Soil‐boron affects straw quality and other agronomic traits in two cultivars of barley

Abstract

Boron (B) toxicity in crops occurs in many dry areas. However, the effect of high external B levels on straw quality is not known. In this greenhouse study, the responses of straw yield, straw quality, and other characters to high soil B levels were investigated in barley. Two cultivars, Galleon and Harmal, were tested. In Experiment I, three B levels were prepared by mixing 0, 25, and 50 mg B kg^‐1 soil‐mix (designated as B0, B25, and B50, respectively). Straw yield, straw quality (nutritional value), and other characters were measured. In Experiment II, an additional soil B level, prepared by adding 12.5 mg B kg^‐1 soil‐mix (designated as B12), was used. Shoots and roots were harvested at tillering and after heading. In Experiment 1, the B50 treatment improved straw quality, had no effect on straw yield, but decreased grain yield, and harvest index. Considering the shoot B concentrations and B uptake at the tillering stage at moderate to high levels of soil B in both experiments, Galleon was able to restrict B uptake better than Harmal. However, Harmal, unlike Galleon, had a better growth and more tillers at moderate levels of soil‐B than at BO. Since Harmal had higher or similar B concentrations as Galleon, Harmal appeared to tolerate higher tissue B concentrations than Galleon. The limitation of selecting genotypes tolerant to high‐B soil was pointed out, and the need to study adult performance after the initial selection was suggested. The finding on straw quality and yield would be a positive finding for sheep owners in dry areas, where barley straw and stubble are a valuable ruminant feed.     

Internal Boron Requirement of Young Sunflower Plants: Proposed Diagnostic Criteria

Abstract

In a greenhouse study, a significant increase in sunflower (Helianthus annuus L., cv. Hysun 33) dry matter yield was observed with boron (B) application to a B-deficient (hot water-extractable, 0.23 mg B kg^?1) calcareous soil of Missa series (Typic Ustochrept). Six rates of B, ranging from 0 to 8 mg B kg^?1 soil, were applied as H₃BO₃ along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). Four plants of sunflower were grown in each pot; two were harvested after 4 weeks of germination and the other two after 8 weeks. Maximum crop biomass was produced with 1.0 mg B kg ^?1, and application of ≥2.0 mg B kg^?1 proved toxic, resulting in drastic yield suppressions. Critical B concentration range for deficiency diagnosis in 4‐week‐old sunflower whole shoots appears to be 46–63 mg B kg^?1. However, critical concentration in 8‐week‐old plants was much less (i.e., 36 mg B kg^?l), presumably due to a dilution effect. As plant's internal B requirement can vary, in fact manifold, depending on the species, plant part, and plant age, only a relevant criterion can help in diagnosing the deficiency effectively.     

Boron Nutrition of Four Sweet Pepper Cultivars Grown in Boron-Deficient Soil

ABSTRACT

In a greenhouse study, boron (B) application significantly increased dry-matter yield of sweet pepper (Capsicum annum L.) cultivars (‘California Wonder,’ ‘Anahein,’ ‘Narwala,’ and ‘2573’) grown in a B-deficient (hot-water extractable, 0.28 B mg kg^?1), calcareous soil of the Shujabad series (Typic Ustochrepts). Five rates of B, ranging from 0 to 8 mg B kg^?1 soil, were applied as H₃BO₃ along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). Four plants of sweet pepper were transplanted in each pot, two of which were harvested after three weeks of transplanting and the other two after six weeks. Maximum crop biomass was produced with ～1 mg B kg^?1, but application of higher rates proved toxic, resulting in dry-matter yield reductions. The four cultivars significantly differed in relative growth rate (RGR) and relative accumulation rate of B (RARB). Cultivar ‘2573’ showed the highest RGR while ‘Anahein’ showed the highest RARB. Relative accumulation rate was positively correlated (R² = 0.83) with dry-matter yield of four cultivars. Critical B concentration in sweet pepper whole shoots was 69 mg B kg^?1 for three-week-old plants and 49 mg B kg^?1 for six-week-old plants.     

