SEEDING RATE EFFECTS ON LOW-TILLERING SPRING WHEATS IN A SEMIARID ENVIRONMENT

1990 ◽  
Vol 70 (1) ◽  
pp. 9-17 ◽  
Author(s):  
P. HUCL ◽  
R. J. BAKER

To determine if increased seeding rates would alter relative yields of traditional and low-tillering genotypes, a high-tillering (Neepawa), a low-tillering (Siete Cerros), and an oligoculm (M1417) spring wheat (Triticum aestivum L.) genotype were seeded in replicated field trials at two locations in 1984 and 1985. A four-replication split-plot design, with genotypes assigned to main plots and seeding rates (40, 80 160, 320 and 640 seeds m−2) to subplots, was used for each experiment. Grain yield and its components were measured on individual plots or on main stems of five plants in each plot. All three genotypes expressed maximum yield at the same seeding rate (640 seeds m−2 in 1984 and 320 seeds m−2 in 1985) in the semiarid conditions of these experiments. Despite diverse tillering habits, the relative yields of these three genotypes could not be altered by changing seeding rates. On average, Siete Cerros (low-tillering) yielded 15% more than Neepawa and 17% more than M1417. Neepawa had lower grain yields than M1417 at all seeding rates in 1984, but higher grain yields in 1985. A similar change in relative performance of these two genotypes was observed for harvest index of the main stem but not for main stem grain yield kernels spike −1 on the main stem or kernel weight.Key words: Wheat (spring), oligoculm, yield components, genotype-environmental interaction.

2016 ◽  
Vol 47 (5) ◽  
Author(s):  
Baktash & Naes

This research was carried out at the Swerah Research Station –Office of Agricultural Researches Ministry of Agriculture, during 2014-2015 season. The objective of this research was to evaluation 15 pure lines (Triticum aestivum L.). genotypes ,the seventh generation developed by half dialled method between 6 parents. The experiment was conducted using split plot design with three replicates ,The main plots were four seeding rates (120, 160, 200 and 240 kg.ha-1 ), while the 21 genotypes occupied sub plots .The two pure lines S97 and S148 out yielded other genotypes except A4.10 and Abu-Ghraib in grain yield which, produced 6.35 and 6.09 t.ha-1, respecting .increasing seeding rates caused to increase in number of spikes .plant-1 and flag leaves angle. Significant difference were found among genotypes due to seeding rate.The pure line S148 ,using 200 kg.ha-1 seeding rate produced highest grain yield (7.49 t.ha-1) which did not differed from using A4.10 under 200 and 240 kg.ha-1 seeding rate. It was recommended to certify the pure line S148  using 200 kg.ha-1 seeding rate for cultivation at central of Iraq.


2017 ◽  
Vol 14 (2) ◽  
pp. 77-85
Author(s):  
Md Sohel Mahmud ◽  
Md Jafar Ullah ◽  
Md Abdullahil Baque ◽  
Lutfun Naher ◽  
Sayed Mohammad Mohsin

The experiment was conducted to determine the effect of irrigations and sowing dates on growth and yield performance of wheat in the experimental field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period of November 18, 2012 to March 30, 2013. The experiment was comprised of two factors, viz. factor A: two irrigations namely irrigation (I) and no irrigation i.e. control (I0), and factor B: three sowing dates such as S1: 1st sowing on 18 November, S2: 2nd sowing on 03 December and S3: 3rd sowing on 18 December. The experiment was laid out in a split plot design with three replications. Irrigation was assigned in the main plot, while sowing time was in the sub-plots. Data on grain yield and different yield contributing characters were taken after harvest. Results indicated that the highest grain yield was obtained with I (2.915 t ha-1) and S1 (2.983 t ha-1). The interaction of irrigation (I) and sowing on 18 November (S1) showed the maximum yield (3.387t ha-1), spike length (17.08 cm), 1000 grain weight (43.4 g), spikelets spike-1 (20.03) and grain spike-1 (65.58) of wheat.The Agriculturists 2016; 14(2) 77-85


1975 ◽  
Vol 55 (2) ◽  
pp. 363-367 ◽  
Author(s):  
K. G. BRIGGS

Three cultivars of wheat (Triticum aestivum L. em Thell.), Glenlea, Pitic 62 and Neepawa, were grown in a seeding rate and row spacing experiment at two locations in 1972 and 1973. In a split-plot design, row spacings of 15, 23 and 30 cm were used as main plots, and subplot seeding rates of 33.6, 67.3 and 100.9 kg/ha were applied for each cultivar. Data were collected on yield, days to maturity, plant height, lodging, kernel weight and test weight. The few significant effects of row spacing indicated that narrow row spacings tend to increase yield and decrease days to maturity. Higher seeding rates per unit area generally resulted in higher yields for all cultivars and, to some extent, earlier maturity. Glenlea wheat seeded at 100.9 kg/ha gave the highest yield in all tests, and at this seeding rate took an average 125 days to reach maturity, compared to 120 days for Neepawa and 129 days for Pitic 62. Seeding rate had virtually no effect on height, kernel weight or test weight of any of the wheats.


