scholarly journals Construction of dominant rice population under dry cultivation by seeding rate and nitrogen rate interaction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hao Jiang ◽  
Tebogo Thobakgale ◽  
Yunzhe Li ◽  
Liwei Liu ◽  
Qingwang Su ◽  
...  

AbstractThis study used the rice cultivar Suijing 18 to investigate the effects of morphological characteristics, photosynthetic changes, yield, as well as nitrogen absorption and utilization. The interaction between seeding rate and nitrogen rate was also assessed to identify the most suitable values of the dominant population for both factors under dry cultivation. Furthermore, the photosynthetic physiological characteristics of the upper three leaves in the dominant population were also explored. The results showed that a combination of 195 kg/ha seeding rate and 140 kg/ha nitrogen rate achieved high yield, high nitrogen utilization, and moderate morphological characteristics. This was achieved by a coordination of the combined advantages of population panicle number and spikelets per panicle. The photosynthetic potential of the population was improved by coordinating the reasonable distribution of light energy in the upper three leaves, which led to the emergence of a dominant rice population under dry cultivation.

2021 ◽  
Author(s):  
Hao Jiang ◽  
Tebogo Thobakgale ◽  
Yunzhe Li ◽  
Liwei Liu ◽  
Qingwang Su ◽  
...  

Abstract In order to construct the dominant population of rice under dry cultivation, the external characteristics of the population and the photosynthetic physiological characteristics of the upper three leaves were investigated. In this study, a double factor interaction method of seeding rate and nitrogen rate was used to construct the dominant population of rice under dry cultivation. We determined 195 kg·ha-1 seeding rate and 140 kg·ha-1 nitrogen rate as the appropriate configuration. To achieve high yield, high nitrogen utilization and moderate morphological characteristics by coordinating the comprehensive advantages of population spike number and spike grain number, and to increase the photosynthetic potential of the population by coordinating the reasonable distribution of light energy in the upper three leaves to construct the dominant population of rice under dry cultivation. Photosynthetic potential of 105.55m2·d/m2, light energy interception rate of 31.21% in the inverted second leaf and plant height of 101 cm at 10 days after flowering were important external characteristics of the dominant population of rice under dry cultivation. The ability of the inverted second leaf to intercept light energy is the basis for ensuring the photosynthesis of the population. The simultaneous coordination of photosynthetic enzyme activity, net photosynthetic rate and chlorophyll content in the inverted second leaf is an important physiological characteristic of the photosynthetically dominant group. The variation of photosynthetic physiological indexes in the inverted second leaf was characterized by ‘from genes to enzyme activity to net photosynthetic rate and chlorophyll, and the spatial variation was from the upper leaves to the lower leaves’. ‘ Protect the flag, promote the second, stabilize the third ’ (Maintaining photosynthetic capacity of the flag leaf , promoting photosynthetic enzyme activity in the inverted second leaf, and stabilizing photosynthetic gene expression in the inverted third leaf ) is an important tool to construct the dominant population of rice under dry cultivation. These studies have significant implications for the future construction of dominant rice under dry cultivation in different regions and provide an important basis for the study of the regulatory mechanisms of photosynthetic pathways in different leaf positions.


2008 ◽  
Vol 88 (3) ◽  
pp. 485-500 ◽  
Author(s):  
G. P. Lafond ◽  
B. Irvine ◽  
A. M. Johnston ◽  
W. E. May ◽  
D. W. McAndrew ◽  
...  

