A comparison of barley cultivars with different leaf inclinations

1972 ◽  
Vol 23 (6) ◽  
pp. 945 ◽  
Author(s):  
JF Angus ◽  
R Jones ◽  
JH Wilson
Keyword(s):  
Dry Matter ◽  
Canopy Structure ◽  
The Other ◽  
Dry Matter Production ◽  
Visible Radiation ◽  
Area Index ◽  
Assimilation Chamber ◽  
Barley Cultivars ◽  
Matter Production ◽  
Erect Leaf

Under conditions of adequate moisture an erect-leaf barley cultivar, Lenta, responded to an increase in density (resulting from doubling of the sowing rate) with increases in dry matter production and in grain yield, whereas the cultivar Research, which has long lax leaves, responded with decreases in dry matter production and yield. In a study of canopy structure and its effects on light interception and utilization, it was found that in Research, with a leaf area index (LAI) of 6.1, the leaves were concentrated near the canopy surface and a relatively small proportion of the above-crop light penetrated through this layer. The net crop photosynthesis of this canopy (measured in a field assimilation chamber) was 3.8 g CO2/m2.hr when visible radiation was 313 W/m2. With Lenta (LAI 7.0) on the other hand, leaves were concentrated in the middle layers of the canopy and the light was more evenly distributed throughout the canopy. The net crop photosynthesis with the same radiation as for Research was 4.3 g CO2/m2.hr. The relative rates of photosynthesis at various levels in the canopies were determined by introducing 14CO2 into the assimilation chambers enclosing the cultivars and observing where the 14C was fixed. With Research most of it was localized near the canopy surface while with Lenta most of it was near the centre of the canopy. Of the 14CO2 taken up, 7 % was fixed in the leaf sheaths of Research and 12% in those of Lenta.

EFFECT OF DATES OF CUTTING ON DRY MATTER PRODUCTION AND CHEMICAL CONTENT OF ALFALFA AND BIRDSFOOT TREFOIL

1969 ◽  
Vol 49 (3) ◽  
pp. 339-349 ◽  
Author(s):  
H. Gasser ◽  
L. Lachance ◽  
P. Gervais
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Dry Matter ◽  
The Other ◽  
Dry Matter Production ◽  
Birdsfoot Trefoil ◽  
Dry Matter Yield ◽  
Matter Production ◽  
Chemical Content

In two experiments, one with alfalfa and the other with birdsfoot trefoil, we have been able to show that a late cut in October does not adversely affect dry matter yield (DAI) of the legumes. Three cuts during a harvesting season ending on September 5 were detrimental to alfalfa, since lower yields were obtained the following year of harvest. Birdsfoot trefoil varieties were affected differentially. Three cuts did not affect the yield of Viking the following year, but did so of Empire. Significant differences in dry matter yields were obtained between DuPuits and Vernal and between Viking and Empire. Protein in the forage followed inversely the same pattern as that of DM yields, that is, where the intervals were shortest, the protein content was highest, and conversely. The total available carbohydrate and the nitrogen content of the roots were lowest following the treatments which had the shortest intervals between them.

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 Forages resources in "dehesa" systems: fertilization, tillage, and forage sowing. 2. Productivity and use of rain water

2003 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
J.L. Martin Polo ◽  
C.J. Valle Gutierrez ◽  
A. Blanco de Pablos ◽  
M.E. Sánchez Rodríguez
Keyword(s):  
Primary Production ◽  
Dry Matter ◽  
Nutritive Value ◽  
Rain Water ◽  
The Other ◽  
Dry Matter Production ◽  
Matter Production ◽  
Economic Studies ◽  
Different Soils

In two «dehesa» grasslands with different soils, one over slate and the other over granite, studies were carried out toinvestigate the influence that phosphoric fertilization, surface tillage of pastures and oat sowing have on the primaryproduction and its nutritive value, on the index of utilization of raining water, and on the evolution of oat stubble withtime. Additionally, economic studies of the previous results have been carried out. Phosphoric fertilization and superficialtilling of pastures did not have a relevant influence on the primary production. Additionally, in the successive regrowthover oat stubble there was no response to phosphoric fertilization. The production increments with respect tocontrols are related to the preparatory tillage for sowing the oats, and the changes that the vegetation experimented.This effect decreased with time. The dry matter production in the oat treatments was higher than in the pastures, bothin slate and granite soils. In dehesa systems the use of raining water for the production of 1 kg dry matter ha-1 was verylow, and, on the average, 0.278 and 0.588 l m-2 were needed in pastures, but this amount decreased significantly in theoats: 0.059 and 0.110 l m-2 in slates and granites, respectively; with better use of the water in the more fertile soils. Theeconomic response to the oat sowing was about 252 and of 160 euros ha-1 year-1 in slates and granites, but there was noeconomic response to the fertilization and superficial tilling of pastures during the period of the experiment.

scholarly journals Canopy Structure and Dry Matter production in Grasses

1977 ◽  
Vol 46 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Akihito KUSUTANI ◽  
Kimio NAKASEKO ◽  
Kanji GOTOH
Keyword(s):  
Dry Matter ◽  
Canopy Structure ◽  
Dry Matter Production ◽  
Matter Production

Nodulation and growth of pasture legumes with naturalised soil rhizobia. 1. Annual Medicago spp.