2019 ◽  
Vol 99 (3) ◽  
pp. 345-355
Author(s):  
Richard E. Engel ◽  
Carlos M. Romero ◽  
Patrick Carr ◽  
Jessica A. Torrion

Fertilizer NO3-N may represent a benefit over NH4-N containing sources in semiarid regions where rainfall is often not sufficient to leach fertilizer-N out of crop rooting zones, denitrification concerns are not great, and when NH3 volatilization concerns exist. The objective of our study was to contrast plant-N derived from fertilizer-15N (15Ndff), fertilizer-15N recovery (F15NR), total N uptake, grain yield, and protein of wheat (Triticum aestivum L.) from spring-applied NaNO3 relative to urea and urea augmented with urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT). We established six fertilizer-N field trials widespread within the state of Montana between 2012 and 2017. The trials incorporated different experimental designs and 15N-labeled fertilizer-N sources, including NaNO3, NH4NO3, urea, and urea + NBPT. Overall, F15NR and 15Ndff in mature crop biomass were significantly greater for NaNO3 than urea or urea + NBPT (P < 0.05). Crop 15Ndff averaged 53.8%, 43.9%, and 44.7% across locations for NaNO3, urea, and urea + NBPT, respectively. Likewise, crop F15NR averaged 52.2%, 35.8%, and 38.6% for NaNO3, urea, and urea + NBPT, respectively. Soil 15N recovered in the surface layer (0–15 cm) was lower for NaNO3 compared with urea and urea + NBPT. Wheat grain yield and protein were generally not sensitive to improvements in 15Ndff, F15NR, or total N uptake. Our study hypothesis that NaNO3 would result in similar or better performance than urea or urea + NBPT was confirmed. Use of NO3-N fertilizer might be an alternative strategy to mitigate fertilizer-N induced soil acidity in semiarid regions of the northern Great Plains.


Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1213 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Shahab Pathan ◽  
James Easton ◽  
David J. M. Hall ◽  
Rajesh Sharma

Surface (0–10 cm) and subsoil (soil layers below 10 cm) acidity and resulting aluminum (Al) toxicity reduce crop grain yields. In South Western Australia (SWA), these constraints affect 14.2 million hectares or 53% of the agricultural area. Both lime (L, CaCO3) and gypsum (G, CaSO4) application can decrease the toxic effect of Al, leading to an increase in crop grain yields. Within the region, it is unclear if G alone or the combined use of L and G has a role in alleviating soil acidity in SWA, due to low sulfate S (SO4–S) sorption properties of the soil. We present results from three experiments located in the eastern wheatbelt of SWA, which examined the short-term (ST, 2 growing seasons), medium-term (MT, 3 growing seasons), and long-term (LT, 7 growing seasons over 10 years) effects of L and G on grain yield and plant nutrient concentrations. Despite the rapid leaching of SO4–S and no self-liming impact, it was profitable to apply G, due to the significant ST grain yield responses. The grain yield response to G developed even following relatively dry years, but declined over time due to SO4–S leaching. At the LT experimental site had received no previous L application, whereas, at the ST and MT sites, L had been applied by the grower over the previous 5–10 years. For the LT site, the most profitable treatment for wheat (Triticum aestivum L.) grain yield, was the combined application of 4 t L ha−1 with 2 t G ha−1. At this site, the 0–10 cm soil pHCaCl2 was 4.6, and AlCaCl2 was greater than 2.5 mg kg−1 in the 10–30 cm soil layer. In contrast, at the ST and MT sites, the pHCaCl2 of 0–10 cm soil layer was ≥5.5; it was only profitable to apply G to the MT site where the soil compaction constraint had been removed by deep ripping. The use of L increases soil pHCaCl2, resulting in the improved availability of anions, phosphorus (P) in the LT and molybdenum (Mo) at all sampling times, but reduced availability of cations zinc (Zn) in the LT and manganese (Mn) at all sampling. The application of G reduced Mo concentrations, due to the high SO4–S content of the soil.


