Agronomic studies on the productivity of kenaf (Hibiscus cannabinus L. cv. Guatemala 4) under rainfed and irrigated conditions in the Northern Territory

1990 ◽  
Vol 30 (3) ◽  
pp. 395 ◽  
Author(s):  
RC Muchow ◽  
JD Sturtz ◽  
MF Spillman ◽  
GE Routley ◽  
S Kaplan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Northern Territory ◽  
Growth And Yield ◽  
Stem Length ◽  
Yield Potential ◽  
Yield Response ◽  
Rainfall Season ◽  
Wide Range ◽  
Average Rainfall

Field experiments were conducted at Berrimah, Douglas Daly and Katherine in the Northern Territory (NT) during the 1987-88 and 1988-89 wet seasons to obtain yield data for kenaf (Hibiscus cannabinzis L. cv. Guatemala 4) grown under rainfed and irrigated conditions. Under rainfed conditions, maximum stem yield was obtained from sowings early in the wet season. Yield decreased with delay in sowing until the late-December-January period. The maximum rainfed stem yield at Katherine in an above-average rainfall season was 18 400 kg/ha. The maximum yield in a below average rainfall season was 11 700 kg/ha at Katherine, 9200 kg/ha at Douglas Daly and 9400 kg/ha at Berrimah. The applicability to the NT of growth and yield relationships established for irrigated kenaf in the Ord Irrigation Area (OIA) was assessed. The yield potential under irrigated conditions in the NT (21 600 kg/ha at 131 days after sowing) was higher than that reported elsewhere in Australia for the same growth period, but similar to that reported elsewhere for longer growth duration (180-300 days). In the NT, in contrast to the OIA, stem yield showed little or no response to N fertilisation. Stem yield was not related to N uptake, and at high levels of N application, there was marked N accumulation in the stem. Kenaf was able to accumulate up to 110 kg N/ha from the soil reserve where no N was applied. The yield response to plant density varied with the yield level and was similar to that in the OIA. Bark and core yield could be estimated directly from biomass, and indirectly from stem length and plant density, over a wide range of yield levels and cultural conditions. It was concluded that data relating to yield potential and response to N fertilisation cannot be transferred directly from the OIA to the NT.

scholarly journals Plant density and peanut crop yield (Arachis hypogaea) in the peanut growing region of Córdoba (Argentina)

2018 ◽  
Vol 45 (2) ◽  
pp. 82-86 ◽  
Author(s):  
F.D. Morla ◽  
O. Giayetto ◽  
E. M. Fernandez ◽  
G. A. Cerioni ◽  
C. Cerliani
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Yield Response ◽  
Factors Affecting ◽  
Growing Seasons ◽  
Peanut Crop ◽  
Wide Range ◽  
Plant Densities ◽  
Growing Conditions ◽  
Growing Region

ABSTRACT Plant density is one of the most important management factors affecting the peanut growth, modifying the capacity to capture radiation, water and nutrients. Peanut yield response to increased plant density changes according to environmental conditions, the genotype used, and planting date. Therefore, the optimum plant density (OPD) may vary with location. The aim of this project was (i) to fit the Mitscherlich's equation of diminishing productivities to the yield response of runner-type peanuts to increasing plant density under different growing conditions in the peanut growing region of Cordoba Argentina; and (ii) validate this model with independent experimental data. The first stage was based on the analysis of data from different projects of plant densities carried out in the peanut growing area of Córdoba. This information was adjusted to the decreasing yield equation and the OPD was calculated. For validation, a field experiment was conducted during the 2013/14 and 2014/15 growing seasons under irrigated and rain-fed conditions where pod yield was evaluated for 5, 12, 18, 25 and 36 plants/m2. No interaction was detected between soil moisture conditions and plant density. Yield response to plant density had a high degree of fitness for a wide range of environmental and crop conditions. In field experiments, the peanut yield decreased only at the lowest plant density (5 plants/m2). Yield response to density adjusted to the Mitscherlich equation indicated that OPD ranged from 10.5 to 24.8 plants/m2. Using a single adjustment equation y = 1(1 – e−0.1784x), OPD was estimated to be 16.8 plants/m2 at harvest (11.7 plants per linear meter in 0.7 m between rows) for the peanut growing region of Cordoba. This approach can be a valuable input, along with other variables to analyze, when choosing peanut sowing density.

