The visual assessment of pasture yield

1973 ◽  
Vol 13 (62) ◽  
pp. 263 ◽  
Author(s):  
NA Campbell ◽  
GW Arnold
Keyword(s):  
Dry Matter ◽  
Large Range ◽  
Visual Assessment ◽  
Growth Stages ◽  
Botanical Composition ◽  
Visual Estimation ◽  
Wide Range ◽  
Trained Observers ◽  
The Relationship ◽  
Single Calibration

The methodology of using a visual estimation technique to assess dry matter yield of pastures was studied in eight experiments. Various aspects were examined, viz: the shape of the relationship between actual and visually assessed yield; whether observers could maintain consistency over a period of hours; the effects on consistency of prediction of the sequence of yield of pastures; whether a wide range in botanical composition could be accommodated; whether green and dry pasture could be assessed with equal precision. A linear relation, or occasionally a curvilinear relation, was obtained over a large range in yield. No consistent bias due to immediate previous values in a sequence was found. However, it was found that, without training, observers over-estimated the effects of height and under-estimated the effects of density in yield. In practice, trained observers gave much more accurate regressions; for green annual pastures at all growth stages, dry annual pastures, and irrigated lucerne, lovegrass and pangola grass, r2 values were greater than 0.70 on all but 11 per cent of 126 occasions.A wide range of botanical composition was able to be included in a single calibration, i.e. ryegrass, capeweed, sub clover and erodium. Recommendations are made for routine use of the technique in the field.

scholarly journals Relación entre el peso freco y el peso seco del rastrojo de maíz en diferentes estados fenológicos del cultivo.

2016 ◽  
Vol 8 (1) ◽  
pp. 20 ◽  
Author(s):  
M. Bänziger ◽  
G. O. Edmeades ◽  
J. Bolaños
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Important Variable ◽  
Growth Stages ◽  
Simple Method ◽  
Plant Parts ◽  
Maturity Period ◽  
Area Unit ◽  
Drying Conditions ◽  
The Relationship

The amount of dry matter produced during various stages of corn growth is a important variable to be taken into consideration. However, the lack of drying facilities makes its measurement a difficult task in the fields. A simple method to convert the fresh weight of a crop in the field into dry weight, could be an answer to that problem. In this study, we calculated the relationship between fresh and dry weight of corn stovers, over several, growth, stages of eight corn cultivars of different vigour and maturity period, at two Mexican locations. The differences between cultivars were for percent stover dry weight (%SDW) most evident in the second half of the grain growth stage, when late cultivars showed less humidity than the early ones. The % SDW was regressed against the phenological developmental stage and expressed as a ratio against antesis (R, days to sampling /days to 50% antesis). The equations (R2 = 0.97 - 0.99) with best results were: Early maturing cultivars: %SDW = 12.6 + 0.94R2 + 1.68R4; Late: %SDW = 16.1 - 4.00 R2 + 3.36R4. There were no consistant differences among cultivars with different vigour levels, even though certain differences were noted among the locations and they were attributed to differences in relative humidity. We describe a protocol for determining the dry weight of corn stover by area unit (t/ha) when drying conditions are not available, by utilizing only a scale and a ruler.We also suggest a method to calculate percent dry matter for a real plant parts (including grain).

The effect of density of planting on the growth of two Phaseolus vulgaris varieties in England

1976 ◽  
Vol 87 (1) ◽  
pp. 89-99 ◽  
Author(s):  
E. O. Lucas ◽  
G. M. Milbourn
Keyword(s):  
Phaseolus Vulgaris ◽  
Seed Yield ◽  
Dry Matter ◽  
Planting Density ◽  
High Yield ◽  
Vegetative Tissue ◽  
Wide Range ◽  
The Relationship ◽  
Pod Photosynthesis ◽  
Number Of Branches

