scholarly journals Physiological Responses to N-NO3 and N-NH4 of Triazine Resistant and Susceptible Plants of Horseweed (Erigeron canadensis L.)

2013 ◽  
Vol 46 (1) ◽  
pp. 5-14
Author(s):  
Ryszard Stanek

Triazine resistant and susceptible biotypes of horseweed (<i>Erigeron canadensis</i> L.) were grown under controlled conditions in nutrient solution with NH<sub>4</sub> or NO<sub>3</sub> ions as nitrogen source. Indicators such as: dry matter, CO<sub>2</sub> assimilation, chloroplasts activity, dark respiration and the content of K, Ca, Mg in the above ground parts displayed lower levels when plants were fed with NH<sub>4</sub> than with NO ions. Reduction of these indicators was stronger for the triazine susceptible plants which grew better than their resistant counterparts when fed with N-NO<sub>3</sub>. The triazine resistant plants grown with N-NH<sub>4</sub> contained more protein-N and K than the susceptible ones. Chloroplasts of the resistant plants were also less sensitive to NH<sub>4</sub>CL treatment. It is concluded that the resistant plants appear to be more tolerant to NH<sub>4</sub> ions as compared with their susceptible counterparts. For this reason application of ammonium forms of nitrogen fertilization in horticultural practice could favour spreading of triazine resistant horseweed.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Luis Felipe Lata Tenesaca ◽  
José Lucas Farias da Silva ◽  
Ben-Hur Mattiuz

AbstractCalcium (Ca) deficiency in cabbage plants induces oxidative damage, hampering growth and decreasing quality, however, it is hypothesized that silicon (Si) added to the nutrient solution may alleviate crop losses. Therefore, this study aims at evaluating whether silicon supplied in the nutrient solution reduces, in fact, the calcium deficiency effects on cabbage plants. In a greenhouse, cabbage plants were grown using nutrient solutions with Ca sufficiency and Ca deficiency (5 mM) without and with added silicon (2.5 mM), arranged as a 2 × 2 factorial in randomized blocks, with five replications. At 91 days after transplanting, the plants were harvested for biological evaluations. In the treatment without added Si, Ca deficiency promoted oxidative stress, low antioxidant content, decreased dry matter, and lower quality leaf. On the other hand, added Si attenuated Ca deficiency in cabbage by decreasing cell extravasation while increasing both ascorbic acid content and fresh and dry matter, providing firmer leaves due to diminished leaf water loss after harvesting. We highlighted the agronomic importance of Si added to the nutrient solution, especially in crops at risk of Ca deficiency.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 192-192
Author(s):  
Alice Brandão ◽  
Reinaldo F Cooke ◽  
Kelsey Schubach ◽  
Bruna Rett ◽  
Osvaldo Souza ◽  
...  

Abstract This experiment compared performance and physiological responses of the offspring from cows supplemented with Ca salts of soybean oil (CSSO) or prilled saturated fat (CON) during late gestation. Non-lactating, pregnant Angus × Hereford cows (n = 104) that conceived during the same fixed-time artificial insemination protocol, using semen from 2 sires, were used in this experiment. Cows were ranked by pregnancy sire, body weight (BW), and body condition score (BCS). On d 180 of gestation (d -15), cows were randomly assigned to receive (dry matter basis) 415 g of soybean meal per cow daily in addition to 1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows were maintained in 2 pastures (26 cows/treatment per pasture), and received daily 12.7 kg/cow (dry matter basis) of grass-alfalfa hay. From d 0 until calving, cows were segregated into 1 of 24 feeding pens thrice weekly and received treatments individually. Cow BW and BCS were recorded, and blood samples were collected on d -15 of the experiment and within 12 h after calving. Calf BW was also recorded and blood sample collected within 12 h of calving. Calves were weaned on d 290 of the experiment, preconditioned for 35 d (d 291 to 325), and transferred to a feedyard where they remained until slaughter. Upon calving, CSSO cows and calves had greater (P &lt; 0.01) plasma concentrations of linoleic acid and total ω - 6 FA compared with CON cohorts. No differences in calf birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36) between treatments. Average daily gain and final BW in the feedlot were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON (Table 5). Upon slaughter, longissimus muscle area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results suggest that supplementing CSSO to late-gestating beef cows stimulated programming effects on postnatal offspring growth and Page 2 of 15 For Peer Review health. Therefore, supplementing late-gestating beef cows with CSSO appears to optimize offspring welfare and productivity in beef production systems.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1291
Author(s):  
Nasr M. Abdou ◽  
Mohamed A. Abdel-Razek ◽  
Shimaa A. Abd El-Mageed ◽  
Wael M. Semida ◽  
Ahmed A. A. Leilah ◽  
...  

Sustainability of rice production under flooding conditions has been challenged by water shortage and food demand. Applying higher nitrogen fertilization could be a practical solution to alleviate the deleterious effects of water stress on lowland rice (Oryza sativa L.) in semi-arid conditions. For this purpose, field experiments were conducted during the summer of 2017 and 2018 seasons. These trials were conducted as split-split based on randomized complete blocks design with soil moisture regimes at three levels (120, 100 and 80% of crop evapotranspiration (ETc), nitrogen fertilizers at two levels (N1—165 and N2—200 kg N ha−1) and three lowland Egyptian rice varieties [V1 (Giza178), V2 (Giza177) and V3 (Sakha104)] using three replications. For all varieties, growth (plant height, tillers No, effective tillers no), water status ((relative water content RWC, and membrane stability index, MSI), physiological responses (chlorophyll fluorescence, Relative chlorophyll content (SPAD), and yield were significantly increased with higher addition of nitrogen fertilizer under all water regimes. Variety V1 produced the highest grain yield compared to other varieties and the increases were 38% and 15% compared with V2 and V3, respectively. Increasing nitrogen up to 200 kg N ha−1 (N2) resulted in an increase in grain and straw yields by 12.7 and 18.2%, respectively, compared with N1. The highest irrigation water productivity (IWP) was recorded under I2 (0.89 kg m−3) compared to (0.83 kg m−3) and (0.82 kg m−3) for I1 and I3, respectively. Therefore, the new applied agro-management practice (deficit irrigation and higher nitrogen fertilizer) effectively saved irrigation water input by 50–60% when compared with the traditional cultivation method (flooding system). Hence, the new proposed innovative method for rice cultivation could be a promising strategy for enhancing the sustainability of rice production under water shortage conditions.


