strong in the southern regions and occur during SWM, whereas in the northern regions, they occur during SWM as well as NEM. The Indian Ocean Dipole (IOD) and Niño3.4 is negatively correlated with Chl-a concentration in southern regions only during a few months. Similarly, only for a few months do the northern regions show negative correlations between Niño3.4 and Chl-a concentration. The Chl-a blooms are positively correlated with concurrent Ekman mass transport and precipitation and with a lag of four to seven steps of eight-day cycles in southern regions, whereas the northern regions are positively correlated with concurrent precipitation only. The time of onset and end of blooms and the time span for their northward spread during SWM and southward spread during NEM vary from year to year. The different onset and end times of blooms and varying periods of blooms are vital for policy decisions on regulating fishing activity and establishing a ban period along the west coast of India for sustainable utilization of fishery resources.

Blueberry Yields Increase With Bee Visitation Rates, but Bee Visitation Rates are not Consistently Predicted by Colony Stocking Densities.

Pollinator-dependent crops rely on the activity of managed and wild pollinators. While farm management and surrounding landscape can influence wild pollinator contributions, managed pollinator contributions may be primarily driven by their stocking densities, though this is not well studied across crops. We selected 20 southern highbush blueberry farms along two independent gradients of honey bee Apis mellifera L. (Hymenoptera: Apidae) stocking density (~1-11 hives/acre) and bumble bee Bombus impatiens Cresson (Hymenoptera: Apidae) stocking density (0 - 3 colonies/acre) ensuring that stocking densities were not correlated with farm or landscape attributes. Across farms, we observed managed and wild bee visitation rates, and measured yield estimates. Farms with greater bumble bee stocking densities had higher bumble bee visitation rates and yield estimates, but farms with higher honey bee stocking densities only received higher honey bee visitation rates at the end of bloom and did not have higher yield estimates. The main wild pollinator, the southeastern blueberry bee Habropoda laboriosa (Fabricius) (Hymenoptera: Apidae), showed higher visitation rates on organic farms and in late bloom. In general, higher visitation rates by honey bees, bumble bees, and H. laboriosa were correlated with higher yields. Our results suggest that yields are limited by bee visitation rates, and that within the stocking density ranges studied, increasing managed bumble bees, but not honey bees, increases their visitation rates. While H. laboriosa had the greatest effect on yield estimates, its activity appears to be limited by both a phenological mismatch with crop bloom and farm management.

Influence of urban heat island on Tilia tomentosa Moench. blooming

Temperature increase in urban areas due to a high share of paved and impermeable surfaces affects indigenous woody species by making changes in their biological processes. Field research includes monitoring the blooming period of 18 individuals of Tilia tomentosa Moench. in one vegetation season located in three different habitats (green strip, paved surface, and park). The beginnings of four blooming phenophases are monitored (beginning of blooming, beginning of full blooming, end of full blooming, and end of blooming), as well as the total duration of blooming. Analyzed individuals are located in the densely built-up part of Novi Sad in Serbia which is under the influence of the urban heat island effect. The results show that the blooming period of individuals located in the park lasted longer and occurred later. Between individuals from green strips and paved surfaces there are no significant dif?ferences in the blooming period and the occurring of phases, but in relation to park individuals, blooming duration is shorter and occurs earlier. Besides age and hereditary traits, air temperature as a part of the microclimate of analyzed habitats is a very important factor when analyzing the blooming phenophase. In that way, the change in blooming phenophases can be an indicator of the adaptability of indigenous species to the urban heat effect and climate change.

Hand-held mechanical device improves thinning efficiency of peach trees

The objective of this study was to evaluate the effect of mechanical-manual thinning (MmT) at different developmental stages in the thinning efficiency and productive performance of ‘Sensação’ peach trees. The experiment was performed during the 2013 and 2014 growing seasons, in a commercial orchard located in Morro Redondo (RS), Brazil. Plant material consisted of 7-year-old peach trees grafted on Capdeboscq rootstock and trained as an open-vase system. The experiment was arranged as a randomized block design, with five three-trees replications. In order to reduce the effect of personal experience, the treatments and measurements were applied by the same person in a set of replications throughout the experiment. Treatments consisted of: control I [without thinning (WT)]; control II [hand thinning (HT) 40 days after full bloom (40 DAFB)]; MmT at full bloom (FB): 50% of open flowers; MmT at the end of bloom (EB): 80-100% of open flowers; MmT at petal fall (PF); and MmT at the green fruit (GF) stage (fruit with ~1 cm of diameter). The MmT was performed using a hand-held portable device. The parameters assessed were: percentage of thinning, fruit set, thinning time, work economy, production per tree, fruit mass, estimated yield and fruit size distribution. The use of the MmT at the stages tested reduces thinning time of ‘Sensação’ peach trees, resulting in labor saving, as well as increases the percentage of fruit in category (CAT) 1. The MmT when performed at GF results in a higher percentage of thinning. The treatment MmT at FB increases the average fruit mass.

