scholarly journals Sowing date reduces the incidence of wheat blast disease

2016 ◽  
Vol 51 (5) ◽  
pp. 631-637 ◽  
Author(s):  
Maurício Antônio de Oliveira Coelho ◽  
Gisele Abigail Montan Torres ◽  
Paulo Roberto Cecon ◽  
Flávio Martins Santana

Abstract: The objective of this work was to assess the effect of sowing date on the intensity of wheat blast disease, as well as the yield losses caused by this disease in different wheat (Triticum aestivum) genotypes. The experiments were conducted in 2013 at the Sertãozinho experimental station of Empresa de Pesquisa Agropecuária de Minas Gerais (Epamig), in the municipality of Patos de Minas, in the state of Minas Gerais, Brazil. Fourteen wheat genotypes and two sowing dates were evaluated. The experimental design was a randomized complete block with three replicates. The evaluated variables were: incidence, severity, thousand grain weight (TGW), grain yield, and yield losses. A disease index (DI) was calculated, based both on the incidence and the severity of the disease, to measure blast intensity in wheat. The sowing date significantly affected DI, TGW, and grain yield. Significant linear correlations were observed between DI and yield losses (0.89), between losses and TGW (-0.85), and between losses and grain yield (-0.93). For wheat blast, DIs greater than or equal to 0.5 indicate potential yield losses equal to or greater than 70%. The EP063030 line and the MGS Brilhante and BRS 264 cultivars are the most tolerant to blast, when exposed to high disease pressure.

1991 ◽  
Vol 27 (1) ◽  
pp. 71-77 ◽  
Author(s):  
H. M. Ishag ◽  
O. A. A. Ageeb

SUMMARYThe potential yield of wheat and the physiological basis of yield limitation in the lowland irrigated tropics was investigated in three cultivars planted at five sowing dates. Maximum grain yields were achieved by cultivars that flowered in January when the weather was coolest. The period from sowing to terminal spikelet initiation was similar for all varieties and all sowing treatments. The period from terminal spikelet initiation to ear emergence was increased when seed was sown in late November or early December rather than in October or early November. Manipulation of the sowing date in relation to the choice of cultivar had a considerable effect on grain yield.H. M. Ishag and O. A. A. Ageeb: Rendimiento del trigo en las zonas tropicales.


2018 ◽  
Vol 16 (02) ◽  
pp. 65-74
Author(s):  
R Islam ◽  
Abdullah Al Mamun ◽  
M Jahangir Alam ◽  
MB Anwar ◽  
MA Hakim

A trial was conducted during 2015-16 to 2017-18 at the Regional Agricultural Research Station (RARS) of Bangladesh Agricultural Research Institute (BARI), Jashore to select some tolerant varieties against wheat blast. Fourteen varieties including eight old varieties (Sonalika, Kanchan, Sourav, Gourab, Shatabdi, Sufi, Bijoy, Prodip) and six newly released varieties (BARI Gom 25, BARI Gom 26, BARI Gom 27, BARI Gom 28, BARI Gom 29 and BARI Gom 30) were evaluated. The experiments were non-replicated and were planted in two sowing dates, at optimum (mid November) and late (mid December) conditions. Three irrigations were applied, at crown root initiation (CRI), heading and grain filling stages. Plants of border rows were inoculated by Magnaporthe oryzae triticum (MoT) spores (104 conidia ml-1) for infection once per week from three weeks after sowing until primary infection was observed. The significantly higher grain yield was observed in 2016-17 (3505 kg ha-1) which was similar to 2017-18 (3448 kg ha-1) and the lowest was in 2015-16 (1680 kg ha-1). The higher grain yield was obtained due to the higher grains spike-1 (45 no.) and 1000 grain weight (36.6 g) and lower blast disease incidence (% blast index 18.1%). In all three years, there was heavy infection of wheat blast in late sowing condition (% blast index 40.7) compared to the optimum sowing condition (% blast index 1.4), resulting in very poor crop yield (1696 kg ha-1). Among the varieties, the variety Gourab produced the highest yield (3395 kg ha-1) which was similar to the newly released variety BARI Gom 28 (3196 kg ha-1) and BARI Gom 30 (3134 kg ha-1). In case of blast disease severity, old varieties were less infested with some exception in Sonalika and Kanchan. On the other hand, BARI Gom 25 and BARI Gom 26 were more susceptible (% blast index 35.3-36.5) to wheat blast compared to BARI Gom 28 and BARI Gom 30 (% blast index 20.2-22.5). The Agriculturists 2018; 16(2) 65-74


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. 


2018 ◽  
Vol 64 (No. 7) ◽  
pp. 310-316 ◽  
Author(s):  
Mirosavljevic Milan ◽  
Momcolovic Vojislava ◽  
Maksimovic Ivana ◽  
Putnik-Delic Marina ◽  
Pržulj Novo ◽  
...  

The aim of this study was to improve understanding of (1) the effect of genotypic and environmental factors on pre-anthesis development and leaf appearance traits of barley and wheat; (2) the relationship of these factors with grain yield, and (3) the differences between these two crops across different environments/sowing dates. Therefore, trials with six two-row winter barley and six winter wheat cultivars were carried out in two successive growing seasons on four sowing dates. Our study showed that the observed traits varied between species, cultivars and sowing dates. In both growing seasons, biomass at anthesis and grain yield declined almost linearly by delaying the sowing date. There was no clear advantage in grain yield of wheat over barley under conditions of later sowing dates. Generally, barley produced more leaf and had shorter phyllochron than wheat. Both wheat and barley showed a similar relationship between grain yield and different pre-anthesis traits.