Interacting effects of topsoil water and nitrogen supply on subsoil aluminium toxicity

Abstract

The interacting effects between topsoil water supply, nitrogen (N) placement and subsoil aluminum (Al) toxicity on wheat growth were studied in two split‐root pot experiments. The native nitrate‐N (NO₃‐N) in the topsoil used in each experiment differed and were designated as high (3706 μM) and low (687 μM) for experiments one and two, respectively. Wheat was grown in pots that enabled the root system to be split so that half of the roots were in topsoil and the other half were in subsoils containing varying concentrations of soluble Al. Treatments were imposed which varied the supply of water to the topsoil (either ‘wet’ or ‘dry'). Placement of applied N in either the topsoil or subsoil had little effect on either shoot or root fresh weight, or on the length of roots produced in the subsoil section of the split pots. When water supply to the topsoil was decreased, both shoot and root growth of wheat declined and the yield decrease increased with subsoil Al. In the high‐N experiment, wheat grown in the low Al subsoil with the high native soluble subsoil (NO₃ (3002 μM) was able to exploit the N and subsoil water, hence both shoot and root growth increased considerably in comparison to shoot and root growth of wheat grown in soils containing higher concentrations of subsoil Al. When the native NO₃ was lower (i.e. the low‐N experiment) inadequate root proliferation restricted the ability of plants to use subsoil N and water irrespective of subsoil Al. The results from this study suggest that wheat, grown on yellow earths with Al‐toxic subsoils, will suffer yield reductions when the topsoil dries out (e.g. in the spring when winter rainfall ceases) because subsoil reserves of water and nitrogen are under utilised.     

Screening of Wheat Genotypes for Boron Efficiency

Several sand culture and field experiments were conducted to screen out a number of Bangladeshi wheat varieties and advanced lines for boron (B) efficiency against Thai B efficient (‘Fang 60’) and inefficient (‘SW41’ and ‘E12’) varieties. Performances of wheat genotypes were evaluated with respect to flag leaf B concentration, pollen viability, grain set index, and grain yield. Wheat genotypes responded differently to boron deficiency. Pollen viability was found to be 67% in ‘Kanchan’, 35% in ‘Gourab’, 80% in ‘Sourav’, 90% in ‘Fang 60’, and 25% in ‘SW 41’ when B was not added. Pollen viability of all varieties was above 90% when B was applied. Based on grain set index and leaf B concentration, ‘Sourav’ was found to be the moderately B efficient variety. Thus, ‘Sourav’ can be regarded as a breeding material for development of new wheat varieties for tolerance to B deficiency.     

Critical Levels of Boron in Soils for Cauliflower (Brassica oleracea Var. Botrytis)

Influence of boron (B) application to cauliflower (Brassica oleracea var. botrytis) was investigated in a pot experiment taking 15 Inceptisols with four levels of B. The critical levels of B for deficiency, adequacy and toxicity in soil and in cauliflower plant were also determined. Hot-calcium chloride (CaCl₂) extractable B in these soils varied from 0.33 to 0.78 mg kg^-1 and its content for deficiency to cauliflower was 0.48 mg kg^-1. Boron application significantly increased cauliflower yield, plant B concentration and uptake of B. The critical plant B concentrations for deficiency, sufficiency and toxicity varied with the growth stages and the values being 26, 31 and 48 mg kg^-1 at 50 days of growth and 17, 24 and 35.5 mg kg^-1 at harvest, respectively. The study also recommends application of fertilizer B at the rate 0.9–4.5 kg ha^-1 for optimum B nutrition to cauliflower in Inceptisols of the Gangetic plains of India.     

Comparing the Calcium Requirements of Wheat and Canola

Spring wheat (Triticum aestivumL.) is the major crop species grown in south-western Australia and no responses of wheat to applied calcium (Ca) have been obtained in field experiments though responses have been obtained in glasshouse pot studies for wheat grown on the predominantly sandy acidic soils of the region. Since the mid 1990s canola (oilseed rape, Brassica napus L.) has been grown in rotation with wheat and has often developed symptoms of Ca deficiency when grown on sandy acidic soils in the field. The Ca requirement of canola in these soils is not known and was measured and compared with Ca requirements of wheat in the glasshouse study reported here when 5 amounts of Ca (0–630 mg Ca/pot), as calcium sulfate, were applied.

