Ca Deficiency Symptoms Research Articles

Calcium fertilization on the Phalaenopsis ssp. cultivation (Orchidaceae)

The cultivation efficiency and quality improvement of Phalaenopsis sp. production through mineral nutrition has been widely studied. The objective of this study was to evaluate the effects of different concentrations of calcium (Ca) in the nutrient solution on the growth, nutrient uptake, and overall health of Phalaenopsis sp. Seedlings obtained from in vitro propagation at 6 months of age were fed biweekly with a nutrient solution suggested by Hoagland and Arnon with modified Ca concentrations of 0 mM, 1.25 mM, 2.5 mM, 5 mM, 7.5 mM, and 10 mM. After 24 months, characteristics such as number of leaves, width and length of the largest leaf, total leaf area, dry mass of leaves and roots, leaf texture, and number and dry mass of flowers were evaluated. Macronutrient content was determined from leaf dry mass. Substrate pH and electrical conductivity were also measured. Increasing Ca concentrations up to 6.25 mM improved leaf length, total leaf area, number of flowers and flower dry mass. Leaf texture and electrical conductivity of the substrate increased up to a Ca concentration of about 2.5 mM. Leaf nitrogen and phosphorus contents increased with higher Ca concentrations. Optimal Ca fertilization at 6.25 mM had positive effects on both vegetative and reproductive growth, with no visual symptoms of Ca deficiency observed during vegetative development. These results emphasize the importance of precise and tailored nutrient management, not only to avoid hidden deficiencies, but also to maximize the quality and commercial value of Phalaenopsis sp. plants.

Дефицит кальция у детей: причины, последствия и возможности профилактических вмешательств

Calcium deficiency is a commonly occurring condition in children of different age groups, primarily due to the inadequate calcium intake with food, high requirements for Ca to support rapid growth and bone accretion, and various genetic, congenital or acquired disorders of the body systems and organs, accompanied by the impaired mineral metabolism and the development of secondary calcipenia. The article summarizes data on the biological role and functions of calcium in children's body, elucidates the physiology of calcium metabolism, and highlights the major exogenous and endogenous causes of calcipenia development and the clinical symptoms of Ca deficiency at the early stages. In view of a high prevalence of the calcium deficiency worldwide, the authors review potential outcomes of this condition, depending on the children's age. The article discusses the opportunities for preventive measures with an emphasis on primary specific and nonspecific prevention of calcium deficiency to be achieved by making changes in diet and lifestyle and using vitamin and mineral complexes (VMC) and dietary supplements. Thus, it would be possible to meet the physiological needs for calcium in children and to manage the cases of developed calcium deficiency. KEYWORDS: children, calcium, vitamin D, calcium deficiency, calcipenia, bone tissue, prevention. FOR CITATION: Samorodnova E.A. Calcium deficiency in children: causes, effects, and opportunities for preventive interventions. Russian Journal of Woman and Child Health. 2023;6(1):60–67 (in Russ.). DOI: 10.32364/2618-8430-2023-6-1-60-67.

Calcium Deficiency Diagnosis in Maize Leaves Using Imaging Methods Based on Texture Analysis

The artificial vision system (AVS) uses image analysis methods that can interpret images and identify nutritional deficiency symptoms in plant, even in the early stages of development. The objective of this study was to propose methods of image processing using analysis by texture to identify the deficiency of calcium (Ca) in maize (Zea mays L.) plants grown in nutrient solution. Plants were grown in nutrient solution in a greenhouse. Calcium doses were 0.0; 1.7; 3.3 and 5.0 mM of Ca, with four replications. Plant and leaf images were sampled at three main stages of maize development: V4 (plants with four leaves fully developed), V6 (plants with six leaves fully developed) and V8 (plants with eight leaves fully developed). Sampled material was split into (i) index leaf (IL) of the growing stage (V4 = leaf 4, V6 = leaf 6, and V8 = leaf 8), and (ii) new leaf (OL), both to image capture and chemical analysis. Such leaves were scanned, processed by the AVS and chemically analyzed. The texture methods used by the AVS to extract deficiency characteristics in the leaf images were: Volumetric Fractal Dimension (VFD), Gabor Wavelet Energy (GWE) and VFD with canonical analysis (VFDCA). The amount of Ca in the solution resulted in variation in the concentration of Ca in NL and IL, allowing the observation of typical symptoms of Ca deficiency. The AVS method was able to identify all Ca levels in leaves, being the GWE the best indicator using color images, scoring 80% of rights in images of the middle section of new leaves in V4.