SummaryThe growth and development of two varieties of Phaseolus vulgaris (Purley King and Limelight) were compared in two experiments in 1973 and 1974 at a range of planting density from 20 to 100 seeds/m2. Within this range, the relationship between seed yield and density in Purley King was asymptotic, although there was a suggestion that if even higher densities had been tested, a downward trend in yield might have occurred. The optimum density of planting for Purley King in Expt 1 was 50 seeds/m2 while that for Limelight was 40 seeds/m2. The corresponding densities in Expt 2 were 75 and 50 seeds/m2 respectively. Although number of branches per plant generally decreased with increasing density, there was no significant density effect on the number of nodes per plant. Thus stabilization of seed yield occurred even at quite low densities. Although in the low-density treatments, less vegetative tissue was produced, the peak of dry-matter yield occurred later after flowering and the slower subsequent senescence ensured the presence of active photosynthetic tissue throughout the pod-fill stage. Less pod retention occurred at high density which, combined with the ability of widely spaced plants to produce pods over a longer period, resulted in a similar number of pods per unit area over a wide range of density.Although the variety Purley King produced more than double the number of mature pods from its extra nodes and branches, it was outyielded by Limelight by 35% from the combined effect of more seeds per pod and a higher mean seed weight. Limelight also produced this high yield with less vegetative tissue. In both varieties it appeared that pod photosynthesis could take place, in Purley King because the pods were borne on higher nodes above the canopy and in Limelight due to the earlier senescence of its smaller leaf area. However, in spite of the apparent physiological advantages of Limelight, the pods are not borne high enough on this plant to enable satisfactory mechanical harvesting.

A note on the relationship between the digestible dry matter and the digestible energy content of ruminant diets

1961 ◽  
Vol 1 (1) ◽  
pp. 24 ◽  
Author(s):  
RJ Moir
Keyword(s):  
Dry Matter ◽  
Energy Content ◽  
Accurate Description ◽  
Digestible Energy ◽  
Dry Matter Digestibility ◽  
Wide Range ◽  
Ruminant Diets ◽  
The Relationship

The digestible energy content (y, in Calories per gram) of a wide range of foodstuffs for ruminants may be accurately estimated from the dry matter digestibility (x per cent) by the regression y = 0.0467 x - 0.158 (r = 0.998). It follows that dry matter digestibility itself is a simple and accurate description of the digestible energv content of foodstuffs for ruminants.

scholarly journals Persistence of dry matter yield among New Zealand perennial ryegrass (Lolium perenne L.) cultivars: insights from a long-term data set

2015 ◽  
Vol 77 ◽  
pp. 177-184 ◽  
Author(s):  
D.F. Chapman ◽  
P.D. Muir ◽  
M.J. Faville
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Heading Date ◽  
Early Years ◽  
Grass Species ◽  
Data Set ◽  
High Performing ◽  
Wide Range ◽  
The Relationship

Persistence of herbage yield is an important productivity trait of grass species and cultivars in New Zealand pastures. However, relatively little is known about genetic variation in this trait, principally because few studies comparing yield have continued beyond 3 years. This paper reports results from a comparison of 25 perennial ryegrass cultivars representing a wide range of functional types and genetic backgrounds conducted under sheep grazing in a summer-dry environment. Dry matter (DM) yield was measured for the first 3 years after sowing, then again in years seven and eight post-sowing, and in year ten post-sowing. Endophyte DNA fingerprinting conducted mid-way through year seven confirmed that, with one exception, ryegrass populations remained true-to-type in the cultivars sown with novel endophyte strains. The cultivar effect on DM yield was statistically significant in all measurement periods. Differences in yields among cultivars in years seven and eight were significantly and positively correlated with yield differences in years one to three (r=0.685 to 0.831 depending on which year contrasts were used). Thus, high-performing cultivars in the early years of the trial were also generally highperforming cultivars in years seven and eight, and vice-versa, indicating a high degree of yield stability in perennial ryegrass cultivars. Yield differences did not appear to be related to differences in cultivar heading date, ploidy, endophyte status, or genetic background. The relationship between yield in year ten and yields in years one to three was much weaker (r=0.392) than the relationship in years seven and eight. Possible reasons for this are discussed. Keywords: Perennial ryegrass; traits; persistence

scholarly journals Relationships between sheep liveweight production and dry matter yield for lucerne-based pastures in spring

2019 ◽  
pp. 69-74 ◽  
Author(s):  
Annamaria Mills ◽  
Malcolm C. Smith ◽  
Derrick J. Moot
Keyword(s):  
Dry Matter ◽  
Dry Matter Yield ