Effects of Planting Density on Water Use and Productivity of Pearl Millet (Pennisetum Typhoides) Grown on Stored Water. II. Water Use, Light Interception and Dry Matter Production

1984 ◽  
Vol 20 (3) ◽  
pp. 215-224 ◽  
Author(s):  
S. N. Azam-Ali ◽  
P. J. Gregory ◽  
J. L. Monteith
Keyword(s):  
Pearl Millet ◽  
Water Use ◽  
Dry Matter ◽  
Dry Weight ◽  
Planting Density ◽  
Area Index ◽  
Wide Spacing ◽  
Neutron Probe ◽  
Matter Production ◽  
Intercepted Radiation

SUMMARYPearl millet was grown on stored water at Niamey, Niger, using three row spacings. Water extraction based on neutron probe readings was compared with crop transpiration using a porometer and allied measurements. Between 23 and 52 days after sowing, plants at the narrow and medium spacings used about 77 and 100 mm of water, respectively, and those at the wide spacing used between 59 and 75 mm. Estimates of seasonal crop evaporation from leaf resistances and from the green leaf area index (GLAI) of the crops were 103, 130 and 123 mm for the narrow, medium and wide spacings, respectively. The water use per unit of dry weight produced was similar for both narrow and medium spacings but water was used more efficiently in the wide spacing. Dry weight increased in proportion to intercepted radiation with the same efficiency (1·3 g MJ−1) irrespective of spacing.

The growth and performance of cotton in a desert environment: II. Dry matter production

1969 ◽  
Vol 73 (1) ◽  
pp. 75-86 ◽  
Author(s):  
A. B. Hearn
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Initial Period ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Area Index ◽  
Vegetative Phase ◽  
Matter Production ◽  
Sink Size ◽  
And Performance

SUMMARYVariety, water and spacing were treatments in two experiments with cotton in 1963 and 1964 in which fruiting points, flowers and bolls were counted and the dry weights and leaf areas of plants were measured at intervals during the season.Until leaf-area index, L, started to decrease, the equation described how dry weight, W, changed. The equation gave smoothed estimates of crop growth rate, C, which were consistent with estimates of photosynthesis made with de Wit's (1965) model. The relationship between G and L conformed to , derived from Beer's Law, rather than C = aL — bL2 derived from the linear regression of E on L. When L > 3 the crop appeared to use most of the available light, so that C approached a maximum. Treatments initially affected dry-matter production through the numbers and types of branches and nodes, which in turn affected the sinks available and thus the proportion of dry matter reinvested in new leaf. This initial period, when growth was simple to describe in conventional terms, was denned as the vegetative phase of growth.The start of the reproductive phase of growth overlapped the vegetative phase. The change from one to the other was completed when the rate of dry weight increase of the bolls, CB, equalled C. This indicated that the sink formed by the bolls had increased sufficiently in size to use all the assimilates available for growth. Sink size increased as the crop flowered and was estimated from the product of the number of bolls and the growth rate of a single boll.When CB equalled C, bolls were shed which prevented the size of the sink to increase beyond the ability of the plant to supply it with assimilates. This agrees with Mason's nutritional theory of boll shedding. Because of the crop's morphology and because age decreased the photosynthesis of the crop, the size of the sink inevitably increased out of phase with the supply of assimilates. The extent to which this was so determined when CB equalled C. It is postulated that environment, genotype and agronomic practice affect yield according to whether they increase or decrease the extent to which the sink size and the supply of assimilates are out of phase.

scholarly journals Supplementary irrigation in Sudan grass: Leaf area index, dry matter production and water use efficiency

Científica ◽  
2020 ◽  
Vol 48 (2) ◽  
pp. 85
Author(s):  
Wellington Mezzomo ◽  
Marcia Xavier Peiter ◽  
Adroaldo Dias Robaina ◽  
Jardel Henrique Kirchner ◽  
Rogério Ricalde Torres ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Water Use ◽  
Dry Matter ◽  
Area Index ◽  
Sudan Grass ◽  
Matter Production ◽  
Supplementary Irrigation ◽  
Use Efficiency