Seasonal patterns of near-bottom chlorophyll fluorescence in the eastern Chukchi Sea: 2010–2019

The Chukchi Sea consists of a broad, shallow (<45 m) shelf that is seasonally (November–July) covered by sea ice. This study characterizes the seasonal patterns of near-bottom primary production using moored instruments measuring chlorophyll fluorescence, oxygen, nitrate, and photosynthetically active radiation. From 2010 to 2018, moorings were deployed at multiple sites each year. Instruments were restricted to within 10 m of the seafloor due to ice keels, which can reach 30 m below the surface in this region. Near-bottom blooms were common at all mooring sites. The bloom onset directly followed ice retreat whereas the end of the bloom followed loss of light in September. The intensity of light at the seafloor (~40 m deep) was similar to levels observed under 1–2 m thick ice floes in the spring/early summer, and was sufficient to support photosynthesis near the seafloor, utilizing nitrate and producing oxygen. We hypothesize that the near bottom bloom originated from aggregates of ice algae that sank during ice retreat. As a consequence of climate warming and earlier ice retreat, we predict that the near-bottom bloom onset will occur earlier, but the timing of the end of the near-bottom bloom will remain the same pending a sufficient nutrient supply. The Chukchi Sea is highly productive even though the growing season is short. This production is promoted by a shallow seafloor, which allows multiple production layers (surface open water, bottom of the mixed layer, under-ice algae, and disassociated ice algae which settles near the seafloor). We term this the Multiple Production Layers (MPL) hypothesis.

Bacteria associated with moon jellyfish during bloom and post-bloom periods in the Gulf of Trieste (northern Adriatic)

Jellyfish are a prominent component of the plankton community. They frequently form conspicuous blooms which may interfere with different human enterprises. Among the aspects that remain understudied are jellyfish associations with microorganisms having potentially important implications for organic matter cycling. To the best of our knowledge, this study is the first to investigate the bacterial community associated with live moon jellyfish (Aurelia solida, Scyohozoa) in the Adriatic Sea. Using 16S rRNA clone libraries and culture-based methods, we have analyzed the bacterial community composition of different body parts: the exumbrella surface, oral arms, and gastric cavity, and investigated possible differences in medusa-associated bacterial community structure at the time of the jellyfish population peak, and during the senescent phase at the end of bloom. Microbiota associated with moon jellyfish was different from ambient seawater bacterial assemblage and varied between different body parts. Betaproteobacteria (Burkholderia, Cupriavidus and Achromobacter) dominated community in the gastral cavity of medusa, while Alphaproteobacteria (Phaeobacter, Ruegeria) and Gammaproteobacteria (Stenotrophomonas, Alteromonas, Pseudoalteromonas and Vibrio) prevailed on ‘outer’ body parts. Bacterial community structure changed during senescent phase, at the end of the jellyfish bloom, showing an increased abundance of Gammaproteobacteria, exclusively Vibrio. The results of cultured bacterial isolates showed the dominance of Gammaproeteobacteria, especially Vibrio and Pseudoalteromonas in all body parts. Our results suggest that jellyfish associated bacterial community might have an important role for the host, and that anthropogenic pollution in the Gulf of Trieste might affect their community structure.

Role of the foliar fertilization treatments on quality attributes of sweet cherry fruits (Prunus avium)

This study was carried out in a cherry in 2017 in Suşehri, Sivas. Eight -years old “0900 Ziraat” sweet cherry trees grafted on MaxMa 14 rootstocks were used as the plant material of the study. In the study, per 100 liters of water 250 gram of Azro select, a foliar fertilizer which contains 35% potassium and 5% nitrogen, and per 100 liters of water 200 gram of Zinc salt (Zinc Sulphate Hepta Hydrate) foliar fertilizer, which contains 22 % Zinc, were applied. The treatment was done twice: first, at the end of blooming, second, 15 days after the first treatment. As a result of the study, fruit weight, size, fruit firmness, SSC and vitamin C values of fruits obtained from potassium treated trees were significantly higher whereas fruit color values were lower. However, the effect of potassium on the titratable acidity values was not significant. With zinc application, while statistically significant increase in the fruit size, SSC and vitamin C values have not occurred, the highest values in terms of flesh firmness, fruit color and titratable acidity were recorded in the sweet cherries treated with zinc. The combination of zinc and potassium led to an increase in fruit weight, fruit size, SSC and titratable acidity, and decrease in vitamin C and color values.

