Effects of Photoinhibition Induced by Water Stress on Growth and Yield of Grain Sorghum

1988 ◽  
Vol 15 (2) ◽  
pp. 179 ◽  
Author(s):  
MM Ludlow ◽  
SB Powles

The significance of photoinhibition induced by water stress for growth and grain yield of sorghum was investigated by shading water-stressed plants for a 7-day period during panicle development. Thereafter, shading was removed, stressed plants were rewatered, and all plants were kept well-watered until physiological maturity. Shading water-stressed plants for a 7-day period increased grain number and grain yield of primary heads by 10- and 13-fold, respectively. Even though plants were severely stressed, photoinhibition was only 20%. Moreover, reduction of photoinhibition by shading did not improve carbon supply to the developing panicle. Therefore, the response of grain yield to shading was attributed to a 15% higher average leaf water potential in shaded plants, which arose despite attempts to keep water status similar in shaded and unshaded plants. The effect of water stress on the primary head was so severe that many plants produced secondary heads. The grain yield from these secondary heads compensated for the low yield of primary heads so that the total dry matter production and total grain yield of water-stressed plants were similar to those of unstressed plants. In view of the ability of this relatively determinate species to compensate for potential yield losses, as well as the mechanisms to avoid water stress, high temperatures and excessive absorption of light, it seems unlikely that photoinhibition induced by water stress will be of agronomic significance in grain sorghum.

1985 ◽  
Vol 36 (1) ◽  
pp. 73 ◽  
Author(s):  
GC Wright

An experiment was conducted during the dry season in monsoonal tropical Australia to determine the influence of applied nitrogen (N) and period of inundation during furrow irrigation on the growth and yield of grain sorghum. Water was run in the furrows for 3, 6, 12 and 24 h at all irrigations, which were applied every 7-10 days throughout the season. A sprinkler irrigated crop was used to represent zero inundation. Increasing the period of inundation from 0 to 24 h at each irrigation reduced grain yield by 43.8, 49.5 and 43.2% for crops supplied with 0, 80 and 170 kg N ha-1 respectively. This yield reduction was associated with fewer grains per plant, grain weight having only a small influence on final yield. Air-filled porosity of the soil recovered more slowly as the period of inundation increased. The time taken to reach an air-filled porosity of 0.10 at the 10-20 cm depth interval was highly correlated with grain yield. The results indicate that grain yield is strongly influenced by the duration of waterlogging associated with flood irrigation. To minimize yield losses crops should be irrigated and drained rapidly to reduce the duration and severity of soil anaerobiosis.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Thierry E. Besançon ◽  
Ranjit Riar ◽  
Ronnie W. Heiniger ◽  
Randy Weisz ◽  
Wesley J. Everman

Dicamba and 2,4-D are among the most common and inexpensive herbicides used to control broadleaf weeds. However, different studies have pointed the risk of crop injury and grain sorghum yield reduction with postemergence applications of 2,4-D. No research data on grain sorghum response to 2,4-D or dicamba exists in the Southeastern United States. Consequently, a study was conducted to investigate crop growth and yield response to 2,4-D (100, 220, and 330 g acid equivalent ha−1) and dicamba (280 g acid equivalent ha−1) applied on 20 to 65 cm tall sorghum. Greater stunting resulted from 2,4-D applied at 330 g acid equivalent ha−1or below 45 cm tall sorghum whereas lodging prevailed with 2,4-D at 330 g acid equivalent ha−1and dicamba applied beyond 35 cm tall crop. Regardless of local environmental conditions, 2,4-D applied up to 35 cm tall did not negatively impact grain yield. There was a trend for yields to be somewhat lower when 2,4-D was applied on 45 or 55 cm tall sorghum whereas application on 65 cm tall sorghum systematically decreased yields. More caution should be taken with dicamba since yield reduction has been reported as early as applications made on 35 cm tall sorghum for a potentially dicamba sensitive cultivar.


2019 ◽  
Vol 3 (1) ◽  
pp. 81
Author(s):  
Saroj Thapa ◽  
Khagendra Thapa ◽  
Jiban Shrestha ◽  
Amit Chaudhary

Rice (Oryza sativa L.) is first staple crop of Nepal. The national average yield of rice is less than its potential yield, for which poor agronomic management has been reported as the critical factor. Among various agro-management practices seedling age, seeding density and nitrogen rates significantly affect the growth and yield of rice. The lower seeding density produces the taller plant, more effective tiller, lower sterility and higher grain yield. On the other hand, seedling of older age from higher seeding density gives the lowest yield. Transplanting younger seedling with low seeding density and application of recommended dose of nitrogen gives a higher yield. This article summarizes various effects of seedling age, seeding density and nitrogen rates on plant height, number of effective tillers, number of filled grains, thousand grain weight and grain yield of rice. This information may be useful for maize growers and researchers.


