scholarly journals Phenotypic Traits, Grain Yield and Yield Components of Maize Cultivars Under Combinations of Management Practices in Semi-arid Conditions of Iran

Author(s):  
Maryam Rahimi Jahangirlou ◽  
Gholam Abbas Akbari ◽  
Iraj Alahdadi ◽  
Saeid Soufizadeh ◽  
Uttam Kumar ◽  
...  

AbstractIn semi-arid regions, selecting cultivars and planning management practices are critical issues for improving yields and reducing risks of maize cultivation in the short summer cropping season. This study aimed to assess the responses of grain yield (GY) and important phenotypic characteristics of maize cultivars from different maturity groups under various irrigation regimes, planting dates, and nitrogen rates, in a 2-year experiment. According to the clusters identified in the loading plot, stover yield, radiation use efficiency (RUE), height, leaf greenness index, stem weight, and ear size during flowering (VT/R1) were strongly correlated with GY, yield components and harvest index. Based on analysis of variance, more irrigation or N, or their interaction often increased GY, rows ear−1, grains row−1 and hundred-grain weight. Late planting decreased GY of KSC704 (late maturity cultivar). KSC260 (early maturity cultivar) had greater flexibility in planting time, required less days for maturity, and had less water consumption. The findings highlight the physiological basis of the relationship between the different phenotypic characteristics and how they affect GY and its components. They were in line with the established theories that higher RUE, biomass and sink activity (e.g. grain weight and numbers, and larger ear size) are associated with better genetic gains to produce high GY. Although the results were not consistent between years, findings suggested the good performance of recently released early maturity cultivars for use during the summer growing season.

2001 ◽  
Vol 49 (1) ◽  
pp. 103-105 ◽  
Author(s):  
A. M. Tawaha ◽  
M. A. Turk

Field experiments were conducted during the winter seasons of 1998–1999 and 1999–2000 at Houfa in northern Jordan, to study the effect of the date and rate of sowing on the yield and yield components of narbon vetch (Vicia narbonensis L.). Progressive delays in sowing beyond 1 st January led to yield reductions of 11.1 and 17.9 at successive 15-day intervals. Plant height, pods stem –1, stems m –2 and 1000-grain weight followed the same trend as the yield. Grain yield was not significantly affected by the sowing rate.


2013 ◽  
Vol 5 (2) ◽  
pp. 91-96
Author(s):  
MR Sultana ◽  
MA Alim ◽  
MB Hossain ◽  
S Karmaker ◽  
MS Islam

An experiment was conducted at Agronomy Field Laboratory of Rajshahi University to evaluate the effect of variety and weeding regime on yield and yield components of wheat. Four varieties viz. Prodip -V1, Gourab -V2, Shatabdi -V3, Bijoy -V4 and five weeding regime viz. a) No weeding -W0, b) Weed free -W1, c) One hand weeding at 20 DAS -W2, d) Two hand weeding (1st at 20 DAS and 2nd at 42 DAS) -W3 and e) Lintur 70 WG @ 250 g ha-1 -W4 were included as treatments in the experiment. The experiment was laid out in a Split-plot Design with three replications. The results revealed that Prodip produced the highest grain yield (5.33 t ha-1) followed by Gourab (4.85 t ha-1), while the lowest grain yield (3.98 t ha-1) was obtained from Shatabdi. The highest grain yield (5.09 t ha-1) was obtained in Weed free (W1) followed by W3 (Two hand weeding) (4.89 t ha-1) and the lowest grain yield (4.13 t ha-1) was obtained in no weeding treatment (W0). The highest grain yield (5.64 t ha-1) was obtained from the combination of Prodip and weed free treatment (V1W1) and the lowest (3.57 t ha-1) was obtained from the combination between Shatabdi and no weeding treatment (V4W0).DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14800 J. Environ. Sci. & Natural Resources, 5(2): 91-96 2012