The effects of salt and boron on growth of wheat

1992 ◽  
Vol 43 (5) ◽  
pp. 987 ◽  
Author(s):  
RE Holloway ◽  
AM Alston
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Root Length ◽  
Dry Matter ◽  
Sandy Loam ◽  
Dry Weight ◽  
Matter Production ◽  
Use Efficiency ◽  
Total Dry Weight

Wheat (Triticum aestivum L. cv. Warigal) was grown in a glasshouse in deep pots (0.125 x 0.125 x 1.2 m) containing sieved solonized brown soil (calcixerollic xerochrept) comprising 0.2 m sandy loam topsoil above 0.6 m treated calcareous sandy loam subsoil and a base layer of light clay 0.26 m thick. The subsoil was treated with a mixture of salts (0, 13, 39, 75 mmolc kg-1) and with boric acid (0, 20, 38 and 73 mg B kg-1) in factorial combination. The soil was initially watered to field capacity and water use was determined by regularly weighing the pots. The soil was allowed to dry gradually during the season, but the weights of the pots were not permitted to fall below that corresponding to 17% of the available water holding capacity of the soil. Tillering, dry weight of shoots and grain, and root length density were determined. Water-use efficiency was calculated with respect to total dry weight and grain production. Salt decreased tillering, dry matter production, grain yield, root length and water-use efficiency (total dry weight): it increased sodium and decreased boron concentrations in the plants. Boron decreased dry matter production (but not tillering), grain yield, root length and water-use efficiency (total dry weight and grain yield): it increased the concentrations of boron and decreased the concentration of sodium in the plants. At the concentrations of salt and boron used (which cover the range normally encountered in subsoils in much of Upper Eyre Peninsula), boron had more deleterious effects on wheat than did salt. Yield was depressed by salt at concentrations of sodium in the tissue commonly found in field-grown plants.

Analysis of the regrowth of a tropical grass/legume sward subjected to different frequencies and intensities of defoliation

1980 ◽  
Vol 31 (4) ◽  
pp. 673 ◽  
Author(s):  
MM Ludlow ◽  
DA Charles-Edwards
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Dry Weight ◽  
Light Interception ◽  
Photosynthetic Characteristics ◽  
Dry Matter Production ◽  
Canopy Photosynthesis ◽  
Area Index ◽  
Matter Production ◽  
Cutting Height

Dry weight, leaf area, light interception and canopy photosynthesis were measured during 3- or 5-week regrowth periods of Setaria anceps/Desmodium intortum swards cut to 7.5 or 15 cm. Dry matter production during the experiment and over the growing season increased with cutting height and with interval between defoliations, but the proportion of grass to legume was unaffected. These effects of defoliation on dry matter production were similar to those estimated for integrated canopy photosynthesis from measured light interception and calculated leaf photosynthetic characteristics. Height and frequency of defoliation had no effect on canopy extinction coefficient for light, nor on the leaf photosynthetic characteristics, except for the first 1-2 weeks after defoliation when leaf photosynthetic rates appeared to be depressed. The main effects of height and frequency of defoliation on dry matter production were through their effects on leaf area index and light interception.

scholarly journals Relative fitness of s-triazine susceptible and resistant biotypes of Chenopodium album

2005 ◽  
Vol 74 (3) ◽  
pp. 143-152 ◽  
Author(s):  
G.D. Leroux
Keyword(s):  
Dry Matter ◽  
Chenopodium Album ◽  
Relative Proportion ◽  
Root Competition ◽  
Planting Density ◽  
Relative Fitness ◽  
Replacement Series ◽  
Area Index ◽  
Matter Production ◽  
Shoot Competition

The relative fitness of s-triazine susceptible and resistant biotypes of Chenopodium album from Quebec were compared in three greenhouse experiments. Under non-competitive conditions, there was no difference in dry matter production between biotypes, but the resistant biotype allocated less dry matter to seed production and produced fewer seeds than the susceptible. Results from de Wit replacement series performed at 400 plants m2 indicated that the relative proportion of biomass and seeds produced by the susceptible biotype was always greater than the proportion of susceptible plants present in any given treatment. The effects of root, shoot, and full (root + shoot) competition were compared between and within biotypes at planting densities of 400,666,934,1200, and 1466 seedlings m-2. Biotype had the most pronounced effect on all variables among the factors studied. The susceptible seedlings were taller, had a greater leaf area index (LAI), more leaves, and greater leaf, stem, and above-ground dry matter yields than the resistant seedlings, regardless of the planting density or the mode of competition. The fitness of the susceptible biotype was greatest when both biotypes were competing for light. The effects of shoot competition for light on yield, LAI, leaf numbers, and seedling height, were as important as those of full competition. The effects of root competition, although significant, were not nearly as important. The data indicate that if s-triazines are no longer used in a field, the C. album population will revert naturally to susceptibility because of the superior fitness of the susceptible biotype.

