scholarly journals Influence of the K+ and Ca2+ on the Presence of Sugars in the Phloem, and Growth Parameters in Capsicum

2018 ◽  
Vol 7 (2) ◽  
pp. 1
Author(s):  
Pedro Alberto Rojas-Rojas ◽  
Saul Parra-Terraza ◽  
Sixto Velarde-Felix ◽  
Luis Alberto Lightbourn-Rojas

The effect of various K+ and Ca2+ nutrient solutions were evaluated to measure the growth rate, amount of reducing sugars and the production of Capsicum annuum Plants were grown directly in soil under shade house conditions in two separate experiments across two consecutive years. Nine nutrient solutions containing three levels of K+ (27, 35 and 43%) combined with three levels of Ca2+ (37, 45 and 53%) were used, along with the Steiner solution treatment as a control. Irrigation was calculated every week according to Kc, volumetric humidity and ETo, the experimental design was a block (furrows) with a 3(x)3 factorial arrangement. There was no interaction between growth rate, sugars and yield. Plants treated with the combination 27% of potassium with 53% of calcium presented a yield of 500 g/fruit greater than the control treatment (Steiner), and produced on average 2 more fruits per plant with a weight of 160 g/fruit (<0.05) higher than Steiner, the low potassium concentration (27%) induced a lower concentration of sugars with a value >3 mg/ml during the first crop cycle, it were analyzed during the flowering stage, and in the second agricultural cycle, during the fruiting stage it was < 4 mg/ml.

2021 ◽  
Vol 43 ◽  
pp. e57549
Author(s):  
Laenne Barbara Silva de Moraes ◽  
Géssica Cavalcanti Pereira Mota ◽  
Renata da Silva Farias ◽  
Yllana Ferreira Marinho ◽  
Luis Otávio Brito Silva ◽  
...  

This study aimed to evaluate the growth of Arthrospira (Spirulina) platensis cultivated in Zarrouk culture medium and effluent from Nile tilapia (Oreochromis niloticus) reared in biofloc system. Four treatments were used: Control (100% Zarrouk), E50 (50% Zarrouk + 50% Tilapia effluent), E75 (25% Zarrouk + 75% Tilapia effluent), and E100 (100% Tilapia effluent), and the experiment lasted 10 days. Growth parameters such as maximum cell density (MCD), doubling time (DT), and growth rate (K) were daily evaluated, as well as pH and water temperature. In addition, the concentrations of total ammonia nitrogen (TAN), nitrite-N (NO2-N), and nitrate-N (NO3-N) were analyzed in order to compare nitrogen absorption. Among treatments, E50 and E75 obtained higher maximum cell densities and presented an exponential growth rate similar to the control treatment. Regarding the concentrations of nitrogen compounds, a significant reduction was observed in all treatments, with an NO3-N uptake of 99%, followed by 80% of TAN and 90% of NO2-N. Thus, giving the results obtained, besides being able to grow in wastewater, A. platensis can also be used in bioremediation processes, confirming the potential of this species.


2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Rosa S. Santos ◽  
Marcus R. da Costa ◽  
Francisco G. Araújo

ABSTRACT Studies on age and growth of fish populations have direct application in fisheries and contribute for policies of conservation. Our aim was update information on the Micropogonias furnieri growth parameters based on sagittae otoliths annulis readings, and we expected that the studied population from Southeast Brazil can reach more longevity than the reported in the available literature. We examined 286 individuals between August-2010 and July-2011 from Ubatuba Bay, SP. The Total Length ranged 200-480 mm. The determined growth parameters were: Males, L∞ =523.4mm, k = 0.05×year-1, t0 = -8.78 year; Females L∞ = 573.5mm, k = 0.06 × year-1, t0 = -7.49 year. The MI and % of edge type evidenced the formation of one ring per year during autumn/winter, coinciding with low temperature and low growth rate. These results differed from those reported for the Vazzoler’s Population I (summer), and we detected higher longevity (45-48 years) as compared with the recorded in the available information.