Red:Far-Red Light Effects on Corn Growth and Productivity in Field Environments

Weed Science ◽  
2009 ◽  
Vol 57 (2) ◽  
pp. 208-215 ◽  
Author(s):  
Melinda Y. Markham ◽  
David E. Stoltenberg
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Plant Density ◽  
Red Light ◽  
Control Plant ◽  
Morphological Characteristics ◽  
Growth And Yield ◽  
Stem Length ◽  
Early Season ◽  
Weed Communities

Increased reflection of far-red light among plants can lower the red:far-red ratio (R:FR) of horizontally-propagated light before substantial shading among plants occurs. Although previous research suggests that altered R:FR can affect corn growth, it is not understood how early-season low R:FR (associated with higher plant densities in corn–weed communities than in weed-free corn) affects corn productivity in the field. We conducted field experiments from 2005 to 2007 to determine the effects of reduced R:FR on corn growth and yield. Corn was established at 53,800 plants ha−1for a control R:FR treatment (weed-free corn) and at 107,600 plants ha−1for a low R:FR treatment (simulated corn–weed community). The low R:FR treatment was thinned to the control plant density at V7 corn (seven fully-expanded leaf collars), which simulated total weed removal. Before thinning, R:FR (645:735 nm) at V7 corn in the low R:FR treatment (0.23) was less than 50% of that in the control R:FR treatment (0.49) across years. In 2005, stalk diameter, stem length, stem mass, leaf mass, specific leaf area, and total plant mass were less for V5 corn in the low R:FR treatment than in the control R:FR treatment. In 2006, V5 corn was taller in the low R:FR treatment than in the control R:FR treatment, but other morphological characteristics were similar between treatments. The shoot:root ratio of V5 (five fully-expanded leaf collars) (2005) and V7 corn (2006) was not affected by R:FR treatment, nor was shoot mass and grain yield of R6 corn (physiological maturity). Measurements in 2006 indicated that soil moisture and nutrient availability were not limiting and did not differ between treatments. Early-season R:FR in simulated corn–weed communities was similar to that in in situ corn–weed communities. These results suggest that low R:FR typical of early-season corn–weed communities was not associated with corn grain yield loss under field conditions in which water and nutrients were not limiting resources.

scholarly journals Fall and spring seeding date effects on herbicide-tolerant canola (Brassica napus L.) cultivars

2004 ◽  
Vol 84 (2) ◽  
pp. 419-430 ◽  
Author(s):  
G. W. Clayton ◽  
K. N. Harker ◽  
J. T. O’Donovan ◽  
R. E. Blackshaw ◽  
L. M. Dosdall ◽  
...  
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Early Spring ◽  
Yield Response ◽  
Management Options ◽  
Brassica Napus L ◽  
Seeding Date ◽  
Herbicide Tolerant ◽  
Root Maggot ◽  
Crops Yield

More flexible and effective weed control with herbicide-tolerant B. napus canola allows for additional seeding management options, such as fall (dormant) and early spring (ES) seeding. Field experiments were conducted at Lacombe and Beaverlodge (1999–2001), Didsbury (1999–2000), and Lethbridge (2000–2001), Alberta, Canada, primarily to evaluate the effect of fall (late October-November), ES (late April-early May), and normal spring (NS) (ca. mid-May) seeding dates on glufosinate-, glyphosate-, and imidazolinone-tolerant canola development and yield. Fall seeding resulted in 46% lower plant density and nearly double the dockage than spring seeding. ES-seeded canola had 19% higher seed yield and 2.1% higher oil content than fall-seeded canola. ES seeding significantly increased yield compared to fall-seeded canola for 8 of 10 site -years or compared to NS seeding for 4 of 10 site-years; ES-seeded canola equalled the yield of NS-seeded canola for 6 of 10 site-years. Yield response to seeding date did not differ among herbicide-tolerant cultivars. Seeding date did not influence root maggot damage. Seeding canola as soon as possible in spring increases the likelihood of optimizing canola yield and quality compared to fall seeding and traditional spring seeding dates. Key words: Dormant seeding, seeding management, root maggot, herbicide-resistant crops, yield components, operational diversity

