Boron Nutrition Research Articles

Boron nutrition and mobility, and its relation to the elemental composition of greenhouse grown root crops I. Rutabaga

Abstract The nutrition and mobility of B, and its relation to the elemental composition of two cultivars of rutabaga (Brassica napus ssp. rapifera cv. Laurentian and Wilhelmsberger) plants were investigated in greenhouse experiments. Laurentian exhibited a greater response than Wilhelmsberger to continuing B deficiency as indicated by the severity in the roots of brown heart, of external roughness and elongation and of the decrease in B concentration. Signs of B deficiency were not found when the B contents of the root and young leaves were 27 and 56 ug g‐1 DM respectively. Root B levels of 14 and 17–20 μg g‐1 gave moderate and slight internal signs of brown discoloration. Foliar applications of B partially restored the B concentrations of the roots; however, the mechanism of movement was unclear. The Mg, Mn and Zn contents of roots were the only elements that consistently increased and accumulated under B deficiency. The relative element composition of the root compared to the mature leaves is consistent with the root being supplied predominantly with nutrients by the phloem. Nutrient retranslocation was assessed from the ratio of element concentration in the roots or young leaves to that in the mature leaves. Although Mg, Mn and B exhibited limited mobility under adequate B nutrition they were translocated from mature leaves to younger tissues under B starvation. It is concluded that Wilheimsberger is by virtue of its greater capacity for the retranslocation of B to roots, less sensitive to B deficiency and the brown heart disorder.

Boron nutrition and mobility, and its relation to hollow stem and the elemental composition of greenhouse grown cauliflower

Abstract The growth and elemental composition of various parts of cauliflower (Brassica oleracea var botrytis cv White Top) plants were investigated under greenhouse conditions with plants grown in vermiculite medium as a function of B added at concentrations of 0.0, 0.25, 1.0, 2.5 and 12.5 mg L‐l. Optimal plant and head yield, and the maximum fresh weight harvest index were found at 1.0 mg B L‐l; B levels in the head, and old and young leaves were 41, 543 and 145 μg g‐1 DM respectively. Above and below 1.0 mg B L‐l foliar symptoms of toxicity and deficiency were evident. In the absence of added B, the head also showed slight internal signs of necrosis and browning, and curd surface discoloration, symptoms which may be associated with the hollow stem disorder under field conditions. In this case, the B levels were 21, 35, 48 and 55 μg g‐1 DM respectively in the head, and old, young and intermediate leaves. Comparison of the relative element composition of younger tissues to old leaves indicated that the f...

Boron nutrition and mobility, and its relation to the elemental composition of greenhouse grown root crops. II radish

Abstract The elemental distribution between the leaves and roots of mature radish (Raphanus sativus cv Cherry Belle) plants grown in the greenhouse with various concentrations of nutrient solution B or Ca was determined to assess the role of phloem in the provision of nutrients to the root, and the retranslocation of B under deficient conditions. The relative composition and accumulation of elements in different parts, and the ratio of their concentrations in leaves:roots were used as a measure of their uptake, relative mobility and retranslocation. The data indicate that B, but not Ca is retranslocated in the phloem to the roots when that particular element was in short supply in the nutrient solution. B deficiency induced brown heart disorder in radish roots but the severity was dependent on the degree of deficiency below 28 μg g‐l DM in the root. These symptoms were alleviated when the root B concentrations were enhanced by foliar applications of B. It is concluded that radish responded to B deficiency in a fashion similar to that reported previously for rutabaga and that it might serve as a time‐saving model system for examining the mechanisms responsible for brown heart in rutabaga.

Relation between hot-water-soluble boron and uptake of boron by cacao (Theobroma cacao L.) in Nigeria

Boron (B) nutrition problems of cacao (Theobroma cacao L.) in Nigeria deserve continuous attention in view of the fact that more cocoa-growing areas showing B deficiency are being brought to light. Omotoso (1975) examined plant tissue B and B extractable by hot water in relation to the appearance of B deficiency symptoms on cacao leaves and found that B deficiency symptoms had no direct relation to hot-water-soluble (HWS) B in the Nigerian soils studied. Omotoso (1975) then suggested further investigations to identify soil properties that can improve the capacity of HWS B to predict cacao uptake of B.

