Calcium nutrition of the tomato as influenced by total salts and ammonium nutrition

1971 ◽  
Vol 11 (52) ◽  
pp. 562 ◽  
Author(s):  
RE Barke ◽  
RC Menary

Calcium deficiency in tomatoes was induced by adding ammonia nitrogen to the rooting medium. Ammonia was found to inhibit the absorption of calcium by the plant. When total soil nutrient concentration was varied, but the ratio of calcium to other ions held constant, blossom-end rot incidence was inversely related to the calcium level in fruits but was not necessarily associated with low calcium levels in leaves or whole plants. In the presence of high total salts, the incidence of the disorder could not be explained by a reduction in calcium content of whole plants and factors affecting distribution of the calcium within the plant were involved. The physiological disorder pith rot is described and evidence presented suggesting it is caused by a deficiency of calcium. Ammonia increased the incidence of the disorder but was not essential for its occurrence. In field trials on a red loam soil, ammonium sulphate reduced the pH values from 6.0 to 4.7, which prevented nitrification and induced pith rot and blossom-end rot through an accumulation of ammonia nitrogen. Calcium foliar sprays were able to offset yield reductions that were induced by moderate fertilizing with ammonium sulphate even where blossom-end rot did not occur. High total plant calcium was associated with reduced fruit yields.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


2021 ◽  
Vol 1 (1) ◽  
pp. 021-028
Author(s):  
Mukhtar Iderawumi ABDULRAHEEM ◽  
Sulaimon Abidemi LAWAL

Many see organic agriculture as the most sustainable form of farming and as the paradigm for global food production in the future. One of the solutions to food insecurity and malnutrition in Sub-Saharan Africa is to promote local crops, encourage the use of locally source materials as amendment, improve their traditional system of production, and so diversify subsistence crop. The major reasons are the lack of knowledge and skill in land preparation and agronomic practices, weather uncertainties, pest outbreak and above all the use of fertilizer. Hence, this research will be carried out to investigate the effects of integrated application of Urea fertilizer and Goat Manure on soil Nutrient Availability and Okra performance. Field trials were conducted with four treatments replicated three times in a Randomized Complete Block Design (RCBD). The treatments were Control (no Urea, no goat manure), 8t/ha-1 goat manure + 200kg/ha-1 urea fertilizer; 8t/ha-1 goat manure + 175kg/ha-1 urea fertilizer and 8t/ha-1 goat manure + 150kg/ha-1 urea fertilizer. Treatments were applied three weeks after planting by ring method with Urea and goat manure mixed. Soil physical and chemical properties, growth and yield parameters were evaluated. Data were analyzed using Analysis of Variance (ANOVA) and Duncan Multiple Range. 8t/ha-1 goat manure + 200kg/ha-1 urea fertilizer gave the highest plant height, leaf area as well as number of leaves than other treatment. However, the fruits weight, days of 50% flowering, number of fruit, fruits diameter and fruits length were significantly increased at 8t/ha-1 goat manure + 200kg/ha-1 urea fertilizer.


2019 ◽  
Vol 11 ◽  
pp. 117954331985602 ◽  
Author(s):  
Azubuike Christian Ukubuiwe ◽  
Chioma Cynthia Ojianwuna ◽  
Israel Kayode Olayemi ◽  
Francis Ofurum Arimoro ◽  
Innocent Chukwuemeka James Omalu ◽  
...  

Larval crowding is one of the abiotic factors affecting biological fitness in mosquitoes. This study aims at elucidating, quantitatively, the influence of more larval crowding on aspects of fitness in Culex quinquefasciatus mosquito. To this end, day-old larvae of the species were reared in 4 density regimens equivalent to 1 larva in 1.25, 2.5, 5, and 10 mL of distilled water. Developmental indices, adult fitness indices, and accumulation and utilisation of teneral reserves for metamorphosis were determined at these density regimens. The results revealed varying significant negative effects of larval density on all fitness indices measured for the species. The study also revealed high utilisation of teneral reserves for metamorphosis at high larval densities. The information generated will be useful in making informed-decisions in allocating scare resources for vector control, although field trials are advocated to establish these laboratory findings.