scholarly journals Weed control under integrated nutrient management systems in faba bean (Vicia faba) production in Egypt

2008 ◽  
Vol 26 (3) ◽  
pp. 585-594 ◽  
Author(s):  
I.M. El-Metwally ◽  
M.T. Abdelhamid
Keyword(s):  
Weed Control ◽  
Faba Bean ◽  
Field Experiments ◽  
Nutrient Management ◽  
Weight Ratio ◽  
Nutrient Release ◽  
Growth And Yield ◽  
Yield Potential ◽  
Mineral Fertilizers ◽  
Net Assimilation

Two field experiments were conducted in two successive seasons, 2005/2006 and 2006/2007, to determine whether management can improve faba bean competitiveness with weeds, thus helping to achieve its yield potential. The experiment included five treatments, composed of organic and mineral fertilizers, alone and mixed at different rates, along with a control and six weed control treatments, including oxadiargyl, prometryn, hand hoeing treatments alone or mixed with the herbicides, and a nonweeded treatment (control).The herbicide treatments were not superior to the two hand-hoeing treatments. Using compost favored growth and yield of faba bean more than of weeds. Adding fertilizer also improved most yield parameters. Application of compost alone or combined with 50 or 100% of the recommended NPK rate improved faba bean growth in terms of net assimilation rate, specific leaf area, and leaf weight ratio as components of relative growth rate. This improvement in growth resulted in increase of seed yield, yield components and protein of faba bean. Faba bean yield performance improved under interactive fertilizer effects and weed control treatments as growth improved, as a result of nutrient release from fertilizers and weed control.

The effect of fertilizers and season on the yield and composition of wheat in southern New South Wales

1963 ◽  
Vol 3 (8) ◽  
pp. 51 ◽  
Author(s):  
JD Colwell
Keyword(s):  
Vegetative Growth ◽  
Field Experiments ◽  
Application Rate ◽  
Early Spring ◽  
Nitrogen Fertilizers ◽  
Yield Response ◽  
Nitrogen Levels ◽  
South Wales ◽  
Wide Range ◽  
Common Application

Twenty two fertilizer experiments with wheat were carried out over a wide range of soil and environmental seasonal conditions in southern N.S. W. The effects of phosphorus and nitrogen fertilizers on the yield and composition of wheat are described. Seasonal environmental effects were examined by comparing the relative response to fertilizers of vegetative growth in the early spring with the final response of the harvested grain. Grain yield response to fertilizers is commonly restricted by seasonal conditions. Overcorrection of the phosphorus or nitrogen deficiencies may cause excessive early vegetative growth which exhausts soil moisture reserves before grain development has been completed. Loss of grain yields through this phenomenon is described locally as haying off. The chief danger in this respect seems to be from excessive nitrogen levels in the soil following a clover pasture. Assessments of economically desirable fertilizer applications on the basis of field experiments can only be based on statistical averages of seasonal conditions in each locality. The trials indicate, however, that the common application rate of superphosphate to wheat is inadequate in this region and should be at least doubled.