Boron nutrition of carrots and table beets grown in a boron deficient soil

Abstract Soil applications of boron (B) generally had little effect on yield of carrots (Daucus carota L.) and beets (Beta vulgaris L.) in a field study. However, in a greenhouse study B significantly increased the yield of carrots. Boron deficiency impaired the quality of both crops. Boron deficient beets had brown tops and roots were rough, scaby, and off colour. There was a depression on the sides of most of the beet roots and cut sections of affected roots were darker and necrotic compared to bright purplish red roots grown with sufficient B. In carrots, B deficiency resulted in yellow tops and the roots were both rough and small with a distinct white core in the middle. Leaf tissue B concentrations of 32–40 μg/g in beets and 22–28 μg/g in carrots were related to B deficiency. Tissue B levels as high as 121 μg/g in beets and 149 μg/g in carrots were not associated with any B toxicity. Applications of B had no effect on tissue Ca and Mg concentration in the two crops.

Early Effects of Excess Boron on Photosynthesis and Growth ofCucurbita pepo

Summer squash plants (Cucurbita pepo L., cv. 'Early Prolific Straightneck') hydroponically cultured under optimal boron nutrition (+B)3 until age 5 d were transferred to hydroponic solutions supplemented' with excess boron (+ + B)3. As boron accumulated in the leaves with time, leaf conductance to water vapour, 14C02 fixation, and chlorophyll content of the oldest leaf became significantly less than in the + B-control plants of the same age; shoot growth essentially ceased. Boron also accumulated in the roots; concomitant inhibition of root elongation and lateral root development resulted. These metabolic changes all occurred prior to the accumulation of sufficient boron to cause the appearance of any symptoms characteristic of boron toxicity.

Boron nutrition of perennial ryegrass, cocksfoot, and timothy

Abstract Perennial ryegrass (Lotium perenne L.), cocksfoot (Daclytis glomerala L.), and timothy (Phleum pralense L.) were grown in pots with 7 rates of boron (B) to determine if deficiency or toxicity developed in these grasses. No yield response or deficiency symptoms occurred even though B concentrations were only 6-12 ppm in the control plants. B toxicity symptoms occurred at high application rates in ryegrass and timothy for 3 cuts and cocks foot for 2 cuts. Timothy yields were reduced by B toxicity for 2 cuts but ryegrass and cocksfoot yields were reduced only at the first cut. Ryegrass and timothy plants had toxicity symptoms when they contained more than 39-42 and 47 ppm B respectively. It was not possible to establish a precise threshold value for cocksfoot but it was between 34 and 63 ppm B. It is concluded that if B is required for the clover component of established pastures there will be no detrimental effect on the grasses at the recommended application rate.

Boron nutrition of cassava, and the boron x temperature interaction

Abstract Rooted stem tip cuttings of five cassava cultivaes grew well in a complete nutrient solution containing 46 μM boron when the solution temperature was maintained at 28 or 33°C, but developed severe boron deficiency symptoms at 18°C. Mild symptoms of boron deficiency were observed also at a solution temperature of 23°C. The diagnosis of boron deficiency was confirmed both by plant analysis and by the induction of identical symptoms in a subsequent experiment in which the solution temperature was held constant at 25°C and the boron supply varied. In this latter experiment with cv. Mameya, the critical boron concentration in the plant tops for deficiency was estimated at about 17 μg.g−1 dry weight and that for toxicity at about 140 μg.g−1 dry weight. The boron x temperature interaction in cv. Mameya and Seda was further explored over the temperature range 19–40°C with four levels of boron supply ranging from deficient to toxic. It was found that the susceptibility of cassava to boron deficiency at suboptimal root temperatures was due in part to a lowering of the rate of boron uptake per unit root weight and in part to a reduction in the relative size of the root system.

Translocation of Boron to Plant Fruits

Fruit of peanut (Arachis hypogaea L.) and burrs of subterranean clover (Trifolium subterraneaum L.) were shown to develop in white siliceous sand which was low in boron. Fruit and seed production and yield did not vary with the boron nutrition given to the medium in which seeds developed. The results suggest that for the development of their fruits, peanut and subterranean clover translocate boron in their phloem.

