scholarly journals Optimization of Nitrogen Rate and Planting Density for Improving the Grain Yield of Different Rice Genotypes in Northeast China

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 555 ◽  
Author(s):  
Chanchan Zhou ◽  
Yuancai Huang ◽  
Baoyan Jia ◽  
Shu Wang ◽  
Fugen Dou ◽  
...  

Nitrogen fertilization and planting density are two key factors that can interactively affect the grain yield of rice. Three different types of rice cultivars—inbred Shendao 47, inbred Shendao 505, and hybrid Jingyou 586—were applied to investigate the effects of the nitrogen (N) rate and planting density (D) on the aboveground biomass, harvest index, leaf photosynthetic features, grain yield, and yield components using a split-split-plot design at two sites over two continuous years. The main plots were assigned to four nitrogen fertilizer rates: 0 (N0), 140 (N1), 180 (N2), and 220 (N3) kg ha−1 N; the subplots were assigned to three planting densities: 25 × 104 (D1), 16.7 × 104 (D2), and 12.5 × 104 (D3) hills ha-1, and the sub-subplots were assigned to three rice cultivars. The results showed that the grain yield had a significantly positive correlation with the stomatal conductance (Gs), net photosynthesis rate (Pn), transpiration rate (Tr), chlorophyll content (SPAD value), leaf area index (LAI), panicles per unit area, and spikelets per panicle. The N rate and planting density had significant interaction effects on grain yield, and the maximum values of Shendao 47, Shendao 505, and Jingyou 586 appeared in N3D2, N2D1, and N3D3, respectively. The higher grain yield of midsized panicle Shendao 47 was mostly ascribed to both panicles per unit area and spikelets per panicle. More panicles per unit area and spikelets per panicle primarily contributed to a larger sink capacity of small-sized panicle rice Shendao 505 and large-sized panicle rice Jingyou 586. We found that the treatments N3D2, N2D1, and N3D3 could optimize the contradiction between yield formation factors for Shendao 47, Shendao 505, and Jingyou 586, respectively. Across years and sites, the regression analysis indicated that the combinations of nitrogen fertilization of 195.6 kg ha−1 with a planting density of 22 × 104 hills ha−1, 182.5 kg ha−1 with 25 × 104 hills ha−1, and 220 kg ha−1 with 13.1 × 104 hills ha−1 are recommended for medium-, small-, and large-sized panicle rice cultivars, respectively.

1981 ◽  
Vol 97 (1) ◽  
pp. 125-134 ◽  
Author(s):  
E. O. Lucas

SUMMARYThe growth and development of two new maize hybrids (FARZ 27 and FARZ 23) were studied in density experiments located at two contiguous ecological zones in Nigeria. The range of planting density used was from 2·6 to 6·6 plants/m2. Within this range, the relationship between dry-matter yield and density was asymptotic at final harvest. At the forest location of Jago (7·3 °N, 4·2 °E), both varieties attained optimum grain yield at planting density of 4·4 plants/m2, while at the derived savannah location of Alagunmu (7·8 °N, 4 °E), FARZ 23 attained optimum grain yield at 4·4 plants/m2and FARZ 27 attained its optimum grain yield at 6·6 plants/ma2. This response of the new maize varieties to density treatments indicates that they could be planted at higher densities than are now used in the country.Differences between varieties did not quite reach statistical significance but, at both locations, FARZ 27 produced more dry matter and grain per unit area than FARZ 23. FARZ 27 gave its higher grain yield mainly by producing more seeds per unit area than FARZ 23. Physiological measurements like net assimilation rate, crop growth rate and leaf area index were also higher for FARZ 27, although there were no significant differences between the varieties at most sampling dates. The partition of dry matter was identical in both varieties, although FARZ 27 showed a slightly better balance by partitioning more assimilates to the grain. Also, there was an indication of remobilization of stored assimilates from the stem to the grain in both varieties. Both varieties produced more dry matter and grain at the derived savannah location of Alagunmu than at the forest location of Jago. Physiological measurements were also higher at the derived savannah location.


