Article

Efficacy of Boric Acid, Monopotassium Phosphate and Sodium Metabisulfite on the Control of Apple Scab

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  • Bursa Uludag University
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Abstract

In vitro experiments indicated that boric acid, monopotassium phosphate, sodium metabisulfite and synthetic fungicide fluopyram + tebuconazole were effective in inhibiting conidia germination and germ-tube elongation of Venturia inaequalis. Monopotassium phosphate even at the highest concentration used in the study reduced conidia germination and germ-tube elongation of V. inaequalis by 22.1% and 28.8%, respectively; however, the difference between two compounds at lower concentrations except 0.05% (for conidia germination) and 0.1% (for germ-tube elongation) of boric acid was statistically significant (P ≤ 0.05). Complete inhibition was achieved by 0.01% sodium metabisulfite, 0.035% fluopyram + tebuconazole and 0.2% boric acid. Two orchard trials were conducted on the highly susceptible cv. Mutsu to apple scab to ascertain the efficacy of 0.2% boric acid, 0.5% monopotassium phosphate, 0.5% sodium metabisulfite and 0.035% fluopyram + tebuconazole for the control of apple scab. In both 2013 and 2014, except for the applications of monopotassium phosphate and sodium metabisulfite, the applications of boric acid and fluopyram + tebuconazole to trees at 10-day intervals significantly reduced disease incidence and severity on leaves and fruit compared to the water-treated control. In both years, the efficacy of boric acid and fluopyram + tebuconazole treatments was similar in reducing both disease incidence and severity on leaves and fruit in all monthly assessments from July to September. All treatments were neither phytotoxic to leaves and fruit nor did they adversely affect quality parameters of harvested fruit. These results show that boric acid treatment may be applied as an alternative chemical for the control of apple scab.

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... It selectively inhibits complex II or succinate coenzyme Q reductase in the electron transport chain of mitochondrial respiration and interferes with its respiration 5,6 . Bananas are often threatened by fungal/nematode diseases during the plantation process and fluopyram can be used to control such diseases including banana leaf spot 7 , anthracnose 8 , and scab 9 . It can be applied at the early stages of the disease to achieve a good control effect. ...
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Requirements of consumers for products with low residues of pesticides have increased the need for alternative disease management practices. The concentration of boron in fruit affects its quality, shelf life and the development of physiological disorders. However, the effect of boron on the susceptibility of peach to fruit rots has not been reported. This study investigated the effect of boron (Power B and Borax) on the development of Monilinia laxa on peaches (cv Andross). Mycelial growth of M. laxa was inhibited on potato dextrose agar supplemented with 750μgml−1 of Borax or 1000μgml−1 of Power B. The EC 50 values were 107.9 and 522.4 for Borax and Power B respectively. Field investigations showed that the incidence of peach infections by M. laxa was negatively correlated with the content of Boron in the leaves. Post-harvest dipping of peaches in Power B or Borax solution, at concentrations recommended by manufacturer (2μgml−1 for Power B and 1mgml−1 for Borax), significantly reduced the development of M. laxa. Power B, at rates of 6μgml−1, and Borax at rates of 3mgml−1 were the most effective in reducing infections by M. laxa. Finally, post-harvest dipping of fruit in Power B or Borax reduced losses of fruit weight and improved fruit firmness one month after storage, showing that boron increased the maintainability of peaches in cold storage. Peaches treated with 6μgml−1 Power B or 3mgml−1 Borax had the highest flesh firmness and the lowest water losses, while untreated control peaches were the least firm. Generally, Borax was significantly less effective than Power B, but better than the control treatment.
Article
A detached leaf bioassay was used to determine the influence of several film forming polymers and a conventional triazole fungicide on apple scab (Venturia inaequalis (Cooke) G. Wint.) development under laboratory in vitro conditions, supported by two field trials using established apple cv. Golden Delicious to further assess the efficacy of foliar applied film forming polymers as scab protectant compounds. All film forming polymers used in this investigation (Bond, Designer, Nu-Film P, Spray Gard, Moisturin, Companion PCT12) inhibited germination of conidia, subsequent formation of appressoria and reduced leaf scab severity using a detached leaf bioassay. Regardless of treatment, there were no obvious trends in the percentage of conidia with one to four appressoria 5 days after inoculation. The synthetic fungicide penconazole resulted in the greatest levels of germination inhibition, appressorium development and least leaf scab severity. Under field conditions, scab severity on leaves and fruit of apple cv. Golden Delicious treated with a film forming polymer (Bond, Spray Gard, Moisturin) was less than on untreated controls. However, greatest protection in both field trials was provided by the synthetic fungicide penconazole. Higher chlorophyll fluorescence Fv/Fm emissions in polymer and penconazole treated trees indicated less damage to the leaf photosynthetic system as a result of fungal invasion. In addition, higher SPAD values as measures of leaf chlorophyll content were recorded in polymer and penconazole treated trees. Application of a film forming polymer or penconazole resulted in a higher apple yield per tree at harvest in both the 2005 and 2006 field trials compared to untreated controls. Results suggest application of an appropriate film forming polymer may provide a useful addition to existing methods of apple scab management.