Flaxseed is known to have significant health benefits in human nutrition and when included in animal rations. There is pressing need to improve flaxseed production to meet the growing demand. The objective was to study the effects of three seeding rates (22, 45 and 67 kg ha-1), two seeding dates (early May and late May), three rates of nitrogen (66, 100 and 133% of recommended) and three cultivars (Norlin, AC McDuff and CDC Valour) and at five locations representative of the flax-growing area of the Canadian prairies from 1999 to 2001. The variables of interest were plant density, seed yield and yield formation, seed oil content and oil quality. Plant establishment was always highest with Norlin, but bolls m-2 was similar between the three cultivars. Plant density was always highest with the later plantings. No overall effect of seeding date was observed on grain yield, but the site-year by seeding date interaction showed that the later planting was favoured by the most northerly sites and early planting at the most southerly sites. The sites intermediate in latitude showed little response to seeding date. This finding provides important information with respect to the inclusion of flax in cropping systems depending on the latitude and deciding on the order of planting. Later planting resulted in a small decrease in oil content. Seed yields were increased with seeding rates going from 22 to 45 kg ha-1, which corresponded to plant populations > 300 plants m-2, with no increases thereafter. Increases in seeding rates always reduced the number of bolls plant-1 with little effect on seeds boll-1. Seeding rate had no effect on seed oil quantity and quality and maturity. A seed yield increase was observed with nitrogen when going from 66 to 100% of the recommended rate with no increases past 100%. Adding nitrogen resulted in a small drop in seed oil content. The seeding date × nitrogen rate interaction revealed a lack of response to nitrogen with the later planting date beyond 66% of the recommended N rate, suggesting reduced nitrogen rates with later plantings are possible. The absence of a site-year by seeding date by nitrogen rate interaction implies that findings of this study can be applied to a wide geographical area. In conclusion, attention needs to be given to seeding rates to target plant density > 300 plants m-2. Even with the high seeding rates, the target plant population was achieved only 60 and 73% of the time for the early and late planting, respectively. Using soil test recommendations for nitrogen will maximize seed yields under most situations. Best agronomic practices to maximize seed yield were found to maintain adequate seed oil quality and quantity. Key words: Linum usitatissimum L., nitrogen rate, seeding rate, seeding date, cultivar


2016 ◽  
Vol 24 (2) ◽  
pp. 157
Author(s):  
Ahmad - Muliadi

Tungro disease is one of the important diseases of rice because it has a high potential for causing damage. The use of varieties resistant to the tungro disease effectively prevent an explosion tungro disease. Testing of promising lines resistant to the tungro at several locations is a stage in the breeding program before a line is released as a new variety that has resistance to tungro disease, as well as having the potential for high yields and good adaptation at several locations. Six of tungro resistant promising line (OBSTG02-137, OBSTG02-124, OBSTG02154, OBSTG02-130, OBSTG02-56, dan OBSTG02-37) and four check varieties (Inpari 9 Elo, Tukad Unda, Ciherang, and IR64) were evaluated for their yield potential and adaptability at 16 locations in tungro endemic area during the dry season of 2011-2013. The experiment was arranged in a randomized block design with 3 replications. Each line were transplanted in 4 m x 5 m plot size with plant spacing 25 cm x 25 cm. Observation were made on yield, 50% flowering date, plant heights, panicle number per hill, number filled and unfilled spikelets per panicle, and weigh of 1000 grains in gram. The results showed that effect of genotype x location interaction was significantly different for all component observed. Based on the performance of grain yield and yield components obtained, four lines i.e. OBSTG02-137 (6.74 t/ha), OBSTG02-124 (6.20 t/ha), OBSTG02-154 (6.37 t/ha ), and OBSTG02-130 (5,92 t/ha) has a high yield with the support of filled grain number and weight of 1000 seeds is high. Based on the combined value of bi and the general average of yield, then line OBSTG02-137, OBSTG02-154, and OBSTG02-130 were suitable to adapt to all environments, OBSTG02-124 is adapted in an optimal environment, OBSTG02-56 and OBSTG02-37 were adapted to the less productive environment.


