Defoliation studies in hybrid maize: I. Grain yield, quality and leaf chemical composition

1975 ◽  
Vol 85 (2) ◽  
pp. 241-245 ◽  
Author(s):  
R. P. Singh ◽  
K. P. P. Nair

SUMMARYIn order to examine whether high yield of maize could still be maintained at high plant densities by creating an ‘erectophile canopy’ through artificial defoliation of laminae, an experiment at Pantnagar, India, was made on the effect of density, stage and degree of defoliation in two divergent seasons, Kharif (rainy) and spring, of the year 1972. The defoliation treatments were either partial (clipping off the apical half of individual leaves) or complete (full leaf removal) and were imposed at three stages of plant growth, namely when 10 or 16 leaves were fully open or 12 days after silking. These treatments were applied at two plant densities, 60000 and 90000 plants/ha.Grain yield of maize increased significantly with the increase in population density in the spring season. The trend was diametrically opposite in the Kharif season. Defoliation at the 10th fully open leaf stage produced more grains than defoliating 12 days after silking, which in turn produced more than defoliating at the 16th fully open leaf stage, when plants were in full bloom. Increase in the degree of defoliation at the latter two stages of plant growth reduced grain yield, the effect being more at the 16th leaf stage. However, 50% defoliation at the 10th leaf stage increased grain yield in the Kharif season.The percentage protein content of grain declined with the increase in population density whereas increase in degree of defoliation increased the grain protein content. Higher protein content of grain was recorded in the spring than in the Kharif season. The leaf protein decreased as the plants neared maturity, especially at the higher degree of defoliation treatments.Sucrose and reducing sugars declined significantly with the increase in degree of defoliation. The reduction in sucrose was large enough to account for the reduction in total sugar percentage. Similar trends were observed in the sugar-to-protein ratio.

2021 ◽  
Author(s):  
Ivica Djalovic ◽  
◽  
Vuk Radojevic ◽  
Vojislav Mihailovic ◽  
Sanja Vasiljevic ◽  
...  

Maize density is an important factor in cultivation which has significant effect on growth parameters. Newer hybrids have greater grain yield at higher plant densities than older hybrids. Differences in grain yield between older and newer maize hybrids were shown to be a function of plant population density. Optimum plant density for maximum grain yield per unit area may differ from hybrid to hybrid on account of significant interactions between hybrids and densities. Modern hybrids have shown tendencies to withstand higher levels of stress (i.e.- low N, high plant densities), which allow them to better sustain suitable photosynthetic rates, appropriate assimilate supplies, and maintain plant growth rates attributable to enhanced mineral nutrition and water use efficiency.


Agronomy ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 139 ◽  
Author(s):  
Abdullah Jaradat

Future challenges to the role of durum and bread wheat in global food security will be shaped by their potential to produce larger yields and better nutritional quality, while increasingly adapting to multiple biotic and abiotic stresses in the view of global climate change. There is a dearth of information on comparative assessment of phenotypic plasticity in both wheat species under long-term multiple abiotic stresses. Phenotypic plasticities of two durum and bread wheat genotypes were assessed under increasing abiotic and edaphic stresses for six years. Combinations of normal and reduced length of growing season and population density, with or without rotation, generated increasing levels of competition for resources and impacted phenotypic plasticity of several plant and yield attributes, including protein and micronutrients contents. All the phenotypic plasticity (PPs) estimates, except for the C:N ratio in both genotypes and grain protein content in T. aestivum genotype, were impacted by abiotic stresses during the second stress phase (PS II) compared with the first (PS I); whereas, covariate effects were limited to a few PPs (e.g., biomass, population density, fertile tillers, grain yield, and grain protein content). Discrimination between factor levels decreased from abiotic phases > growth stages > stress treatments and provided selection criteria of trait combinations that can be positively resilient under abiotic stress (e.g., spike harvest and fertility indices combined with biomass and grain yield in both genotypes). Validation and confirmatory factor models and multiway cluster analyses revealed major differences in phenotypic plasticities between wheat genotypes that can be attributed to differences in ploidy level, length of domestication history, or constitutive differences in resources allocation. Discriminant analyses helped to identify genotypic differences or similarities in the level of trait decoupling in relation to the strength of their correlation and heritability estimates. This information is useful in targeted improvement of traits directly contributing to micronutrient densities, yield components, and yield. New wheat ideotype(s) can be designed for larger grain yield potential under abiotic stress by manipulating yield components that affect kernels m−2 (e.g., number of tillers, number of florets per spikelet, and eventually spike fertility and harvest indices) without impacting nutrient densities and kernel weight, thus raising harvest index beyond its current maximum.


