Effects of sowing time and nitrogen fertiliser on canola and wheat, and nitrogen fertiliser on Indian mustard. I. Dry matter production, grain yield, and yield components

2001 ◽  
Vol 52 (6) ◽  
pp. 623 ◽  
Author(s):  
P. J. Hocking ◽  
M. Stapper

Canola, Indian mustard, and wheat were grown under dryland conditions at Ariah Park and Cowra (canola only) in the cropping belt of New South Wales, Australia, to determine the effects of sowing time (canola and wheat) and nitrogen (N) fertiliser on the growth, grain yield, and yield components of the crops. Compared with an April sowing, the grain yield of canola at Ariah Park was reduced by 35% for a May sowing and by 67% for a July sowing. Canola yield at Cowra was reduced by 45% between early and late May sowings. Wheat yield declined by 35% between the May and July sowings at Ariah Park. Grain yields of canola and wheat at Ariah Park responded to N fertiliser in the April and May sowings, but not in the July sowing. Indian mustard had a higher yield than thecomparable sowing of canola. Canola yields at Cowra were more responsive to N fertiliser than at Ariah Park, and increased from 0.5 to 2.9 t/ha with 100 kg N/ha. For each day that sowing canola was delayed at both sites after Aprill—early May, anthesis was delayed on average by 0.52 days. For Dollarbird wheat, the delay in anthesis was 0.39 days per day sowing was delayed. Dry matter accumulation by the oilseeds was greatest during flowering, but before anthesis for wheat. Late sowing had little effect on the proportions of dry matter accumulated in a particular growth period. Irrespective of sowing time, grain yields and dry-matter harvest indices of the oilseeds were similar to values for wheat when differences in the biosynthetic costs of grain and straw production were taken into account. Late sowing usually resulted in a greater reduction in canola oil concentration than high N fertiliser rates. Canola oil concentration was reduced by 1.7 percentage points per 1mp;deg;C increase in mean temperature during grain filling as a result of sowing late. It was concluded that N fertiliser could not compensate for the yield reduction in canola and wheat due to sowing late. Early sowing was essential to achieve high oil levels in canola.

1996 ◽  
Vol 47 (3) ◽  
pp. 427 ◽  
Author(s):  
PJ Gregory ◽  
J Eastham

Crops of lupin (Lupinus angustifolius L. cv. Gungurru) and wheat (Triticum aestivum cv. Kulin or Spear) sown close to the break of the season and 3-6 weeks later were grown on a duplex soil at East Beverley, WA, over 3 seasons. The overall aim of the work was to examine the influence of time of sowing on growth and water use of the crops, and this paper reports their growth and yield. Early sowing resulted in greater shoot weight of all crops (up to 2.8 t/ha for lupin and 1.7 t/ha for wheat at maturity) and grain yield of lupin, but grain yield of wheat was increased in only 1 of the 3 seasons. The principal effect of the delayed sowing was to reduce the duration of linear growth; the rate of the initial exponential phase was slightly reduced by later sowing as was the rate of growth during the linear phase in lupin (by about 1.5 g/m2day) but not in wheat. Late sowing generally reduced both the number of pod/ears per unit area and the number of grains per pod/ear. Doubling the density of sowing in one of the seasons had no effects on the shoot weight and grain yield of lupin with early or late sowing but decreased those of wheat. Downward root growth of early-sown crops averaged 5.2 mm/day for lupin and 8.7 mm/day for wheat in the 3 seasons and ceased at about 0.8 m; time of sowing had no effect on these measures. Root weight at flowering was greater in lupin than in wheat crops, and root weight of lupin was about 0.5 of total plant weight during vegetative growth compared with 0.25-0.3 in wheat. Typically, only 5-6% of the root length of both crop species was present in the clay layer at flowering irrespective of sowing time. The proportion of radiation intercepted reached a higher maximum value for early-sown crops (about 0.75 in 1991 and 0.90 in 1992) than late-sown crops (about 0.60 in 1991 and 0.8 in 1992). The conversion coefficients of radiation to dry matter were very similar (about 1.8 g/MJ) for both species, but the greater partitioning of dry matter to roots in lupin than wheat meant that conversion coefficients for shoot dry matter were greater in wheat (1.43-1.68 g/MJ) than in lupin (0.93-1.16 g/MJ). The results demonstrate that early sowing produced larger crops of both lupin and wheat; this resulted in larger lupin yields, but yield of wheat was affected by disease and drought during grain filling.