Variation in the degree of reciprocal herkogamy affects the degree of legitimate pollination in a distylous species.

Distyly is a widespread floral polymorphism characterized by the flowers within a population showing reciprocal placement of the anthers and stigma. Darwin hypothesizes that distyly evolves to promote precise pollen transfer between morphs. Primula chungensis exhibits two types of anther heights, and these two types of anthers show pollen of two different size classes. To understand whether the stigma could capture more pollen grains from the anthers of the pollen donor as the separation between the stigma of pollen receiver and the anther of pollen donor decreased, the present research assessed the source of the pollen load in a series of open-pollinated flowers with continuous variation of style lengths. Individuals with continuous variation of style length were tagged, and the selected flowers in the tagged plants were emasculated the day before dehiscence. The stigma of the emasculated flowers was fixed in fuchsin gel at the end of blooming. We assessed the pollen sources on each stigma by taking photos under a microscope and measured the diameter of each conspecific pollen grain with ImageJ. We found that a shorter distance from the stigmas to the anthers of a pollen donor gave the flower a higher capacity to receive pollen from those anthers. Our result provides a new evidence that distyly could promote the pollen transfer between morphs, which is consistent with Darwin’s hypothesis of disassortative pollination. An alternative hypothesis for the evolution of distyly (e.g. selfing avoidance) might also be true, but less likely, because self-incompatibility would greatly avoid self-fertilization for many distylous species.

Differences in Flower Transcriptome between Grapevine Clones Are Related to Their Cluster Compactness, Fruitfulness, and Berry Size.

Grapevine cluster compactness has a clear impact on fruit quality and health status, as clusters with greater compactness are more susceptible to pests and diseases and ripen more asynchronously. Different parameters related to inflorescence and cluster architecture (length, width, branching, etc.), fruitfulness (number of berries, number of seeds) and berry size (length, width) contribute to the final level of compactness. From a collection of 501 clones of cultivar Garnacha Tinta, two compact and two loose clones with stable differences for cluster compactness-related traits were selected and phenotyped. Key organs and developmental stages were selected for sampling and transcriptomic analyses. Comparison of global gene expression patterns in flowers at the end of bloom allowed identification of potential gene networks with a role in determining the final berry number, berry size and ultimately cluster compactness. A large portion of the differentially expressed genes were found in networks related to cell division (carbohydrates uptake, cell wall metabolism, cell cycle, nucleic acids metabolism, cell division, DNA repair). Their greater expression level in flowers of compact clones indicated that the number of berries and the berry size at ripening appear related to the rate of cell replication in flowers during the early growth stages after pollination. In addition, fluctuations in auxin and gibberellin signaling and transport related gene expression support that they play a central role in fruit set and impact berry number and size. Other hormones, such as ethylene and jasmonate may differentially regulate indirect effects, such as defense mechanisms activation or polyphenols production. This is the first transcriptomic based analysis focused on the discovery of the underlying gene networks involved in grapevine traits of grapevine cluster compactness, berry number and berry size.

Toxicity of diatom polyunsaturated aldehydes to marine bacterial isolates reveals their mode of action

Diatoms produce and release polyunsaturated aldehydes (PUAs) during senescence in culture and at the end of blooms in nature and these compounds play different ecological roles, as infochemicals, allelochemicals and pheromones In order to elucidate the toxic effects of PUAs, we isolated six bacterial strains from the Mediterranean Sea during a diatom bloom and tested their tolerance to PUA in terms of growth and cell membrane properties. Based upon 16S rRNA sequencing, these bacteria were assigned to the genera Pseudomonas, Sufflavibacter, Halomonas, Vibrio, Idiomarina, and Labrenzia. Growth of these strains was reduced by 50% (EC50) at PUA concentrations ranging from 600 to 1700 μM of 2E,4E/Z-heptadienal (HEPTA), 400–800 μM of 2E, 4E/Z-octadienal (OCTA), and 70–400 μM of 2E, 4E/Z-decadienal (DECA). Two of these strains, Vibrio sp. and Halomonas, sp. were also investigated for membrane fatty acid composition in terms of adaptive modifications of their degree of saturation (ratio between saturated and unsaturated fatty acids) by GC-FID. A direct correlation between hydrophobicity and PUA toxicity was observed, and these bacteria were also found to react to PUAs by increasing the degree of saturation of their membranes fatty acids.Tested PUAs were 4-fold more toxic than the well-investigated n-alkanols, most probably due to their additional chemical aldehyde toxicity to disrupting proteins by the formation of Schiff's bases, and therefore, they act as very toxic and effective poison, probably accumulating in cytoplasmic membranes because of their high hydrophobicity.

