scholarly journals Evaluation of Popcorn Hybrids for Nitrogen Use Efficiency and Responsiveness

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 485 ◽  
Author(s):  
Adriano dos Santos ◽  
Antônio Teixeira do Amaral Júnior ◽  
Samuel Henrique Kamphorst ◽  
Gabriel Moreno Bernardo Gonçalves ◽  
Pedro Henrique Araújo Diniz Santos ◽  
...  

The global boom in agricultural production has been associated with the exponential increase of nitrogen (N) fertilizer application. This heavy use of nitrogen in agriculture has caused negative impacts on the environment. Therefore, new alternatives are needed to maintain or increase maize yield but reduce the environmental impact. For this purpose, one possibility is to plant N-use efficient (NUE) cultivars. In this context, the objective of this study was to identify popcorn hybrid cultivars that are highly NUE and N-responsive, bred from crosses between inbred lines with contrasting levels of N-use efficiency. For this purpose, 90 hybrids were evaluated in a 10 × 10 triple lattice design at two sites and two levels of N availability (low and ideal availability). The results indicated that for the environment with low nitrogen availability, the lack of nitrogen reduced the chlorophyll content, extended the interval between male and female flowering, and affected the performance of the tested hybrids. However, we observed the existence of hybrids with greater efficiency than the responsiveness to nitrogen and with high productivity. These can even be used on farms where the level of production inputs is low, thus contributing to ensure food security.

2006 ◽  
Vol 42 (1) ◽  
pp. 51-63 ◽  
Author(s):  
WILKSON MAKUMBA ◽  
BERT JANSSEN ◽  
OENE OENEMA ◽  
FESTUS K. AKINNIFESI

Asynchrony between nitrogen (N) released by organic materials and N demand by the crop leads to low N use efficiency. Optimizing the time of application could increase the N recovery. A field experiment was designed to determine the effects of time of application of Gliricidia sepium prunings and of the addition of small doses of inorganic N fertilizer on N recovery and yield of maize. Six split applications of gliricidia prunings (in October, December and February) were compared. The prunings were incorporated into the soil while fresh. The application in October was done four weeks before planting the maize. Higher N uptake and maize yields were obtained when gliricidia prunings were applied in October than when applied in December and February. The corresponding substitution values were 0.66, 0.32 and 0.20. Split applications of prunings prolonged mineral N availability in the soil until March but did not increase N uptake and maize grain yield compared to a sole application in October. Combinations of gliricidia prunings and inorganic fertilizer increased N uptake and maize yield over prunings alone but the effect was only additive. We concluded that application of gliricidia prunings in October was more efficient than application in December and February.


2020 ◽  
Vol 21 (5) ◽  
pp. 1824
Author(s):  
Yubin Wang ◽  
Qingqing Yao ◽  
Yushi Zhang ◽  
Yuexia Zhang ◽  
Jiapeng Xing ◽  
...  

Modified gibberellin (GA) signaling leads to semi-dwarfism with low nitrogen (N) use efficiency (NUE) in crops. An understanding of GA-mediated N uptake is essential for the development of crops with improved NUE. The function of GA in modulating N uptake capacity and nitrate (NO3−) transporters (NRTs) was analyzed in the GA synthesis-deficient mutant zmga3ox grown under low (LN) and sufficient (SN) N conditions. LN significantly suppressed the production of GA1, GA3, and GA4, and the zmga3ox plants showed more sensitivity in shoots as well as LN stress. Moreover, the higher anthocyanin accumulation and the decrease of chlorophyll content were also recorded. The net NO3− fluxes and 15N content were decreased in zmga3ox plants under both LN and SN conditions. Exogenous GA3 could restore the NO3− uptake in zmga3ox plants, but uniconazole repressed NO3− uptake. Moreover, the transcript levels of ZmNRT2.1/2.2 were downregulated in zmga3ox plants, while the GA3 application enhanced the expression level. Furthermore, the RNA-seq analyses identified several transcription factors that are involved in the GA-mediated transcriptional operation of NRTs related genes. These findings revealed that GAs influenced N uptake involved in the transcriptional regulation of NRTs and physiological responses in maize responding to nitrogen supply.