1993 ◽  
Vol 33 (6) ◽  
pp. 751 ◽  
Author(s):  
DR Coventry ◽  
TG Reeves ◽  
HD Brooke ◽  
DK Cann

A 3-year study was conducted to measure the effect of sowing time and seeding rate on the development and yield of wheat (Triticum aestivum L.) grown under high-yielding conditions in north-eastern Victoria. A range of wheat cultivars with different development responses, including 'winter' types, was used in 2 experiments in each season. High grain yields for dryland wheat were measured in the first 2 seasons (1985-86), and in 1985, near-optimal water use efficiencies (>18 kg/ha. mm effective rainfall) were obtained. In the third season (1987) grain yield was limited by adverse climatic conditions-in the me- and post-anthesis period. In each season, grain yield declined with delay in sowing time. In 1985 there was a loss of 200-250 kg grain/ha for each week's delay in sowing time. In 1987, yield loss with delayed sowing was 50-110 kg grain/ha. In each season, cultivars with late or midseason maturity development gave the highest mean yields, and the use of these maturity types allowed earlier sowing, in mid April. However, with late sowing of wheat there was a trend for early maturity types to give higher yields, and so the use of 2 wheat cultivars with distinct maturity development responses to climate is recommended. If only 1 wheat cultivar is to be used, then a late maturity type is recommended. Higher wheat yields were also obtained as spike density increased, as a result of higher seeding rates. Our data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.


1997 ◽  
Vol 77 (2) ◽  
pp. 207-213 ◽  
Author(s):  
G. Opoku ◽  
T. J. Vyn

Corn (Zea mays L.) yield reduction following winter wheat (Triticum aestivum L.) in no-till systems prompted a study on the effects of tillage and residue management systems on corn growth and seedbed conditions. Four methods for managing wheat residue (all residue removed, straw baled after harvest, straw left on the soil surface, straw left on the soil surface plus application of 50 kg ha−1N in the fall) were evaluated at two tillage levels: fall moldboard plow (MP) and no-till (NT). No-till treatments required at least 2 more days to achieve 50% corn emergence and 50% silking, and had the lowest corn biomass at 5 and 7 wk after planting. Grain yield was similar among MP treatments and averaged 1.1 t ha−1 higher than NT treatments (P < 0.05). Completely removing all wheat residue from NT plots reduced the number of days required to achieve 50% corn emergence and increased grain yields by 0.43 and 0.61 t ha–1 over baling and not baling straw, respectively, but still resulted in 8% lower grain yields than MP treatments. Grain yield differences among MP treatments were insignificant regardless of the amount of wheat residue left on the surface or N application in the fall. Early in the growing season, the NT treatments where residue was not removed had lower soil growing degree days (soil GDD) compared with MP (baled) treatment, and higher soil moisture levels in the top 15 cm compared with all other treatments. The application of 50 kg N ha−1 in the fall to NT (not baled) plots influenced neither the amount of wheat residue on the soil surface, nor the soil NO3-N levels at planting. Our results suggest that corn response in NT systems after wheat mostly depends on residue level. Key words: Winter wheat, straw management, no-till, corn, soil temperature, soil moisture


1990 ◽  
Vol 70 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P. HUCL ◽  
R. J. BAKER

Three spring wheat (Triticum aestivum L.) genotypes (Neepawa, Siete Cerros and M1417) were subjected to four levels of tiller removal (MS remaining, MS + T1 remaining, MS + T1 + T2 remaining, control) at three plant densities (two, four and eight plants per 15-cm-diameter pot) in a controlled environment to assess the effects of interplant and intraplant competition on stem dimensions and yield-related traits of genotypes with diverse tillering habits. Both types of competition resulted in reduced kernel weight and main stem grain yield and increased yield per pot. Interplant competition also reduced harvest indices while intraplant competition reduced main stem length and main stem diameter. The oligoculm genotype, M1417, was more sensitive to interplant competition than Siete Cerros and Neepawa. The increased sensitivity of M1417 appears to result from plant mortality combined with the inability to maintain kernel mass under severe interplant competition.Key words: Triticum aestivum, wheat (spring), tiller removal, grain yield, plant competition.


1980 ◽  
Vol 60 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
H. G. NASS

The use of harvest index as a selection criterion for grain yield in F2 populations of spring wheat (Triticum aestivum L.) grown at two population densities was investigated. Harvest index was useful in delineating yield differences between lines for both crosses. The F4 lines selected in F2 for a high harvest index yielded about 9% more per plot in 1978 than F4 lines having a low harvest index in F2. Generally, lines selected at the higher commercial seeding rate yielded more than lines selected at the lower plant density. In 1979, a heavy Fusarium infection reduced the mean grain yield of the F6 lines and suppressed any significant response to selection resulting from population density and harvest index in F2. While selection based on high harvest index at low population density can be used to select higher yielding plants it was not as effective as selection at high population density which more closely approximates commercial crop densities. Additional research is needed before the use of harvest index as a selection tool in wheat breeding programs can be recommended for use in Atlantic Canada.


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