2021 ◽  
Vol 22 (4) ◽  
pp. 495-506
Author(s):  
Sergey N. Ponomarev ◽  
Mira L. Ponomareva ◽  
Gulnaz S. Mannapova ◽  
Lubov V. Ilalova

The aim of the study is to characterize winter triticale samples by protein content in grain and productivity, to identify sources of high protein content and high grain yield for use in breeding process. Experimental work was carried out in the conditions of Tatarstan Republic in 2013-2017. The collection of 93 varieties of winter triticale of Russian selection, obtained from the Federal Research Center “All-Russian Institute of Plant Genetic Resources"(VIR) was evaluated in field trials. Wide genetic diversity of the studied gene pool was demonstrated by grain protein content (11.69...16.15 %) and grain yield (277...579 g/m2). Protein content and grain yield were mostly determined by the growing conditions – the factor “year” (58.1 % and 61.8 %, respectively), with a relatively small share of the factor “genotype” (23.9 % and 15.4 %, respectively). Significant variation in the values of the studied indicators, both by genotype and by year, was observed. There were identified 19 sources of high protein content in grain (over 14.5 %) and 17 sources of high grain yield (over 510 g/m2), which showed a significant excess of the standard Bashkirskaya korotkostebelnaya. A group of samples with a relatively high protein content (13.8 ... 14.1 %) and yield higher than the average value (450...500 g/m2) was identified. The highest breeding value among the sources of high yield was shown by samples Zimogor, Kornet, Privada, Vodoley, 3/9 oh Ag 4418, and among the sources of high protein content – Kurskaya stepnaya, Mir, Student, Svyatozar. The listed variety samples additionally possessed a complex of positive features: high ear productivity, high full-scale weight and large grains. In varieties Dokuchaevsky 8 and Privada there was noted a favorable combination of significantly high levels of yield (542 and 527 g/m2, respectively) and protein content in the grain (14.28 and 13.93 %, respectively). The finding of a reliable moderate negative correlation (r = -0.682) between yield and grain protein content indicates that grain protein content can be increased by breeding methods at relatively high or medium yields of varieties.


2018 ◽  
Vol 17 (03) ◽  
pp. 289-292
Author(s):  
Pranesh ◽  
S. Ramesh

AbstractProtein energy malnutrition (PEM) is prevalent in south-east Asian countries including India. Breeding and introduction of grain protein-rich varieties of legumes such as dolichos bean is considered as cost-effective approach to combat PEM. Exploitation of genetic variability within germplasm accessions (GAs) and/or breeding populations is the short-term strategy for identification and delivery of protein-rich dolichos bean cultivars to cater to the immediate needs of the farmers and target population. A set of 118 dolichos bean genotypes consisting of 96 GAs and 20 advanced breeding lines (ABLs) and two released varieties (RVs) was field evaluated in augmented deign for dry grain yield per plant and their grain protein contents were estimated. The grain protein content among the genotypes ranged from 18.82 to 24.5% with a mean of 21.73%. The magnitude of estimates of absolute range, standardized range, and phenotypic coefficient of variation (PCV) for grain protein content was higher among GAs than those among ABLs + RVs. However, average grain protein contents of GAs were comparable to those of ABLs + RVs. Nearly 50% of the genotypes (mostly GAs) had significantly higher grain protein content than those of RVs, HA 3 and HA 4. The grain protein contents of the genotypes were poorly correlated with grain yield per plant. These results are discussed in relation to strategies to breed grain protein-rich dolichos bean cultivars.