Hydroponic Fertilizer Supply for Basil Using Controlled-release Fertilizer

Small-scale hydroponics is a growing urban horticulture trend, but nutrient solution management remains a challenge for small growers. The objective was to investigate the potential to use controlled-release fertilizer (CRF) to simplify nutrient management in small-scale hydroponic systems. Three experiments were conducted with the goal of a single fertilizer application during the crop cycle of basil (Ocimum basilicum). Nutrient release curves were quantified by adding prills to water and measuring nutrient content weekly in the solution for CRF products without plants. In all seven products tested (Osmocote Bloom 2–3M, Osmocote Plus 3–4M, E-Max Calcium Nitrate 2–3M, Agrocote MAP 3–4M, E-Max Keiserite 3–4M, E-Max K-Mag 2–3M, and Agrocote SOP 3–4M) an initial rapid release was followed by a plateau, but release rates differed between products varying from 100% (MgSO4) to 60% release [(NH4).(H2PO4)] over an 11-week evaluation period. Total nutrient content in two commercial N–P–K CRF products (3–4 months 15N–3P–10K and 2–3 months 12N–3.1P–14.9K) provided lower Ca and Mg compared with a typical hydroponic solution based on water-soluble fertilizer (WSF). A subsequent experiment evaluated plant growth response using the same two commercial CRF products (single application) or a WSF (replaced weekly) in growth chamber environment. Plants grown for 4 weeks under CRF treatments yielded less than half the shoot fresh weight of plants grown with WSF and exhibited symptoms of Ca deficiency and micronutrient toxicity (confirmed with tissue analysis). Electrical conductivity (EC) of CRF solutions increased over time indicating excess dose compared with plant uptake, reaching a maximum of 5.4 dS·m−1. Nutrient release curves from the first experiment were then used to estimate product release and create a single-application nutritional program based on a customized “Blend” developed from CRF macronutrients plus WSF micronutrients. Plants were grown hydroponically with two dosages of Blend (1X and 2X) and compared with a commercial WSF with weekly replacement of solution. Blend 2X and WSF treatments had similar shoot fresh weight (241 and 244 g/four plants, respectively) with healthy plant appearance and tissue nutrient levels generally within published survey ranges for basil. Commercial CRF products designed for soil or container production were unsuitable for hydroponics, but acceptable plant performance with the customized CRF Blend demonstrated proof-of-concept for a single CRF application.

Effect of postharvest sodium benzoate treatment on some fruit parameters of two organic apple cultivars

The aim of this study was to investigate the effect of postharvest sodium-benzoate treatment on some fruit parameters of two organic apple cultivars (’Topaz’ and ’Florina’). Assessments were made at three times during storage: 17 November 2019, 20 December 2019 and 23 January, 2020. During every assessment dates, each fruit was observed separately, and determined the proportion of i) healthy fruits (%), ii) post-harvest fruit rot diseases iii) fruits with mechanical injury (%), iv) fruit with russetting (%), v) damage of codling moth and vi) Ca-deficiency symptoms. In addition, fruit weight (g) was measured at each assessment date. Sodium benzoate reduced the fruit decay and the proportion of healthy fruit was higher in this treatment compared to water treated fruit. This effect could be seen in all assessment dates and on both cultivars. Effects on other parameters were various according to cultivar and assessment dates. Loss of fruit weight was similar in both treatments and cultivars compared to control treatment.

Genetic and Physiological Characterization of a Calcium Deficiency Phenotype in Maize.

Calcium (Ca) is an essential plant nutrient, required for signaling, cell wall fortification and growth and development. Calcium deficiency (Ca-deficiency) in maize causes leaf tip rot and a so-called “bull-whipping” or “buggy-whipping” phenotype. Seedlings of the maize line B73 displayed these Ca-deficiency-like symptoms when grown in the greenhouse with excess fertilizer during the winter months, while seedlings of the Mo17 maize line did not display these symptoms under the same conditions. These differential phenotypes could be recapitulated in ‘mini-hydroponic’ systems in the laboratory in which high ammonium, but not nitrate, levels induced the symptoms in B73 but not Mo17 seedlings. Consistent with this phenotype being caused by Ca-deficiency, addition of Ca2+ completely relieved the symptoms. These data suggest that ammonium reduces the seedling’s ability to absorb calcium, which causes the Ca-deficiency phenotype, and that this trait varies among genotypes. A recombinant inbred line (RIL) population derived from a B73 x Mo17 cross was used to map quantitative trait loci (QTL) associated with the Ca-deficiency phenotype. QTL associated with variation in susceptibility to Ca-deficiency were detected on chromosomes 1, 2, 3, 6 which explained between 3.30–9.94% of the observed variation. Several genes predicted to bind or be activated by calcium map to these QTL on chromosome 1, 2, 6. These results describe for the first time the genetics of Ca-deficiency symptoms in maize and in plants in general.