1982 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. U. Remison ◽  
E. O. Lucas

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.


2021 ◽  
Vol 34 (4) ◽  
pp. 780-790
Author(s):  
PAULO VINICIUS DEMENECK VIEIRA ◽  
PAULO SÉRGIO LOURENÇO DE FREITAS ◽  
ANDRÉ LUIZ BISCAIA RIBEIRO DA SILVA ◽  
ANA CLAUDIA SOSSAI SOUZA ◽  
JULIANA MARQUES VORONIAK

ABSTRACT Sorghum is a commonly grown plant in the Central-West region of Brazil as a second crop; however, it is grown almost exclusively as a second crop after maize in the state of Paraná (South region). The growth of sorghum crops is an option for areas or times in which the growth of maize crops can be risky. Thus, the objective of this work was to evaluate the agronomic characteristics of eight sorghum hybrids (ADV-123, ADV-114, 1G100, 50A10, 1G244, 50A40, 50A50, and 1G282) grown in three sowing times in two agricultural years: 2014 (February 20, March 02, and March 03) and 2015 (February 09, February 19, and March 01), and four maize hybrids in 2014 (DKB-330-Pro, P-3431-HX, Formula-TL, and AG-9010-Pro) and five maize hybrids in 2015 (DKB-330-Pro, P-3431-HX, Formula-TL, DKB-275-Pro, and DKB-290-Pro), in the same sowing times used for sorghum. A randomized complete block experimental design with a split-plot factorial arrangement was used, with the sowing times in the plots and the hybrids in the sub-plots. The variables evaluated were: number of days from sowing to flowering, leaf area index, 1,000-grain weight, grain yield, number of spikelets per panicle, for the sorghum crop; and number of rows per ear and number of grains per row, for the maize crop. The comparison between the two crops showed that the sorghum maintained higher production stability in the different sowing times.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 269 ◽  
Author(s):  
Guangzhou Liu ◽  
Yunshan Yang ◽  
Wanmao Liu ◽  
Xiaoxia Guo ◽  
Jun Xue ◽  
...  

Increasing planting density is an important practice associated with increases in maize yield, but densely planted maize can suffer from poor light conditions. In our two-year field experiments, two morphologically different cultivars, ZD958 (less compact) and DH618 (more compact), were planted at 120,000 plants ha−1 and 135,000 plants ha−1, respectively. We established different leaf area index (LAI) treatments by removing leaves three days after silking: (1) control, no leaves removed (D0); (2) the two uppermost leaves removed (D1); (3) the four uppermost leaves removed (D2); (4) the leaves below the third leaf below the ear removed (D3); (5) the leaves of D1 and D3 removed (D4); (6) the leaves of D2 and D3 removed (D5). Optimal leaf removal improved light distribution, increased photosynthetic capacity and the post-silking source-sink ratio, and thus the grain yield, with an average LAI of 5.9 (5.6 and 6.2 for ZD958 and DH618, respectively) for the highest yields in each year. Therefore, less-compact cultivars should have smaller or fewer topmost leaves or leaves below the ear that quickly senesce post-silking, so as to decrease leaf area and thus improve light distribution and photosynthetic capacity in the canopy under dense planting conditions. However, for more compact cultivars, leaves below the ear should senesce quickly after silking to reduce leaf respiration and improve the photosynthetic capacity of the remaining top residual leaves. In future maize cultivation, compact cultivars with optimal post-silking LAI should be adopted when planting densely.