Article
Stump treatment with sodium tetraborate (borax) to control infection by Heterobasidion annosum and to reduce losses was tested in 10 true fir stands in California. These stands were thinned in 1978, 1979, or 1980, and borax was applied to stumps on 0.5 ha plots. Adjacent 0.5 ha plots were left untreated. Borax reduced stump surface infection but did not affect tree mortality between paired treated and untreated plots. The incidence of H. annosum increased for borax-treated stumps whose protected surfaces were removed 1 year earlier. The number of firs that died over the period of the study was positively correlated with the average age of the trees. Differences in mortality were not significant between treated and untreated plots West. J. Appl. For. 7(1):29-31
Article
An environmentally benign, easy to operate, and practical protocol for the regioselective bromination of aromatic compounds using boric acid as a recyclable catalyst, KBr as the source of bromide and hydrogen peroxide as the oxidant is described. Peroxoborate generated in solution, from the reaction of boric acid and H2O2, very effectively catalyses the bromination of organic substrates at room temperature in a selective manner. The catalyst used is inexpensive, eco-friendly, safe to handle, and recyclable. The methodology is chemoselective for dibenzylidineacetone and regioselective for the other substrates. High yields of the products, mild reaction conditions, high selectivity, use of H2O or C2H5OH as solvent, and redundancy of bromine are some of the major advantages of the synthetic protocol.
Article
A 3-year field trial was conducted using established apple cv. Crown Gold and English oak (Quercus robur L.) to assess the efficacy of eight fungicides applied via microcapsule trunk injection against the foliar pathogens apple scab (Venturia inaequalis) and powdery mildew (Phyllactinia sp). In both apple cv. Crown Gold and English oak, the fungicide myclobutanil was not taken up when microcapsules were inserted into the tree vascular system at the root flare. Disease severity in injected trees, excluding myclobutanil, was lower over the following two growing seasons compared to water-injected controls indicating seven of the eight fungicides used in this study provided a significant degree of protection against scab and powdery mildew infection. A difference in the magnitude of pathogen control achieved was recorded between fungicides. Of the fungicides tested, penconazole, pyrifenox and carbendazim significantly reduced disease severity and significantly increased leaf chlorophyll (Fv/Fm) and SPAD values as a measure of tree vitality and chlorophyll content, respectively, in both apple cv. Crown Gold and English oak over two growing seasons after microcapsule injection. Based on the results of this investigation, it is suggested that these three fungicides be used in preference to thiabendazole, fosetyl-aluminium, triadimefon and propiconazole for the control of apple scab and powdery mildew where outbreaks of these foliar pathogens are problematic.
Article
In view of the essential role of phenolic compounds in the development of pathogen resistance in plants, and given the influence that fungicides and boron (B) exert over phenolic metabolism, the aim of the present study was to determine the individual effect of the application of a fungicide, as well as to determine the joint effect of the fungicide and B on the metabolism of phenolic compounds in tobacco plants (Nicotiana tabacum L. cv. Tennessee 86). The fungicide applied was carbendazim (carb), a preventative fungicide, with a purity of 100% at a concentration of 2.6 mM. Boron was applied in the form of H3BO3 at: 1.6 mM (B1), 4 mM (B2), 8 mM (B3), 16 mM (B4), 32 mM (B5), or 64 mM (B6). In all, there were eight treatments: one without carb and without B (control), one with only carb, and six combinations of carb with each concentration of B. The results indicated that the foliar application with carb alone led to increases in phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) activity and a foliar accumulation of phenols. This effect of the carb alone could signify an additional tolerance mechanism to pathogenic infection, given the participation of phenolic compounds in the lignification of plant cell walls. The joint application of carb and B increased both the biosynthesis and the oxidation of the phenolic compounds, especially in carb plus B3, while the application of carb plus B5 or carb plus B6 reduced these processes as well as the foliar biomass.
