Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment

1989 ◽  
Vol 40 (3) ◽  
pp. 473 ◽  
Author(s):  
KHM Siddique ◽  
RK Belford ◽  
MW Perry ◽  
D Tennant

A field experiment was conducted at Merredin in the eastern wheat belt of Western Australia, comparing 10 wheat cultivars representing old and modern wheats. The aim of the study was to identify any morphological and physiological characters associated with higher grain yield of modern wheat cultivars.The modern cultivars reached double ridge, terminal spikelet, anthesis and maturity earlier than the old cultivars, but modern cultivars had a longer duration between double ridge and terminal spikelet stage. The number of leaves on the main stem generally decreased from old, Purple Straw (14) to modern cultivars like Kulin (8). The modern cultivars had a shorter phyllochron interval than the old cultivars. The old cultivars also produced more tillers per plant (7.3) and had a lower percentage (35%) of ear bearing tillers, as compared with 3.9 and 51% for modern cultivars.The green area index and ground cover was higher in old than modern cultivars. However, the efficiency of conversion of photosynthetically active radiation to dry matter was slightly greater for modern cultivars. Although dry matter at final harvest was similar between cultivars, there was a trend for higher dry matter production with modern cultivars. The post-anthesis green area duration was longer with modern cultivars and grain yield increased with increase in post-anthesis green area duration.Grain yield and HI increased consistently from old to modern cultivars. The most recent cultivar Kulin had the highest yield and second highest harvest index, which were 63% and 48% respectively higher than the oldest cultivar, Purple Straw. Increases in grain yield in the modern cultivars were associated with increased grains spikelet-1 and grains ear-1. Mean grain weight showed a slight reduction with modern cultivars. The results are discussed in relation to future improvement in yield.

1989 ◽  
Vol 40 (3) ◽  
pp. 473
Author(s):  
KHM Siddique ◽  
RK Belford ◽  
MW Perry ◽  
D Tennant

A field experiment was conducted at Merredin in the eastern wheat belt of Western Australia, comparing 10 wheat cultivars representing old and modern wheats. The aim of the study was to identify any morphological and physiological characters associated with higher grain yield of modern wheat cultivars.The modern cultivars reached double ridge, terminal spikelet, anthesis and maturity earlier than the old cultivars, but modern cultivars had a longer duration between double ridge and terminal spikelet stage. The number of leaves on the main stem generally decreased from old, Purple Straw (14) to modern cultivars like Kulin (8). The modern cultivars had a shorter phyllochron interval than the old cultivars. The old cultivars also produced more tillers per plant (7.3) and had a lower percentage (35%) of ear bearing tillers, as compared with 3.9 and 51% for modern cultivars.The green area index and ground cover was higher in old than modern cultivars. However, the efficiency of conversion of photosynthetically active radiation to dry matter was slightly greater for modern cultivars. Although dry matter at final harvest was similar between cultivars, there was a trend for higher dry matter production with modern cultivars. The post-anthesis green area duration was longer with modern cultivars and grain yield increased with increase in post-anthesis green area duration.Grain yield and HI increased consistently from old to modern cultivars. The most recent cultivar Kulin had the highest yield and second highest harvest index, which were 63% and 48% respectively higher than the oldest cultivar, Purple Straw. Increases in grain yield in the modern cultivars were associated with increased grains spikelet-1 and grains ear-1. Mean grain weight showed a slight reduction with modern cultivars. The results are discussed in relation to future improvement in yield.


1991 ◽  
Vol 42 (1) ◽  
pp. 13 ◽  
Author(s):  
MM Karimi ◽  
KHM Siddique

An analysis of the dynamics of green area index (GAI), dry matter (DM), relative growth rate (RGR) and crop growth rate (CGR) based on growing degree days (GDD) is presented for a historical series of wheats commercially released in Western Australia. Relative to the old cultivars, modern wheats were characterized by a greater RGR during the vegetative phase. This was achieved at a lower initial GAI, which persisted as the season progressed and was associated with a higher CGR at anthesis and greater grain yield at the end of the season. In the old cultivars, a greater GAI during the mid season declined rapidly as temperatures and soil moisture stress increased in spring, resulting in a lower GAI at anthesis. Together with lower CGR at anthesis this resulted in less dry matter and grain yield at final harvest. The higher grain yield of modern wheat cultivars was achieved with a high RGR during the vegetative phase and greater CGR from ear emergence to harvest.