Yield and Fruit Quality of Tomato as Influenced by Calcium and Mulching in Rooftop Cultivation

The experiment conducted in containers known as pot placed on rooftop of a building using noncalcareous grey terrace soil was carried out from October, 2012 to March, 2013 at Kazla, Motihar, Rajshahi, Bangladesh to investigate the influences of calcium and mulching practices on yield and fruit quality of tomato. The study was laid out in a split-split plot design with three replications. The trials comprised three factors: 1) three tomato varieties viz, BARI F1Tomato-5, BARI F1Tomato-6 and BARI F1Tomato-7; 2) four levels of calcium (Ca) treatment (40 ppm, 60 ppm, 80 ppm, 120 ppm) and 3) mulching practices. Results of the experiment revealed that fresh yield of tomato was significantly increased by applying mulching practices due to conservation of soil moisture by mulches and therefore, reduced Ca-deficiency symptoms. The highest number of fruits per plant and fresh yield were obtained from the variety BARI F1Tomato-5. The same trend of yield and yield contributing parameters were likely to be better by using T3treatment (80 ppm) than those of other treatments. In contrast, BARI F1Tomato-7 variety in control treatment without mulching practice gave poor quality and yield of tomato. Results suggested that BARI F1Tomato-5 variety receiving 80 ppm calcium treatment with mulching condition exposed better quality, yield and yield contributing characters of tomato. However, the T3 treatment (80 ppm) with mulching would be recommended as the best combination to grow BARI F1Tomato-5 for the farmers in Bangladesh.

Cerium negatively impacts the nutritional status in rapeseed

Cerium (Ce) has been reported to be both beneficial and harmful to plants. This contradiction deserves explanation in the light of increased anthropogenic release of Ce in the environment.Ce tolerance and accumulation were evaluated in hydroponically cultivated Brassica napus L. (rapeseed). Ce and other nutrient concentrations were measured with increasing Ce concentration in the nutrient solution. Moreover, Ce and calcium (Ca) accumulation were evaluated at different Ca and Ce concentrations in nutrient solution and a Michaelis-Menten type inhibition model considering Ce and Ca competition was tested. Plants were also sprayed with Ce solution in Ca-deficient media.Ce decreased the growth and root function, which affected shoot nutritional status. Calcium was the most severely inhibited nutrient in both roots and shoots. High Ca concentrations in the nutrient solution inhibited Ce accumulation in a non-competitive way. Moreover, phosphorus (P) precipitated Ce inside root cells. Ce spraying did not alleviate Ca deficiency symptoms and the results were critically compared to the available literature.

Growth and physiological responses of teak (Tectona grandis Linn. f.) clones to Ca, H and Al stresses in solution and acid soils

The adaptation of teak to acid soils was tested by studying physiological responses of teak clones to varying concentrations of Ca, H (pH) and Al in solution and soil culture. Nutrient solutions containing 0.05, 0.8 or 10 mM Ca were adjusted to pH 4, 5, 6, or 7. Overall, the greatest growth was obtained with nutrient solutions containing 0.8 mM Ca at pH 6. Foliar Ca deficiency symptoms developed at 0.05 mM Ca. Sensitivity of teak clones to Al was tested at pH 4 and 0, 50 or 300 µM Al by staining of roots. Roots that were stained with Chromezurol S (CAS) also stained with hematoxylin, but not necessarily with Eriochrome Cyanine R (ECR). On the other hand, roots that stained with hematoxylin did not necessarily stain with CAS or ECR. This indicates that hydrolysis of Al (as detected by CAS) leads to membrane damage which is detected by hematoxylin. A selection of clones were grown in split pots containing either limed or non-limed soil, and Al activity in the soil solution related to root biomass. Five clones were identified as Al resistant in the solution screening, and two clones were Al resistant in the soil screen, with two clones resisting low pH and Al toxicity in soil and solution screens. This study revealed that some teak clones tolerate low pH soils and moderately toxic 25 µM {Al3+} activity, and may be suitable for poor soils, but soils used in Australia for teak plantations are often too hostile and would require amelioration.