Author(s):  
K K Ayisi ◽  
L Munjonji ◽  
K V Masekela

Despite the importance of common bean (Phaseolus vulgaris) in human nutrition, its production in developing countries is far below consumption rates. A study was established to understand the yield performance and physiological response of common bean under three farmers’ field in the Limpopo Province. The results revealed significant variation in grain yield and biomass between the locations. Physiological parameters such as the Normalised Difference Vegetation Index (NDVI), Leaf Area Index (LAI), SPAD value and leaf gas exchanges were strongly influenced by the location, the crop growth stage and crop management. Dry bean crop performance was significantly lower at Masemola. Grain yield at Masemola was 30% less than that achieved at Dalmada and Mokopane. NDVI and LAI were also consistently lower at Masemola when compared to the other locations. This study revealed that poor yields by emerging farmers in dry areas are due to poor agronomic and irrigation management.


Irriga ◽  
2010 ◽  
Vol 15 (4) ◽  
pp. 386-400 ◽  
Author(s):  
Pryscilla Ferrraz Câmara Monteiro ◽  
Rubens Angulo Filho ◽  
Rodrigo Otávio Câmara Monteiro

Este trabalho teve como objetivo analisar, em condições de campo, o efeito de lâminas de irrigação e de doses de nitrogênio sobre os parâmetros biofísicos da cultura do feijoeiro. O experimento foi conduzido na área experimental da Fazenda Areão – ESALQ/USP, localizada no município de Piracicaba, SP, de setembro a dezembro de 2007, utilizando-se o cultivar de feijão Pérola. O manejo da irrigação foi feito via clima, baseado em dados obtidos da estação meteorológica localizada próxima à área experimental. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas, sendo que nas parcelas foram alocados os tratamentos relacionados com os níveis de irrigação (179,5; 256,5; 357,5 e 406,2 mm) e, nas subparcelas, os tratamentos relativos às doses de nitrogênio (0; 80 e 160 kg ha-1), totalizando assim doze tratamentos em cada bloco, dispostos em 48 parcelas experimentais. As variáveis biofísicas analisadas foram: altura das plantas, índice de área foliar, produtividade de grãos, número de vagens por planta e número de grãos por vagem. O fator água influenciou todas as variáveis biofísicas, encontrando-se valores maiores nas plantas que receberam maiores quantidades de água. A adubação nitrogenada não influenciou as variáveis biofísicas da cultura do feijão.   PALAVRAS-CHAVE: Phaseolus vulgaris L., evapotranspiração, manejo de irrigação, produtividade de grãos     MONTEIRO, P.F.C.; ANGULO FILHO, R.; MONTEIRO, R.O.C. IRRIGATION AND NITROGEN FERTILIZATION EFFECTS ON BEAN  AGRONOMIC VARIABLES     2 ABSTRACT   The objective of this research was to analyze the effect of irrigation levels and nitrogen fertilization on the common bean biophysical parameters. The experiment was carried out at  the University of São Paulo (ESALQ/USP),  Piracicaba, São Paulo, Brazil, from September to December, 2007, using Perola cultivar. Irrigation schedule was based on the weather data  given  by  meteorological station located near the experimental area. The experimental design was randomized blocks, with split plots, having 12 treatments, being: 4 irrigation levels (179.5; 256.5; 357.5 e 406.2 mm) and 3 nitrogen rates (0; 80 e 160 kg ha-1);  and four repetitions, totalizing 48 plots. The biophysical variables analyzed were: plant height, leaf area index, grain yield, the pod number per plant, and the grain number per pod. The irrigation influenced the biophysical variables and the largest medium values of plants were found on those that received the largest irrigation depth. The nitrogen fertilization did not influence the biophysical variables. KEYWORDS: Phaseolus vulgaris L., evapotranspiration, irrigation management, grain yield  


2008 ◽  
Vol 13 (1-2) ◽  
pp. 170 ◽  
Author(s):  
P. MÄKELÄ ◽  
S. MUURINEN ◽  
P. PELTONEN-SAINIO