THE RELATION OF SOIL TEST VALUES TO FERTILIZER RESPONSE BY THE POTATO: IV. AVAILABLE PHOSPHORUS AND PHOSPHATIC FERTILIZER REQUIREMENTS

1967 ◽  
Vol 47 (3) ◽  
pp. 175-185 ◽  
Author(s):  
R. F. Bishop ◽  
C. R. MacEachern ◽  
D. C. MacKay
Keyword(s):  
Field Experiments ◽  
Yield Response ◽  
Available Phosphorus ◽  
Soil Test ◽  
Soil Series ◽  
Response Curves ◽  
Fertilizer Response ◽  
Soil P ◽  
Wide Range ◽  
Mitscherlich Equation

In field experiments, conducted at 18 locations during a 3-year period, tuber yields on zero-P plots ranged from 49.7–95.5% of those obtained with optimum P fertilization. Each of three chemical methods used to estimate available soil P showed a wide range of values for the different locations.When Bray's modification of the Mitscherlich equation was used to express the relationship between soil test values and yield response to applied P, there were appreciable differences in c1 values which varied with soil series and soil test methods.Polynomial response curves showed that, irrespective of the chemical method used, if soils were grouped on the basis of available P into "high", "medium" and "low" classes, response to applied P was much less in the high than in the medium and low classes. Response curves also showed that both P requirements and maximum yields varied with different soil series.

The effect of plant density upon the growth and yield of barley

1967 ◽  
Vol 68 (3) ◽  
pp. 317-324 ◽  
Author(s):  
E. J. M. Kirby
Keyword(s):  
Seedling Establishment ◽  
Yield Components ◽  
Plant Density ◽  
Growth Parameters ◽  
Tiller Number ◽  
Growth And Yield ◽  
Wide Range ◽  
Cereal Plant ◽  
Variety Effect ◽  
Ear Number

1. Cereal plant density affects yield and growth parameters of fundamental importance. An experiment is described in which growth and development, and yield and yield components of barley grown over a wide range of density were examined.2. Four varieties of barley—Proctor, Plumage-Archer, Domen, and Moore—were grown at densities approximately equivalent to 35, 70, 140 and 280 lb/acre. Density was found not to affect seedling establishment or plant survival, but there was a variety effect on seedling establishment.3. Varietal differences were seen in maximum tiller number, and the percentage of tillers surviving to form ears. These differences were most marked between the six-row variety and two-row varieties. The effect of increasing density was to increase the maximum tiller number, but this was followed by different rates of tiller death until early June, after which there was no further compensation for tiller number. Ear emergence and ear number were affected both by variety and density.

Grading monogerm sugar-beet seed and its influence on performance

1974 ◽  
Vol 83 (1) ◽  
pp. 125-133 ◽  
Author(s):  
P. C. Longden ◽  
R. K. Scott ◽  
D. W. Wood
Keyword(s):  
Sugar Beet ◽  
Seed Weight ◽  
Field Experiments ◽  
Plant Density ◽  
Seedling Emergence ◽  
Growth And Yield ◽  
Viable Seed ◽  
True Seed ◽  
High Plant Density ◽  
Fruit Diameter

SUMMARYFrom monogerm sugar-beet seed as harvested non-viable fruits have to be eliminated, multigerm ones rejected and the size made sufficiently uniform for use in precision drills. Seed which had been gently rubbed to remove some of the cortex was graded for diameter, thickness and by aspiration, either singly or in combination. Effects of grading were determined by laboratory germination tests, radiography and field sowings in which seedling emergence and crop growth and yield were recorded.Grading by thickness was effective in removing multigerm fruits. Grading by aspiration and diameter rejected non-viable seed and reduced the variation in size. By combining all three grading methods, samples of seed of 80% germination and 90% monogermity were produced, provided the seed lot as threshed gave at least 50% germination. True seed weight increased with fruit diameter but only the first aspiration was effective in removing light true seeds. Radiography showed that both aspiration and, to a less extent, grading by diameter were effective in removing most empty fruits but neither eliminated those with shrivelled seed. The field experiments confirmed that increase in fruit diameter or aspiration gave more seedlings. Even at uniform, high plant density, sugar yields were less from the smallest (less than 3 mm diameter) than from the other grades of seed. The initial aspiration also improved sugar yield but further aspiration decreased yield.