2017 ◽  
Vol 80 (3) ◽  
pp. 447-453 ◽  
Author(s):  
Ai Kataoka ◽  
Hua Wang ◽  
Philip H. Elliott ◽  
Richard C. Whiting ◽  
Melinda M. Hayman

ABSTRACT The growth characteristics of Listeria monocytogenes inoculated onto frozen foods (corn, green peas, crabmeat, and shrimp) and thawed by being stored at 4, 8, 12, and 20°C were investigated. The growth parameters, lag-phase duration (LPD) and exponential growth rate (EGR), were determined by using a two-phase linear growth model as a primary model and a square root model for EGR and a quadratic model for LPD as secondary models, based on the growth data. The EGR model predictions were compared with growth rates obtained from the USDA Pathogen Modeling Program, calculated with similar pH, salt percentage, and NaNO2 parameters, at all storage temperatures. The results showed that L. monocytogenes grew well in all food types, with the growth rate increasing with storage temperature. Predicted EGRs for all food types demonstrated the significance of storage temperature and similar growth rates among four food types. The predicted EGRs showed slightly slower rate compared with the values from the U.S. Department of Agriculture Pathogen Modeling Program. LPD could not be accurately predicted, possibly because there were not enough sampling points. These data established by using real food samples demonstrated that L. monocytogenes can initiate growth without a prolonged lag phase even at refrigeration temperature (4°C), and the predictive models derived from this study can be useful for developing proper handling guidelines for thawed frozen foods during production and storage.


1990 ◽  
Vol 41 (3) ◽  
pp. 399 ◽  
Author(s):  
MCL Dredge

Movement, growth and natural mortality rate of the red spot king prawn, Penaeus longistylus, occurring in waters of the Great Barrier Reef off Townsville, Queensland, were investigated in a series of tagging experiments. Adult P. longistylus did not migrate after leaving nursery areas. Their growth rate was slower than that of the conspecific species P. plebejus, and significant inter-annual variation in growth parameters was observed. The natural mortality rate, assessed by sequential tagging experiments that eliminated the possibility of confounding with the rate of fishing mortality, was estimated to be 0.072 (week-1).


2013 ◽  
Vol 67 (7) ◽  
Author(s):  
Ľubomír Valík ◽  
Alžbeta Medveďová ◽  
Michal Čižniar ◽  
Denisa Liptáková

AbstractThe application of secondary temperature models on growth rates of Lactobacillus rhamnosus GG, the much studied probiotic bacterium, is investigated. Growth parameters resulting from a primary fitting were modelled against temperature using the following models: Hinshelwood model (H), Ratkowsky extended model (RTK2), Zwietering model (ZWT), and cardinal temperature model with inflection (CTMI). As experienced by other authors, the RTK2, ZWT, and CTMI models provided the best statistical indices related to fitting the experimental data. Moreover, with the biological background, the following cardinal temperatures of L. rhamnosus GG resulted from the study by the model application: t min = 2.7°C, t opt = 44.4°C, t max = 52.0°C. The growth rate of the strain under study at optimal temperature was 0.88 log10(CFU mL−1 h−1).


Author(s):  
Gamze Kaya

The study aimed to evaluate the use of germination indices as a screening tool for salinity tolerance during germination and early seedling growth of pepper cultivars, and to distinguish the potential for genetic responses to salt tolerance. In the study, the seeds of seven pepper cultivars were germinated at increasing NaCl levels of 5, 10, 15 and 20 dS/m and distilled water as the control treatment for 14 days. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), seedling length (SL), seedling fresh weight (SFW) and vigor index (VI) were investigated. Results showed that germination percentage decreased with increasing NaCl levels while the highest germination percentage at 20 dS/m was 92% in BT Burdem with no significant reduction. Seedling growth of pepper cultivars was severely inhibited by increasing salinity stress. SFW was depressed depending on reduction in SL due to increasing NaCl. BT-Burli and BT İnce Sivri were the most tolerant cultivars to NaCl and they were used for genetic resources towards salinity. Seedling growth was much more sensitive to salinity than germination because of the highest percent reduction in seedling growth parameters. Among the parameters, GSTI gave the highest significant correlation coefficient with SL and SFW; indicating that it would be useful for estimating seedling growth. It was concluded that genotypic variation was observed among pepper cultivars for salinity tolerance and GSTI could be used for a predictor for salinity tolerance.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1087
Author(s):  
Muhammad Israr ◽  
Naila Chand ◽  
Rifat Ullah Khan ◽  
Ibrahim A. Alhidary ◽  
Mutassim M. Abdelrahman ◽  
...  

