Nutrient uptake and distribution by bread and durum wheat under drought conditions in South Australia

1999 ◽  
Vol 39 (6) ◽  
pp. 721 ◽  
Author(s):  
A. Zubaidi ◽  
G. K. McDonald ◽  
G. J. Hollamby

Summary. An important limitation to the production of durum wheat in South Australia is its poor adaptation to the alkaline, sodic soils of the cereal belt, which often results in nutrient imbalances in the crop. A field experiment was conducted at Palmer, South Australia, to measure the nutrient uptake and distribution between grain and straw of 3 bread wheat cultivars and 9 cultivars and breeding lines of durum wheat. The purpose of the work was to characterise the patterns of nutrient uptake and to examine whether there were major, consistent differences between bread wheat and durum wheat. Rainfall during the growing season was below average and the crops suffered from drought stress after anthesis. Plants were marginally deficient or deficient in nitrogen (N), phosphorus (P) and zinc (Zn), and boron (B) concentrations were high. Compared with bread wheat, durum wheat had a very much higher concentration of sodium (Na), higher concentrations of calcium (Ca) and sulfur (S), but lower concentrations of potassium (K), magnesium (Mg), manganese (Mn) and copper (Cu). Total amounts of P, Zn and Na in the shoot continued to increase throughout the growing season with significant increases occurring during grain filling, whereas there was little increase in the amount of N, K, B and Mn during grain filling. The maximum rate of nutrient uptake occurred before the time of maximum crop growth rate, and was in the order K (10.1 weeks after sowing), N (10.6), P (11.3), Mn (12.0), Zn (12.5) and B (14.6); maximum growth rate occurred at 14.8 weeks. There was no consistent difference between bread and durum wheat in the partitioning of nutrients to the grain. The importance of N and Zn uptake to the growth of the durum wheat genotypes was shown by significant correlations between maximum uptake rates of these nutrients and maximum crop growth rate, with the strongest correlation being with Zn. Growth rate was not correlated with uptake rates of other nutrients. A number of genotypes of durum wheat had maximum rates of Zn and Mn accumulation up to twice those of the current commercial genotypes. Some of these lines have yielded well at Zn- and Mn-deficient sites which indicates that the micronutrient efficiency of durum can be improved. Late in the season the experiment showed signs of infection by crown rot (Fusarium graminearum Schw. Group 1). Durum wheat showed more severe symptoms than bread wheat and the number of white heads in durum wheat was inversely correlated with the concentration of Zn in the shoot during the pre-anthesis period.

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016


1982 ◽  
Vol 62 (4) ◽  
pp. 855-860 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. B. DAYNARD

The effect of source-sink ratio (i.e., the ability of the leaves to produce photosynthate versus the capacity of the grain to accommodate the assimilates) on dry matter accumulation and leaf senescence during the grain filling period of two short-season maize (Zea mays L.) hybrids was investigated in 1979 and 1980. Source-sink ratio of the maize hybrids was altered by ear removal at midsilking and at 3 wk after midsilking; by partial fertilization of the topmost ear so that treatment ears contained approximately 50% of kernel number of the control; and by removal of all leaf blades but that of the ear leaf at 2 wk after midsilking. Crop growth rate during the period from 3–5 wk after midsilking was reduced by 30% for the partly fertilized treatment and by 60% for both ear removal treatments. During the period from 5 to 7 wk after midsilking, the treatment-by-hybrid interaction for crop growth rate reflected different patterns of leaf senescence. In one hybrid, treatments which caused reductions in sink size delayed leaf senescence and increased the crop growth during the 5 to 7-wk postsilking interval, relative to the control. The reverse was evident for the other hybrid. Partial defoliation tended to cause the remaining ear leaf to senescence slightly earlier than in the control. Apparently two types of leaf senescence occurred: senescence due to assimilate starvation, and senescence due to excessive assimilate accumulation. The former caused by excessively low source-sink ratio and the latter caused by excessively high source-sink ratio. These results indicate that a delicate balance exists between sink and source during the grain-filling period of maize, and that disturbance of this balance can cause substantial yield reductions, plus an acceleration of leaf senescence and maturation processes.


1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.