Article
In the search for alternatives to synthetic fungicides to control postharvest disease, sulfur-containing salts were evaluated for their effects on the mycelial growth of various fungal or fungus-like pathogens and their ability to control carrot cavity spot (Pythium sulcatum) and potato dry rot (Fusarium sambucinum). Results showed that metabisulfite-containing salts provided strong inhibition of all the tested fungi. Furthermore, some sulfate-containing salts were also directly inhibitory to P. sulcatum (calcium sulfate and ammonium sulfate) and to F. sambucinum (sodium sulfate). The metabisulfite salts also provided 100% inhibition of cavity spot and dry rot at concentrations of 50 and 200 mM, respectively. Calcium sulfate and sodium sulfate also significantly reduced carrot cavity spot lesions at 50 mM and ammonium sulfate, magnesium sulfate, potassium sulfate and sodium sulfate reduced potato dry rot lesions at 200 mM. These results indicate that various sulfate and metabisulfite salts could be used to control these postharvest microorganisms.Highlights► Sulfur-containing salts inhibited growth of pathogens in vitro. ► Sulfur-containing salts inhibit carrot and potato disease. ► Metabisulfite-containing salts were most effective. ► Sulfate-containing salts were effective against specific fungi and postharvest diseases.
Article
Boron is a microelement required for normal growth and development of plants but its positive effect is restricted to a narrow range of concentrations. The gradual increase in use of recycled water, which contains high concentrations of boron for irrigation, has already raised the level of boron in soils and plants in southern Israel. This research was conducted to examine the direct effects of sub-phytotoxic boron concentrations on potato late blight epidemics and to explore the mode of action of boron against Phytophthora infestans. When boron was applied alone to field grown potato plants it did not affect the epidemic. However, together with a reduced rate of the fungicide Melody Duo (propineb + iprovalicarb), boron improved late blight suppression compared to plants treated with the fungicide alone. The ED50 of boron against P. infestans (256·4 mg L−1) was about 6400 times higher than the ED50 value of the fungicide chlorothalonil (0·04 mg L−1), indicating that boron does not have a direct fungicidal activity that would explain the level of protection seen in the field. In greenhouse experiments conducted with potted tomato plants, boron decreased late blight severity in both treated leaves and distant leaves not treated with boron. The results suggest that boron is active locally but also may induce systemic acquired resistance against P. infestans.
Article
The efficacy of several antifungal compounds, chosen among salts, oils, plant extracts, and of the hyperparasitic fungus Ampelomyces quisqualis, were tested in seven glasshouse trials against powdery mildew on roses (Sphaerotheca pannosa var. rosae) in Sanremo (N. Italy). In the presence of a high disease incidence (55% of untreated leaves infected in six out of seven trials), all the antifungal compounds and the biocontrol agent A. quisqualis, applied individually, provided satisfactory control of powdery mildew. Most treatments were as efficient as the fungicide dodemorph, which, sprayed at weekly intervals, provided a 75% average efficacy throughout the trials. Among the test compounds, KH2PO2, at 0.5 and 1%, offered good and consistent disease control, NaHCO3, at 0.5%, showed a satisfactory level of activity, while at 1% it was phytotoxic. Wine vinegar, applied at 5 and 10%, gave good control, but acetic acid was phytotoxic. JMS Stylet oil, the canola oil, Synertrol and neem extract provided satisfactory disease control. Fatty acids formulated as potassium salts significantly and consistently reduced powdery mildew severity, but caused some phytotoxicity. Milsana, a concentrated extract from leaves of Reynoutria sachalinensis, only partially controlled powdery mildew. Several strategies based on the rotation of different antifungal compounds, with or without the application of dodemorph, provided very good, consistent disease control. The potential of some of the antifungal compounds and of the biocontrol fungus A. quisqualis against rose powdery mildew is discussed.
Article
The effect of foliar application of boron, manganese and zinc on tan spot disease in winter durum wheat, caused by Drechslera tritici-repentis (Died.) Shoem., was investigated during a 2 years field study. Micronutrients were applied when plants were at the first node stage. In both years, in the sprayed plots the flag leaf had significantly fewer lesions than the untreated ones, at booting through milk stages. The treatment with B significantly reduced the number of lesions per leaf compared to the other treatments at booting stage in both years. There was no difference in the number of lesions per leaf between Mn and Zn treatments in the first year. In the second year, Zn treatment showed the lowest number of lesions at the booting and heading stage, whereas Mn treatment showed the lowest number of lesions at milk stage. There was a significant influence of Zn treatment on flag leaf area which might have negatively affected disease severity. In the case of Mn and B treatments there was no significant influence on flag leaf area. Moreover there was no significant difference in yield components. These findings suggest that foliar application of micronutrients can be used to reduce the severity of tan spot on wheat, however the physiological basis of this remains unknown.