배지경 자루 재배를 통한 '설향' 딸기의 번식에서 칼슘 혼합비료가 모주 및 자묘의 생장과 생리장해에 미치는 영향

'설향' 딸기의 육묘과정에서 발생하는 칼슘 결핍 교정을 위하여 배지경으로 모주를 재배하면서 Ca이 혼합된 비료를 시비할 때 모주 생육 및 생리장해 발현과 런너 및 자묘의 생장에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 연구목적을 달성하기 위하여 1.125mM <TEX>$Ca(OH)_2$</TEX>, 0.375mM <TEX>$MgCl_2$</TEX> 그리고 1.25mM KCl를 혼합한 비료와 시판비료인 CalMag(13-0-1.9-16-6:N-<TEX>$P_2O_5$</TEX>-<TEX>$K_2O$</TEX>-CaO-MgO)를 전기전도도(EC)가 0.6 또는 <TEX>$1.0dS{\cdot}m^{-1}$</TEX>가 되도록 지하수로 용해시켜 2주일에 1회 관주처리하였고, 정식 120일 후 모주생장과 자묘 발생에 미치는 효과를 비교하였다. 칼슘 결핍증상 발현 식물체수는 대조구인 무시비구에서 가장 많았으며, 칼슘비료를 시비함으로써 개체수가 감소하였으나, 비료의 종류 및 농도에 따른 처리별 차이는 크지 않았다. 무시비구에 비해 Ca이 포함된 비료를 시비할 때 모주의 생체중과 건물중이 무거웠고, CalMag를 시비한 경우보다 본 연구에서 조합한 비료를 처리한 경우 생장량이 많았다. 또한 두 종류 비료를 <TEX>$0.6dS{\cdot}m^{-1}$</TEX>로 시비한 처리보다 <TEX>$1.0dS{\cdot}m^{-1}$</TEX>로 시비한 처리의 생장량이 많았다. 혼합 비료를 <TEX>$1.0dS{\cdot}m^{-1}$</TEX>로 시비한 처리에서 모주로부터 발생한 런너의 길이가 가장 길었고, 혼합비료와 CalMag 모두 <TEX>$0.6dS{\cdot}m^{-1}$</TEX> 처리보다 <TEX>$1.0dS{\cdot}m^{-1}$</TEX> 처리에서 발생된 런너의 길이가 길었다. 런너의 생체중과 건물중도 혼합비료 <TEX>$1.0dS{\cdot}m^{-1}$</TEX> 처리에서 가장 무거웠으며, 두 종류 비료를 <TEX>$1.0dS{\cdot}m^{-1}$</TEX>로 시비한 경우 <TEX>$0.6dS{\cdot}m^{-1}$</TEX> 처리보다 더 많은 생장량을 보였다. 2차 자묘를 선택하여 생장량을 비교해 본 결과 본 연구의 혼합비료 처리가 동일한 농도로 CalMag를 시비한 처리보다 생체중과 건물중이 무거웠다. 이상의 연구결과를 고려할 때 '설향' 딸기의 자묘 생산을 위해서는 주기적인 Ca 시비가 필수적이지만 Ca을 단독으로 처리하기보다는 알칼리성 원소인 K:Ca:Mg의 비율을 조절하여 시비하는 것이 더욱 효과적이라고 판단하였다. The objective of this research was to investigate the impact of Ca fertilizer on the growth of mother plants, physiological disorders, and occurrence of daughter plants in propagation of 'Seolhyang' strawberry through plastic bag cultivation. To achieve this, chemicals of 1.125 mM <TEX>$Ca(OH)_2$</TEX>, 0.375 mM <TEX>$MgCl_2$</TEX>, 1.250 mM KCl were blended and designated to combined fertilizer (CF). Then, the effect was compared to the treatment of no Ca application (control) and a commercial fertilizer, CalMag (13-0-1.9-16-6:N-<TEX>$P_2O_5$</TEX>-<TEX>$K_2O$</TEX>-CaO-MgO), when those were applied every two weeks with controlled electrical conductivity (EC) of solution such as 0.6 or 1.0 <TEX>$dS{\cdot}m^{-1}$</TEX>. The number of plants showing Ca deficiency symptoms was the highest in control treatment, but those decreased significantly in CF or CalMag treatments. The differences between CF and CalMag in appearance of Ca deficient plants were not significant when two fertilizers were applied with same EC. The fresh and dry weights of mother plants were the greater in the treatments of CF or CalMag than those of control treatment. The treatments of 1.0 <TEX>$dS{\cdot}m^{-1}$</TEX> of CF or CalMag were more effective than those of 0.6 <TEX>$dS{\cdot}m^{-1}$</TEX> on the fresh and dry weight of the mother plants. The runner lengths in the treatment of 1.0 <TEX>$dS{\cdot}m^{-1}$</TEX> of CF were the longest among the all treatments tested. The treatments of 1.0 <TEX>$dS{\cdot}m^{-1}$</TEX> were more effective than those of 0.6 <TEX>$dS{\cdot}m^{-1}$</TEX> of CF or CalMag in lengths and fresh and dry weight of runners. The fresh and dry weights of daughter plants were heavier in the treatments of CF than those of CalMag. Based on the above results, we concluded that the Ca deficiency in raising 'Seolhyang' strawberry can be lessened by the application of Ca containing fertilizers, but combined application of Ca, K and Mg was more effective than that of Ca alone for seedling production.