2015 ◽  
Vol 31 (1–2) ◽  
pp. 21-32
Author(s):  
K. Olech ◽  
Z. K. Blamowski

Measurements were carried out of the assimilation area, NAR value, the crop growth rate (C) and of the yield of roots and leaves of sugar beet plants in a production field during two successive vegetation years. An interdependence was found between the formation of the assimilation area in the canopy and the final yield of biomass. The assimilation area depended mainly on the date of sowing. In 1975, the sowing was earlier by 15 days, amid this resulted in a much more favourable LAI and in a higher yield of biomass. During both vegetation years, a violent decrease of the crop growth rate was observed at the end of August and at the beginning of September. This may be due to an unfavourable change in the ratio of the area of younger, photosynthetically active leaves to older, less active leaves and also to the increased participation of the loss of the assimilates resulting from stronger respiration of the fast growing roots while the photosynthesis of the whole plants decreases.


1983 ◽  
Vol 63 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. TOLLENAAR

Duration of the growing season appears to be the single most important factor limiting vegetative productivity in Canada. A theoretical estimate of annual vegetative productivity in the absence of limitations due to water, nutrients or soil structure, shows that potential productivity in the 5-mo growing season of Southern Canada is in the range of 25–55 tonne/ha. Maximum productivity, however, lies considerably below the potential productivity estimate due to lower-than-expected photosynthetic efficiency during periods of high solar irradiance. Crop growth rates appear to be rather independent of variation in radiant flux density during the growing season. Consequently, a realistic estimate of maximum vegetative productivity can be obtained by multiplying number of days of full light interception by a crop canopy, by a crop growth rate of 230 kg∙h−1∙day−1 and adding the weight of the crop at the onset of full light interception by the canopy. Maximum vegetative productivity could likely be improved by extending the period of full light interception by crop canopies through the cultivation of perennial species or double-crop sequences. Alternatively, vegetative productivity could likely be improved through increased photosynthetic efficiency. Very high photosynthetic efficiencies of crops grown under field conditions have been reported occasionally in the literature, but factors underlying this high photosynthetic efficiency have not yet been identified.Key words: Vegetative production, photosynthetic efficiency, potential productivity, duration of growing season, crop species


1979 ◽  
Vol 30 (1) ◽  
pp. 53 ◽  
Author(s):  
JH Silsbury ◽  
L Adem ◽  
P Baghurst ◽  
ED Carter

Shoot dry matter yield data for swards of Medicago truncatula cv. Jemalong established on two occasions at Adelaide in 1975 have been used to examine the influence of sowing rate on the seasonal growth pattern of this species. The patterns of dry matter growth are assessed: (i) by the use of a logistic function; (ii) by a growth stage approach involving an initial phase of approximately exponential growth (stage I) followed by a phase of almost constant growth rate (stage II). Two methods are given for determining the duration of these stages. It was found that stage I1 began at a shoot dry weight of about 300 g m-2, irrespective of sowing rate. End-of-season yield at about 10 t ha-1 was largely independent of sowing time and of sowing density. A maximum crop growth rate of 14.9 g m-2 d-1 was recorded for low density and late sowing. Sowing density had a marked effect on the shape of the growth curves; both the maximum crop growth rate and the average crop growth rate in stage II decreased with increase in sowing rate for each time of sowing.


1977 ◽  
Vol 4 (4) ◽  
pp. 485 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury

Small swards of subterranean clover were grown at 20°C at different times of the year and at the same time under shades of different light transmission. Dry matter production and net CO2 exchange rates at different levels of irradiance were measured during growth. Crop growth rates and net CO2 exchange rates are examined in relation to plant attributes and to the daily solar radiation. Dry matter growth curves varied according to the daily solar radiation. Increase in crop growth rate with increase in daily solar radiation was taken to be linear for swards with similar dry weight and was more rapid for closed canopies than for those not showing full light interception. Once a closed canopy was attained, further increase in total dry matter resulted in decreased crop growth rate due, apparently, to increased loss of dry weight through increased respiration rate. The shape of the CO2 exchange/irradiance curve was linear up to 100 W m-2 (PAR) and curvilinear above that value. The rate of net CO2 exchange at 50 W m-2 (PAR) decreased with increase in shoot dry matter above 100 g m-2 due, apparently, to an increased rate of dark CO2 efflux: the rate was not affected by daily solar radiation during growth. The net CO2 exchange rate at 250 W m-2 (PAR) increased with increase in LAI up to 3 after which it became almost constant, varying only with the variation in daily solar radiation during growth. The rate of dark CO2 efflux was strongly affected by the amount of dry matter present and to a smaller extent by the crop growth rate or the daily solar radiation.


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