Application of Ca did not affect shoot production of wheat but increased grain yields by about 25% and 50 mg Ca/pot was required to produce 90% of the maximum grain yield. Two canola cultivars were grown, and both showed no shoot yield responses to applied Ca at early growth (GS1.5). However, at flower bud visible (GS3.5) shoots of triazine tolerant canola cv. ‘Karoo’ showed about 17% increase to applied Ca and required ～47 mg Ca/pot to produce 90% of the maximum yield, while corresponding values for cv. ‘Outback’ were 42% and 185 mg Ca/pot. Both canola cultivars showed large seed (grain) yield responses to applied Ca. Canola cv. ‘Outback’ produced no grain when no Ca was applied and showed ～ 97% increase to applied Ca and required about 462 mg Ca/pot to produce 90% of the maximum grain yield. The triazine tolerant cv. ‘Karoo’ produced about 22% of the maximum grain yield when no Ca was applied, showed approximately 78% grain yield response to applied Ca and required about 475 mg Ca/pot to produce 90% of the maximum grain yield. However, to produce 50% of the maximum grain yield, cv. ‘Outback’ required 250 mg Ca/pot while cv. ‘Karoo’ required about 100 mg Ca/pot. The grain yield response curve for cv. ‘Karoo’ was exponential and that for cv. ‘Outback’ was sigmoid so differences in the response curves were largest when small amounts of Ca were applied and decreased as more Ca was applied. Evidently canola cultivars differ in their ability to access soil and applied Ca providing opportunity to breed and select cultivars efficient at accessing soil and applied Ca. For both wheat and canola the concentration of Ca in dried shoots increased as more Ca was applied and, for each amount of Ca applied, the concentration of Ca in shoots decreased as plants matured. Both canola cultivars consistently had larger concentrations of Ca in shoots than wheat, either when no Ca was applied and for each amount of Ca applied, suggesting canola roots were better able to access soil and applied Ca than wheat roots. The Ca concentration in young wheat (GS15) and canola (GS1.5) shoots that was related to 90% of the maximum grain yield (critical Ca concentration) was 0.33% for wheat and 2.5% for both canola cultivars.     

Risks of Boron Toxicity in Canola and Lupin by Forms of Boron Application in Acid Sands of South-Western Australia

Boron (B) deficiency frequently occurs on soils that are low in organic carbon (C) (<1.0% organic C), pH (soil pH_Ca <5.0), and clay content (<5% clay). Acid sands with these soil properties are common in south-western Australia (SWA). Moreover, hot calcium chloride (CaCl₂) extractable B levels are commonly marginal in the acid sands of SWA. This study examined the effects of soluble and slow release soil-applied B fertilizer and foliar B sprays on crops most likely to respond to B fertilizer on these soils, canola (oil-seed rape, Brassica napus L.) and lupin (Lupinus angustifolius L.).

At 25 sites over three years, canola was grown with (0.34 kg ha-¹) or without B applied as borax [sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O) 11% B], and this was followed by nine experiments with B rates [0, 0.55, 1.1 kg ha^?1, applied as borax or calcium borate (ulexite, NaCaB₅O₆(OH)₆·5(H₂O), 13% B] and foliar sprays (0.1% solution of solubor, 23% B) in 2000–2001. A further five sites of B rates and sources experiments were carried out with lupin in 2000–2001. Finally, foliar B sprays (5% B w/v as a phenolic complex) at flowering were tested on seven sites in farmers’ canola crops for seed yield increases. No seed yield increases to soil-applied B were found while foliar B application at flowering increased canola seed yield in only one season across seven locations. By contrast, borax fertilizer drilled with the seed at sowing decreased canola seed yield in nine of 34-farm sites, and decreased lupin yield in two of five trials. Toxicity from drilled boron fertilizer decreased yield could be explained by decreases in plant density (by 22–40%) to values lower than required for optimum seed yield. Seedling emergence was decreased by borax applied at sowing but less so by calcium borate. Foliar B spray application never reduced seed yield due to toxicity effects.

