RELATIONSHIP BETWEEN SPRING VIGOR AND GRAIN YIELD IN CORN

1974 ◽  
Vol 54 (1) ◽  
pp. 65-69 ◽  
Author(s):  
F. B. GLENN ◽  
T. B. DAYNARD ◽  
J. T. WATSON

In an experiment designed to study the relationship between seedling vigor and grain yield in corn (Zea mays L.), 25 single-cross hybrids, of a range in spring vigor (6 involved crosses between inbred parents of high seedling vigor, 6 were crosses between parents of low seedling vigor, and 13 were crosses between inbreds of high and low vigor) were grown in test for 2 yr near Woodstock, Ontario. In the 1st yr, hybrids were evaluated for differences in: rate of emergence; visual vigor rating; plant height, dry weight, and leaf number at several dates during early vegetative development; leaf area index (measured after pollination); and final grain yield. In the 2nd yr, hybrids were evaluated for differences in seed size (weight/kernel), visual vigor rating, and grain yield. No differences were detected among hybrids in rate of emergence. In the 1st yr, the visual vigor score was positively related to early plant height, but not to any of the other measures of seedling vigor. A positive relationship between seed weight and visual vigor rating was observed in the 2nd yr. The mean grain yield of the three groups of hybrids corresponded directly with their initial vigor rating in the 1st yr (i.e., crosses among high vigor inbreds outyielded high × low crosses; high × low crosses outyielded low × low), but not in the 2nd yr. Among individual genotypes, no relationship was evident between any measure of spring vigor and grain yield, in either year.

1972 ◽  
Vol 52 (3) ◽  
pp. 315-319 ◽  
Author(s):  
D. J. MAJOR ◽  
R. B. HUNTER ◽  
L. W. KANNENBERG ◽  
T. B. DAYNARD ◽  
J. W. TANNER

Grain yield of 44 single crosses and their component inbreds of corn (Zea mays L.) was determined over a wide range of plant populations. Yield was determined for inbreds and single cross hybrids at unit intervals of leaf area index (LAI) of 1–4. Mean inbred yield was no greater than 60% of the mean hybrid yield, regardless of whether yields were compared at a common plant density or LAI. Optimum LAI (LAI where grain yield was at its maximum) was higher for the hybrids than for the inbreds.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
GABRIEL WIEST ◽  
CASSIANO SPAZIANI PEREIRA ◽  
IVAN VILELA ANDRADE FIORINI ◽  
MATEUS EMANUEL SCHOFFEN ◽  
HELCIO DUARTE PEREIRA ◽  
...  

Nitrogen is the most required element by the maize crop and suffers the greatest losses due to its inappropriate management, mainly when the urea is used as a source of nitrogen. The objective of this work was to evaluate the efficiency of urea sources, with or without urease inhibitor, in sidedress fertilization of commercial single-cross in off-season in Sinop/MT. The experimental design was completely randomized blocks, in factorial scheme 3 x 5, with 3 replications. The first factorwas three side-dress fertilization: witness (without fertilizer); fertilization with 250 kg ha-1 of urea and fertilization with 250 kg ha-1 of urea in the presence of urease inhibitor (UREMAX®) NBPT. The second factor was five single-crosses: 2B433, DKB255, DKB335, NS45, and SYN522. Vegetative development and yield characteristics were evaluated. The Nitrogen sources did not affect the plant height, stem diameter, and foliar area index, only the chlorophyll content in the leaves. For the yieldcomponents, there is an effect of fertilization on the number of grain rows and grain yield. The singlecrosses differ among them in vegetative development and yield characteristics. The Nitrogen in sidedress, in the conditions of this study, using the urea with urease inhibitor, increased the fertilization efficiency and raised the grain yield. The single-crosses DKB 255, 2B433, and SYN 522, with the treatment based on UREMAX®, reached the highest yield.


2018 ◽  
Vol 10 (12) ◽  
pp. 233
Author(s):  
Ricardo S. Okumura ◽  
Francisco F. A. Mota ◽  
Yweenns T. Ferraz ◽  
Daiane de C. Mariano ◽  
Cândido F. de Oliveira Neto ◽  
...  

Among the nutritional requirements of corn crop, nitrogen (N) is the element required in greater quantity and, directly responsible for increase or decrease in grain production. The aims of study were to evaluate the effects of applied N rates in topdressing in development and production of corn in Brazilian Amazon. The experiments were installed on 20 January 2014 (Capitão Poço city) and 24 January 2014 (Paragominas city). The experimental design was a randomized block design in a 5 × 2 factorial scheme, consisting of five N rates of topdressing applications (0; 40; 80; 120; and 160 kg ha-1 of N) and two corn double hybrids (AL-Avaré; and AL-Bandeirante), with four replicates. The evaluations of vegetative development components (plant height, height of ear insertion, and leaf area index) were carried out at time of male flowering stage, while evaluations of grain yield components (number of grains per row, grain yield, and harvest index) carried out during the harvest period. The corn hybrids, AL-Avaré and AL-Bandeirante, independent of experimental site, showed the highest technical efficiency between the rates of 80 to 120 kg ha-1 of N. Based on the information obtained in regression analysis verified that Paragominas experiment showed greater vegetative development (plant height, LAI, ear height, number of grains per row, ear length) and higher grain yield compared to corn developed in Capitão Poço experiment.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.


1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.