Author(s):  
А. А. Fadeev ◽  
Z. А. Nikonova

The results of study of the 12 year cycle of studies on the only in Russia collection of hops ordinary (Humulus lupulus L.), which contains 250 samples from different regions of Russia and 17 foreign countries. The number of process varieties, composition and origin, it is unique and corresponds to world level. A collection of accessions of hops is a population of female plants with a set of phenological, morphological and economic importance of signs. In the article, the estimation of the collectible varieties of hops at different ripeness groups according to phenological and morphological characteristics according to the method of test for distinctness, uniformity and stability. As the result of the research the Common Hop (Humuluslupulus) sorts were classified in accordance with their maturity time as early maturity (less than 100 days) – 10%, middle-early (101…110 days) – 14, middle duration (111…120 days) – 40, middle-late (121…130 days) – 10% and slow-maturing (more than 130 days) – 26%. Each group has a phenotypic and morphologies features. The early maturity, middle-early and middle duration varieties with vegetative season approximately 120 days are more adaptive to the conditions of the Chuvashia and central part of the Russia and provide obtaining high yield of the hop cones.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 558
Author(s):  
Xing Huang ◽  
Su Jang ◽  
Backki Kim ◽  
Zhongze Piao ◽  
Edilberto Redona ◽  
...  

Rice yield is a complex trait that is strongly affected by environment and genotype × environment interaction (GEI) effects. Consideration of GEI in diverse environments facilitates the accurate identification of optimal genotypes with high yield performance, which are adaptable to specific or diverse environments. In this study, multiple environment trials were conducted to evaluate grain yield (GY) and four yield-component traits: panicle length, panicle number, spikelet number per panicle, and thousand-grain weight. Eighty-nine rice varieties were cultivated in temperate, subtropical, and tropical regions for two years. The effects of both GEI (12.4–19.6%) and environment (23.6–69.6%) significantly contributed to the variation of all yield-component traits. In addition, 37.1% of GY variation was explained by GEI, indicating that GY performance was strongly affected by the different environmental conditions. GY performance and genotype stability were evaluated using simultaneous selection indexing, and 19 desirable genotypes were identified with high productivity and broad adaptability across temperate, subtropical, and tropical conditions. These optimal genotypes could be recommended for cultivation and as elite parents for rice breeding programs to improve yield potential and general adaptability to climates.


2020 ◽  
pp. 38-42
Author(s):  
Victoria Igorevna Starchak ◽  
Valery Ivanovich Zhuzhukin ◽  
Ekaterina Aleksandrovna Zhuk ◽  
Vera Valeryevna Bychkova

In modern conditions, the need for cultivation of grain sorghum in regions with insufficient moisture is determined by its high yield and grain quality. For practical breeding, with the objective of assessing linkages 19 morphological and physiological traits model of the population including 15 varieties and 2 promising lines of grain sorghum that is created in the Russian Research and Design Technological Institute of Sorghum and Maize. The biochemical composition of the grain of the objects of research is presented graphically. A different degree of variation in the characteristics of grain sorghum was revealed: very strong (V> 40,0%) - productive bushiness, number of grains from 1 panicle; strong (20,0% <V <40,0%) - the width of the panicle, the extension of the panicle leg, the thickness of the upper internode, the area of the flag leaf, the area of the fourth on top of the leaf, the mass of the grain from 1 panicle; weak (V <10,0%) - the height of the plants after 30 days, the height of the plants during maturation. The group with an average degree of variation (10.0% <V <20.0%) includes all other signs measured in the experiment. Factor analysis was used to optimize, interpret the calculated matrix of correlation coefficients. In the analysis of the correlation coefficient matrix, hypothetical factors with a contribution of more than 5% to the accumulated variance are calculated. The first hypothetical factor is determined by the high effects of morphophysiological features. The second factor is largely due to the contribution of plant height 30 days after germination and the extension of the panicle legs. Plant height at maturity, weight of 1000 grains make the greatest contribution to the third factor. The width of the panicle makes the greatest contribution to the accumulated dispersion of the fourth factor. The fifth factor is determined by the effects of plant height at the beginning and end of vegetation, as well as the total contribution of all studied features.