2011 ◽  
Vol 48 (No. 5) ◽  
pp. 230-235
Author(s):  
M. Sabo ◽  
M. Bede ◽  
Ž.U. Hardi

Variability of grain yield components of some new winter wheat genotypes (e.g. Lara, Lenta, Kruna, Fiesta, Perla, and one line of AG-45) was examined. The analysis of grain yield components of these genotypes and the line was undertaken in a two-year research (1997/1998 and 1998/1999) at two different locations. Significant differences among genotypes, locations and research years were established. In the first experimental year (1997/1998) there was a high positive correlation between nearly all components of the grain yield. The most significant correlation was found between the grain number per spike and grain yield. In the second experimental year (1998/1999) the components did not show statistically significant correlation with the grain yield. It seems that the grain yield of examined genotypes depended significantly on the grain number per spike, grain mass per spike, and agroecological conditions during the vegetation period, whereby the potential yield was determined by the interaction among genotypes, location and production year. The biggest differences among examined genotypes of winter wheat were found in the stem height and spike length.


1982 ◽  
Vol 22 (115) ◽  
pp. 76 ◽  
Author(s):  
KA Boundy ◽  
TG Reeves ◽  
HD Brooke

The effect of serial planting on dry matter production, leaf area, grain yield and yield components cf Lupinus angustifoiius (cvv. Uniwhite, Uniharvest and Unicrop) and L. albus (cv. Ultra) was investigated in field plots at Rutherglen in 1973 and 1974. Delayed planting reduced dry matter production of all cultivars, and leaf area for Ultra. Differences in dry matter partitioning were observed between the late flowering Uniharvest, and the early flowering Unicrop and Ultra. In Uniharvest, delayed plantings resulted in a greater proportion of total dry matter being produced during the flowering phase, whereas the reverse was true for Unicrop and Ultra. The later flowering cultivars showed marked grain yield and yield component reduction with later sowing. Yields were reduced by 160.6 kg/ha and 222.5 kg/ha for each week's delay in sowing Uniharvest and Uniwhite, respectively. This effect was offset in the early flowering cultivars by greater development of lateral branches. In addition, when Unicrop and Ultra were planted in April, pod and flower abortion on the main stem resulted from low temperatures at flowering time. Optimum sowing time was early April for Uniwhite and Uniharvest, and early May for Unicrop and Ultra. Excellent vegetative growth under ideal moisture conditions highlighted the poor harvest indices of lupins and the scope for genetic improvement in the genus.


1990 ◽  
Vol 41 (3) ◽  
pp. 449 ◽  
Author(s):  
GK McDonald

The growth and yield of two lines of uniculm barley, WID-103 and WID-105, were compared over a range of sowing rates (50-400 kg/ha) with the commercial varieties Galleon and Schooner. The experiments were conducted at Strathalbyn, S.A., in 1986, 1987 and 1988 and at the Waite Agricultural Research Institute in 1987. A third tillered variety, Clipper, was included in the comparison in 1988. Over the three years plant populations measured early in the season ranged from 39/m2 to 709/m2, and grain yields from 97 to 41 1 g/m2. Dry matter production at ear emergence increased with greater plant density, and both the tillered varieties and the uniculm lines showed similar responses to higher sowing rates. At maturity, dry matter production of the tillered barleys was greater than or equal to that of the uniculms and the harvest indices (HIs) of the two types were similar. Consequently, grain yields of the tillered types were greater than or equal to the yields of the uniculms. Over the four experiments the tillered varieties had a 6% higher yield. The number of ears/m2 was the yield component most affected by plant density in both the tillered and uniculm barleys. The uniculm lines had more spikelets/ear, but tended to set fewer grains/spikelet and produce smaller kernels. The experiments failed to demonstrate any advantage of the uniculm habit to the grain yield of barley. These results differ from previous experiments that showed that a uniculm line, WID-101, had a higher yield than the tillered variety Clipper. It is suggested that the uniculm habit per se was not the cause of this higher yield, but its higher HI resulted in it outyielding Clipper. Current varieties, however, have HIs similar to the uniculm lines and yield equally to or more than the uniculm barleys examined. To further improve the grain yield of uniculm barley, greater dry matter production is necessary as the HIs of these lines are already high.


