Home About us Contact | |||
Full Bloom (full + bloom)
Selected AbstractsCOALESCENTS IN FULL BLOOMEVOLUTION, Issue 12 2009Joe Felsenstein No abstract is available for this article. [source] Mixing calcium chloride with commercial fungicide formulations results in very slow penetration of calcium into apple fruitsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2004Thomas K. Schlegel Abstract Foliar applications of calcium salts are usually combined with fungicides. In the years 2002 and 2003, it was tested if this practice assures high rates of penetration of calcium. Amounts that penetrated in 24 h were measured at 20,°C using 45CaCl2. To ensure maximum penetration rates, humidity was maintained at 100,%. Sample size was 40 to 50 fruits, and data were presented as box plots because distribution of data was not normal. Median rates of penetration of CaCl2, measured with mixtures of fungicides and CaCl2 at 5 or 10 g l,1, respectively, were very slow, and amounted to only a few percent of the dose applied. Rates were a little higher with very young fruits (55 days after full bloom, DAFB). Adding alkyl polyglycoside surfactants at 0.2 g l,1 significantly decreased surface tensions, and increased rates of penetration by up to 15-fold. Still, total penetration of CaCl2 rarely exceeded 20,% of the dose applied (median penetration), even in the presence of an additional surfactant. In all treatments, outliers with 60 to 100,% penetration in 24 h occurred, and this was attributed to penetration into lenticels. This is expected to result in unequal concentrations of calcium in fruits, especially in the sub-epidermal layers. Addition of a suitable surfactant to mixtures of fungicides with CaCl2 is strongly recommended as it enhances wetting and greatly increases penetration rates of CaCl2. Mischen von Calciumchlorid mit Fungiziden resultiert in einer sehr langsamen Penetration von Calcium in Apfelfrüchte Zur Blattdüngung werden Calciumsalze meist mit Fungiziden gemischt. Es wurde untersucht, ob diese Praxis hohe Penetrationsraten für das ausgebrachte Calciumsalz gewährleistet. Die Penetration wurde mit 45CaCl2 bei 20,°C gemessen. Die Luftfeuchte betrug 100,%, so dass maximale Penetrationsraten erzielt wurden. Der Stichprobenumfang betrug 40 bis 50 Früchte. Die Ergebnisse werden als Box-Plots präsentiert, weil die Verteilung der Daten nicht normal war. Bei Mischungen von CaCl2 (5 bis 10 g l,1) mit Fungiziden betrugen die Mediane der Penetrationsraten von CaCl2 nur einige Prozent. Bei sehr jungen Früchten (55 Tage nach Vollblüte, DAFB) waren die Raten etwas höher als bei älteren. Durch Zugabe von Alkyl-Polyglykosiden (0.2 g l,1) wurden die Oberflächenspannungen der Lösungen verringert und die Penetration von Calcium bis zu 15fach erhöht. Trotzdem betrug die Penetration in 24 h nur selten mehr als 20,% der Dosis. In allen Behandlungen wurden Ausreißer beobachtet, bei denen die Penetration in 24 h 60 bis 100,% der Dosis betrug. Das wurde auf Infiltration von Lentizellen zurückgeführt. Dadurch dürfte die Calciumkonzentration in Früchten nach Spritzung mit CaCl2 nicht homogen sein, besonders nicht in den subepidermalen Schichten. Die Zugabe eines geeigneten Netzmittels zu Mischungen von Fungiziden mit CaCl2 wird empfohlen. Dadurch wird die Benetzung der Früchte verbessert, und die Penetrationsraten werden erhöht. [source] Genotypic difference for the susceptibility of Japanese, Chinese and European pears to Venturia nashicola, the cause of scab on Asian pearsPLANT BREEDING, Issue 4 2008K. Abe Abstract Venturia nashicola, the cause of scab on Asian pears, is distinct from Venturia pirina, a causal fungus of European pear scab. Although scab caused by V. nashicola is one of the most serious diseases in the Japanese pear (Pyrus pyrifolia Nakai var. culta Nakai), information available regarding resistant breeding against V. nashicola is limited. In this study, 12 genotypes of Japanese pear, seven genotypes of Chinese pear (Pyrus ussuriensis Maxim.) and four genotypes of European pear (Pyrus communis L. var. sativa DC.) and/or their offspring were evaluated