Relationship between several meteorological factors and phenological features of pear cultivars

The aim of this paper was to investigate the fl owering characteristic of apples and their relationship to meteorological parameters. The trees observed are grown at Újfehértó, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple varieties. Each of the varieties were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001 during this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90th and 147th day of the year over the 18 years of observation. The early blooming varieties start blooming at 10–21April. The varieties of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2–10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor infl uencing the start of bloom in the subsequent spring.

POROVNÁNÍ DVOU ODLIŠNÝCH STANOVIŠŤ RÉVY VINNÉ (VITIS VINIFERA) Z HLEDISKA AGROBIOLOGIE

The aim of the work was to compare the course of agro-ecological indicators according to the internationally acknowledged parameters – bud breaking, the beginning, the main course and the end of blooming, grape mellowing, grape maturation (full ripeness), grape harvest, the beginning, the main course and the end of wood maturing for 7 varieties of grapes on three resistant white varieties Merz­ling, Malverina and Hibernal and one blue – Medina, then on classical varieties Aurelius, Chardonnay and Muscat Moravian in two regions Perna (sub-region Mikulovice) and Sadek (sub-region Znojmo). Remarkable differences between these two areas have been proved. Only for grape harvest and the main wood maturing, no statistically remarkable differences have been found. A highly evidential difference has been found in all the other elements.

Temporal Patterns of Sporulation Potential of Phomopsis viticola on Infected Grape Shoots, Canes, and Rachises.

Phomopsis cane and leaf spot on Vitis spp. (grape) is currently understood to be monocyclic, with primary inoculum only being produced early in the growing season. However, of the few published studies pertaining to sporulation of Phomopsis viticola, none specifically examined rachises, and none were designed to determine when infected tissues become capable of sporulation. The objective of these studies was to determine when grape shoots, canes, and rachises infected with P. viticola develop the capacity to sporulate, and to determine the time period during which those tissues remain capable of sporulation. Starting in 2009 and 2010, infected first-year shoots and rachises were collected biweekly throughout the growing season, into the dormant season, and into the following growing season. Tissues were collected from 'Catawba,' 'Concord,' and 'Reliance' vineyards. Samples were observed for sporulation after 48 h of incubation in a moist chamber at 23°C; the magnitude of the conidia production under these optimal conditions was considered the sporulation potential. For infections that occurred in 2009 and 2010, the production of conidia was not observed until after harvest. In the year following infection, sporulation potential was found from about bud break until shortly after the end of bloom. There was a generally consistent temporal pattern to relative sporulation potential across sampled vineyards, years, and grape tissues (rachises and canes), described by a modified β model, with peak sporulation potential occurring around 16 May. These results confirmed that Phomopsis cane and leaf spot is a monocyclic disease and support control recommendations for use of fungicides in spring.

Improvement of fitness and efficacy of a fire blight biocontrol agent via nutritional enhancement combined with osmoadaptation.

The efficacy of Pseudomonas fluorescens EPS62e in the biocontrol of Erwinia amylovora was improved by a procedure of physiological adaptation to increase colonization and survival in the phytosphere of rosaceous plants. The procedure consisted of osmoadaptation (OA) and nutritional enhancement (NE). OA was based on saline stress and osmolyte amendment of the growth medium during inoculum preparation. NE consisted of addition of glycine and Tween 80 to the formulation. NE and OA increased the growth rate and carrying capacity of EPS62e under high-relative-humidity (RH) conditions and improved survival at low RH on flowers under controlled environmental conditions. NE did not promote growth or affect infection capacity of E. amylovora. The effect of both methods was tested in the field by following the population of EPS62e using quantitative PCR (Q-PCR) (total population) and CFU counting (culturable population) methods. Following field application, EPS62e colonized blossoms, but it was stressed, as indicated by a sharp decrease in culturable compared to total population levels. However, once established in flowers and at the end of bloom, almost all the total population was culturable. The physiological adaptation treatments increased population levels of EPS62e over those of nonadapted cells during the late stage of the flowering period. Control of fire blight infections in flowers and immature fruits was tested by field application of EPS62e and subsequent inoculation with E. amylovora under controlled-environment conditions. The efficacy of fire blight control increased significantly with the combination of nutritional enhancement and osmoadaptation, in comparison with the absence of physiological adaptation.