2000 ◽  
Vol 40 (7) ◽  
pp. 939 ◽  
Author(s):  
R. A. Ballard ◽  
N. Charman
Keyword(s):  
Dry Matter ◽  
Early Growth ◽  
The Other ◽  
Dry Matter Production ◽  
Soil Suspension ◽  
Pasture Legumes ◽  
Matter Production ◽  
Annual Medics ◽  
Annual Medicago ◽  
Inoculation Treatment

The ability of 11 species of annual medics (Medicago doliata, M. laciniata, M. littoralis, M. minima, M. orbicularis, M. polymorpha, M. praecox, M. rigidula, M. rigiduloides, M. tornata and M. truncatula) to nodulate and fix nitrogen with naturalised rhizobia from 28 South Australian soils was assessed. The number of rhizobia in the soils was estimated. Medic shoot dry matter production and nodulation were measured, after inoculation of medic seedlings with a soil suspension, in 2 glasshouse experiments. The number of medic rhizobia ranged from 0.4 10 2 to 1.5 10 6 per gram soil. Medicago laciniata was the only medic species tested which was not consistently nodulated by the soil rhizobia. While all the other species formed nodules, they varied widely in their ability to form an effective symbiosis. Symbiotic performance (which indicates how much growth the medic line achieved, when compared to an effective inoculation treatment) of the medic species ranged from 3% (M. rigiduloides) to 67% (M. praecox). Herald (M. littoralis) achieved a symbiotic performance of 49% and it was estimated that this would be insufficient to meet the nitrogen requirements of a Herald-based pasture during early growth. The symbiotic performance of Santiago (M. polymorpha) was low (17%) and erratic (from –6 to 72%). The ability of the rhizobia to form an effective symbiosis varied widely also between soil regions. For example, the rhizobia in Riverland soils resulted in only 31% of the shoot dry matter of those in Eyre Peninsula soils, in association with M. polymorpha. There are significant opportunities to improve the symbiotic performance of a number of the species of annual medics examined in this study. Options to improve the effectiveness of the symbiosis of medics with naturalised soil rhizobia are discussed.

Genotype and year effects on morphological and agronomical traits of silage maize ( Zea mays L.) hybrids

2010 ◽  
Vol 58 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Z. Tóthné Zsubori ◽  
I. Pók ◽  
Z. Hegyi ◽  
C. Marton
Keyword(s):  
Plant Height ◽  
Dry Matter ◽  
The Other ◽  
Dry Matter Production ◽  
Genetic Determination ◽  
Silage Maize ◽  
Matter Production ◽  
Total Plant ◽  
Number Of Leaves ◽  
Few Data

Leafy hybrids represent a new direction in the breeding of silage maize. Not only does the increased number of leaves above the ear in these hybrids lead to an increase in dry matter production, but the large quantity of carbohydrates formed and stored in the leaves results in silage with better chemical quality. Many papers have been published abroad on this subject, but few data have been reported in Hungary.The present work aimed to examine the effect of genotype and year on six leafy and non-leafy silage maize hybrids over a period of four years (2002–2005), with special emphasis on the plant height, ear attachment height, leaf number, and fresh and dry matter yield.The results showed that the number of leaves above the ear was much higher for the two leafy hybrids (8.00 and 9.35) than the average of the other hybrids (5.56, averaged over the years). This trait was in close negative correlation (r 2 = −0.7346) with the ratio of ear attachment height to total plant height, a trait with strong genetic determination, little influenced by the year. In leafy hybrids the main ear was located far lower down, but the total plant height was similar to that of the other hybrids. The ratio of ear attachment height to plant height was 0.36 for the leafy hybrids, but ranged from 0.41 to 0.45 for the other hybrids (averaged over the years). In wetter years the hybrids were taller and had greater dry matter production per plant than in the dry year.

Nitrogen-limited light use efficiency in wheat crop simulators: comparing three model approaches

2015 ◽  
Vol 154 (6) ◽  
pp. 1090-1101 ◽  
Author(s):  
A. M. RATJEN ◽  
H. KAGE
Keyword(s):  
Dry Matter ◽  
Dry Matter Production ◽  
Wheat Crop ◽  
Light Use Efficiency ◽  
Data Set ◽  
Area Index ◽  
N Concentration ◽  
Matter Production ◽  
Use Efficiency ◽  
Critical N Concentration