2017 ◽  
Vol 10 (1) ◽  
pp. 117-124
Author(s):  
SK Mondal ◽  
MM Rahman

The experiment was conducted to find out the morpho-physiological variability in response to different sowing dates in four lines of Quality Protein Maize (QPM) in in the Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh. The study was carried out with four lines of maize and two sowing dates, 15 November (T1) and 15 December, ((T2). Sowing date differed significantly in plant height, length of leaf blade, length of leaf sheath, leaf breadth, cob length, cob diameter, length of tassel, days to 50% tasselling, days to 50 % silking, days to maturity, number of cobs per plant, cob weight, number of grain per cob. 1000-seed weight, percent underdeveloped cob, total dry matter and grain yield, but did not differ in number of leaves and protein percent. The lines differed significantly among themselves in those characters except number of leaves per plant, length of leaf sheath, cob length, cob diameter, days to 50% tasselling, number of cobs per plants and number of grain per cob. The line Across 8666 (V2) and (V3) gave the highest grain yield 4.57 and 4.55 and the lowest from (V4) lines 4.41 tons per hectare. The 15 November sowing time (T1) gave the highest grain yield 4.86 tons per hectare. In case of interaction, the earlier planting time (T1) showed better performance with all lines. On the other hand, the highest yield was found from combination of line V2 and V3 with earlier planting time (T1).J. Environ. Sci. & Natural Resources, 10(1): 117-124 2017


Helia ◽  
2018 ◽  
Vol 41 (69) ◽  
pp. 253-266
Author(s):  
Ali Asghar Aliloo

AbstractSunflower is an important source for edible oils and biodiesel production. Its productivity is limited by many agronomical practices one of which is the sowing date. In this study, the effects of different sowing dates from early April to late June on phenology and yield of sunflower cultivars were investigated. The results showed that sunflower has a relatively long period of possible sowing dates, stretching from early April to late June in North West of Iran. However, delayed sowing dates significantly decreased the number of days needed for phenophases. For every day of delay, the model predicted (R2=0.97) a losing rate in achene yield by 22.2 kg h−1 from the first sowing date. For relationships between growing degree days (GDD) and yield, almost the same results were obtained. About 22 kg h−1 reduction (R2=0.79) in yield per day was estimated by GDD index when the average GDDs per day was 14.2. However, helio-thermal units (HTU) did not predict this reduction accurately. A suggested comprehensive model, that used the percent of yield losses and changes in vegetative to reproductive ratio, found a significant and positive relationship between the indices and yield losses. For all indices, an increase in vegetative to reproductive ratio resulted in increased grain yield losses.


1992 ◽  
Vol 118 (3) ◽  
pp. 279-287 ◽  
Author(s):  
M. J. Conry ◽  
A. Hegarty

SUMMARYAn experiment, carried out over a 5-year period (1984–88) on medium–heavy textured soil at Athy (Ireland), tested the effect of five sowing dates (early September–early December) and four seed rates (c. 100, 150, 200 and 250 kg/ha) on the grain yield and protein content of winter barley (cv. Panda).September-sown plots gave the greatest yields in all years. Plots sown in mid-October and later gave significantly reduced yields. Yield reductions over the 5-year period averaged 15, 24 and 34% for the mid-October, November and December sowing dates, respectively. Significant differences in yield between the smaller and larger seed rates were obtained, with the latter giving the greatest yields at all sowing dates from late September to December. Increasing the seed rate, however, did not compensate for the yield reduction due to delayed sowing. In the early September-sown plots, the higher seed rates gave reduced yields in four of the five years (1984–87) with the opposite result in 1988. In 1988 the early September-sown plots gave greater yields than the late September-sown plots.Regression analysis showed a strong relationship between yield and log(ears/m2) in four of the five years (1984–87) but the relationship was poor in 1988 primarily due to the inexplicably low ear population of the early-sown plots. The inclusion of 1000-grain weight in the model gave a better fit and accounted for a high proportion (62–80%) of the yield variation.The late September sowing date and the higher seed rates gave slightly lower protein levels in four of the five years. There was an inverse relationship between grain yield and protein for the same four years (1984–87).


1976 ◽  
Vol 16 (78) ◽  
pp. 129
Author(s):  
PN Vance

The relationship between grain yield and five plant characters in grain sorghum hybrid Pioneer 846 was studied. Grain yield was closely correlated with head weight, weight of a standard length of peduncle (WSP), peduncle perimeter (PP), head length and breadth. The close correlation of grain yield on WSP was shown to exist at a number of sites and for a number of varieties. However, regression equations differed for different sites, sowing dates and varieties. Of the two components of grain yield per head, single grain weight and grain number; only grain number was closely correlated with WSP. In one instance where moisture stress affected grain development, grain number but not yield was closely correlated with WSP. WSP was shown not to be affected by damage to the head and could therefore be used to estimate potential yield in agronomic trials where yield loss due to pest activity has occurred.


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.


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