2016 ◽  
Vol 12 (2) ◽  
pp. 279-284 ◽  
Author(s):  
SK Sarkar ◽  
MAR Sarkar ◽  
N Islam ◽  
SK Paul

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, to study the yield and quality of aromatic fine rice as affected by variety and nutrient management during the period from June to December 2013. The experiment comprised three aromatic fine rice varieties viz. BRRI dhan34, BRRI dhan37 and BRRI dhan38, and eight nutrient managements viz. control (no manures and fertilizers), recommended dose of inorganic fertilizers, cowdung at 10 t ha-1, poultry manure at 5 t ha-1, 50% of recommended dose of inorganic fertilizers + 50% cowdung, 50% of recommended dose of inorganic fertilizers + 50% poultry manure, 75% of recommended dose of inorganic fertilizers + 50% cowdung and 75% of recommended dose of inorganic fertilizers + 50% poultry manure. The experiment was laid out in a randomized complete block design with three replications. The tallest plant (142.7 cm), the highest number of effective tillers hill(10.02), number of grains panicle (152.3), panicle length (-1 -122.71cm), 1000-grain weight (15.55g) and grain yield (3.71 t ha-1) were recorded in BRRI dhan34. The highest grain protein content (8.17%) was found in BRRI dhan34 whereas the highest aroma was found in BRRI dhan37 and BRRI dhan38. The highest number of effective tillers hill(11.59), number of grains panicle (157.6), panicle length (24.31 cm-1-1) and grain yield (3.97 t ha-1) were recorded in the nutrient management of 75% recommended dose of inorganic fertilizers + 50% cowdung (5 t ha-1). The treatment control (no manures and fertilizers) gave the lowest values for these parameters. The highest grain yield (4.18 t ha-1) was found in BRRI dhan34 combined with 75% recommended dose of inorganic fertilizers + 50% cowdung, which was statistically identical to BRRI dhan34 combined with 75% of recommended dose of inorganic fertilizers + 50% poultry manure and the lowest grain yield (2.7 t ha-1) was found in BRRI dhan37 in control (no manures and fertilizers). The highest grain protein content (10.9 %) was obtained in the interaction of BRRI dhan34 with recommended dose of inorganic fertilizers which was as good as that of BRRI dhan38 and 75% of recommended dose of inorganic fertilizers + 50% poultry manure. The highest aroma was found in BRRI dhan38 combined with 75% recommended dose of inorganic fertilizers + 50% cowdung.J. Bangladesh Agril. Univ. 12(2): 279-284, December 2014


1982 ◽  
Vol 22 (115) ◽  
pp. 54 ◽  
Author(s):  
WM Strong

On the Darling Downs the growth and yield of a semi-dwarf wheat (cv. Oxley) under supplementary irrigation was increased by the application of up to 400 kg/ha of nitrogen (N) at planting. Nitrogen at 50 or 100 kg/ha applied at the boot stage to supplement 100 kg/ha applied at planting increased grain yield by 459 and 478 kg/ha, respectively. However, yields were still below those where all the N was applied at planting. In contrast, supplementary N (0, 25, 50 or 100 kg/ha) at flowering or after flowering generally did not increase grain yield. One exception to this was where only 50 kg/ha was applied at planting; an additional 100 kg/ha at flowering increased grain yield by 602 kg/ha. Applied at planting, more than 200 kg/ha of N was needed to produce premium grade wheat (i.e. protein content above 11.4%). To achieve this protein content where 100 kg/ha had been applied at planting an additional 100 kg/ha was needed at the boot stage or 50 kg/ha at flowering. Applied after flowering, up to 100 kg/ha of additional N produced wheat of a protein content too low to attract a premium payment. A similar quantity of N was assimilated whether the entire N application was applied at planting or where the application was split between planting and boot or flowering. Less N was assimilated when the application was split between planting and after flowering. More N was assimilated from soil than from foliar applications at the boot stage. Soil and foliar applications were equally effective at flowering in increasing the amount of N assimilated as well as the grain protein content. However, after flowering foliar application was the more effective method. The application of N at flowering to increase the protein content of this semi-dwarf cultivar is not an attractive commercial practice. The price ratio of premium to Australian Standard White wheat in recent years (<1.071 ) is less than that needed (1.0954-1.3013) to justify splitting the N application to lift grain protein content above 11.4% at the expense of yield.