for susceptibility to V. nashicola with leaf and fruit inoculation tests. At 30,40 days after full bloom in their developmental stage, unfolded young leaves and fruit were inoculated with conidial suspensions of V. nashicola for each genotype, and the responses were rated at 30 days postinoculation for the inoculated leaves and at 42 days postinoculation for the inoculated fruits. No visible symptoms were found in European pear ,Bartlett' and ,La France' and their respective offspring ,290-36' and ,282-12', in the Japanese pear ,Kinchaku' and in the Chinese pears ,Cangxili' and ,Hongli'; these genotypes were evaluated as highly resistant to V. nashicola. Necrotic lesions without sporulation were observed in the Chinese pears ,Qiubaili', ,Manyuanxiang', ,Yuanbali' and ,Xiangyali', which were regarded as resistant. Sporulating lesions were formed on the other genotypes, such as the major Japanese pear cultivars ,Kosui' and ,Nijisseiki', which were regarded as susceptible. The response of inoculated leaves coincided well with that of inoculated fruit for each genotype. When the severity of scab symptoms on scab-susceptible genotypes was further rated with disease severity (DS) values, a genotypic difference was observed for overall DS values in a successive 2-year measurement among the susceptible genotypes. Based on the DS values of leaf and fruit scabs, the Japanese pears ,Niitaka', ,Shinko', ,Nijisseiki', ,Gold Nijisseiki', ,Osa Nijisseiki' and ,Shinsui' were considered to be less susceptible to V. nashicola than the typical susceptible cultivar ,Kosui'. [source] Berry infection and the development of bunch rot in grapes caused by Aspergillus carbonariusPLANT PATHOLOGY, Issue 2 2008B. A. Kazi The effects of different levels of inoculum of Aspergillus carbonarius and time of inoculation on berry infection and the development of aspergillus bunch rot on grapevines (cv. Sultana) were studied under field conditions. Inflorescences at full bloom were inoculated with aqueous spore suspensions of A. carbonarius containing 0 or 1 × 106 spores mL,1 in 2004/05 and 0, 1 × 102 or 1 × 105 spores mL,1 in 2005/06. In both years, the incidence of infection in inoculated berries was significantly higher than in uninoculated berries. Incidence of infection in berries from veraison until harvest was higher than at earlier stages of bunch development (berry set to berries that were still hard and green). Inoculation of bunches at veraison did not significantly increase A. carbonarius infection prior to harvest, at harvest, 6 days after harvest or when berries were over-ripe. Bunches inoculated at harvest did not significantly increase infection 6 days after harvest or when berries were over-ripe. Aspergillus carbonarius was isolated more frequently from the pedicel end (53·1%) than from the middle section (37·5%) and distal end (35·0%) of berries that were inoculated with 105 spores mL,1. [source] Phenolic compounds in peach (Prunus persica) cultivars at harvest and during fruit maturationANNALS OF APPLIED BIOLOGY, Issue 1 2008C. Andreotti Abstract Six peach and six nectarine cultivars were evaluated for the phenolic content in their pulp and peel tissues. Chlorogenic acid, catechin, epicatechin, rutin and cyanidin-3-glucoside were detected as the main phenolic compounds of ripened fruits. The concentration was always higher in peel tissue, with average values ranging from 1 to 8 mg g,1 dry weight (DW) depending on cultivar. Of the tested varieties, the white-flesh nectarine ,Silver Rome' emerged as the cultivar with the highest amount of total phenolics. Phenolic compounds were also profiled during fruit growth and ripening in the yellow nectarine cv. ,Stark Red Gold', which showed a decreasing concentration during fruit development in both peel and pulp tissues. Average amounts of total phenolics were approximately 25 mg g,1 DW 60 days after full bloom and decreased to 3 mg g,1 DW at ripening in pulp tissue. Differences among peel and pulp composition show the different dietetic and antioxidant potential of fruits consumed unpeeled and peeled. [source] |