Boron fertilizer drilled with the seed increased the B concentration in plant dry matter at early to mid-flowering. Boron application decreased the oil concentration of grain of canola at four sites. The oil yield of canola was significantly decreased at seven sites.

Notwithstanding the marginal B levels on acid sands of the SWA region, care needs to be taken on use of borax fertilizer as toxicity was induced in canola and lupin; with 0.34 to 1 kg B ha^?1(3-10 kg borax ha^?1) at sowing depressing seed yield, mostly by decreasing plant density. Rather than making general recommendation for B fertilizer application based on 0.01M CaCl₂ soil extractable B, soil and plant analysis should be used to diagnose B deficiency and B fertilizer use limited to calcium borate or foliar borax rather than soil-applied borax on low B sands.     

Mineral element concentration of two barley cultivars in relation to water deficit and aluminum toxicity

The separate and combined effects of water and Al stress on concentrations of P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, Al, Sr, and Ba were determined in tops of ‘Dayton’ (Al‐tolerant) and ‘Kearney’ (Al‐sensitive) barley (Hordeum vulgäre L.) grown in an acid, Al‐toxic, Tatum subsoil (clayey, mixed, thermic, Typic Hapludult). Plants were grown 4 weeks in a plant growth chamber at high (pH 4.7) or low (pH 6.6) Al stress. During the last 2 weeks they were also subjected to low (‐20 to ‐40 kPa), moderate (‐40 to ‐60 kPa), or high (‐60 to ‐80 kPa) water stress. In general, Al stress had a greater overall effect on mineral element concentration of tops than water stress. Aluminum stress significantly decreased concentrations of P, Ca, and Mg and increased concentrations of Zn, Sr, and Ba, irrespective of the cultivar or water stress treatment. Cultivar differences in Mn concentration were observed with Al stress under all water stress conditions. In each case, Mn concentration was lower in ‘Kearney’ than in ‘Dayton’. Potassium, Ca, and Mg were lower in ‘Kearney’ than in ‘Dayton’ only at low and moderate water stress, under low Al stress, ‘Kearney’ had significantly higher concentrations of K and Ca than did ‘Dayton’ under all water stress conditions. The effects of water stress on mineral element concentration varied greatly with cultivar, Al stress treatment, and severity of water stress. Under high Al stress, increasing drought conditions from low water stress (‐20 to ‐40 kPa) to high water stress (‐60 to ‐80 kPa) significantly increased the concentrations of Ca, K, Zn, Sr, and Ba in Al‐sensitive ‘Kearney’ and reduced the concentrations of Zn, Sr, and Ba in Al‐tolerant ‘Dayton'; P and Mg concentration were unaffected by water stress. In contrast, under low Al stress, a corresponding increase in water stress significantly increased the concentrations of Ca and reduced that of P in ‘Kearney’ and increased Ca and B concentration in ‘Dayton'; Mg concentrations were unaffected in either cultivar. Thus, it appears that Al stress and water stress had opposite effects on Ca accumulation in barley tissue.     

Soil Application of Boron Improves the Tillering,Leaf Elongation,Panicle Fertility,Yield and its Grain Enrichment in Fine-Grain Aromatic Rice

Boron (B) is one of the essential micronutrients having a specific role, particularly during reproductive phase, in rice. In a previous experiment on aerobic rice, panicle sterility was noted as one of the major challenges. This experiment was conducted to evaluate the influence of soil-applied B on tillering, panicle sterility, water relations, and grain enrichment in fine-grain aromatic rice cultivars ‘Super Basmati’ and ‘Shaheen Basmati’. Boron was soil applied at 0.50, 0.75, 1, 1.25, and 1.50 kg ha^?1 while the control treatment did not receive B. Rate of leaf emergence and elongation and tiller appearance were significantly improved by B application. Likewise, B application also improved the leaf chlorophyll contents and water relations in both rice cultivars. Substantial improvement in kernel yield and yield contributing traits was also observed by B application owing to decrease in panicle sterility. A linear increase in leaf and kernel B contents was observed with increase in B application rate. However, the range for an optimum B application rate is very narrow and increase of B application beyond 1 kg ha^?1 was toxic. In conclusion, soil application of B is an effective way to decrease panicle sterility and increase the kernel yield and grain B enrichment in rice.     