Author(s):  
Gheith El-Sayed ◽  
◽  
Ola El-Badry ◽  

To evaluate the effect of nitrogen, zinc and iron as soil application on yield and yield component of wheat, the present study was conducted at Agricultural and Experimental Research Station at Giza, Faculty of Agriculture Cairo University, Egypt during 2015/2016 and 2016/2017 seasons. The experimental design was split-plot in randomized complete block design with three replications. Results showed that positive significant effect on plant height, number of spike/m2, spike length; number of grain per spike, grain yield per unit area in both seasons and grain protein content in one season were achieved by application of N and the micronutrients. Whoever, the highest significant in the above mentioned characters was obtained either by application the highest N levels (100kg N /fed.) or in addition to mixture of Zn and Fe. The interaction between the studied factors had significant effect on plant height and grain yield in both seasons as well as on grain protein content in the second season, where the highest values of these parameters were recorded by application of 100kg N/fed., Zn and Fe in mixture.


2000 ◽  
Vol 51 (6) ◽  
pp. 665 ◽  
Author(s):  
M Koç ◽  
C. Barutçular ◽  
N. Zencirci

High grain protein in durum wheat [Triticum turgidum ssp. turgidum L. conv. Durum (Desf.)] is one of the main goals of breeding programs. Landraces may be very useful germplasm for achieving this goal. To examine their potential as a source of high grain protein content, 11 genotypes, including 7 landraces, were evaluated in 8 environments. Environment, genotype, and the interaction of the two (G E) significantly influenced the variation in grain yield, grain protein content, and grain protein yield. The environmental effect was the strongest, mostly due to differences in water supply. Grain yields of the modern genotypes were higher than those of landraces. Yields of the modern genotypes tended to respond more strongly to the higher yielding environments, but they varied more than the yields of landraces. With the exception of VK.85.18, the grain protein content of the high-yielding genotypes was almost as high as that of the best landraces. Moreover, grain protein content of these bred genotypes tended to respond more strongly to the higher protein environments. Differences in grain protein yield were closely related to the differences in grain yield. The results indicate that it is possible to improve grain protein content without grain yield being adversely affected. The results also indicate that potential gene sources should be compared over a number of environments before they can be used as breeding material or as crop varieties producing high grain protein yields.


Author(s):  
N. V. Tupitsyn

The article lights cultivar studies. In global and domestic grain production since the 1950s last century have been used low-height wheat varieties. Agrobiological analysis of low-height varieties which characterized by resistance to lodging are presented. In addition, application of higher ratio of fertilizers allows to low-height forms better realized potential yield. In selection practice are known the low-height, high yield varieties with good protein content. It is possible to influence on grain protein content through additional feeding during formation and filling artificially increasing nitrogen concentration in vegetative bulk. Analysis of the cultivar changing through many decades in different countries, regions of our country allowed to identify common patterns of low-height varieties stress tolerance. Over the past 18-20 years in Russian agriculture have been observed negative trends due to deterioration professional and general culture of land users. It is known that based on the knowledge of biology, a scientifically based varietal agrotechnology is built, the essence of which is the minimum of risks, costs and maximum yield.


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