Some factors influencing the development of sunflower (Helianthus annuus L.) under dry-farming systems in Sudan

1981 ◽  
Vol 97 (1) ◽  
pp. 45-53 ◽  
Author(s):  
F. M. Khalifa

SUMMARYAn experiment was carried out over a 3-year period at two locations in the central rainlands of Sudan under rainfed conditions at one site and under supplementary irrigation at the other to study the effects of cultivars and cultural practices on growth and grain yield of sunflower. Four cultivars, namely, Manohurian, Peredovik, Hungarian-A and Hungarian-B and four intra-row spacings of 15, 30, 45 and 60 cm (in rows 60 cm apart) were tested with three sowing dates starting on 15 July and following at 15-day intervals. Manchurian outyielded the other three varieties under supplementary irrigation whereas under rainfed conditions the reverse was true. This was attributed to the relative earliness in flowering of the varieties and their moisture requirements. Manchurian was the tallest with the thickest stem and a larger head at both locations compared with the other three varieties. Under rainfed conditions, the early sowing date of 15 July gave a significantly higher grain yield than the other two sowing dates, with the last sowing date of 15 August giving significantly least. This is attributed to decreasing moisture availability with delayed sowings. But under supplementary irrigation the effect of sowing date was less marked. Contrasting effects of sowing dates on plant height and stem circumference were obtained under the two systems of production. Under rainfed conditions there was a decrease in plant height and stem circumference with delayed sowing, whereas under supplementary irrigation the reverse was true. A contrasting response of plant height to spacing was also obtained; wider intra-row spacing was associated with taller plants under rainfed conditions and shorter plants under supplementary irrigation. Wider spacing was associated with thicker stems and larger heads at both locations. On the evidence obtained, 45 cm intra-row spacing is recommended for rainfed planting and 30 cm intra-row spacing for irrigated production of sunflower.

Author(s):  
Adinew Getachew ◽  
Thomas Abraham

One of the basic agronomic practices to improve the yield of chickpea are ideal sowing date and high yielding varieties. Thus, a field experiment was conducted to assess the effect of different sowing dates on yield and yield components of chickpea varieties in the main cropping season of 2019 at Toke Kutaye District. Four sowing dates (September 4th, September 14th, September 24th, and October 5th) and four kabuli varieties. Four Kabuli types of chickpea varieties were Dalota, Ejere, Teji and Dube (local check). Experiment was laid out in split plot design using factorial arrangement with three replications and sowing date treatments were assigned to the main plots and varieties to sub plots. The main effect of sowing date showed highly significant effect on days to emergence, days to 50% flowering and physiological maturity. Highest days to emergence                (12.4 days) were recorded from a plot sown on October 5th, while longest days to 50% flowering (54.92 days) and physiological maturity (122.5 days) were recorded from a plot sown on September 14th. Moreover, varieties had significant effect on days to physiological maturity of chickpea. Longest days to physiological maturity (133 days) were recorded from local variety and early days to physiological maturity (113.3 days) was recorded from Dalota variety. The main effects of sowing date and variety were significant on plant height, as the tallest plant height (42.75 cm) was recorded from September 24th sown plants. Similarly, the tallest (41.42 cm) plant was recorded from Dalota variety. In addition, the highest number of primary branches (6.83) and secondary branches (16.42) per plant were recorded from Dalota variety, while the lowest number of primary branch (5.5) and secondary branches (8) were scored from Ejere and Teji varieties, respectively. Highest grain yield (2415.4 kg ha-1) was obtained from plots sown on September 14th whereas Dalota variety produced highest grain yield (2051.25 kg ha-1). Hence, Dalota variety and September 14th sowing date emerged as best among all tested treatments and can be recommended for chickpea production in the study area and similar agro-ecologies. Conclusive recommendation could be obtained if the study is repeated at more locations and seasons in the future.