SUMMARYThree different explanatory indicators for reduced light use efficiency (LUE) under limited nitrogen (N) supply were evaluated. The indicators can be used to adapt dry matter production of crop simulators to N-limited growth conditions. The first indicator, nitrogen factor (NFAC), originates from the CERES-Wheat model and calculates the critical N concentration of the shoot as a function of phenological development. The second indicator, N nutrition index (NNI), calculates a critical N concentration as a function of shoot dry matter. The third indicator, specific leaf nitrogen (SLN) index (SLNI), has been newly developed. It compares the actual SLN with the maximum SLN (SLNmax). The latter is calculated as a function of the green area index (GAI). The comparison was based on growth curves and fitted to empirical data, and was carried out independently from a dynamic crop model. The data set included four growing seasons (2004–2006, 2012) in Northern Germany and seven modern bread wheat cultivars with varying N fertilization levels (0–320 kg N/ha). The influence of N shortage on LUE was evaluated from the beginning of stem elongation until flowering. With the exception of 2005, the highest productivity was observed for the highest N level. A moderate N shortage primarily reduced GAI and therefore light interception, while LUE remained stable under moderate N shortage. The relative LUE (rLUE) of a specific day was defined as the ratio of actual to maximal LUE. None of the indicators was proportional to rLUE, but the relationships were described well by quadratic plateau curves. The correlation between simulated and measured rLUE was significant for all explanatory indicators, but different in terms of mean absolute error and coefficient of determination (R2). The performance of SLNI and NNI was similar, but the goodness of prediction was much lower for NFAC. Compared with NNI and NFAC, SLNI corresponded to leaf N and was therefore sensitive to N translocation from leaves to growing grains during the reproductive stage. For this reason, SLNI may have the potential to improve simulation of dry matter production in wheat crop simulators.

scholarly journals Effect of nitrogen and phosphorus on growth and seed yield of French bean

2016 ◽  
Vol 41 (4) ◽  
pp. 759-772
Author(s):  
SS Kakon ◽  
MSU Bhuiya ◽  
SMA Hossain ◽  
Q Naher ◽  
Md DH Bhuiyan
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Agricultural Research ◽  
Block Design ◽  
French Bean ◽  
Dry Matter Production ◽  
Nitrogen And Phosphorus ◽  
Area Index ◽  
Matter Production

Field experiments were conducted during rabi (winter) seasons of 2010-11 and 2011-12 at the Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur to study the effects of nitrogen and phosphorus on growth, dry matter production and yield of French bean. A randomized complete block design was followed with 10 combinations of N (0,50, 100, 150 and 200) and P (0,22, 33, 44 and 55) kg ha-1 along with a blanket dose of control. All the treatments showed the maximum leaf area index (LAI) at 65 days after sowing (DAS). All the treatments showed the maximum total dry matter production, crop growth rate and net assimilation rate at harvest and at 55-65 DAS, respectively in both the years. LAI, dry matter production, CGR, NAR and seed yield significantly increased with the increase in nitrogen and phosphorus level upto 150 kg N and 44 P kg ha-1 , respectively. Similar trend was followed in maximum number of pods (9.45) and seed yield (1563.33 kg ha-1). The treatment comprises with 150 kg N and 44 P Kg ha-1 gave the highest seed yield which was 51.40 and 54.30 % higher than control plots.Bangladesh J. Agril. Res. 41(4): 759-772, December 2016

The growth of swards of subterranean clover with particular reference to leaf area

1958 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
JL Davidson ◽  
CM Donald
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Substantial Reduction ◽  
Ground Surface ◽  
Subterranean Clover ◽  
Climatic Conditions ◽  
Dry Matter Production ◽  
Leaf Production ◽  
Area Index ◽  
Matter Production

An experiment was conducted to study the growth of subterranean clover (Trifolium subterraneum L.) sown at different densities; the control swards were not defoliated while others were subjected to a single defoliation at various dates. During the final month the rate of dry matter production (tops only) increased to a maximum when the leaf area index (the ratio of the area of the leaves to the area of the ground surface — L.A.I.) was about 4-5, falling by about 30 per cent. as the L.A.I. increased to 8.7. The rate of leaf production was greatest at about L.A.I. 4-5, falling to zero at L.A.I. 8.7. Climatic conditions during the growing season influenced the relationship of L.A.I. to growth; as conditions became more favorable the values of the optimum LA.1. for growth and of the ceiling L.,4.1. progressively rose. Irrespective of the density, all swards tended towards a common ceiling L.A.I. and yield by the end of the season. The effect of defoliation depended on the L.A.I. at which defoliation occurred, on the value to which the L.A.I. was reduced, and on current climatic conditions. If swards near the ceiling L.A.I. were defoliated, total dry matter production was slightly increased and there was a great increase in leaf production. On the other hand, defoliation of swards from about the optimum L.A.I. to very low L.A.I. values led to a substantial reduction in both dry matter and leaf production. It is suggested that all these effects depend on the light relationships within the sward and their influence on the balance of photosynthesis and respiration. Pasture at the optimum L.A.I. will give greater production than swards of lower or higher L.A.I.; defoliation can give greatly increased leaf production, unless L.A.I. is reduced to very low values.

Sign in / Sign up

Export Citation Format

Share Document