2006 ◽  
Vol 46 (1) ◽  
pp. 93 ◽  
Author(s):  
G. K. McDonald

High spatial and temporal variability is an inherent feature of dryland cereal crops over much of the southern cereal zone. The potential limitations to crop growth and yield of the chemical properties of the subsoils in the region have been long recognised, but there is still an incomplete understanding of the relative importance of different traits and how they interact to affect grain yield. Measurements were taken in a paddock at the Minnipa Agriculture Centre, Upper Eyre Peninsula, South Australia, to describe the effects of properties in the topsoil and subsoil on plant dry matter production, grain yield and plant nutrient concentrations in two consecutive years. Wheat (Triticum aestivum L. cv. Worrakatta) was grown in the first year and barley (Hordeum vulgare L. cv. Barque) in the second. All soil properties except pH showed a high degree of spatial variability. Variability in plant nutrient concentration, plant growth and grain yield was also high, but less than that of most of the soil properties. Variation in grain yield was more closely related to variation in dry matter at maturity and in harvest index than to dry matter production at tillering and anthesis. Soil properties had a stronger relationship with dry matter production and grain yield in 1999, the drier of the two years. Colwell phosphorus concentration in the topsoil (0–0.15 m) was positively correlated with dry matter production at tillering but was not related to dry matter production at anthesis or with grain yield. Subsoil pH, extractable boron concentration and electrical conductivity (EC) were closely related. The importance of EC and soil extractable boron to grain yield variation increased with depth, but EC had a greater influence than the other soil properties. In a year with above-average rainfall, very little of the variation in yield could be described by any of the measured soil variables. The results suggest that variation in EC was more important to describing variation in yield than variation in pH, extractable boron or other chemical properties.


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.


Author(s):  
R. G. Upadhyay ◽  
Anita Singh

A pot experiment was conducted to determine the effect of zinc and nitrogen on growth, nodulation pattern and yield of cowpea. The treatments were four levels of nitrogen ( 0 , 10, 20 and 30 kg/ha) and four levels of zinc (0, 5, 10 and 15 kg/ha). Application of various levels of nitrogen significantly increased dry matter production/plant , plant height number of branches/ plant, effective nodules/ plant, total nodule / plant, effective nodules weight /plant, pods/plant , seeds/pod and grain yield. Similarly zinc significantly increased plant height, branches / plant, number of leaves/plant, dry matter /plant, effective nodules weight /plant and grain yield. There was no significant interaction between nitrogen and zinc on grain yield.


1997 ◽  
Vol 37 (2) ◽  
pp. 191 ◽  
Author(s):  
V. F. Burnett ◽  
P. J. Newton ◽  
D. R. Coventry

Summary. Wheat (Triticum aestivum L.) seed was grown at 2 locations differing in phosphorus (P) status (low and high) in north-eastern Victoria (36°S, 146°E), with applied superphosphate (kg P/ha: 0, 12, 24, 100 and 200), to produce seed of different P content. This seed was used in field and glasshouse experiments in 1993 and 1994 to investigate the effects of seed source and P content on the growth and yield of wheat. Wheat seed grown at the low P status site was smaller than seed grown at the high P status site, irrespective of the amount of applied P. Seed from the low P status site produced less early dry matter in both field and glasshouse experiments in 1993, but there was no effect of seed source on grain yield in either experiment. High seed P content either had no effect or reduced seedling emergence in the field experiments. In the glasshouse, low P content in seed from the low P status site resulted in reduced emergence. Increases in dry matter production and grain yield with higher seed P content were only observed in the drought season of 1994. Application of P resulted in increased emergence, dry matter production and grain yield at most seed P content levels but there were no significant interactions between seed P content and applied P. Application of N did not affect dry matter production in either year, but increased grain protein in both years and grain yield in 1993. Seed from low P status environments can affect early seedling growth but in average growing seasons, or in glasshouse conditions, wheat growth compensates so that differences in grain yield are not observed. However, in order to avoid risk of poor early seedling growth and possible yield penalties when the crop is stressed, wheat seed should be collected from adequate soil P status sites.


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