Article
Sodium bicarbonate (SBC) effectively inhibited spore germination and germ tube elongation of Venturia inaequalis in vitro. SBC at 0.5%, 1%, and 2% inhibited spore germination by 59.0%, 96.4%, and 100%, respectively. In two orchard experiments to investigate the efficacy of SBC alone or in combination with a reduced dose of tebuconazole in inhibiting apple scab, applications of 1% SBC to trees at 10-d intervals significantly reduced disease incidence and severity on leaves and fruit compared to the water-treated control. In the first experiment, by the last assessment, the 1% SBC treatment had reduced the disease incidence on leaves to 29.6% compared with 62.6% in the water-treated control. The efficacy of 1% SBC was comparable with that of the label dose of tebuconazole on leaves and fruit. Combining 1% SBC with a reduced dose (10% of label dose) of tebuconazole did not improve the efficacy of 1% SBC alone. Treatments of 2% SBC were phytotoxic to leaves, but 1% SBC was neither phytotoxic to leaves nor did it adversely affect quality parameters of harvested fruit.
Article
A foliar spray of 1% (w/v) solution of the fertilizer mono-potassium phosphate (MKP) (KH2PO4) on the upper surfaces of lower leaves of greenhouse-grown peppers induced local and systemic control against Leveillula taurica, as compared with control plants. This protection was expressed by a reduction in the leaf area covered with sporulating colonies and in conidial production on leaf tissue, 24 or 48 h post-treatment, when MKP was applied on lower leaves of plants that had been exposed to the source of inoculum. Foliar application of MKP, initiated before or after exposure to heavily diseased plants as the source of inoculum, was effective in controlling powdery mildew. Application of MKP efficiently suppressed powdery mildew as expressed by inhibition of the development of new sporulating colonies, as well as the conidial production of the fungus on infected tissue. Microscopic examination indicated destruction of both hyphae and conidial structures on MKP-treated leaves. The efficacy of MKP in controlling powdery mildew on greenhouse-grown plants was compared with a sterol-inhibiting systemic fungicide. Both treatments significantly inhibited powdery mildew as compared with non-treated control plants, although the fungicide-based treatment seemed to be slightly more effective (not significant) in controlling the disease. Phosphate solutions were not phytotoxic to plant tissue and did not affect the yield, as compared with the fungicide treatment. However, a lower yield was recorded for the non-treated control plots because of mildew infection on leaves. These data indicate that MKP spray may be applied as an alternative practice for the control of powdery mildew in peppers.
Article
Post-harvest potato diseases are responsible for significant economic loss. Tuber infection may occur naturally through lenticels and eyes or mechanically through wounds incurred during harvest. There are few fungicides approved for use on human foodstuffs and there is a necessity to evaluate and screen the efficacy of alternative compounds against pathogens responsible for post-harvest disease in potatoes. In vitro trials were conducted to evaluate the effect of several organic and inorganic salt compounds and two commercial fungicides on mycelial growth, sporulation and spore germination of Alternaria alternata, Botrytis cinerea, Fusarium solani var. coeruleum, Phytophthora erythroseptica, P. infestans, Verticillium albo-atrum, and V. dahliae. The effects of various salt compounds on these fungi were evaluated at three concentrations: 0.002, 0.02 and 0.2 M. Overall, mycelium growth and spore germination of all pathogens were strongly inhibited by sodium metabisulfite and propyl-paraben. Spore ge
Article
Boron, an essential plant micronutrient, was effective in the form of potassium tetraborate for control of postharvest gray mold caused by Botrytis cinerea on table grapes stored at room temperature or at 0 degrees C. The inhibition of fruit decay was closely correlated with boron concentrations and partially influenced by pH value of the solution. Boron strongly inhibited spore germination, germ tube elongation, and mycelial spread of B. cinerea in the culture medium. Application of boron at 1% caused the appearance of abnormal spores (disrupted) in some cases. By using propidium iodide fluorescent staining, loss of membrane integrity in B. cinerea was observed after boron treatment. Furthermore, boron led to the leakage of cellular constituents (soluble proteins and carbohydrates) from hyphae of B. cinerea. These data suggest that the mechanisms by which boron decreased gray mold decay of table grapes may be directly related to the disruption effect of boron on cell membrane of the fungal pathogen that resulted in the breakdown of the cell membrane and loss of cytoplasmic materials from the hyphae.