'설향' 딸기의 토경 육묘에서 칼슘 시비가 모주의 생장, 생리장해 발현, 및 자묘 발생에 미치는 영향

국내에서 육성된 '설향' 딸기에서 칼슘결핍 증상이 빈번하게 발생하고 육묘 시 모주의 생육 저하, 자묘 채취량 감소 및 자묘 품질저하의 원인이 되어왔다. 따라서 단일 비료를 조합하여 K, Ca 및 Mg이 4:2:1의 비율이 되도록 조절한 비료 또는 상업용으로 시판되는 Azuro-Calma를 0.6dS <TEX>${\cdot}m^{-1}$</TEX> 또는 1.0dS <TEX>${\cdot}m^{-1}$</TEX>로 조절하여 토양에 관주처리할 경우 모주 생육 및 자묘 발생에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 정식 후 120일 동안 무처리구에 비해 모든 칼슘 비료 시비구에서 칼슘 결핍증상이 발현된 모주 수가 뚜렷하게 감소하였으며 본 연구의 조합비료보다 Azuro-Calma의 효과가 우수하였다. 무처리구에 비해 모든 칼슘 비료 시비구에서 모주의 생체중과 건물중이 무거웠다. 또한 두 종류 비료 모두 0.6dS <TEX>${\cdot}m^{-1}$</TEX> 처리보다 1.0dS <TEX>${\cdot}m^{-1}$</TEX>로 시비 농도를 높일 경우 지상부 생장량이 많았고, 본 연구의 혼합 비료가 Azuro-Calma보다 지상부 생체중과 건물중 증가에 더 효과적이었다. 혼합비료 1.0dS <TEX>${\cdot}m^{-1}$</TEX> 처리에서 가장 긴 런너 길이를 보였고, Azuro-Calma 0.6dS <TEX>${\cdot}m^{-1}$</TEX> 처리는 무처리구와 비슷한 경향을 보였다. 런너의 생체중과 건물중 역시 혼합비료 1.0dS <TEX>${\cdot}m^{-1}$</TEX> 처리에서 가장 무거웠으며 Azuro-Calma 1.0dS <TEX>${\cdot}m^{-1}$</TEX> 처리에서도 생육이 우수하였다. 무처리구보다 칼슘 시비구에서 자묘의 생체중이 더 무거웠지만 칼슘을 시비한 처리중에는 Azuro-Calma 0.6dS <TEX>${\cdot}m^{-1}$</TEX> 처리가 가장 가벼웠다. 이상과 같은 결과는 Ca와 Mg이 주요 구성 성분인 Azuro-Calma가 칼슘 결핍 증상을 감소시키기에는 더 효과적이지만 K:Ca:Mg의 비율을 조절하여 세 종류 비료를 동시에 시비하는 것이 칼슘 결핍증상 억제와 모주 및 자묘의 생장량 증가에 효과적이라고 판단한다. The Ca deficiency is a serious problem in the propagation of domestically bred 'Seolhyang' strawberry through soil cultivation. The objective of this research was to investigate the impact of the Ca containing fertilizers on the decrease of Ca deficiency symptoms and in the growth of mother and daughter plants. To achieve this, chemicals of 1.125 mM <TEX>$Ca(OH)_2$</TEX>, 0.375 mM <TEX>$MgCl_2$</TEX>, and 1.25 mM KCl were blended to contain the K:Ca:Mg (4:2:1) and the influence was compared to a commercial fertilizer, Azuro-Calma (<TEX>$NO_3$</TEX>-N 13%, <TEX>$K_2O$</TEX> 1%, CaO 16%, MgO 6%), when those were applied as solutions with the electrical conductivity (EC) controlled to 0.6 or 1.0dS <TEX>${\cdot}m^{-1}$</TEX>. During 120 days after transplant, the Azuro-Calma was more effective than the combined fertilizer in the reduction of mother and daughter plants on which Ca deficiency was appeared. The application of two Ca containing fertilizers resulted in the heavier fresh and dry weights of mother plants. The treatments of 1.0dS <TEX>${\cdot}m^{-1}$</TEX> of two fertilizers were more effective than those of 0.6dS <TEX>${\cdot}m^{-1}$</TEX>. The combined fertilizer was also more effective than Azuro-calma on the growth of above ground plant tissue. The results in length, fresh and dry weight of runners occurred from a mother plants showed that the treatment of 1.0dS <TEX>${\cdot}m^{-1}$</TEX> of combined fertilizer was most effective followed by those of 1.0dS <TEX>${\cdot}m^{-1}$</TEX> of Azuro-Calma, 0.6dS <TEX>${\cdot}m^{-1}$</TEX> of combined fertilizer, 0.6dS <TEX>${\cdot}m^{-1}$</TEX> of Azuro-Calma, and control. The fresh weights of daughter plants were heavier in the treatments of Ca application than those in the control treatment, but the differences between 0.6dS <TEX>${\cdot}m^{-1}$</TEX> and control were not significant. The above results indicate that Azuro-Calma is more effective in decreasing plants showing the Ca deficiency symptoms. However, the combined fertilizer of K:Ca:Mg is more desirable when we are concerned about the decrease of crops showing Ca deficiency as well as increase of the growth in above ground plant tissue.