1959 ◽  
Vol 39 (3) ◽  
pp. 355-363 ◽  
Author(s):  
R. S. Fulkerson

The effects of six seeding rates and five row spacings on seed yield, seed quality and the yield components—number of fertile culms per square foot, number of seeds per culm and seed weight were studied in orchard grass.Row width had a marked effect on seed yield each year. Rate of seeding affected seed yield to a lesser extent and a row width × seeding rate interaction did occur. Seeding rates and row width caused small relatively unimportant differences in seedling establishment and early seedling vigour only in the third harvest year. Considering seed yield, seed quality and the ease of weed control, the best treatment combination appeared to be a seeding rate in the area of [Formula: see text] in 14-in. rows for stands to produce for 2 or 3 years.Seed yield was positively and closely correlated with the number of fertile culms in the first 2 crop years but a negative relationship was found in the third crop year. Seed weight was negatively correlated with seed yield. The number of seeds per panicle was closely associated with yield in the third crop year and negatively correlated with seed weight and culm numbers.


1995 ◽  
Vol 10 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Didier Jézéquel ◽  
Jean Guenot ◽  
Noureddine Jouini ◽  
Fernand Fiévet

A novel and easy route for preparing submicrometer particles of zinc oxide, involving hydrolysis of zinc salt in a polyol medium, is proposed. Zinc acetate dihydrate and diethyleneglycol appear to be the best candidates for obtaining a high yield of particles with well-defined morphological characteristics. Monodisperse spherical particles in the submicrometer range (0.2−0.4 μm) have been obtained for a salt concentration less than 0.1 mol 1−1. The particle size depends mainly on the heating rate. The particles are microporous (surface area: 80 m2 g−1) and are formed by aggregation of small crystallites (10 nm). Calcination at moderate temperature drastically reduces this porosity without significant interparticle sintering. At higher concentration, no aggregation occurs and tiny single crystallite particles are obtained.


2011 ◽  
Vol 62 (2) ◽  
pp. 115 ◽  
Author(s):  
W. K. Anderson ◽  
A. J. van Burgel ◽  
D. L. Sharma ◽  
B. J. Shackley ◽  
C. M. Zaicou-Kunesch ◽  
...  

When new wheat cultivars are released for commercial production it is desirable to assist farmers to maximise the yield advantage by providing information about their responses to agronomic practices such as seeding rate and nitrogen (N) fertiliser. Over 3 years in 22 field experiments in the Mediterranean-type environment of Western Australia the response to seed rate and applied N fertiliser of current and recently released wheat cultivars was measured in factorial experiments under rain-fed conditions. A cross-site analysis showed that the environment × cultivar (location and year) or management (seed rate and N rate) interactions were relatively minor, explaining only 5% or less of the yield variation, in contrast to 89% accounted for by the environment. The analyses of individual experiments revealed that cultivars interacted more often with seeding rate (12 sites) than with applied N fertiliser rates (4 sites). Further, despite a frequent occurrence, the cultivar × seed rate interaction had only a marginal practical significance because the cultivar rankings at a site varied with season and the differences in optimum plant population were greater between sites and seasons than between cultivars at a site. The number of sites with positive and significant cultivar × N rate interaction was insufficient to generalise about the validity of the responses. The lack of any large differences between cultivars for their response to either seed rate or N rate implies the presence of a high inherent ability for compensation among yield components, thereby enabling the cultivars to exhibit an apparently high similarity for response to input levels. As such, it was not possible to generalise across environments in making clear suggestions for farmers to follow in respect of managing new cultivars differently from each other. It was concluded that despite the apparent desirability of providing information about differences between new and existing cultivars in their responses to seed and N rates at the time of release, they are more likely to be found where the differences between the cultivars are large, the testing sites are chosen so as to reduce the yield variance, and the yield level achieved in the experiments is above 2 t/ha.


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