2014 ◽  
Vol 60 (No. 8) ◽  
pp. 344-350 ◽  
Author(s):  
M. Jiang ◽  
Shen XP ◽  
W. Gao ◽  
Shen MX ◽  
Dai QG

We studied the heterogeneity of soil weed seed-bank in a rice-wheat rotation system after long-term application of different organic or non-organic fertilizers, and the effects of major nutrients on the characteristics of the weed seed-bank. The soil was sampled in the Taihu area after a 31-year long-term fertilization experiment. Weed seeds were identified and counted in the surface soil of 12 differentially treated areas using microscopic examination, and analyzed by the Simpson, Shannon, Margalef, and Pielou indexes. The long-term application of organic fertilizers could significantly reduce the density of soil weed seed-bank; non-organic fertilizers and a combination of non-organic and organic fertilizers had a significant influence on the number of species and diversity of weeds. The application of organic fertilizers improved the Simpson, Shannon and Pielou indexes of soil weed seed-bank community and stabilized the community structure. In terms of the soil nutrient system itself, the soil organic materials and total nitrogen content are the main environmental factors affecting the distribution of soil weed seed-bank.


2018 ◽  
Vol 48 (4) ◽  
pp. 414-419
Author(s):  
Carlos Agostinho Balate ◽  
Douglas Correa de Souza ◽  
Luciane Vilela Resende ◽  
Sergio Tonetto de Freitas

ABSTRACT Water stress in tomato plants may cause the incidence of blossom-end rot. This study aimed to analyze the effect of abscisic acid leaf application for increasing the calcium uptake in irrigated tomato (‘Santa Clara' cultivar) in the field, as a possible mechanism of blossom-end rot inhibition. The treatments consisted of four irrigation levels (25 %, 50 %, 75 % and 100 % of the crop water requirements to fulfil the crop evapotranspiration) and two abscisic acid doses (0 mg L-1 and 500 mg L-1). The fruits were harvested at 15 and 30 days after the anthesis and evaluated for calcium content and percentage of blossom-end rot. The application of abscisic acid increased the calcium partition to the distal region of the fruits at 30 days after the beginning of flowering, as well as reduced the incidence of blossom-end rot by 86 %, when compared with plants not treated with abscisic acid. It is possible to conclude that the foliar application of abscisic acid can significantly reduce the incidence of blossom-end rot.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 275
Author(s):  
Sasha J. Tetzlaff ◽  
Alondra Estrada ◽  
Brett A. DeGregorio ◽  
Jinelle H. Sperry

Although it is widely accepted that juvenile turtles experience high levels of predation, such events are rarely observed, providing limited evidence regarding predator identities and how juvenile habitat selection and availability of sensory cues to predators affects predation risk. We placed three-dimensional printed models resembling juvenile box turtles (Terrapene carolina) across habitats commonly utilized by the species at three sites within their geographical range and monitored models with motion-triggered cameras. To explore how the presence or absence of visual and olfactory cues affected predator interactions with models, we employed a factorial design where models were either exposed or concealed and either did or did not have juvenile box turtle scent applied on them. Predators interacted with 18% of models during field trials. Nearly all interactions were by mesopredators (57%) and rodents (37%). Mesopredators were more likely to attack models than rodents; most (76%) attacks occurred by raccoons (Procyon lotor). Interactions by mesopredators were more likely to occur in wetlands than edges, and greater in edges than grasslands. Mesopredators were less likely to interact with models as surrounding vegetation height increased. Rodents were more likely to interact with models that were closer to woody structure and interacted with exposed models more than concealed ones, but model exposure had no effect on interactions by mesopredators. Scent treatment appeared to have no influence on interactions by either predator group. Our results suggest raccoons can pose high predation risk for juvenile turtles (although rodents could also be important predators) and habitat features at multiple spatial scales affect predator-specific predation risk. Factors affecting predation risk for juveniles are important to consider in management actions such as habitat alteration, translocation, or predator control.


2020 ◽  
Vol 42 ◽  
pp. e42487
Author(s):  
Lucas Baiochi Riboldi ◽  
Sabrina Helena da Cruz Araújo ◽  
Sérgio Tonetto de Freitas ◽  
Paulo Roberto Camargo Castro

Calcium (Ca2+) is a nutrient in tomato plants, of which deficiency usually causes several problems including a physiological disorder known as blossom-end rot (BER) in the fruit. The objective of this study was to evaluate and identify morphological and physiological characteristics related to the susceptibility of tomato varieties to BER. The varieties studied were ‘Amalia’, ‘IPA-6’, ‘M-82’, ‘Mara’, and ‘Nagcarlan’, presenting different fruit formats. Physiological parameters that negatively correlated with BER were plant water potential, leaf area, plant dry mass, relationship between proximal/distal Ca2+, K+ content in the proximal and distal portions of the fruit, and proximal Ca2+ content. Physiological parameters that positively correlated with BER were number of trichomes in the abaxial and adaxial leaf portions, leaf stomatal conductance, distal Ca2+ content bound to the cell wall, leaf transpiration, and fruit length. Our results showed that ‘Mara’ and ‘Nagcarlan’, ‘Amalia’ and ‘IPA-6’, and ‘M-82’ presented low, medium, and high susceptibility to BER, respectively. We also found that total fruit Ca2+ concentration, particularly in the distal fruit tissue, was not the only factor responsible for the development of BER; rather, the balance between factors that increase and decrease the susceptibility of each variety affected development of this disorder.