OPTIMUM RATIO OF CALCIUM AND BORON IN THE NUTRIENT SOLUTION OR IN CASTOR BEAN SHOOT FOR FRUIT YIELD AND SEED OIL CONTENT

Calcium (Ca) and boron (B) have been reported as the major macro- and micronutrient required for castor bean plant yield. The objective of this study was to determine the Ca:B ratios (in the growth media and plant tissue) for fruit yield and shoot dry weight of the castor bean (Ricinus communis L.), grown in a nutrient solution, and to evaluate Ca and B supply on concentration and total uptake of Ca, potassium (K), magnesium (Mg), and B, as well on the seed oil content. The treatments were arranged in a 3 × 3 factorial fashion, consisting of three rates of Ca (40, 80, and 160 mg L−1) and three of B (0.32, 0.96, and 1.60 mg L−1). Calcium and B rates increased the shoot and root dry weight and fruit yield at a Ca:B ratio in the nutrient solution of 166 and 100, respectively. Symptoms of B deficiency were observed in plants supplied with 0.32 mg B L−1, regardless of the Ca concentration in the nutrient solution. Plants which showed visual symptoms of Ca deficiency cultivated with 40 mg Ca L−1 presented concentration of Ca in plant tissue up to 10 g kg−1. The concentration and total Ca and B uptake increased with the rates of them. Notwithstanding, the shoot Ca accumulation was improved by B rates. In addition, there were no decreases in K and Mg uptake due to Ca rates. Furthermore, addition of 80 mg L−1 of Ca and 1.60 mg L−1 of B in the growth media increased the seed oil content. The Ca:B ratio in the diagnostic leaf associated with the highest plant dry weight (shoot and root) and fruit yield, was 500 (16 to 20 g kg−1 of Ca, and for 30 to 40 mg kg−1 of B).

Causes and control of calcium deficiency disorders in vegetables: a review

SummaryThe aim of this study was to provide an overview of the causes and control of calcium (Ca)-deficiency disorders in vegetables. Ca-deficiency is usually related to the inability of the plant to translocate adequate Ca to the affected part. Many vegetables develop unique symptoms: for example blackheart in celery, tipburn in lettuce, chervil, onion, fennel, chinese cabbage and other cabbages, blossom end rot (BER) in tomato. Ca-deficiency disorders in vegetables can be controlled by various means. The growing medium influences the development of Ca-deficiency symptoms in plants. Restriction of the root volume is one factor that favours the development of Ca-deficiency symptoms in leafy vegetables, but reduces the incidence of BER in pepper. Ca-deficiency can also be avoided by using reasonable levels of nitrogen in the nutrient solution. Cations depress Ca-uptake and distribution, while anions depress the development of tipburn in plants. Ca-deficiency can be avoided by using the recommended level of salinity for each crop. Too high a salinity level increases the symptoms of Ca-deficiency in plants. Watering helps to prevent Ca-deficiency injury, as when growing vegetables outdoors. Maintaining an optimum soil moisture level helps to promote adequate movement of Ca to the roots and into the plant. A low relative humidity during the day-time increases the Ca-contents of leaves in leafy vegetables with an open growing point, but reduces the Ca contents of fruit and the inner leaves of leafy vegetables with a closed growing point. Avoiding too long a duration of supplementary lighting, too high a light intensity, and the use of high-pressure sodium lamps can prevent Ca-deficiency injury in plants. Shading may influence the incidence of BER, by reducing the appearance of symptoms of BER. Growing plants under a far-red wavelength filter helps to prevent Ca-deficiency disorders. Avoiding high or low temperatures also prevents Ca-deficiency injury. A negative DIF value (DIF = the difference between the day-time and night-time temperatures; a negative DIF means the night temperature is higher than the day temperature) may influence the incidence of tipburn injury by reducing its appearance. Air flow to the affected parts of plants can help to avoid the symptoms of Ca-deficiency. Ca sprays also help to prevent Ca-deficiency disorders in plants. Mulches can be used to protect plants against Ca-deficiency. Some crop varieties are less susceptible to Ca-deficiency. The plant growth regulator, Cultar (paclobutrazol, an inhibitor of gibberellin-biosynthesis), may influence the symptoms of Ca-deficiency in plants by reducing the appearance of the disorders. Planting a little later than the optimum date can avoid Ca-deficiency symptoms in leafy vegetables in Nordic countries. Harvesting a little earlier than the optimum date can also avoid Ca deficiency- symptoms in leafy vegetables.