Nitrogen and phosphorus nutrition of dryland grain sorghum at Katherine, Northern Territory. 2. Effect of rate and source of phosphorus fertilizer

1978 ◽  
Vol 18 (93) ◽  
pp. 564 ◽  
Author(s):  
RJK Myers
Keyword(s):  
Field Experiments ◽  
Grain Sorghum ◽  
Northern Territory ◽  
Diammonium Phosphate ◽  
Yield Response ◽  
Growth Stages ◽  
Growth Responses ◽  
Triple Superphosphate ◽  
Monoammonium Phosphate ◽  
Nitrogen And Phosphorus

Field experiments were conducted at Katherine, Northern Territory, in 1970-71 and 1971 -72 to examine responses of dryland grain sorghum to applied phosphorus at different growth stages. In the first, the effect of rate of application up to 100 kg P ha-1 as triple superphosphate was investigated. Growth responses to phosphorus were noted from mid-elongation onwards, but the magnitude of response varied between seasons, being greater in the higher rainfall season 1970-71. Maximum yields of grain were 7730 kg ha-1 with 50 kg P ha-1 in 1970-71, and 4440 kg ha-1 with 100 kg P ha-1 in 1971-72, which were increases of 49 and 37 per cent respectively over the appropriate zero phosphorus treatment. These suggested an increased requirement for phosphorus over previous recommendations. Phosphorus reduced the time from emergence to anthesis from 68 to 60 and from 70 to 63 days respectively in the two seasons. About half of the plant phosphorus was taken up after anthesis. It was concluded from soil analysis that phosphate-treated plots had an enhanced supply of phosphorus throughout the period of crop growth. In the second study, four phosphorus sources (superphosphate, triple superphosphate, monoammonium phosphate, and diammonium phosphate) were compared. With 25 kg P ha-1 and with constant nitrogen, grain yield response followed the order superphosphate > monoammonium phosphate > diammonium phosphate > triple superphosphate in both years. Triple superphosphate tended to give lower dry matter yields and nitrogen and phosphorus concentrations than the other three sources.

Response of vetch (Vicia spp.) to plant density in south-western Australia

2002 ◽  
Vol 42 (8) ◽  
pp. 1043 ◽  
Author(s):  
M. Seymour ◽  
K. H. M. Siddique ◽  
N. Brandon ◽  
L. Martin ◽  
E. Jackson
Keyword(s):  
Seed Yield ◽  
Western Australia ◽  
Dry Matter ◽  
Field Experiments ◽  
Plant Density ◽  
Yield Potential ◽  
Dry Matter Production ◽  
Vicia Sativa ◽  
Seeding Rate ◽  
Matter Production

The response of Vicia sativa (cvv. Languedoc, Blanchefleur and Morava) and V. benghalensis (cv. Barloo) seed yield to seeding rate was examined in 9 field experiments across 2 years in south-western Australia. There were 2 types of field experiments: seeding rate (20, 40, 60, 100 and 140 kg/ha) × cultivar (Languedoc, Blanchefleur, and Morava or Barloo), and time of sowing (2 times of sowing of either Languedoc or Blanchefleur) × seeding rate (5,�7.5, 10, 15, 20, 30, 40, 50, 75 and 100 kg/ha).A target density of 40 plants/m2 gave 'optimum' seed yield of vetch in south-western Australia. In high yielding situations, with a yield potential above 1.5 t/ha, the 'optimum' plant density for the early flowering cultivar Languedoc (85–97 days to 50% flowering) was increased to 60 plants/m2. The later flowering cultivar Blanchefleur (95–106 days to 50% flowering) had an optimum plant density of 33 plants/m2 at all sites, regardless of fitted maximum seed yield. Plant density in the range 31–38 plants/m2 was found to be adequate for dry matter production at maturity of Languedoc and Blanchefleur. For the remaining cultivars Barloo and Morava we were unable to determine an average optimum density for either dry matter or seed yield due to insufficient and/or inconsistent data.

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