Effect of Boron Nutrition on Intensity of Red Spider Mite Attack on Oil Palm Seedlings

SUMMARYThe effect of boron nutrition on the susceptibility of young tenera oil palm seedlings to red spider mite attack was studied. Highest concentrations of mites were recorded in seedlings which had received little or no boron in the growing media. Injuries by mites were greatest when the leaves had the highest number of mites per unit area, the lowest boron concentration and the lowest concentration of cyanidin.

Boron nutrition and growth of timothy as affected by soil pH

Abstract Timothy was grown under greenhouse conditions with 6 levels of soil B and A pH values. No significant yield increases were obtained with added B, although values as low as 2.8 ppm B in the tissue were obtained. Boron toxicity symptoms on leaves were obtained with B additions at the rate of A mg/kg soil. Tissue B concentrations of greater than 102 ppm were associated with B toxicity symptoms and decreased yields. Liming decreased the B concentration of the leaf tissue; such decreases were more marked at higher rates than at lower rates of B. Liming the soil to pH 6.5 decreased the yield of timothy. However, the decreased yield at higher pH levels was not corrected by application of B as observed under similar conditions on forage legumes, but was probably caused by Mn deficiency.

Boron nutrition in the growth and sugar content of sugarbeets

The system of analyzing plant tissues chemically has proven very useful in establishing the nutrient status of plants for such elements as nitrogen , phosphorus, potassium and other mac­ ronutrients in sugarbeet plants. There is reason to believe that it may be even more useful for some of the micronutrients . Recent work has shown that a content of 10 ppm in mature blades characterizes a critical value of manganese in sugarbeets (14)2 . Further research with zinc has given a range of 8-10 ppm, also in mature blades (11 ). With iron it has been shown that 05 ppm in young and mature blades represents a deficiency level (9). This study was made to determine the growth, boron content of the tissues and sugar production of sugarbeet plants gTo'wn In nutrient solutions covering a wide range of boron supply.

Boron Nutrition of Sugar Beet, Cotton, and Soybean1

AbstractThe levels of boron in nutrient solutions suitable for plant growth are highest for sugar beet, (Beta vulgaris) lowest for soybean (Glycine max), and intermediate for cotton (Gossipium hirsutum). In spite of pronounced differences in B tolerance (and also of B requirement), tissue levels at which toxicity symptoms appear are similar in the three species. The species differences are therefore due more to B uptake and growth characteristics than to tissue sensitivity. Chlorotic tissues contain around 1,000 ppm B, necrotic tissues above 1,000 ppm.Beet yields and beet sugar contents in greenhouse experiments were not affected by B concentrations up to 40 ppm. Thus the sugar beet might be a suitable plant for high B soils, provided the result is not modified in the field by different climatic conditions.Boron distribution, patterns of B toxicity, leaf venation, correlation between B injury and leaf age all support the hypothesis that within the leaf, B moves largely in the transpiration stream and is accumulated to toxic levels as water is lost to the atmosphere.

Effects of Changes in Boron Nutrition on Growth and Development of Subterranean Clover

In the early stages, boron deficiency had little effect on dry matter accumula-tion by the plant as a whole. Root growth, however, declined significantly and this was accompanied by an accumulation of dry matter in the leaves. At progressive stages of boron deficiency distribution of dry matter to new leaf tissue also became restricted. When plants already deficient in boron were transferred to solutions without boron, increases in dry weight of existing leaves were greater than for the corresponding plants transferred to complete solutions. However, the dry weight of leaves formed after the transfer increased at a much slower rate in the no-boron than in the complete solutions_

The Comparative Boron Nutrition of Several Green and Blue‐Green Algae

AbstractThe boron requirements of filamentous and non‐filamentous species of green and blue‐green algae have been investigated. A primary feature of this study was the quantitative analysis of the cells for boron. This permitted expression of the degree of purification of the environment and the boron requirements of the organisms in terms of cell content. Three species of green algae were shown neither to require boron nor to absorb it in appreciable amounts. In contrast, three species of blue‐green algae readily absorbed boron and nitrogen fixing species showed a marked growth response to boron when nitrate was omitted from the culture medium. The response to boron was less with nitrate in the medium, probably due to increased contamination from the nitrate salt rather than an involvement of boron in the fixation process. The boron content of the deficient blue‐green algae was 1–2 μg/g, suggesting a requirement below dicot angiosperms and comparable to monocots. In agreement with other reports, the fungus Penicillium chrysogenum neither required nor absorbed boron.