1994 ◽  
Vol 21 (6) ◽  
pp. 717 ◽  
Author(s):  
MP Reynolds ◽  
M Balota ◽  
MIB Delgado ◽  
I Amani ◽  
RA Fischer

Sixteen spring wheat genotypes were grown under hot, irrigated, low latitude conditions, during the 1990-1991 and 1991-1992 winter cropping cycles in Mexico, Egypt, India and the Sudan, and in the 1990 and 1991 winter cycles in Brazil. The genotypes were chosen to represent a range of genetlc diversity within modem wheat varieties. In addition to grain yield, in Mexico a number of morphological and physiological traits were measured throughout the growing season on two sowing dates (December and February), to evaluate their correlation with yield in the other countries. The morphological traits - above-ground biomass at maturity, grains m-2, days to anthesis and days to maturity - measured on both sowing dates in Mexico showed generally significant correlations with yields measured at the other sites. Moreover, ground-cover estimates early in establishment, and at anthesis, also showed some association with performance at these sites, but only when measured on the hotter, February sowing date in Mexico. Membrane thermostability (MT), measured on field-acclimated flag leaves showed generally significant correlations with performance at all sites, and with MT measurements made on heat- acclimated seedlings of the same genotypes grown in growth chambers. Flag-leaf photosynthesis measured at booting, anthesis and during grain filling on both sowing dates, was generally significantly correlated with grain yield at all sites, as was rate of loss of leaf chlorophyll content during grain filling. Stomatal conductance was also significantly correlated with performance at all three stages. Canopy temperature depression (CTD) measured with an infrared thermometer was significantly positively correlated with performance at the international sites when measured between 1200 and 1600 hours, after full canopy establishment. The correlation of CTD with yield was not affected by the irrigation status of the crop under well-watered conditions. The possible use of these traits in selection for yield under hot conditions is discussed.


1991 ◽  
Vol 117 (3) ◽  
pp. 325-332 ◽  
Author(s):  
J. Risi ◽  
N. W. Galwey

SUMMARYQuinoa produces a cereal-like grain with a higher protein content and a better balanced amino acid composition than the major cereals. It is cultivated at high altitudes in the Andes, and is believed to have potential for temperate regions. In the development of quinoa as an arable break crop, sowing date, sowing rate and row spacing are identified as agronomic variables having a high priority for investigation. The variety Baer, from high latitudes at sea-level in Chile, and the variety Blanca de Junin, from the inter-Andean valleys of Peru, were sown on 25 March, 14 April and 7 May 1982 at spacings between rows of 0·8 and 0·4 m and sowing rates within rows of 0·2, 0·4 and 0·6 g/m, at Cambridge, England. These varieties were chosen for their strongly contrasting origins and plant types. In another experiment sown on 15 March 1984, Blanca de Junin was replaced by another valley variety, Amarilla de Marangani, somewhat better adapted for cultivation in England. Between-row spacings of 0·4 and 0·2 m, and sowing rates of 15, 20 and 30 kg seed/ha were used. Weed competition was more intense after later sowings, causing the plots sown in May to be abandoned. At the higher sowing rates, plants were shorter, a higher proportion were stunted, branching was reduced and maturity was earlier. These effects were more marked in the valley varieties, particularly Blanca de Junin. Increases in within-row density caused greater increases in competition effects than corresponding reductions in row width, except for the effect on the proportion of branched plants. The highest grain yield, 6·96 t/ha, was obtained with Baer sown in March in rows 0·2 m apart at 20 kg seed/ha. However, Amarilla de Marangani produced a higher yield at 30 kg seed/ha than at 20 kg seed/ha, which is surprising since valley varieties are normally sown with low target population densities or in intercrop, and Amarilla de Marangani was, in other respects, less tolerant of competition than Baer. The implications of these results for the cultivation of quinoa in mechanized farming systems, both in temperate and in highland tropical regions, are discussed.


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.


2018 ◽  
Vol 39 (1) ◽  
pp. 393
Author(s):  
Tiago Zoz ◽  
Fábio Steiner ◽  
André Zoz ◽  
Deise Dalazen Castagnara ◽  
Travis Wilson Witt ◽  
...  