2016 ◽  
Vol 67 (11) ◽  
pp. 1158 ◽  
Author(s):  
Rupinder Kaur ◽  
Seema Bedi ◽  
Gulshan Mahajan ◽  
Gurpreet Kaur ◽  
Bhagirath Singh Chauhan

To achieve high productivity of labour and water in rice cropping, farmers in South Asia have recently shown more interest in dry direct-seeded rice (DSR). An understanding of physiological and biochemical traits associated with high grain yield and efficiency of nitrogen (N) use is important to the development of genotypes for DSR. We investigated this issue with rice genotypes adapted to DSR in response to N rates. A 2-year study was conducted in a factorial randomised complete block design with eight genotypes and two N rates (75 and 150 kg N ha–1). Almost all of the physiological and biochemical traits studied (e.g. plant height, chlorophyll content, panicle weight, soluble sugars, starch) in DSR improved with increasing N from 75 to 150 kg ha–1, resulting in a 6% increase in yield at 150 kg N ha–1 relative to 75 kg N ha–1. Partial factor productivity of N was highest for the genotype IET-23455 (72.4 kg kg–1) and lowest for the genotype AAUDR (37.4 kg kg–1). Our results suggest that genotypes such as IET-23455 can maintain grain yield at low N rates as N-efficient genotypes. The greater biochemical activity (nitrate reductase and glutamine synthetase, sugar, protein and proline) and higher photosynthetic N-use efficiency at low N rates could be used in selection for N-efficient rice genotypes for DSR.


2013 ◽  
Vol 93 (6) ◽  
pp. 1073-1081 ◽  
Author(s):  
E. N. Johnson ◽  
S. S. Malhi ◽  
L. M. Hall ◽  
S. Phelps

Johnson, E. N., Malhi, S. S., Hall, L. M. and Phelps, S. 2013. Effects of nitrogen fertilizer application on seed yield, N uptake, N use efficiency, and seed quality of Brassica carinata . Can. J. Plant Sci. 93: 1073–1081. Ethiopian mustard (Brassica carinata A. Braun) is a relatively new crop in western Canada and research information on its response to N fertilizer is lacking. Two field experiments (exp. 1 at 3 site-years and exp. 2 at 4 site-years) were conducted from 2008 to 2010 in Saskatchewan and Alberta, Canada, to determine effect of N fertilizer application on Brassica carinata plant density, seed and straw yield, N uptake in seed and straw, N use efficiency (NUE), N fertilizer use efficiency (NFUE) and seed quality. N rates applied were 0 to 160 kg N ha−1 and 0 to 200 kg N ha−1 in exps. 1 and 2, respectively. Plant density was not affected by increasing N rate at 5 site-years but declined with high rates of N application at 2 site-years. Seed yield responded to applied N in 6 of 7 site-years, with the non-responsive site having a high total N uptake at the 0 kg N ha−1 rate (high Nt value). There were no sites where seed yields were maximized with the N rates applied. Response trends of straw yield and N uptake were similar to that of seed yield at the corresponding site-years. NUE and NFUE generally declined as N rate increased. Protein concentration in seed generally increased and oil concentration in seed decreased with increasing N rates. In conclusion, the responses of seed yield, total N uptake, NUE, and NFUE to applied N was similar to those reported in other Brassica species with the exception that a rate was not identified in which Brassica carinata yields were maximized.


1998 ◽  
Vol 123 (5) ◽  
pp. 814-820 ◽  
Author(s):  
Margarita R. Villagarcia ◽  
Wanda W. Collins ◽  
C. David Raper