2021 ◽  
Vol 5 (2) ◽  
pp. 428-439
Author(s):  
K. M. Ladan ◽  
M. G. Abubakar ◽  
J. Suleiman

The Study was conducted to evaluate the effect of solid and liquid organic fertilizer on growth and yield of rosselle in 2016 cropping season at Institute of Agricultural Reserve Zaria, Samaru (11011’N 07038E and 686m) and Institute of Horticultural Research Farm Bagauda (12000’N 8031”Em 488m) in Northern Guinea Savannah and Sudan Savannah Ecological Zones of above sea level Nigeria. Treatments consisted of four levels of solid poultry manure (0.0, 1.0, 2.0 and 3.0) tons/ha and five levels of liquid organic manure from Grand Total Organic Fertilizer Limited (0.0, 0.5, 1.0, 1.5 and 2.9) litres/ha, which were factorially combined in a randomized complete block design (RCBD) and replicated three times. Data on growth parameter were collected on plant height (cm), plant dry weight (g), leaf Area index crop growth rate (CGR) Relative Growth Rate (RGR) and Net assimilation rate (NAR) while data on yield parameters like number of calyx per pant, 100 seed weight (g) and  calyx yield per hectare kg/ha were collected. Results showed that plant height, plant dry weight(g), 100 seed weight(g) and calyx dry yield kg/ha had a significant increase with application of 2.0 litres/ha of liquid fertilizer than other rates. While application of solid poultry manure at 3.0ton/ha significantly increases plant height, net assimilation rate, leaf area index and calyx dry weight when compared with other rates. From the results obtained, the combination of 2.0 litres/ha liquid organic fertilizer and 3.0 ton/ha solid poultry manure produce the highest calyx yield at both location.


1979 ◽  
Vol 59 (3) ◽  
pp. 585-601 ◽  
Author(s):  
G. O. EDMEADES ◽  
T. B. DAYNARD

In an attempt to explain plant-to-plant variation in dry weight of maize (Zea mays L.), a computer program was developed to predict daily assimilation per plant and its distribution throughout the shoot at flowering. Inputs to the model were meteorological data, photosynthetic rate-irradiance curves, measurements of intraplant assimilate distribution at flowering, and the positions of individual leaves of plants grown in the field at three densities (50 000, 100 000 and 150 000 plants/ha). Dry weights were recorded on these same plants following black layer formation. Predicted effects of plant density on shoot growth compared favorably with available data. The correlation coefficient between predicted assimilation 1 day after anthesis and grain yield on the same plants, with treatment effects removed, was 0.67 (N = 360). The coefficient of variation of predicted assimilate flux per plant increased significantly with increasing density, and the fluxes were generally normally distributed. Results supported the concept of a threshold assimilation rate per plant below which grain would not normally form, and this appears to be the cause of the bimodal frequency distribution of grain yield per plant observed at high densities.


2008 ◽  
Vol 146 (3) ◽  
pp. 287-300 ◽  
Author(s):  
P. MONNEVEUX ◽  
C. SANCHEZ ◽  
A. TIESSEN

SUMMARYThe use of secondary traits such as number of ears per plant, grains per ear, the interval from anthesis to silking, leaf senescence and leaf rolling, together with management of water stress and recurrent selection, have permitted a considerable increase in drought tolerance in the CIMMYT maize source germplasm populations Drought Tolerant Population (DTP) and La Posta Sequía (LPS). Inbred lines were extracted from DTP C9 and LPS C7 cycles and then used for generating single and three-ways hybrids. These were evaluated under normal irrigation and managed drought conditions. A weak, and in some cases no longer significant, correlation was found between grain yield and the traits initially used for selection. Most prominently, the relationship between anthesis-silking interval and grain yield became much weaker in these hybrids. Conversely, significant negative correlations were found between tassel dry weight and grain yield. Three-way hybrids involving two DTP lines yielded more than those involving one only, indicating the feasibility of gene pyramiding for drought tolerance. Overall, the results suggested that the relationship between grain yield and secondary traits has been modified due to continuous selection in the LPS and DTP populations. Some long-established secondary traits have become less important, while others have become more relevant. Mean grain weight, previously not used within a drought selection index, was strongly correlated with yield in the present study. The importance of traits related to the availability in C products for the development of ears and grains are discussed. The results indicate that the traits of source organs contribute marginally to drought tolerance; variation of leaf or root traits seems to be less important than variation in tassel parameters for increasing drought tolerance. For ensuring further progress in drought tolerance in maize, the solution might reside in the manipulation of sink organs. It is therefore suggested that selection for even greater number of ears, bigger grains and smaller tassels may help to increase grain yield under water limited environments in the near future. A short discussion on the optimal choice of parental lines for developing hybrids with maximum expression of drought tolerance concludes the paper.


1974 ◽  
Vol 16 (4) ◽  
pp. 861-870
Author(s):  
G. H. Liang ◽  
A. D. Dayton ◽  
T. L. Walter

Epistasis, or interaction between nonallelic genes in grain sorghum (S. bicolor (L.) Moench), was estimated by comparing means of 20 balanced sets of single- and 3-way crosses. Each balanced set consisted of three single crosses and three 3-way crosses derived from three of the six parental varieties used. Results indicated that epistasis was present in nine sets for grain yield, in 13 sets for half-bloom date, and in 11 sets for plant height and for kernel weight. Epistasis seemingly fluctuates over years and locations. On the average, 3-way hybrids yielded less grain, flowered later, and were taller than the single-cross hybrids.


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