Impact of Boron Deficiency on Changes in Biochemical Attributes,Yield, and Seed Reserves in Chickpea

To determine the effect of boron (B) deficiency on biomass, reproductive yield, metabolism, and alterations in seed reserves of chickpea (Cicer arietinum L.) cv. ‘13.G‐256,’ plants were grown in refined sand until maturity at deficient (0.033 mg L^?1) and adequate (0.33 mg L^?1) B, supplied as boric acid (H₃BO₃). Boron‐deficient plants exhibited visible deficiency symptoms in addition to reduced number of pods and seeds, resulting in lowered biomass and economic yield. Boron deficiency lowered the concentration of B in leaves and seeds, photosynthetic pigments (leaves), Hill reaction activity, starch (in leaves and seeds), and proteins and protein N (in seeds), whereas phenols, sugars (in leaves and seeds), and nonprotein N (in seeds) were elevated. Specific activity of peroxidase (POX) increased in leaves and pod wall and decreased in seeds, while activity of acid phosphate and ribonuclease were stimulated in leaves, seeds, and pod wall in B‐deficient chickpea.     

Identifying critical limit in soil and plant for determining response of groundnut (Arachis hypogea) to boron application in Madurai soils of Tamil Nadu,India

To establish critical limit in soils and plant, soil samples were collected from twenty; 12, 5 and 3 soil locations of low, medium and high boron (B) status from Madurai district of Tamil Nadu, India for pot culture experiment. Based on the results of pot culture experiment, the critical limit was determined to be 42.7 mg kg^?1 for groundnut plants and 0.39 mg kg^?1 in Madurai soils. Groundnut plants were highly responded to B application in soils below the critical limit whereas soils with B greater than 0.51 mg kg^?1 did not respond. For the confirmation of pot culture results, a field experiment was conducted with different B treatments comprised of soil and foliar applications and results revealed that the pod yield of groundnut increased with increasing levels of B and the soil application of 20 kg ha^?1 as borax has showed significantly higher pod yield in the district.     

Boron Foliar Application in Nutrition and Yield of Beet and Tomato

The objective of this work was to evaluate the effect of the application of boron (B) by foliar spraying for the yield of beet (Beta vulgaris L.) and tomato (Solanum lycopersicum L.) crops. An experiment for each crop was done in a greenhouse at the São Paulo State University (UNESP), Jaboticabal campus, in Brazil. The experiments evaluated the B concentrations of 0, 0.085, 0.170, 0.255, and 0.340 g L^?1; applied in the 20, 35, and 50 days after the transplant (DAT) of beet cv. ‘Tall Top Early Wonder’, and in the 20, 40, and 60 DAT for the tomato cv. ‘Raisa N’. The plants were cultivated in pots with washed sand with 5 dm³ for the beet crop and 10 dm³ for the tomato crop. The beet and tomato crops were harvested 58 and 154 DAT, respectively. The leaves and fruits numbers; the foliar area; the dry matter of leaves, bark and roots; the fresh and dry matter of the fruits and the tuberous root; the dry matter of the total plant and the B foliar content were evaluated. The total dry matter of beet and tomato the plant were influenced by the concentration of the foliar B spray. The highest yield of the tuberous root and the total plant dry matter of beet occurred with B foliar concentration of 0.065 g L^?1 and it was associated with the B foliar content of 26 mg kg^?1. The highest yield of fruit and total plant dry matter of tomato occurred with the B foliar spraying of 0.340 g L^?1 and it was associated with the B foliar content of 72 mg kg^?1.     