1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.


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


1982 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. U. Remison ◽  
E. O. Lucas

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.


1990 ◽  
Vol 41 (3) ◽  
pp. 431 ◽  
Author(s):  
KHM Siddique ◽  
D Tennant ◽  
MW Perry ◽  
RK Belford

Water use and water use efficiency of old and modern wheat cultivars and one barley cultivar were measured in a Mediterranean environment at Merredin, W.A. Water use efficiency for grain increased substantially from old to modern cultivars, with little difference among modern cultivars. Water use efficiency for dry matter was similar between cultivars. Barley had the highest water use efficiency of both grain and dry matter. Improved water use efficiency for grain in modern cultivars was associated with faster development, earlier flowering, improved canopy structure and higher harvest index. Modern cultivars used slightly less water than old cultivars. The pattern of water use was also different, with late-maturing old cultivars using more water in the pre- than the post-anthesis period. The ratio of pre- to post-anthesis water use was highest with the late-maturing, old cultivar Purple Straw (5.2:1) and lowest with early-maturing, modern cultivar Gutha (3.0:1). Soil evaporation estimates showed that modern cultivars had lower rates of soil evaporation in the early part of the growing season. This was associated with their faster leaf area development and improved light interception. About 40% of the total water use was lost by soil evaporation with very little difference between wheat cultivars. Barley had 15% less soil evaporation than wheat. Water use efficiency for grain based on transpiration (transpiration efficiency) for the four modern cultivars was 15.8 kg ha-1 mm-1, similar to other studies in comparable environments. Some further improvement in water use efficiency appears possible through improvement in crop biomass and harvest index. However, given the frequent and severe limitations of total water supply at low rainfall sites such as Merredin, there appears to be more scope for improvement in yield and water use efficiency in the medium and high rainfall areas of the wheatbelt.


2002 ◽  
Vol 138 (2) ◽  
pp. 153-169 ◽  
Author(s):  
M. J. FOULKES ◽  
R. K. SCOTT ◽  
R. SYLVESTER-BRADLEY

Experiments in three dry years, 1993/94, 1994/95 and 1995/96, on a medium sand at ADAS Gleadthorpe, England, tested responses of six winter wheat cultivars to irrigation of dry-matter growth, partitioning of dry matter to leaf, stem and ear throughout the season, and to grain at final harvest. Cultivars (Haven, Maris Huntsman, Mercia, Rialto, Riband and Soissons) were selected for contrasts in flowering date and stem soluble carbohydrate. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (>75 mm) from early June in 1994 and from May in 1995 and 1996. The main effects of drought on partitioning of biomass were for a decrease in the proportion of the crop as lamina in the pre-flowering period, and then earlier retranslocation of stem reserves to grains during the first half of grain filling. Restricted water availability decreased grain yield by 1·83 t/ha in 1994 (P<0·05), and with more prolonged droughts, by 3·06 t/ha in 1995 (P<0·001) and by 4·55 t/ha in 1996 (P<0·001). Averaged over the three years, grain yield responses of the six cultivars differed significantly (P<0·05). Rialto and Mercia lost only 2·8 t/ha compared with Riband and Haven which lost 3·5 t/ha. Losses for Soissons and Maris Huntsman were intermediate. In the two years with prolonged drought, the biomass depression was on average greater for Haven (6·0 t/ha) than for Maris Huntsman (4·2 t/ha) (P<0·05). Thus, the grain yield sensitivity of Haven to drought derived, in part, from a sensitivity of biomass growth to drought. Harvest index (HI; ratio of grain to above-ground dry matter at harvest) responses of the six cultivars to irrigation also differed (P<0·05) and contributed to the yield responses. The smallest decrease in HI of the six cultivars with restricted water availability was shown by Rialto (−0·033); this partially explained the drought resistance for this cultivar. The largest decrease was for Maris Huntsman (−0·072). The cultivars differed in flowering dates by up to 9 days but these were poorly correlated with grain yield responses to irrigation. Stem soluble carbohydrate at flowering varied amongst cultivars from 220 to 300 g/m2 in the unirrigated crop; greater accumulation appeared to be associated with better maintenance of HI under drought. It is concluded that high stem-soluble carbohydrate reserves could be used to improve drought resistance in the UK's temperate climate, but that early flowering seems less likely to be useful.