The Finnish growing season is particularly short, with an intensive growth period, unfavourable rainfall distribution and frequently occurring fluctuations in climate that affect crop growth and yield formation. A three-year study was conducted in the field to determine the contribution of alterations in canopy structure, tillering and stem elongation among dwarf (D), semidwarf (SD) and tall (T) oat (Avena sativa L.) lines to yield formation. Yield components, leaf characteristics and straw traits were measured from six oat lines (D lines Pal and Grane, SD lines Hja 76416 and Salo, and T lines Veli and Jalostettu maatiainen) separately on the main shoot and tillers. Results indicated that long leaf area duration and high leaf area index were associated with increased grain yield probably due to more persistent and active assimilation. Also, higher number of leaves increased the grain yield. Higher peduncle, straw and node weights associating with increased grain yield may result from more abundant assimilate reserves; however, the longer the straw and peduncle, the lower the grain yield, which may result from increased lodging of SD and T lines. The traits contributing most to the grain yield varied greatly from year to year. It is concluded that no single dominant trait determined grain yield, since yield is a product of several different traits. SD lines seemed to be most promising for further breeding programs on the basis of their growth pattern and yielding ability.;


2021 ◽  
Vol 25 (01) ◽  
pp. 43-51
Author(s):  
Qinglong Yang

To better understand the accumulation and transport of substances under different planting densities, the adaptation of maize root and leaf in response to increasing planting densities was investigated. In this two-year filed study, three maize varieties, Fumin108 (FM), Xianyu335 (XY) and Dika159 (DK), were sown under three different planting densities: 15,000 (D1), 60,000 (D2) and 90,000 plants ha-1 (D3) during 2018 and 2019. Increase in planting density gradually increased leaf area index along with reduced leaf area and net photosynthetic rate of individual leaves. In the 0–20 cm soil layer, the average root dry matter decreased by 55.88 and 80.92%, and the average root number decreased by 31.18 and 38.71% under D2 and D3, respectively, compared with D1. With increase in planting density, yield and dry matter per plant of maize gradually decreased while yield and dry matter per ha was increased with increase in D1-D2 density and then flattened in D2-D3 density. Compared with D1, two-year average yield per plant was decreased by 34.10 and 51.87% under D2 and D3, respectively. The difference in the number of roots of XY, FM and DK were not significant, so change in variety did not alleviate the decrease in the number of roots. At higher planting densities (above D2), the increase in density did not increase per ha grain yield. In conclusion, the suitable plant density was about 60,000 plants ha-1 to harvest more yield of spring maize while density higher than that reduced leaf area and photosynthesis per plant. Moreover, leaf area, root number and net photosynthesis per plant was higher in lower planting density coupled with overall less yield on ha basis and thus seemed wastage of soil nutrients and light resources. © 2021 Friends Science Publishers


1972 ◽  
Vol 12 (55) ◽  
pp. 165 ◽  
Author(s):  
JR Syme

Four wheats of similar maturity were compared at two seed rates and two nitrogen levels. The cultivars were two high-yielding Mexican semi-dwarf wheats, Pitic 62 and accession WW 15, one local semidwarf crossbred, HMR, and one Australian variety, Robin. At each of two sites WW 15 yielded most grain and Robin the least. Yield components, growth, development and leaf characters were studied at one site. The semi-dwarf wheats had a higher proportion of ear weight at anthesis and set more grains per ear and per unit area. The high yield of WW 15 was associated with many grains per ear and a dense ear population. There were relatively small differences in total dry matter yield and leaf area index. WW 15 formed the most leaves on the main stem, had the shortest period from flag leaf emergence to anthesis and showed delay in the senescence of its flag leaves. Its leaves were also particularly narrow and small. The early effects of a higher seed rate on crop growth diminished with time in the main experiment but resulted in a small increase in grain yield. Nitrogen stimulated growth throughout the season, but the increased vegetative potential was not fully reflected in grain yield. Both nitrogen and the higher seed rate hastened flag leaf senescence.


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