Hypericum species in Estonian folk traditions and in local scientific studies

Both Hypericum perforatum and H. maculatum are common species throughout Estonia and neighbouring countries. The study used folklore texts from the HERBA [1] database collected between 1868-1994 on medicinal plants in Estonia. 117 texts describing 137 usage cases of plants bearing vernacular names related to naistepuna [Hypericum in Estonian, direct translation women's red] were selected and analyzed using textological methods. Almost 30% of the usage cases were related to gynecological problems (as the name implies), followed by 14% for stomach problems, 10% for bladder and kidney problems and 5% each for stomachache caused by overexertion, skin diseases and pain. Although altogether 8 species belonging to 7 genera or even families bore such vernacular names in different places, the most frequently used plants were two species of genus Hypericum. Those two externally very similar species were not distinguished by ordinary people and were used in folk medicine as one. The content of hypericin [2] and total flavonoids before [3] and after [4] hydrolysis of glucosides was determined spectrophotometrically in both Hypericum species. The standard deviations of these methods did not exceed 0.5%, 8.7% and 5.4%, respectively (n=4). The flowering tops (15cm) and flowers in three different blooming stages (at the beginning of blooming, in full bloom and at the end of blooming) of H. perforatum and H. maculatum, collected in 2008 from South-Estonia (Antsla parish), were used as plant material. H. maculatum contained about a 2.5 times more hypericin (141-228mg%) than H. perforatum (75-81mg%). The amount of hypericin detected was higher in the flowers and lower in the flowering tops of both analyzed Hypericum species, but the comparative analysis of H. perforatum ja H. maculatum showed no similar tendencies for flavonoid content. Both species contained practically the same amount of total flavonoids (5,6-6,2% and 4,6-6,0%, respectively), but H. perforatum contained somewhat more flavonoid aglycones (1,1-2,0%) than H. maculatum (0,7-1,5%). It is necessary to continue this work.

RELATIONSHIPS BETWEEN SOIL CHARACTERISTICS AND LEAF NUTRIENT CONCENTRATIONS IN GRAPEVINE

The results of a study investigating the relationships between different soil chemical-physical characteristics and nutrient concentrations in leaf tissues of grapevine (Vitis vinifera L.) are reported. The main feature of the experimental site, its high soil spatial variability, allowed examination of the variables of interest while keeping constant crop variety, plant age, climatic conditions and agronomic techniques management, the variability of which is often cause of data misinterpretation. The research was carried out on a winegrape vineyard, cv. Trebbiano Toscano grafted on 1103P rootstock, in Southern Italy. Ten areas characterised by different soil average fertility were selected within the experimental field and, within each area, two representative plants were chosen as test plants. Soil samples at three depths and leaf blades at three sampling times (end of bloom, fruit set and veraison) were collected. In the soil, total N content was positively correlated with organic C, available P and exchangeable K and inversely related to total CaC0 3 content. Among the leaf mineral nutrients, P showed the highest variation in relation to soil parameters (positive correlation with N content, organic C, available P; negative with CaC0 3 ) at the end of bloom and at veraison. Total leaf N was positively correlated with soil organic C and available P only at veraison. Moreover, in this stage, a higher Ca and Mg leaf content was observed in the areas characterised by a lower chemical fertility (lower total N and organic C; higher CaCO 3 ). Principal component analysis clearly discriminated areas of different soil fertility and underlined the variation in tissue nutrient concentrations as a function of soil chemical and physical properties.