2003 ◽  
Vol 140 (4) ◽  
pp. 395-407 ◽  
Author(s):  
R. E. RUSKE ◽  
M. J. GOODING ◽  
S. A. JONES

Field experiments were conducted over 3 years to assess the effect of a triazole fungicide programme, and additions of strobilurin fungicides to it, on nitrogen uptake, accumulation and partitioning in a range of winter wheat cultivars. Commensurate with delayed senescence, fungicide programmes, particularly when including strobilurins, improved grain yield through improvements in both crop biomass and harvest index, although the relationship with green area duration of the flag leaf (GFLAD) depended on year and in some cases, cultivar. In all years fungicide treatments significantly increased the amount of nitrogen in the above-ground biomass, the amount of nitrogen in the grain and the nitrogen harvest index. All these effects could be linearly related to the fungicide effect on GFLAD. These relationships occasionally interacted with cultivar but there was no evidence that fungicide mode of action affected the relationship between GFLAD and yield of nitrogen in the grain. Fungicide treatments significantly reduced the amount of soil mineral N at harvest and when severe disease had been controlled, the net remobilization of N from the vegetation to the grain after anthesis. Fungicide maintained the filling of grain with both dry matter and nitrogen. The proportionate accumulation of nitrogen in the grain was later than that of dry matter and this difference was greater when fungicide had been applied. Effects of fungicide on grain protein concentration and its relationship with GFLAD were inconsistent over year and cultivar. There were several instances where grain protein concentration was unaffected despite large (1·5 t/ha) increases in grain yield following fungicide use. Dilution of grain protein concentration following fungicide use, when it did occur, was small compared with what would be predicted by adoption of other yield increasing techniques such as the selection of high yielding cultivars (based on currently available cultivars) or by growing wheat in favourable climates.


Author(s):  
D. Dev Kumar ◽  
D. Vishnu Vardhan Reddy ◽  
P. Raghuveer Rao ◽  
M. Sheshu Madhav ◽  
V. Gouri Shankar

The experimental field was laid in RBD replicated thrice with 30 high yielding rice genotypes which includes 26 advanced breeding lines (ABL) (SP-351, SP-352, SP-353, SP-354, SP-355, SP-356, SP-357, SP-358, SP-359, SP-360, SP-70, SP-72, SP-63, SP-61, SP-69, SP-55, SP-80, SP-25, SP-13,  SP-03, SP-02, SP-34, SP-37, SP-08, SP-75 and SP-57) and four checks (NDR-359, BPT-5204, IR-64, Jaya). Seven genotypes showed significantly higher leaf weight over the BPT-5204. Further, leaf weight at panicle initiation stage showed a positive relationship with TDM (Total Dry Matter) (r=0.51**). At the panicle initiation stage, only three genotypes (SP-354, SP-358, and SP-72) were superior to BPT-5204 in leaf weight. The shoot biomass and total dry weight was superior only in one genotype SP-72 as compared to BPT-5204. Similarly, the net assimilation rate at panicle initiation stage was maximum in SP-08 (9.92g m-2 day-1) and SP-72 (9.35g m-2 day-1) as compared to check BPT-5204 (6.47g m-2 day-1). These genotypes maintained higher photosynthetic rate (SP-72) and higher grain yield (SP-08). The relationship between CGR (Crop Growth Rate) and TDM (Total Dry Matter) and grain yield (r=0.61**) was positive and significant at physiological maturity. Genotypes SP-08 and SP-72 showed significantly higher CGR (Crop Growth Rate) over BPT-5204 and hence, yielded higher. In the present study compared to BPT-5204, genotypes SP-72, SP-08 maintained higher lea area index at all crop growth stages. These genotypes maintained higher photosynthetic rate (SP-72) and higher grain yield (SP-08). Positive significant relationship between LAI (Leaf Area Index) and total dry matter at harvest and; grain yield has been observed.


1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.


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