Understanding the influence of row spacing and plant density on grain yield and yield components of crambe is critical in order to obtain higher grain yields. Therefore, the objective of this study was to evaluate the effects of row spacing and plant density on grain yield and its components in crambe in two distinct regions of Brazil (Marechal Candido Rondon-PR, MCR-PR, and Botucatu-SP, BTU-SP). Narrow and wide row spacing (0.20 and 0.40 m) combined with four plant densities (15, 25, 35, and 45 plants m-1) were evaluated in a randomized block layout with four replications in a 2 × 4 factorial design. The experiment at BTU-SP was run under rainfed conditions with supplementary irrigation, whereas the experiment at MCR-PR was run under rainfed conditions without supplementary irrigation. Both experiments were run in soils classified as Oxisols. There was no interaction between row spacing and plant density. Highest grain yield with supplementary irrigation was observed at 0.20 m row spacing. Without irrigation, row spacing did not affect grain yield owing to the plasticity of crop. The highest grain yield was observed with approximately 30 plants m-1 at both experimental locations. A strong negative correlation was observed between final plant population and number of grains per plant. There was high plant mortality, particularly at high plant densities cultivated under irrigation. Higher mortality occurred because of high intraspecific competition and a larger disease incidence due to the higher humidity in the irrigated experiment. A mechanism of self-adjustment by plant density was observed in crambe, with its intensity dependent on plant density and environmental conditions, such as water and nutrient availability and light incidence.


2001 ◽  
Vol 49 (3) ◽  
pp. 293-297
Author(s):  
S. O. Bakare ◽  
M. G. M. Kolo ◽  
J. A. Oladiran

There was a significant interaction effect between the variety and the sowing date for the number of productive tillers, indicating that the response to sowing date varied with the variety. A significant reduction in the number of productive tillers became evident when sowing was delayed till 26 June in the straggling variety as compared to sowing dates in May. Lower numbers of productive tillers were also recorded when the sowing of the erect variety was further delayed till 10 July. The grain yield data showed that it is not advisable to sow the straggling variety later than 12 June, while sowing may continue till about 26 June for the erect variety in the study area.


2012 ◽  
pp. 89-93
Author(s):  
Tamás Árendás ◽  
Zoltán Berzsenyi ◽  
Péter Bónis

The effect of crop production factors on the grain yield was analysed on the basis of three-factorial experiments laid out in a split-split-plot design. In the case of maize the studies were made as part of a long-term experiment set up in 1980 on chernozem soil with forest residues, well supplied with N and very well with PK. The effects of five N levels in the main plots and four sowing dates in the subplots were compared in terms of the performance of four medium early hybrids (FAO 200). In the technological adaptation experiments carried out with durum wheat, the N supplies were moderate (2010) or good (2011), while the P and K supplies were good or very good in both years. Six N top-dressing treatments were applied in the main plots and five plant protection treatments in the subplots to test the responses of three varieties. The results were evaluated using analysis of variance, while correlations between the variables were detected using regression analysis.The effect of the tested factors on the grain yield was significant in the three-factorial maize experiment despite the annual fluctuations, reflected in extremely variable environmental means. During the given period the effect of N fertilisation surpassed that of the sowing date and the genotype. Regression analysis on the N responses for various sowing dates showed that maize sown in the middle 10 days of April gave the highest yield, but the N rates required to achieve maximum values declined as sowing was delayed. In the very wet year, the yield of durum wheat was influenced to the greatest extent by the plant protection treatments, while N supplies and the choice of variety were of approximately the same importance.  In the favourable year the yielding ability was determined by topdressing and the importance of plant protection dropped to half,  while no  significant difference could be detected between the tested varieties. According to the results of regression analysis, the positive effect of plant protection could not be substituted by an increase in the N rate in either year. The achievement of higher yields was only possible by a joint intensification of plant protection and N fertilisation. Nevertheless, the use of more efficient chemicals led to a slightly, though not significantly, higher yield, with a lower N requirement. 