Effects of row width and planting density on growth and yield of two maincrop potato varieties. 1. Plant morphology and dry-matter accumulation

1978 ◽  
Vol 91 (2) ◽  
pp. 265-278 ◽  
Author(s):  
O. P. Ifenkwe ◽  
E. J. Allen
Keyword(s):  
Dry Matter ◽  
Leaf Growth ◽  
Dry Weight ◽  
Planting Density ◽  
Stem Length ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Potato Varieties ◽  
Row Width ◽  
Axillary Branches

SUMMARYData are reported from three experiments from 1972 to 1974 in which the effects of two row widths (66 and 132 cm) and five planting densities on the growth of two maincrop potato varieties (Désirée and Maris Piper) were studied. The results were consistent over the 3 years and showed that the effects of widening the row width were to reduce the number of axillary branches and their leaves per plant, in Maris Piper L (leaf area index), and early in the season in both varieties dry weights of leaf, stem and underground parts per plant. Row width had no effect on tuber dry weight for most of the season but at the end of sampling, tuber dry weights were greater from 132cm than from 66 cm rows. Increasing planting density reduced number of axillary branches and their leaves per plant, dry weight of leaf, stem, underground parts and tubers per plant, but increased stem length and tuber dry weight per unit area.Leaf growth of all treatments was rapid during May and high planting densities reached an Lof 3 before the end of this month. L was increased by increased planting density throughout growth, but the lower densities were able to maintain an L of 2–3 formuch of the season. The rapid early increase in L was not associated with any prematuredecline and high rates of tuber dry-matter accumulation were achieved and maintained throughout the season. It is suggested that as the pattern of leaf growth in this environment is coincident with changing light receipts, the environment is almost ideal for the growth of maincrop potatoes.

Above-Ground Dry Matter Production in Three Stands of Trembling Aspen

1972 ◽  
Vol 2 (1) ◽  
pp. 27-33 ◽  
Author(s):  
D. F. W. Pollard
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Dry Weight ◽  
Annual Production ◽  
Above Ground Biomass ◽  
Area Index ◽  
Mature Stand ◽  
Matter Production ◽  
Net Assimilation

Above-ground biomass, annual production, and leaf area index (LAI) were estimated for several years in aspen stands aged 6, 15, and 52 years old in 1968. Based on regressions of dry weight on stem diameter, biomass (stems and branches) estimates for 1968 were 21 500 kg ha−1 in the juvenile stand, 51 200 kg ha−1 in the intermediate stand, and 91 800 kg ha−1 in the mature stand. Net annual above-ground production (stems and branches) for these stands in 1968 was 6900, 7000, and 1340 kg ha−1 respectively. In 1969, foliage amounted to 2600, 2600, and 1500 kg ha−1, providing LAI of 2.4, 2.9, and 1.6 for the stands. Net assimilation rates were roughly 20, 17, and 9 g m−2 week−1.Aspen stands regenerated as suckers may attain maximum annual production within a few years, coincident with the development of maximum LAI.

Root and shoot growth, and water and light use efficiency of barley and wheat crops grown on a shallow duplex soil in a mediterranean-type environment

1992 ◽  
Vol 43 (3) ◽  
pp. 555 ◽  
Author(s):  
PJ Gregory ◽  
D Tennant ◽  
RK Belford
Keyword(s):  
Water Use ◽  
Dry Matter ◽  
Flag Leaf ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Root Weight ◽  
Plant Weight ◽  
Leaf Emergence ◽  
Matter Production ◽  
Use Efficiency