1998 ◽  
Vol 130 (3) ◽  
pp. 287-295 ◽  
Author(s):  
C. L. MORGAN

Twenty-eight F1 hybrids of wheat and their parents were grown in field trials at Trumpington, Cambridge during 1986/87 and 1987/88. They were derived from crosses between seven ‘modern’ varieties, used as female parents, and either two ‘old’ (Squareheads Master and Partridge) or two ‘modern’ varieties (Bert and Motto), which were used as male parents. Grain yield, yield components, biomass and height were determined. The male parents were chosen to provide contrasting phenotypes and genetic backgrounds for the F1 hybrids. Mid-parent advantage, the increase of a hybrid for a given character above the mean of its parents, and heterosis, the increase of a hybrid above the ‘better’ parent for that character, were calculated. Most F1 hybrids showed mid-parent advantage for the characters studied. This tended to be greatest for hybrids derived from parents with the largest phenotypic differences in that character. In contrast, where heterosis occurred it tended to be greatest where the phenotypic difference between the parents was least. This suggests that the beneficial effects of hybridization, resulting from the dispersion of dominant genes between the parents, was insufficient to overcome the detrimental effects of other genes present where the ‘less good’ parent was substantially lower than the ‘better’ parent. Hybrids derived from the ‘modern’ male parents had greater heterosis for grain yield and mean grain weight than those from the ‘old’ parents. Of the yield components, positive heterosis for mean grain weight resulted in heavier seeds and was the most important yield component in determining heterosis in grain yield. Heterosis for the number of grains/ear was small or did not differ significantly from zero while number of ears/m2 showed negative heterosis resulting in fewer ears/m2 in the hybrids.


2021 ◽  
Vol 23 (1) ◽  
pp. 3-13
Author(s):  
HARPREET SINGH ◽  
PRABHJYOT KAUR ◽  
S.K. BAL ◽  
B.U. CHOUDHURY

Physiology of green gram is highly sensitive to fluctuations in the thermal environment. Abnormally high temperatures during pod setting to pod development stage induces reduction in pod setting, nonhealthy development and early maturity of grain which results in yield decline. We evaluated the effect of elevated temperatures in a Temperature Gradient Tunnel (TGT) on phenology, physiology and crop performance of green gram cultivars at semi-arid climate of Indian Punjab (Ludhiana). Five green gram cultivars were grown in TGT chambers in a factorial randomized block design with varying level of elevated temperatures (+3.3° C to 5.2° C) for two consecutive kharif seasons (2015-2016). The results reveal that the phenological stages of green gram, were advanced under elevated temperature within the TGT compared to open / ambient condition by 12-13 days. Maximum influence was observed in pod formationand pod maturity stages. With rise in temperatures by 3.3 to 5.2°C in TGT over ambient condition, the plant height increased but the number of branches per plant and the total above ground biomass as well as grain yield decreased consistently. It was found that with 1 oC increase in average seasonal temperature, the grain yield decreased by 75 kg ha-1. On the other hand, the harvest index was in general lower inside TGT chamber implying adverse influence of elevated temperature on biomass production although the partitioning of biomass was more efficient inside the TGT as evident from increase in harvest index. There was strong negative correlation of elevated temperature (inside TGT) with different yield attributes like 1000 seed weight, number of seeds per pod and number of pods per plant. Among the five green gram cultivars, ML-2037 was the most tolerant while cv. SML-1811 was the most susceptible to elevated temperature condition. In general, the grain yield decreased linearly with gradual increase in temperature.Average seasonal temperature of 29-30 oC may be considered as the favourable thermal conditions for the green gram crop in semi-arid conditions of Punjab. However, the future thrust will be to create more temperature gradients in the lower side so that the critical temperature threshold limits for optimum yield of green gram can be ascertained more accurately.


Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 313-319 ◽  
Author(s):  
D. J. Pantone ◽  
J. B. Baker ◽  
P. W. Jordan

During 1985 to 1989, a series of field experiments were conducted at the Rice Research Station in Crowley, LA. Path analysis was employed to evaluate the competitive interaction between a weed (red rice) and cultivated rice (Mars). The path analysis quantified direct effects of red rice and Mars rice densities on the yield components (grain weight, percent filled florets, number of florets panicle−1, and panicles plant−1) of red rice and Mars rice. The model illustrated the direct and indirect effects of the yield components on fecundity and grain yield plant−1. The direct effects of Mars and red rice densities on panicles plant−1and florets panicle−1were always negative. In contrast, the effects of density on percent filled florets and grain weight varied from positive to negative and were relatively small, implying that they were determined primarily by density-independent factors. Path analysis indicated that the number of panicles plant−1and florets panicle−1were the most important yield components determining the responses of fecundity and grain yield to competition.


2004 ◽  
Vol 44 (1) ◽  
pp. 37
Author(s):  
M. K. J. El-Shatnawi ◽  
N. I. Haddad

Greenhouse pot trials and field experiments were carried out under rain-fed condition in north-eastern Jordan during 1997–98 and 1998–99 growing seasons, to test 3 barley genotypes for their suitability for both forage and grain production. The varieties Rehani and ACSAD176 produced higher forage yields than Rum. In the field, clipping reduced subsequent grain yield per plant by about 18%, lowering grain weight of the main spike from 2.3�g in the control to 1.8 g in the clipped plants. Clipping increased tiller density of barley plants in the field. Decreases in grain yield following clipping could also be attributed to reductions in the number of grains per spike. Clipping decreased the number of grains per spike by about 9% by reducing the number of spikelets per spike. Cutting reduced 1000-grain weight by about 9%. Clipping induced changes in the relative importance of yield components influencing subsequent grain yield. The yield components reduced by clipping were the most important contributors to loss of grain yield.