2009 ◽  
Vol 7 ◽  
pp. 63-69
Author(s):  
PCP Chaurasia ◽  
E Duveiller

An experiment was conducted at agronomy farm of Agriculture research Station, Tarahara,Nepal for three consecutive years viz 2000/2001,2001/2002, and 2002/2003 to evaluate theeffects of different cultural practices on leaf blight diseases of wheat caused by Bipolarissorokiniana under terai conditions. The experiment was conducted in factorial RandomizedComplete Block Design with four replications. Four factors, two wheat verities RR-21 andNepal 297,two number of irrigations (two and three irrigations), two doses of Nitrogen fertilizerviz. 60kg N/ha and 120 kg N/ha and two dates of sowing of wheat were examined. Differentyield components, grain yield (kg/plot) and disease severity were recorded to judge the effects ofthese factors on severity of leaf blight of wheat. Nepal Line 297 had significantly less AUDPCbased on flag leaf infection and whole plan as compared to RR-21. Number of irrigations had nosignificant effect on AUDPC, as there was frequent rain during experimental period. Doses ofNitrogen fertilizer had significant effect on AUDPC based on flag leaf infection. It was higher incase of 60 kg N/ha. The third week of November sowing of wheat had lower value of AUDPCas compared to December sowing. Plant height, panicle lengths were highly significantly higherin case of RR-21 as compared to Nepal-297. Thousand kernel weight, and grain yield kg/ha weresignificantly higher in Nepal-297. All agronomic parameters except thousand kernel weight andnumber of tillers/plan were significantly higher in 120kg N/ha. The third week of Novembersowing of wheat had less plant height and panicle length, higher thousand kernel weight andmore grain yield. Leaf blight severity was highly significantly less in case of Nepal-297. Dosesof Nitrogen fertilizer had significant effect on plant height, panicle length, thousand kernelweight, percentage flag leaf infection and AUDPC based on flag leaf infection. Based on theresults of three years of experimentations, it can be concluded that Nepal-297 had less disease,number of irrigations had no effect on disease severity, higher doses of nitrogen fertilizer hadless flag infection and late sowing of wheat also had less disease. Numbers of irrigation's effectswere inconclusive as there were frequent rains during experimentation period. Based on aboveconclusion, it is recommended that growing wheat verity like Nepal-297, use of higher doses ofnitrogen fertilizer and sowing of wheat / first week of Dec help in minimizing the severity of leafblight. However late sowing had lowered grain yield.Key words: AUDPC; culture practices; disease management; leaf blightDOI: 10.3126/narj.v7i0.1870Nepal Agriculture Research Journal Vol.7 2006 pp.63-69


1987 ◽  
Vol 27 (5) ◽  
pp. 721 ◽  
Author(s):  
IA Rose

Seven genotypes, including 5 in the final stages of cultivar selection, were evaluated for their phenological development, yield, seed size, oil concentration and protein concentration in response to changes in sowing date and row spacing over 3 seasons, 1982-83, 1983-84and 1984-85. Genotype x sowing date interactions were detected for both phenological development and yield, particularly with the cultivar Sxy 59. This genotype was most affected by temperature during the pre-flowering phase of early November sowings. It was lower yielding in November sowings but was the highest yielding genotype in January sowings. Its adaptation to January sowings was unexpected because this genotype also showed high photoperiod sensitivity and flowered and matured rapidly in the late sowings. With early sowing, yield of the other cultivars was equivalent, or superior to (P=0.05), that obtained with the recommended early December sowing date, depending on the season. Late sowings caused yield reductions of about 34%. Increases in yield with narrow rows (50 v. 100 cm) were significant (P = 0.05) in 1 season and averaged 5% overall. Genotypexrow spacing interactions were only detected in 1 season, but no genotype was superior to the standard cultivar, Forrest, in adaptation to narrow rows. Thus this study revealed genotype responses which would affect adoption of newly released cultivars. It was concluded that this type of study is valuable in the final stages of a selection program and that these studies should include both early and late sowing dates and be conducted over several seasons.


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