Boron absorption by crop plants as affected by other nutrients of the medium

Abstract Numerous reports on boron nutrition of plants have been published since WARINGTON (15), using Vicia faba, first discovered in 1923 that boron is essential for the growth of higher plants. Inorganic (7, 9, 11) and organic (1) constituents of the growth medium and climatic conditions such as light intensity (13), photoperiod (5, 16), and drying and wetting of the soil (10) are some of the factors affecting boron uptake by plants.

The Boron Nutrition of the Diatom, Cylindrotheca Fusiformis, Grown on Agar, and the Biological Activity of Some Substituted Phenylboronic Acids

The boron requirement of the diatom Oylindrotheca fusiformis Reimann & Lewin, grown in liquid culture, was confirmed, Methods are described in which this requirement is also easily demonstrated on agar, when it is satisfied by 10-5M boric acid, Using this agar technique, the ability of various organic (and other) boron compounds to elicit a growth response on boron-deficient agar media was studied. Aqueous solutions of germanium dioxide were inactive. The results are discussed in relation to the various hypotheses regarding the relationship between the chemical structure and biological activity of boron compounds. The results obtained are consistent with the "complexing hypothesis" for the biological activity of borate.

Effect of Imbalance of Boron Nutrition on the Peanut1

AbstractThe ‘Florigiant’ variety of peanut (Arachis hypogaea L.) was grown 2 years in pot cultures on Lakeland fine sand, a soil deficient in boron, to determine the effects of imbalanced boron nutrition on peanuts. Variations in fertilization were: no treatment, complete fertilizer and lime treatment including the micronutrients, and the same as the latter except without boron. The containers were low‐boron and each held 60 pounds of soil. Reagent grade chemicals and distilled water, which was then passed through an ion exchange demineralizer, were used throughout the experiments. Flower counts, yields of shoots, roots and fruit and quality studies on the fruit were used to determine the effects of imbalanced boron nutrition. Without boron in the fertilizer, shoots were stubby, leaves frequently were mottled, dark areas appeared at the internodes of the branches, and stems sometimes cracked. Roots were also stubby and yields of fruit negligible. In contrast, plants with boron in the fertilizer were free of these abnormalities and produced many peanuts. With boron in the fertilizer, peak flower production came early in the flowering period, while without boron more flowers were produced but the distribution pattern was changed. With no treatment the plants were small, appeared normal, and yielded more peanuts of a better quality than plants with complete fertilization minus boron.

Boron Nutrition and Lignification in Sunflower and Tobacco Stems

Sunflower plants (Helianthus annuus L.) decapitated above the third node and tobacco plants (Nicotiana tabacum L.) decapitated above the tenth node were grown in plus- and minus-boron solutions in an attempt to determine whether boron plays a role in tissue lignification. After 18 days the stems of sunflower and after 82 days those of tobacco were harvested and analyzed for lignin. The percentage lignin in the stems of the minus-boron sunflower plants was higher, although there was no significant difference between the two series in total quantity of lignin. The percentage and total quantity of lignin in the seventh and eighth internodes of tobacco stems were lowest in the minus-boron plants; in the ninth internode these values were highest in the minus-boron plants. The present results seem to indicate that boron has some function in lignin production, but it was not established whether this is a direct role. Some of the factors which have resulted in the apparent discrepancies in the literature with res...

The Distribution of Normal and Toxic Amounts of Boron in Leaves of Rough Lemon

SynopsisThe distribution of boron in rough lemon leaves is non‐uniform. Concentrations can be found in areas near the tip a hundred times higher than that in the petiole. Symptoms of disorders in boron nutrition are reflected in the boron distribution in the tissues.