2004 ◽  
Vol 55 (7) ◽  
pp. 797 ◽  
Author(s):  
D. L. Sharma ◽  
W. K. Anderson

Small grains that pass through a 2-mm slotted screen (sievings or screenings) are one of the most important causes of price dockages of wheat in Australia because grain size variation greatly affects flour yield and commercial value. The aims of this study were to examine the effects of season, time of sowing, plant population, and applied nitrogen, and their interactions with cultivars, on small grain screenings. Twenty-one field experiments involving 16 new cultivars and elite crossbreds, and various management variables, were conducted in the medium (annual rainfall 325–450 mm) and low (annual rainfall <325 mm) rainfall zones of the Northern Agricultural Region of Western Australia over 3 diverse cropping seasons (1999–2001). Rainfall events towards the end of the season were critical to the level of screenings. Screenings were higher in season 2000 with terminal drought stress, but were low in 2001 despite severe drought stress during early growth. Delayed seeding caused higher screenings in 1999 (average rainfall with even distribution) and in 2000 (terminal drought) but not consistently in 2001 when early drought stress restricted tillering and spike size thereby constraining the yield level. Strong varietal and time of sowing interactions were evident but the relationship between maturity group and the level of screenings was not consistent. Rather, the ability of cultivars to adjust yield components was more important; 82% of the total variance in small grain screenings was accounted for by a regression model based on variety-specific kernel weight, post-heading rainfall (from about 2 weeks before anthesis), and location factors. The effect of increasing plant population on screenings was mostly negative, with some minor exceptions for a few cultivars in the low-rainfall zone. As applied nitrogen was increased, screenings generally increased and cultivar influenced this trend more than rainfall zone. It is postulated that for a cultivar to be unaffected by applied nitrogen, it should have inherently higher grain weight as well as high stability of grain weight across nitrogen levels. Applied nitrogen had a significant effect on screenings only at higher plant populations. In experiments where the level of screenings exceeded 5%, the yield components that were significantly associated with screenings, in order of relative importance, were grain weight > grain number/area > grain number/head > grain yield. Cultivars differed in production of screenings in response to plant population, nitrogen fertiliser and sowing time. Harrismith was the most sensitive cultivar and Wyalkatchem was overall the most tolerant cultivar. Delayed seeding had the least effect on the screenings of cultivars Westonia, Carnamah, and Wyalkatchem. Carnamah was the most stable cultivar against higher levels of applied nitrogen, whereas Westonia required high plant numbers to contain screenings. It is concluded that cultivars can be classified according to specific sensitivities, and appropriate management practices may be suggested to growers.


1983 ◽  
Vol 101 (2) ◽  
pp. 383-387 ◽  
Author(s):  
A. Hadjichristodoulou

SUMMARYA series of trials were conducted during 1979–82 under semi-arid conditions in a Mediterranean-type environment to study the edge effects in mechanized durum wheat and barley variety trials when uncropped pathways are left between plots. Varietal differences in edge effects on grain yield were in most trials not significant. Thus, edge effects do not distort significantly the relative ranking of varieties.Edge effects were significant for all traits studied and higher in grain and straw yields. These effects were also higher in drier seasons. The overestimation of grain yield from whole plots was 13–18% in relatively high rainfall seasons and 29% in a dry season. In two seasons the scores on the two outer rows were higher than on the two central rows by 89 and 117 % for grain yield, by 72 and 73% for straw yield, by 44 and 48% for numbers of tillers, by 6% for 1000-grain weight and by 14 and 40% for number of grains per tiller. The edge effect was not confined to the outer rows, but it extended to the inner rows of the plot; the magnitude of this effect varied with season and trait.Rows adjacent to the pathway and unprotected from wind had a lower value for all traits than the opposite rows of the pathway, which were protected by the inner rows.


1984 ◽  
Vol 20 (3) ◽  
pp. 225-233 ◽  
Author(s):  
A. M. Alghali ◽  
E. O. Osisanya

SUMMARYRice varieties were compared for their response to infestation by the stalk-eyed fly, Diopsis thoracica (West), both when a choice of varieties was available to the pest and when there was no choice. The fly significantly decreased the number of panicles produced (both total and mature), the percentage of tillers with panicles, grain weight and total yield of unprotected plants, and increased the number of immature panicles and time to 50% flowering. Reductions in grain yield of between 2 and 97% were recorded but these losses were unrelated to the percentage of damaged tillers. Production of new tillers did not fully compensate for damaged ones in most varieties. However, photoperiod-sensitive rice varieties were better able to compen- sate for pest damage than most.


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