A total of 300 day old broiler chicks (Hubbard) were assigned to 30 floor pens (10 birds per pen) under cyclic heat stress. Three diets including a control, as well as two levels of grape seed powder (GSP) and zinc (OZ) at the rates of 2.5 g/kg GSP + 50 mg/kg OZ and 5 g/kg GSP + 50 mg/kg OZ, were supplied to the broilers for 35 days. According to the results, broiler feed intake improved (p < 0.05) in GSP + OZ groups from 3–5 weeks and on an overall basis compared to the control diet. Body weight increased (p < 0.05) in GSP-5 + OZ-50 during weeks 2–5 and on an overall basis. The findings indicated that feed conversion ratio (FCR) decreased (p < 0.05) during week 5 in broilers supplemented with GSP-5 + OZ-50. The antibody titer (HI) against Newcastle disease (ND) was higher (p < 0.05) in GSP + OZ groups compared to control treatment. The value of malondialdehyde (MDA) decreased (p < 0.05) under GSP + OZ diets compared to control. Moreover, paraoxonase (PON1) was higher (p < 0.05) in GSP + OZ groups compared to untreated broilers. In conclusion, GSP + OZ positively supported growth traits, reduced MDA, and augmented PON1 and HI titer against ND in broilers exposed to heat stress.


2019 ◽  
Vol 32 ◽  
pp. 282-290
Author(s):  
Nada A. El-Qatrani

This study was carried out in the nursery of Department of Horticulture and Landscape Design, College of Agriculture, University of Basrah during 2018 growing season. Completely randomized blocks design (C.R.B.D.)  was used to investigate the effect of different concentrations of super swing (0, 0.5 and 1) g.l-1 and whey (0, 50 and 75) % and their interactions to enhance the growth parameters and chemical characteristics of Sour orange transplants. The results showed a significant increase in most of the measured growth parameters of transplants treated with high concentration of foliar spraying to both fertilizers. Application of super swing at 1 g.l-1 with whey at 75% together significantly increased the height of plant, the number of leaves, leaf area, the diameter of stem, number of flowers, the leaves content of both nitrogen and potassium, percentage of dry matter, and content of chlorophyll. Whereas, control treatment was significantly increased the water content compared to other treatments. Addition of growth-enhancing compounds such as super swing and whey extract to the plant can improve the metabolic performance and enhances the plant's ability to absorb nutrients from the soil.


Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 388
Author(s):  
Mary-Rus Martínez-Cuenca ◽  
Amparo Primo-Capella ◽  
María Ángeles Forner-Giner

This work compares the tolerance to long-term anoxia conditions (35 days) of five new citrus ‘King’ mandarin (Citrus nobilis L. Lour) × Poncirus trifoliata ((L.) Raf.) hybrids (named 0501XX) and Carrizo citrange (CC, Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.), the widely used citrus rootstock in Spain. Growth parameters, chlorophyll concentration, gas exchange and fluorescence parameters, water relations in leaves, abscisic acid (ABA) concentration, and PIP1 and PIP2 gene expressions were assessed. With a waterlogging treatment, the root system biomass of most hybrids went down, and the chlorophyll a and b concentrations substantially dropped. The net CO2 assimilation rates (An) and stomatal conductance (gs) lowered significantly due to flooding, and the transpiration rate (E) closely paralleled the changes in gs. The leaf water and osmotic potentials significantly increased in most 0501 hybrids. As a trend, flooding stress lowered the ABA concentration in roots from most hybrids, but increased in the leaves of CC, 05019 and 050110. Under the control treatment (Ct) conditions, most 0501 hybrids showed higher PIP1 and PIP2 expressions than the control rootstock CC, but were impaired due to the flooding conditions in 05019 and 050110. From this study, we conclude that 0501 genotypes develop some adaptive responses in plants against flooding stress such as (1) stomata closure to prevent water loss likely mediated by ABA levels, and (2) enhanced water and osmotic potentials and the downregulation of those genes regulating aquaporin channels to maintain water relations in plants. Although these traits seemed especially relevant in hybrids 050110 and 050125, further experiments must be done to determine their behavior under field conditions, particularly their influence on commercial varieties and their suitability as flooding-tolerant hybrids for replacing CC, one of the main genotypes that is widely used as a citrus rootstock in Spain, under these conditions.


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