Article
Boron (B) is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is undoubtedly its structural role in the cell wall; however, there is increasing evidence for a possible role of B in other processes such as the maintenance of plasma membrane function and several metabolic pathways. In recent years, the knowledge of the molecular basis of B deficiency and toxicity responses in plants has advanced greatly. The aim of this review is to provide an update on recent findings related to these topics, which can contribute to a better understanding of the role of B in plants.
Article
Boron is an essential nutrient for certain organisms, notably vascular plants and diatoms. Cyanobacteria require boron for formation of nitrogen-fixing heterocysts and boron may be beneficial to animals. Boron deficiency in plants produces manifold symptoms: many functions have been postulated. Deficiency symptoms first appear at growing points, within hours in root tips and within minutes or seconds in pollen tube tips, and are characterized by cell wall abnormalities. Boron-deficient tissues are brittle or fragile, while plants grown on high boron levels may have unusually flexible or resilient tissues. Borate forms cyclic diesters with appropriate diols or polyols. The most stable are formed with cis-diols on a furanoid ring. Two compounds have this structure physiologically: ribose in ribonucleotides and RNA, and apiose in the plant cell wall. Germanium can substitute for boron in carrot cell cultures. Both boron and germanium are localized primarily in the cell wall. We postulate that borate-apiofuranose ester cross-links are the auxin-sensitive acid-growth link in vascular plants, that the cyanobacterial heterocyst envelope depends on borate cross-linking of mannopyranose and/or galactopyranose residues in a polysaccharide-lipid environment, and that boron in diatoms forms ester cross-links in the polysaccharide cell wall matrix rather than boron-silicon interactions. Complexing of ribonucleotides is probably a factor in boron toxicity.
Article
California, the leading agricultural state in the United States, has maintained a population-based cancer registry since 1988, and it also maintains a comprehensive, state-wide pesticide reporting system. Data on cancer incidence and pesticide use reporting are available, by county, for all 58 counties in California. Average annual age-adjusted cancer incidence rates (1988-1992), on a county-, sex-, and race/ethnicity-specific basis, were obtained from the California Cancer Registry (CCR), which maintains the population-based cancer registry throughout California. Pesticide use data (i.e., pounds of active ingredient applied annually in each county) were obtained from the California Department of Pesticide Regulation for 1993. Investigators used Pearson product-moment correlation coefficients (r) to correlate age-adjusted incidence rates for selected cancers with the use data for selected pesticides. For most sex- and race/ethnicity-specific groups, the correlation coefficients were very close to zero or negative in sign, indicating no correlation between pesticide use and cancer incidence. There were, however, several exceptions, particularly in Hispanic males for whom the following correlations were observed: leukemia and atrazine (r=.40), leukemia and 2,4-dichlorophenoxyacetic acid (r=.41), leukemia and captan (r=.46), atrazine and brain cancer (r=.54), and atrazine and testicular cancer (r=.41). For black males, we observed the following: atrazine and prostate cancer (r=.67) and Captan and prostate cancer (r=.49). In females, only a few of the correlations were elevated. Although most of the correlations examined in this analysis were not elevated, several of those in the Hispanic and black male populations were. These segments of the population have traditionally been employed as farm workers in California and have had the greatest potential for exposure to pesticides. This was an ecological study for which no data about exposure to pesticides at the individual level were available for analysis. In addition, no latency period was allowed between potential exposure and diagnosis with cancer. However, the results obtained in two minority groups who represented the majority of farm workers in the fields suggested that additional research studies, in which more rigorous study designs are used, should be conducted in those groups.
Article
The article describes a laboratory experiment to determine the effect of copper oxychloride on the earthworm Eisenia fetida. Copper oxychloride was used because it is the most commonly used fungicide in South African vineyards but not much is known about its toxicity to earthworms. In an experiment lasting 8 weeks, newly hatched earthworms of the species E. fetida were exposed to copper oxychloride mixed into a urine-free cattle manure substrate. Four groups of 10 worms were used per concentration level (control (4.02), 8.92, 15.92, 39.47, 108.72, 346.85 mg Cu kg substrate(-1)). The following life-history parameters were measured: earthworm growth in consecutive weeks, survival rate, maturation time, cocoon production, reproduction success, total number of hatchlings produced, and incubation time. Earthworm growth and cocoon production were significantly reduced at copper oxychloride exposure concentrations of 8.92 mg kg(-1) and higher. Reproduction success in the 8.92 mg Cu kg substrate(-1) was highest. From an exposure concentration of 15. 92 mg Cu kg substrate(-1) and higher, there was a considerable impact of copper oxychloride on reproduction. This could be seen from a reduced reproduction success, a reduced mean and maximum number of hatchlings per cocoon, and a longer incubation time, indicating a strong effect of low copper oxychloride concentrations on this earthworm species.