Soil N availability is an important component in storage root production of sweetpotato [Ipomoea batata (L.) Lam.]. A controlled-environment experiment was conducted to characterize effects of N availability on patterns of dry matter, nonstructural carbohydrates, and N accumulation, and to determine possible components of N use efficiency that vary between two genotypes of sweetpotato. Rooted cuttings of `Jewel' and MD810 were transplanted into pots filled with sand and kept in a growth chamber for 72 days. Plants were watered during the first 30 days with a complete nutrient solution that contained 14 mm NO3- and then for the next 42 days with one of three complete nutrient solution that contained either 2, 8, or 14 mm NO3-. At 30, 44, 58, and 72 days after transplanting, three plants from each cultivar and treatment combination were sampled and separated into leaves, stems plus petioles, fibrous roots, and storage roots. Each plant fraction was freeze-dried, weighed, ground, and analyzed for total N, soluble sugars, and starch. Availability of N in the substrate, which limited dry matter accumulation at 2 mm NO3-, was nonlimiting at 8 and 14 mm NO3-. In both genotypes, net assimilation rate, efficiency of N use (i.e., increments of dry matter accumulated per increment of N taken up), and proportion of dry matter allocated to storage roots were greater for N-stressed (2 mm NO3-) than N-replete (8 and 14 mm NO3-) plants. For the N-stressed plants, however, efficiency of N use was greater in MD810 than in `Jewel'. Although rate of NO3- uptake per unit fibrous root mass was similar in the two genotypes under the N stress treatment, MD810 had greater uptake rate than `Jewel' under nonlimiting availability of NO3- in the substrate. The increased rate of uptake under nonlimiting NO3- supplies apparently was related to enhanced rates of carbohydrate transport from shoots to roots. As tissue concentration of N declined in response to the lowest application of NO3-, shoot growth was limited prior to, and to a greater extent than, the photosynthetic rate. The resulting relative decline in sink activity of shoots thus presumably increased the availability of carbohydrates for transport to roots.


2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Sami Ullah JAN ◽  
Ayesha LIAQAT ◽  
Yonghong ZHU ◽  
Jing LI ◽  
Huangyang ZHANG ◽  
...  

Abstract Background Nitrogen (N) is a required macronutrient for cotton growth and productivity. Excessive N fertilizers are applied in agriculture for crop yield maximization, which also generates environmental pollution. Improving crop N use efficiency (NUE) is the most economical and desirable way of reducing fertilizer application and environmental pollution. NUE has been an important issue in cotton. So far there is no report on cotton NUE improvement via transgenic approach. Nin-like proteins (NLP) are transcription factors regulating NUE. We previously demonstrated that AtNLP7 improved NUE and biomass when overexpressed in Arabidopsis. However, it is not known whether AtNLP7 can be used to improve NUE in crops. Results To test the feasibility, we expressed AtNLP7 in cotton and evaluated NUE and yield of the transgenic cotton in the field. Transgenic cotton showed improved NUE and yield under both low and high N conditions. In addition, plant biomass, amount of absorbed N, N contents, activities of N-assimilating enzymes, and the expression of N-related marker genes were significantly increased in transgenic cotton compared with the wild type control, suggesting that AtNLP7 enhances NUE in cotton. Conclusion Together, our results demonstrate that AtNLP7 is a promising candidate to improve NUE and yield in cotton.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
J. Vladimir Torres-Rodríguez ◽  
M. Nancy Salazar-Vidal ◽  
Ricardo A. Chávez Montes ◽  
Julio A. Massange-Sánchez ◽  
C. Stewart Gillmor ◽  
...  

Abstract Background Nitrogen (N) and phosphorus (P) are macronutrients essential for crop growth and productivity. In cultivated fields, N and P levels are rarely sufficient, contributing to the gap between realized and potential production. Fertilizer application increases nutrient availability, but is not available to all farmers, nor are current rates of application sustainable or environmentally desirable. Transcriptomic studies of cereal crops have revealed dramatic responses to either low N or low P single stress treatments. In the field, however, levels of both N and P may be suboptimal. The interaction between N and P starvation responses remains to be fully characterized. Results We characterized growth and root and leaf transcriptomes of young maize plants under nutrient replete, low N, low P or combined low NP conditions. We identified 1555 genes to respond to our nutrient treatments, in one or both tissues. A large group of genes, including many classical P starvation response genes, were regulated antagonistically between low N and P conditions. An additional experiment over a range of N availability indicated that a mild reduction in N levels was sufficient to repress the low P induction of P starvation genes. Although expression of P transporter genes was repressed under low N or low NP, we confirmed earlier reports of P hyper accumulation under N limitation. Conclusions Transcriptional responses to low N or P were distinct, with few genes responding in a similar way to the two single stress treatments. In combined NP stress, the low N response dominated, and the P starvation response was largely suppressed. A mild reduction in N availability was sufficient to repress the induction of P starvation associated genes. We conclude that activation of the transcriptional response to P starvation in maize is contingent on N availability.


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