Growth, interception of radiation and water use of three genotypes of barley (Beecher, O'Connor and Syrian) and one of wheat (Gutha) were measured on a duplex soil at East Beverley, W.A. All crops received 11 kg P ha-1 with the seed but no nitrogen fertilizer. Growth was initially slow until 69 days after sowing (das) with only small and inconsistent differences between crops. Thereafter, Beecher and O'Connor grew faster than Syrian and Gutha, maintained growth for longer, and at harvest weighed about 7.5 t ha-1 shoot dry matter, while Syrian and Gutha were about 5.0 t ha-1. Total root weight and length of Gutha increased until anthesis but reached their maxima at 83 das in all barley crops. Root weight as a percentage of total plant weight was about 40% during the winter decreasing to about 15% by anthesis. Root distributions of Beecher and O'Connor were similar but different from those of Syrian and Gutha; the former had up to 25% of the total root length at anthesis below 40 cm, but the latter had only about 5%. Dry matter production was linearly related to the amount of photosynthetically active radiation (PAR) intercepted, although the relations showed a break at about the time of flag leaf emergence, and efficiencies of conversion of PAR to dry matter were higher prior to this than after. Efficiencies for the barley crops were similar (about 2 g total dry weight MJ-1 before flag leaf emergence) and about 20% greater than for Gutha. Despite the large differences in dry matter production between crops, evapotranspiration (ET) was similar. For Beecher and O'Connor, evaporation E was about 40% of seasonal ET but for Syrian and Gutha it was about 50%. Values of water use efficiency (about 30 kg shoot ha-1 mm-1 for Beecher and OIConnor and 20 kg ha-1 mm-1 for Syrian and Gutha) were similar to other cereal crops and the amount of shoot dry matter per unit of water transpired for barley crops grown in W.A., U.K. and Syria was nearly constant; the value of the 'crop specific constant' was 3.0 Pa.

Prediction of the influence of water, sowing date and planting density on dry matter production of wheat

1980 ◽  
Vol 31 (1) ◽  
pp. 1 ◽  
Author(s):  
RJ Hanks ◽  
DW Puckridge
Keyword(s):  
Dry Matter ◽  
South Australia ◽  
Sowing Date ◽  
Planting Density ◽  
Dry Matter Production ◽  
Balance Model ◽  
Area Index ◽  
Matter Production ◽  
Influence Of Water ◽  
Good Agreement

A water balance model was used to calculate dry matter yields for wheat. The prediction used initial soil water, irrigation, rainfall and pan evaporation as inputs. Leaf area index (LAI) was estimated by an empirical equation and changes in LAI were determined by the ratio of predicted to potential transpiration and relative density. Time of sowing influenced time of maximum LAI. Dry matter production was calculated from equations relating LAI and photosynthesis. The model was tested with data from wheat crops in South Australia which had been grown with large differences in water supply, planting density and sowing date between seasons. There was good agreement between predicted and measured production.

scholarly journals Effects of Planting Density on Water Use and Productivity of Pearl Millet (Pennisetum Typhoides) Grown on Stored Water. I. Growth of Roots and Shoots

1984 ◽  
Vol 20 (3) ◽  
pp. 203-214 ◽  
Author(s):  
S. N. Azam-Ali ◽  
P. J. Gregory ◽  
J. L. Monteith
Keyword(s):  
Pearl Millet ◽  
Water Use ◽  
Dry Matter ◽  
Shoot Growth ◽  
Planting Density ◽  
Soil Cores ◽  
Physiological Basis ◽  
Pennisetum Typhoides ◽  
Different Populations

SUMMARYPearl millet (Pennisetum typhoides) was grown on stored water at Niamey, Niger, using three row spacings (38, 75 and 150 cm), to determine the physiological basis of exploitation and conservation of water by crops during drought Between 18 and 32 days after sowing, roots grew rapidly beneath all crops reaching 140 cm in the narrow spacing, but there were differences between crops in the pattern of growth. Soil cores and trench profiles indicated that plants in wider rows had fewer, deeper roots. Substantial differences in both the amount and pattern of shoot growth were recorded in the different populations. Initially growth was fastest at the narrow spacing but stopped by day 45 and eventually the wide spacing produced most dry matter due mainly to greater survival of tillers. The partitioning of above ground dry matter into vegetative and reproductive fractions was similar at all three spacings and was consistent with figures for comparable crops elsewhere. The important role of tillers is discussed in relation to the development and maintenance of a canopy.

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