Article
Reports from several European countries of the breakdown of the Vf resistance, the most frequently used source of resistance in breeding programs against apple scab, emphasize the urgency of diversifying the basis of apple scab resistance and pyramiding different apple scab resistances with the use of their associated molecular markers. GMAL 2473 is an apple scab resistant selection thought to carry the resistance gene Vr. We report the identification by BSA of three AFLP markers and one RAPD marker associated with the GMAL 2473 resistance gene. SSRs associated with the resistance gene were found by (1) identifying the linkage group carrying the apple scab resistance and (2) testing the SSRs previously mapped in the same region. One such SSR, CH02c02a, mapped on linkage group 2, co-segregates with the resistance gene. GMAL 2473 was tested with molecular markers associated with other apple scab resistance genes, and accessions carrying known apple scab resistance genes were tested with the SSR linked to the resistance gene found in GMAL 2473. The results indicate that GMAL 2473 does not carry Vr, and that a new apple scab resistance gene, named Vr 2, has been identified.
Article
It is now more than 80 years since boron was convincingly demonstrated to be essential for normal growth of higher plants. However, its biochemical role is not well understood at the moment. Several recent reviews propose that B is implicated in three main processes: keeping cell wall structure, maintaining membrane function, and supporting metabolic activities. However, in the absence of conclusive evidence, the primary role of boron in plants remains elusive. Besides plants, growth of specific bacteria, such as heterocystous cyanobacteria and the recently reported actinomycetes of the genus Frankia, requires B, particularly for the stability of the envelopes that control the access of the nitrogenase-poisoning oxygen when they grow under N2-fixing conditions. Likewise, a role for B for animal embryogenesis and other developmental processes is being established. Finally, a new feature of the role of boron comes from signaling mechanisms for communication among bacteria and among legumes and rhizobia leading to N2-fixing symbiosis, and it is possible that new roles for B, based on its special chemistry and its interaction with Ca would appear in the world of signal transduction pathways. In conclusion, the diversity of roles played by B might indicate that either the micronutrient is involved in numerous processes or that its deficiency has a pleiotropic effect. The arising question is why such an element? Since all of the roles clearly established for B are related to its capacity to form diester bridges between cis-hydroxyl-containing molecules, we propose that the main reason for B essentiality is the stabilization of molecules with cis-diol groups turning them effective, irrespectively of their function.
Article
Calcium phosphate-boric acid treatments and UDP-glucose both elicited aniline blue fluorescent, periodic acid-Schiff's reagent-resistant, deposits in association with the cell walls of cowpea (Vigna sinensis [Torner] Savi cv. Early Ramshorn) tissue. Those deposits induced by calcium phosphateboric acid treatment ultrastructurally resembled the "wound callose" commonly triggered by cell damage; they were formed in seemingly intact cells of stems and leaves and their formation was associated with an increase in the surface density of rough endoplasmic reticulum in the cell cytoplasm. In contrast, UDP-glucose induced a more rapid accumulation of aniline blue fluorescent material, but only at the cut edges of stem slices. Comparative light and electron microscopy indicated that the material was incorporated into the walls of the damaged cells, even when such cells were devoid of organized cytoplasm. These results indicate a difference in the mode and site of synthesis between wound callose and that elicited by exogenous UDP-glucose. They support the hypothesis that externally supplied UDP-glucose cannot be utilized by intact cells.
Role of nutrients in controlling plant diseases in sustainable agriculture. A review
  • Dordas
Boric acid, borates and household pests
  • Quarles
Forms of boron application and its influence on quality and yield of apples (Malus domestica)
  • De Sa AA
  • Paulo Roberto E
  • Gilberto N
  • do Amarente CVT
  • Pereira AJ
Apple Scab, Biology, Epidemiology and Management
  • MacHardy WE
Some exploratory experiments on the permeability of papillae induced in barley coleoptiles by Erysiphe graminis f. sp. hordei
  • Smart