Author(s):  
Alide M. W. Cova ◽  
Fabio T. O. de Freitas ◽  
Paula C. Viana ◽  
Maria R. S. Rafael ◽  
André D. de Azevedo Neto ◽  
...  

ABSTRACT The objective of this study was to evaluate the growth and accumulation of ions in lettuce grown in different hydroponic systems and recirculation frequencies. The experimental design was randomized blocks with 8 treatments and 4 replicates. The evaluated hydroponic systems were Nutrient Flow Technique (NFT) and an adapted Deep Flow Technique (DFT), the latter with recirculation frequencies of 0.25, 2 and 4 h. Both systems used fresh water and brackish water. Plant growth, accumulation of inorganic solutes (Na+, K+, Cl- and NO3-) and the correlation between dry matter production and Na+/K+ and Cl-/NO3- were evaluated. The salinity of the water used to prepare the nutrient solution caused decrease in growth and K+ and NO3- levels, and increased contents of Na+ and Cl- in the plants. When using fresh water the highest dry matter production was obtained in the NFT system. In case of brackish water the adapted DFT system increased the production, in relation to NFT system (at same recirculation frequency: 0.25 h). It was found that the choice of the type of hydroponic system and recirculation interval for the cultivation of lettuce depends on the quality of the water used to prepare the nutrient solution.


2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.


2012 ◽  
Vol 34 (4) ◽  
pp. 1235-1244 ◽  
Author(s):  
Layara Alexandre Bessa ◽  
Fabiano Guimarães Silva ◽  
Marialva Alvarenga Moreira ◽  
João Paulo Ribeiro Teodoro ◽  
Frederico Antônio Loureiro Soares

Knowledge of the mineral nutrition requirements of mangabeira (Hancornia speciosa Gomes) is relatively scarce and rudimentary because there is a lack of consistent data concerning its nutritional demands at different developmental stages. The aim of this research was to characterize the visual symptoms of macronutrient deficiencies and to evaluate the effects of these deficiencies on the growth, the production of dry matter, and the leaf content of mangabeira. To achieve this goal, a greenhouse experiment was conducted at the Goiano Federal Institute (Instituto Federal Goiano) in Rio Verde - GO, from January to June 2011 in which mangabeira plants were arranged in a random block design and grown in nutrient solutions. This experiment was replicated four times. The plants were treated with either a complete nutrient solution or a nutrient solution from which the individual macronutrient of interest (nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca), or sulfur (S) had been omitted. The omission of a macronutrient from the nutrient solution resulted in morphological alterations that were characteristic symptoms of the particular nutritional deficiency and caused decreases in growth and dry matter mass production. The accumulation of macronutrients displayed the following order in mangabeira leaves: N>K>Ca>P>S>Mg.


2013 ◽  
Vol 37 (5) ◽  
pp. 1334-1342 ◽  
Author(s):  
Elcio Ferreira dos Santos ◽  
Bruno José Zanchim ◽  
Aline Grella de Campos ◽  
Raphael Florencio Garrone ◽  
José Lavres Junior

Few studies in Brazil have addressed the need for micronutrients of physic nut focusing on physiological responses, especially in terms of photosynthesis. The objective of this study was to evaluate the effects of omission of boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on Jatropha curcas L.. The experimental design was a randomized block with four replications. The treatments were complete solution (control) and solution without B, Cu, Fe, Mn, and Zn. We evaluated the chlorophyll content (SPAD units), photosynthetic rate, dry matter production and accumulation of micronutrients in plants, resulting from different treatments. The first signs of deficiency were observed for Fe and B, followed by Mn and Zn, while no symptoms were observed for Cu deficiency. The micronutrient omission reduced the dry matter yield, chlorophyll content and photosynthetic rate of the plants differently for each omitted nutrient. It was, however, the omission of Fe that most affected the development of this species in all parameters evaluated. The treatments negatively affected the chlorophyll content, evaluated in SPAD units, and the photosynthetic rate, except for the omission of B. However this result was probably due to the concentration effect, since there was a significant reduction in the dry matter production of B-deficient plants.


Bragantia ◽  
2012 ◽  
Vol 71 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Djeimi Isabel Janisch ◽  
Jerônimo Luiz Andriolo ◽  
Vinícius Toso ◽  
Kamila Gabriele Ferreira dos Santos ◽  
Jéssica Maronez de Souza

The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control), 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested) were collected weekly and counted during the growth period. The number of leaves, dry matter (DM) of leaves, crown and root, specific leaf area and leaf area index (LAI) was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.


2017 ◽  
Vol 30 (3) ◽  
pp. 670-678 ◽  
Author(s):  
ROGÉRIO PERES SORATTO ◽  
TIAGO ARANDA CATUCHI ◽  
EMERSON DE FREITAS CORDOVA DE SOUZA ◽  
JADER LUIS NANTES GARCIA

ABSTRACT The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.


Sign in / Sign up

Export Citation Format

Share Document