The effectiveness of seed priming and foliar application of zinc- amino acid chelates in comparison with zinc sulfate on yield and grain nutritional quality of common bean

Abstract

The efficacy of seed priming and foliar application of zinc-amino acid chelates including zinc-histidine [Zn(His)₂] and zinc-methionine [Zn(Met)₂] in comparison with zinc sulfate (ZnSO₄) on yield and grain nutritional quality of two common bean cultivars (Phaseolus vulgaris L., cvs Talash and Sadri) was investigated in a severely Zn-deficient calcareous soil (DTPA-Zn: 0.38?mg kg^?1 soil) in a pot experiment. Bean response to Zn application varied depending on the Zn fertilizer, application method and cultivar. In ‘Talash’, seed priming with [Zn(His)₂] and [Zn(Met)₂] led to 24.1 and 11.6% increase in the grain yield of bean in comparison with ZnSO₄ treatment, respectively. In both cultivars, foliar application of [Zn(His)₂] led to significant increase in the grain yield in comparison with ZnSO₄. The highest grain Zn concentration was obtained by seed priming with [Zn(Met)₂] in ‘Sadri’ and [Zn(His)₂] in ‘Talash’, respectively. For Zn-amino acid chelates, seed priming was more effective than foliar application in increasing grain yield and Zn concentration. Foliar application of [Zn(His)₂] and [Zn(Met)₂] in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ resulted in higher protein content in bean grain as compared with ZnSO₄. In both cultivars, foliar application of [Zn(Met)₂] was the more effective than seed priming to increase grain protein content. The highest water-soluble carbohydrates concentration of grain was obtained by seed priming with [Zn(Met)₂] and [Zn(His)₂] in ‘Sadri’ and ‘Talash’ cultivars, respectively. Therefore, seed priming with [Zn(His)₂] and ZnSO₄ in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ can effectively be used for improving yield of common bean in Zn-deficient calcareous soils.     

BORON NUTRITION OF PEANUT GROWN IN BORON-DEFICIENT CALCAREOUS SOILS: GENOTYPIC VARIATION AND PROPOSED DIAGNOSTIC CRITERIA

Field studies were conducted to assess boron (B) requirement, critical concentrations in diagnostic parts based on yield response curves and genotypic variation by growing three peanut (Arachis hypogaea L.) cultivars (‘Golden’, ‘BARD-479’, ‘BARI-2000’) on two B-deficient calcareous soils. Boron application significantly increased pod yield of all the cultivars over control. Maximum pod yield increases were: ‘Golden’, 16?23%; ‘BARD-479’, 21?27%; and ‘BARI-2000’, 25?31%. The cultivars varied in B efficiency and cv. ‘Golden’ was the most B efficient (81?86%) while cv. ‘BARI-2000’ was the least efficient (76?80%). Boron requirements for near-maximum (95%) dry pod yield were 0.65 kg ha^?1 for ‘Golden’, 0.75 kg ha^?1 for BARD-479 and 0.80 kg ha^?1 for BARI-2000. Critical B concentrations in shoots and seeds were: ‘Golden’, 33 mg kg^?1 and 26 mg kg^?1; ‘BARD-479’, 38 mg kg^?1 and 31 mg kg^?1; and ‘BARI-2000’, 42 mg kg^?1 and 33 mg kg^?1.     

Silicon Increases Tolerance to Boron Toxicity and Reduces Oxidative Damage in Barley

ABSTRACT

Silicon (Si) protects plants from multiple abiotic and biotic stresses The effect of exogenous Si levels (50, 75, and 100 mg kg^?1) on the growth, boron (B) and Si uptake, lipid peroxidation (MDA), lipoxygenase activity (LOX; EC 1.13.11.12), proline, and H₂O₂ accumulation, non-enzymatic antioxidant activity (AA) and the activities of major antioxidant enzymes (superoxide dismutase, SOD, EC 1.15.1.1; catalase, CAT, EC 1.11.1.6 and ascorbate peroxidase, APX, EC 1.11.1.11) of barley (Hordeum vulgare L.) were investigated under glasshouse conditions. Increasing levels of Si supplied to the soil with 20 mg kg^?1 B counteracted the deleterious effects of B on shoot growth. Application of B significantly increased the B concentration in barley plants. However, Si application decreased B concentrations. Increasing application of Si increased the Si concentration in barley plants. The concentration of H₂O₂ was increased by B toxicity but decreased by Si supply. Boron toxicity decreased proline concentrations and increased lipid peroxidation (MDA content) and LOX activity of barley. Compared with control plants, the activities of AA, SOD, CAT, and APX in B stressed plants grown without Si decreased, and application of Si increased their activities under toxic B conditions. The LOX activity was decreased by Si. Based on the present work, it can be concluded that Si alleviates B toxicity by possibly preventing oxidative membrane damage, both through lowering the uptake of B and by increasing tolerance to excess B within the tissues.     