1979 ◽  
Vol 59 (1) ◽  
pp. 185-190 ◽  
Author(s):  
R. P. DOSS ◽  
J. K. CHRISTIAN ◽  
J. M. LANGAGER

"Iris topple" is a physiological disorder of bulbous Iris that is characterized by weakness of the flower stalk at the uppermost node and the concommitant failure of the flower bud to remain erect. This condition occurs when bulbous Iris is forced in calcium-deficient growth media. An acropetal pattern of stem elongation in Iris and the general immobility of calcium within plants lead to a localized calcium-deficient region that exhibits severe cellular and ultrastructural abnormalities. The innermost three leaves and flower stalk from plants showing "Iris topple" as the only symptom of calcium deficiency have an average tissue calcium concentration of 0.3%.


1968 ◽  
Vol 35 (1) ◽  
pp. 31-47 ◽  
Author(s):  
J. F. Hayes ◽  
Pamela M. Southby ◽  
L. L. Muller

SummaryThe physical effects of various cations in caseinate dispersions of high concentrations were investigated over a range of temperature and pH.With calcium and strontium the temperature-viscosity relationships of the caseinates were abnormal in that the viscosity decreased rapidly from 30 to about 40 °C and a gel formed at temperatures in the region of 50–60 °C. On cooling, the gel reliquefied. No gel formed with barium, aluminium or magnesium. On cooling, magnesium preparations separated into 2 phases.The supernatant phase from the magnesium caseinate and a corresponding phase prepared by centrifuging the calcium caseinate showed depletion of α-casein and enrichment of κ-casein and β-casein. The supernatant phase from the calcium caseinate showed the reversible gel formation on heating. The magnesium supernatant phase did not. κ-Casein and a mixture of κ- and β-caseins gave reversible gels at similar levels of calcium and pH.For reversible gel formation to occur, calcium caseinate was required to be in fairly high concentration, to have a calcium content of about 1·0% of the protein and to be within the pH limits 5·2–6·0. The temperature at which gelation occurred was affected by the concentration of calcium and protein and by pH.The behaviour of the material was compared with that of methyl cellulose with and without addition of urea.Some potential commercial applications of the findings on viscosity relationships are outlined.


Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1370
Author(s):  
Ziguan Wang ◽  
Guangcai Wang ◽  
Chengshu Wang ◽  
Xiaohui Wang ◽  
Meiling Li ◽  
...  

Underground coal mining can result in land deformation (e.g., land subsidence and ground fissures), and may consequently change the soil nutrients. Soil organic matter (SOM), total nitrogen (TN), and available phosphorus (AP) are critical indicators of soil fertility and eco-restoration in mining areas. In this study, soil samples (depth: 0–20 cm) were collected twice from 20 sampling points in pre-mining and post-mining in the No.12 panel of Caojiatan coalfield, in the Loess Plateau of China. SOM, TN, and AP in soil samples were measured, and the nutrient loss was evaluated. Ten environmental factors affecting soil nutrient loss were identified from a 5-m resolution digital elevation map (DEM). The paired t-test was utilized to evaluate the differences between SOM, TN, and AP in pre-mining and post-mining soil. The mechanisms of the effects of environmental factors on soil nutrient loss were revealed based on multiple linear regression, redundancy analysis (RDA), and the random forest algorithm (RF). Ordinary kriging and RF were utilized to predict and optimize the spatial distribution of the soil nutrient loss. The results showed that significant differences existed between the SOM, TN, and AP in the pre-mining and post-mining soil. The model established by RF provided a higher accuracy in terms of fitting the correlation between soil nutrient loss and environmental factors compared to the model established by multiple linear regression, and the feature importance obtained by RF showed that profile curvature, distance to working panel margin, and surface roughness were the most significant factors affecting the loss of SOM, TN, and AP, respectively. This study provides a theoretical reference for eco-restoration, as well as soil and water conservation, in subsided lands in coalfields.


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