Comparing the Calcium Requirements of Wheat and Canola

ABSTRACT 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.

Effects of relative humidity, calcium supply, and forcing season on tulip calcium status during hydroponic forcing

The tulip ( Tulipa gesneriana L.) cultivars ‘Abra’, ‘Christmas Marvel’, ‘Golden Melody’, and ‘Jingle Bell’ were forced hydroponically during two early forcing periods (FPs) and ‘Golden Melody’ and ‘Oscar’ during two late FP. Treatments were factorial combinations of two relative humidity (RH) levels (42 and 82%) and five Ca(NO 3) 2 levels (0, 2.5, 5, 10, and 20 mM). The study was conducted in growth chambers at a constant 19 °C and a 14 h daylength in which 70 μmol s −1 m −2 PPF was provided by cool white florescent lamps. Calcium uptake and accumulation were less at 82% RH as compared to 42% RH; however, the incidence of Ca deficiency symptoms did not increase at the higher RH. A 2.5 mM Ca(NO 3) 2 solution prevented Ca deficiency symptoms in all cultivars except ‘Abra’ during all FP. Plants in FP4 (26 March–18April) weighed less and accumulated less Ca than the same cultivars in the earlier FP. Calcium uptake and transpiration were lower in distilled water and 20 mM Ca(NO 3) 2 than other Ca(NO 3) 2 treatments after day 22 in FP1 (22 December–26 January). Total Ca content was lower in the flowers of ‘Golden Melody’ tulips forced in distilled water than the Ca(NO 3) 2 treatments. Calcium dry weight (DW) concentration and total Ca content in the flowers of ‘Golden Melody’ tulips forced at 42% RH were higher than at 82% RH. Total Ca content in the flowers of ‘Golden Melody’ tulips decreased from FP3 to FP4.

Calcium deficiency provoked by the application of different forms and concentrations of Ca 2+ to soil-less cultivated muskmelons

The influences of deficiency concentrations of calcium compounds other than the calcium nitrate usually used, on the development of Cucumis melo L. cv. Revigal cultivated in rockwool were studied under adverse calcium absorption conditions (low solar radiation, temperature and calcium and high sodium and magnesium levels in the nutrient solution). A standard Ca(NO 3) 2 concentration was used for comparison and two different concentrations of Ca-EDTA, CaCl 2 and CaSO 4 (equivalent to half and to one quarter of the calcium in the control) were used to create calcium deficiencies. The demand for calcium increased substantially during the period of the greatest vegetative growth. Ca-EDTA produced greater Ca deficiency symptoms than CaCl 2 and CaSO 4, and was not effective in alleviating calcium-associated problems. There were no significant differences in biomass production between the sulphate and chloride treatments with the same calcium levels, although there were great differences in biomass production in the different plant fractions between the two calcium levels applied. The biomass differences were greater half way through the cultivation cycle than at the end. The use of calcium concentrations below 3 mM in the nutrient solution, which represents a net daily calcium uptake of less than 1 mmol per plant throughout the cultivation cycle was insufficient and provoked deficiency symptoms in leaves and fruits in the conditions of this experiment. Calcium levels at the end of the growing cycle were significantly higher in the control than in other treatments in all plant fractions. There were very few differences in calcium content in fractions between the chloride and sulphate treatments, while the Ca-EDTA treatments led to noticeably lower calcium levels in the different fractions.

Effect of ancymidol in combination with temperature regime, calcium nitrate, and cultivar selection on calcium deficiency symptoms during hydroponic forcing of tulip