1979 ◽  
Vol 19 (96) ◽  
pp. 64 ◽  
Author(s):  
AL Garside

Experiments to examine the effect of sowing time on the lupin cultivars Uniwhite, Uniharvest and Unicrop (L. angustifolius) and Weiko Ill (L. luteus) were sown in northern Tasmania in 1973 and 1974. The best yields resulted from autumn sowings in 1974 (3.7 t ha- 1) and from winter and spring sowings in 1973 (3.5 and 3.3 t ha-1, respectively). The results indicate that acceptable yields can be obtained from both autumn and early spring sowings. In addition, a number of factors are discussed that suggest spring sowing is safer and better suited to the cropping system. Yield differences between Uniwhite, Uniharvest and Unicrop were small for sowings between May and September, but Unicrop yielded better with later sowing. The yield of Weiko IIIwas poorer than the other cultivars except after very late sowing. Uniwhite and Uniharvest failed to mature when sown after late October.


2004 ◽  
Vol 55 (2) ◽  
pp. 147 ◽  
Author(s):  
Hamit Kavak

The effect of sowing date on severity of scald and yield components of barley was studied over 2 years, using 15-day intervals between sowing dates under dryland conditions in Turkey. Disease severity was greatest at the first sowing time, and it decreased linearly at subsequent sowing times in both years. Disease did not develop on flag and second leaves for the third sowing date, and was not observed on any leaf after the fourth and fifth dates of sowing in 2000 and 2001, respectively. After the third sowing date, a decrease in total grain yield and yield components, number of ears per plant, grains per head, and plant height was observed in both infected and control plots. Yield was also reduced by scald and resulted in total grain yield reductions of 10.1% and 6.0% for the first and second sowing dates in 2000, and 16.2%, 9.2%, and 3.0% on the first 3 sowing dates in 2001, respectively. At the first 2 sowing dates only ears per plant was decreased by scald, with respective reductions of 8.3% and 4.4% in 2000, and 14.3% and 8.5% in 2001, when compared with the control plots.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


1978 ◽  
Vol 14 (3) ◽  
pp. 239-244 ◽  
Author(s):  
W. Godfrey-Sam-Aggrey

SUMMARYEffects of plant population on mean yield and yield components of 2-year sole cassava crops were studied on Njala upland soils of Sierra Leone in two experiments. Increasing plant population of multi-shoot Cocoa cassava over 7000/ha decreased all the parameters studied except top/root weight ratio, which increased. The observed effects were attributed to competition for environmental resources, since area of land/plant unit decreased as plant population increased. The relations between plant populations and yields of fresh root and cortex dry matter were asymptotic, indicating that the respective yields were products of the vegetative phase of cropping.


1996 ◽  
Vol 36 (4) ◽  
pp. 443 ◽  
Author(s):  
MG Mason ◽  
RW Madin

Field trials at Beverley (19911, Salmon Gums (1991; 2 sites) and Merredin (1992; 2 sites), each with 5 rates of nitrogen (N) and 3 levels of weed control, were used to investigate the effect of weeds and N on wheat grain yield and protein concentration during 1991 and 1992. Weeds in the study were grasses (G) and broadleaf (BL). Weeds reduced both vegetative dry matter yield and grain yield of wheat at all sites except for dry matter at Merredin (BL). Nitrogen fertiliser increased wheat dry matter yield at all sites. Nitrogen increased wheat grain yield at Beverley and Merredin (BL), but decreased yield at both Salmon Gums sites in 1991. Nitrogen fertiliser increased grain protein concentration at all 5 sites-at all rates for 3 sites [Salmon Gums (G) and (BL) and Merredin (G)] and at rates of 69 kg N/ha or more at the other 2 sites [Beverley and Merredin (BL)]. However, the effect of weeds on grain protein varied across sites. At Merredin (G) protein concentration was higher where there was no weed control, possibly due to competition for soil moisture by the greater weed burden. At Salmon Gums (G), grain protein concentration was greater when weeds were controlled than in the presence of weeds, probably due to competition for N between crop and weeds. In the other 3 trials, there was no effect of weeds on grain protein. The effect of weeds on grain protein appears complex and depends on competition between crop and weeds for N and for water at the end of the season, and the interaction between the two.


2017 ◽  
Vol 14 (2) ◽  
pp. 155-160
Author(s):  
MAR Sharif ◽  
MZ Haque ◽  
MHK Howlader ◽  
MJ Hossain

The experiment was conducted at the field laboratory of the Patuakhali Science and Technology University, Patuakhali, Bangladesh during the period from November, 2011 to March 2012 under the tidal Floodplain region to find out optimum sowing time for the selected three cultivars (BARI Sharisha-15, BINA Sharisha-5 and BARI Sharisha-9). There were four sowing dates viz. 30 November, 15 December, 30 December and 15 January. Significant variations due to different sowing dates were observed in plant height, total dry matter, leaf area index, number of siliqua plant-1, seeds silique-1, 1000-grain weight, grain yield and HI. Results showed that the highest grain yield (1.73 t ha-1) was obtained from the first sowing (30 November) with BINA Sharisha-5 and it was significantly different from the yields of all other combination.J. Bangladesh Agril. Univ. 14(2): 155-160, December 2016


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