Effect of 6-benzyladenine application time on apple thinning of cv. 'Golden Delicious' and cv. 'Idared'

Apple thinning of cv. 'Golden Delicious' and cv. 'Idared' was studied after the application of 6-benzyladenine (BA) 100 mgl-1 and 50 mgl-1 respectively, applied at different time of blooming period and over a wider range of fruitlet diameter. When BA 100 mgl-1 was applied on cv. 'Golden Delicious', significant reduction in final fruit number per tree was observed if applied at the end of blooming period or when fruitlet diameters were 6 mm, 15 mm or 20 mm, but thinning was not significant if applied at full bloom or at 10 mm or 25 mm fruitlet diameter. The share of bigger fruits of cv. 'Golden Delicious' (&gt; 65mm) was increased at all BA application time treatments, but significantly only in the treatment of hand thinned trees. Regarding the BA applications carried out on cv. 'Idared', significant thinning response was noticed in the case of BA sprayed at the end of bloom and at 10 mm of fruit diameter. The mean fruit weight of cv. 'Idared' apples was increased significantly only if BA was applied at 10 mm fruitlet diameter. Although the thinning results were inconsistent for two studied cultivars it was demonstrated from the trial that BA could be active as a thinner if applied over a wider phenological interval, at the end of blooming period up to 20 mm fruitlet diameter.

Relationship beetwen the phenological features of pear cultivars and the main meteorological parameters in a gene bank with 555 pear

The trees observed are grown at Ujfehert6, Eastern Hungary in a gene bank with 555 pear cultivars. Each of the cultivars was monitored for its dates of: the beginning of bloom, main bloom and the end of bloom and ripe phenophasis separately between I 984 and 2002. We analyzed the statistical features, frequency, distribution of these phenophasis and its' correlation the meteorological variables bet ween the interval. During this period the meteorological database recorded the following variables: daily mean temperature (°C), daily maximum temperature (0C), daily mini m um temperature (0C), daily precipitation (mm), daily hours of bright sunshine, daily means or the differences between the day-time and night-time temperatures (0C). For the analysis of data the cultivars have been grouped according to dates of maturity, blooming period as well as types of the seasons. Groups of maturity dates: summer ripe, autumnal ripening, winter ripe cultivars. Groups of blooming dates: early blooming, intermediate blooming, late blooming cultivars. At all the separated groups we analyzed the relationship between phenophasis and meteorological variables. During the 18 years of observation , the early blooming cultivars started blooming on 10-21 April, those of intermediate bloom date started flowering bet ween 20 April and 3 May, whereas the late blooming group started on 2- 10 May. Among the meteorological variables of the former autumn and winter periods, the winter maxima were the most active factor influencing the start dates of bloom in the subsequent spring. For the research of fruit growing-weather relationships we used simple, well known statistical methods, correlation and regression analysis. We used the SPSS 1 1.0 software for the linear regression fitting and for calculation of dispersions as well. The 1ables made by Excel programme.

Effect of Preharvest Treatment with Seaweed Products, Kelpak® and Goëmar BM 86®, on Fruit Quality in Apple

ABSTRACT The effect of two formulations made from seaweed extracts on apple tree productivity and fruit quality was evaluated in seven experiments conducted during the period 2001–2005 on apple trees ‘Gala Must’, ‘Golden Delicious’, ‘Jonagold Decosta’, and ‘Elstar’. One of the formulations, Kelpak®, contains natural auxins and cytokinins extracted from Ecklonia maxima, while the other one, Goëmar BM 86®, contains amino acids, vitamins, phytohormones, and poligosaccharides extracted from Ascophyllum nodosum, and the mineral nutrients N, Mg, B. The preparations were used, separately and together in a mixture, by spraying trees at the end of bloom, and subsequently four times at intervals of 4 weeks, the last time being about 4 weeks before harvest. In the other three experiments, Kelpak® and Goëmar BM 86® were used separately by spraying trees at full bloom only. It was found that Kelpak® and Goëmar BM 86®, applied five times during the period from the end of bloom until up to 4 weeks before harvest, sometimes improved fruit set and the size of apples, to a greater or lesser extent depending on the fruit set, but above all they caused an improvement in the distribution of apples in size classes and somewhat reduced russeting. Depending on the cultivar, the preparations caused a deterioration (‘Gala Must’) or an improvement (‘Jonagold Decosta’) in the red coloration of apples. Sometimes, a negative effect of the treatments on the internal quality of apples, expressed mostly by the refraction value after storage, was noticed. The apples treated with the preparations were found to have high levels of total nitrogen. No effect of the two seaweed preparations on the storage quality of apples was found. Both preparations stimulated the growth of shoots and leaves, caused an improvement in flower quality, and prolonged the blooming time, but no effect on the blooming of trees a year after their application was observed. When the preparations were used only once at full bloom, they had a small effect on the size distribution of apples but a distinct effect on the vegetative growth of the trees.