Experiments were conducted to determine the effect of ancymidol, as impacted by temperature, Ca(NO 3) 2, and cultivar, on the prevention of Ca deficiency symptoms during hydroponic forcing of tulip ( Tulipa gesneriana L.). In all treatments where tulips were forced in distilled water, Ca deficiency symptoms occurred. Symptoms included scape topple; flower abortion; and chlorosis, water soaking, cracking, exudation, and purple pigmentation of the lower leaves. All symptoms except topple were avoided when tulips were forced in 5 mM Ca(NO 3) 2 solution. Topple was prevented by Ca(NO 3) 2 in a low temperature regime (21°C day–18°C night) in two of three experiments. Ca deficiency was not prevented in a high temperature regime (24°C day–21°C night). Plants forced in Ca(NO 3) 2 were too tall for commercial use. When forced in a solution of ancymidol, topple was prevented but all other symptoms of Ca deficiency persisted. An ancymidol rate of 0.25 mg per 650 ml pot containing five bulbs caused abortion, unrelated to Ca deficiency, in the cultivar Oscar. Forcing in a combination of 5 mM Ca(NO 3) 2 plus ancymidol prevented all symptoms of Ca deficiency in all experiments except in the high temperature regime of one. Ancymidol rates of 0.0625 and 0.125 mg per pot did not always provide adequate height control. A rate of 0.18 mg per pot in combination with 5 mM Ca(NO 3) 2 was sufficient to prevent Ca deficiency symptoms and provide adequate height control in all but one cultivar. `Jingle Bell' required an ancymidol rate of 0.24 mg for adequate height control. Prevention of topple by ancymidol did not appear to be due to the correction of Ca deficiency since ancymidol added to Ca(NO 3) 2 resulted in lower total Ca uptake per shoot. It was likely due to shorter, stronger scapes masking this Ca deficiency symptom.

Effects of calcium source and temperature regime on calcium deficiency during hydroponic forcing of tulip

Tulips ( Tulipa gesneriana L.) forced hydroponically in distilled water developed Ca deficiency symptoms, including topple and flower bud abortion. Prevention of Ca deficiency and uptake of Ca was greater when Ca was supplied in the NO 3 − form rather than as Cl − or SO 4 2−. Calcium EDTA was injurious to plants at a concentration of 2.5 mM, a level too low to correct Ca deficiency. Addition of BO 3 3−, K +, H 2PO 4 −, or Hoagland's all nitrate solution with modified micronutrient levels to the Ca substrate failed to improve growth. The complete nutrient formulation reduced Ca uptake. Ca deficiency could not be prevented at the high temperature regime (22°C day–18°C night), due in part to suppress uptake of Ca. In the low temperature regime (18°C day–14°C night), a 5-mM solution of Ca(NO 3) 2 prevented Ca deficiency during all forcing periods. Similar results were obtained with a 7.5 mM solution of CaCl 2.

Strong synergistic effects of gibberellins with the synthetic cytokinin N-(2-chloro-4-pyridyl)-N-phenylurea on parthenocarpic fruit set and some other fruit characteristics of apple

The induction of parthenocarpic fruit set was investigated using the apple cvs. Golden Delicious and Jonagold. The gibberellins GA3, GA4, GA5 and GA7 and the synthetic phenylurea-type cytokinin CPPU (N-(2-chloro-4-pyridyl)-N-phenylurea), were applied alone and in combination to unpollinated flowers at the end of petal fall. Gibberellins induced only a marginal final set of parthenocarpic fruits. CPPU sprays were more effective, particularly in the first year. When applied in combination, CPPU and gibberellins had a positive synergistic effect on parthenocarpic fruit set and fruit size, but a negative effect on flower induction the next year. After CPPU + GA sprays, percent fruit set was similar, or greater, compared to natural pollinated trees. The parthenocarpic fruits induced by CPPU + GA had an increased length to diameter ratio. CPPU stimulated, and GA4 and GA7 reduced, the russeting of the parthenocarpic fruits. The internal quality of the fruits was hardly affected, but Ca-deficiency symptoms occurred more frequently in parthenocarpic fruits.

A HYDROPONICS NUTRIENT SOLUTION BASED ON COMMERCIAL FERTILIZER'

Many people want to use hydroponics in production of plants but often are hobbyists with limited access to the reagents necessary to formulate a nutrient solution. Several readily available commercial fertilizers and chemicals with tomato-(Lycopersicon esculentum Mill.) as the test plant were used to develop a nutrient solution. A 20-8.8-16.6 IN-P-K) general purpose fertilizer was added (1 g/liter) to deionized water to make a basic solution. This solution was fortified with slow-release fertilizer (approx. 17N-2.6P-8.5K with Ca, Hg, and minor elements) at 1 g/liter added directly to hydroponics vessels. Tomato developed severe foliar symptoms of Ca deficiency in this medium. Addition of CaSO4 or CaCO3 at 0.5 or 1 g/liter to give a solid phase of these chemicals in the vessels prevented development of symptoms of Ca deficiency; however, plants now showed symptoms of Mg deficiency. Addition of MgS0 at 0.25 g/liter to the basic solution prevented symptoms o Mg deficiency. Analyses confirmed that leaf N, P, K, Ca, and Mg were sufficient. This solution was as good as Hoagland's No. 1 solution for growth of tomato, marigold, and cucumber and was better than Hoagland's solution for growth of corn and wheat.