Boron Fertilization and Evaluation of Four Soil Extractants: Russet Burbank Potato

Yield‐response correlations with old and improved soil extraction methods for boron (B) are needed. Russet Burbank potato (Solanum tuberosum L.) was grown with two, four, and six B treatments applied in 2004, 2005, and 2006, respectively. Zero and 1.1, 2.2, or 3.4 kg B ha^?1 soil and 0.22 or 0.28 kg B ha^?1 foliar treatments were applied. Boron fertilization did not significantly increase tuber yield or quality despite initially low hot‐water‐extractable B (0.34–0.50 mg kg^?1), although postseason B for unfertilized treatments increased (0.51–0.57 mg kg^?1). Soil‐applied B generally reflected B application relative to the untreated control and the low foliar rates in all three years for the four soil extractions utilized [hot water, pressurized hot water, diethylenetriaminepentaacetic acid (DTPA)–sorbitol, and Mehlich III]. Boron content of potato petiole did reflect application of B in 2 years, but tuber and peel tissues did not consistently reflect application of B.     

Boron and Amino Acid Foliar Application on Wheat-Soybean Intercropping in a Non-Tillage System

Micronutrient and amino acid (AA) foliar fertilization has generally been sprayed onto plants to increase the crop yield. The experiment had the aim of evaluating the foliar boron (B) and AA application on grain yield (GY), physiological characteristics, nutritional status, and yield components in wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merrill] intercropping in a non-tillage system (NTS). The experiment was set up as a randomized block design with eight treatments and four replicates. The treatments had the following boron (B) rates: [0, 1, 2, 4, and 8 kg ha^?1, source: boric acid (H₃BO₃)] + AAs (2 L ha^?1) applied by foliar spraying and the additional treatments [(Control - without B and AAs), 2 kg ha^?1 B, 2 L ha^?1 AAs and 2 kg ha^?1 B + 1 L ha^?1 AAs] applied at the end of the elongation and spike beginning of wheat plants and development growth stage (V5) of soybean for two growing seasons. Boron and AAs had no influence on the physiological and yield components and had no increases in the foliar and grain B content in wheat and soybean. No matter the dose, the foliar B + AAs (2 L ha^?1) application did not increase the GY in wheat-soybean under a rotational NTS in loamy soil with suitable available B.     

Einfluß von Monoethanolamin auf Ertrag und Wasserausnutzung von Sommergerste

Effect of monoethanolamine on yield and water use efficiency of barley The effect of monoethanolamine (EA) on yield and water use efficiency (WUE) of spring barley plants was tested in pot experiments. The application of EA (8 to 12 mg/pot) increased the grain yield and WUE by about 4 to 15 per cent under stress conditions. In addition, EA improved the utilization of fertilizer nitrogen. The yield-increasing effect of EA was associated with an increase of the number of ear-bearing tillers and an improved root growth. The effects of EA were only significant at α = 0.05.     

Critical Ratio of Calcium and Boron in Maize Shoot for Optimum Growth

Boron (B) deficiency is widely reported in alkaline calcareous soils of the world, including Pakistan. High calcium (Ca) content in such soils can affect the availability and utilization of B by plants. Effect of applied B at different levels of Ca addition on maize was studied in hydroponics. Four maize cultivars (‘EV-5089’, ‘SWL-2000’, ‘EV-6089’, and ‘Sultan’) were grown at three levels of Ca (0.25 mM, 1 mM, and 2 mM) and two levels of B (0 and 25 μ M). Application of both the nutrients increased shoot dry matter production. However, application of Ca antagonized the B concentration in shoot of four maize cultivars. A curvilinear relationship existed between Ca/B ratio in shoot and relative shoot dry matter of maize cultivars. Implication of using of Ca/B ratio for managing commonly occurring B deficiency in calcareous soils is suggested.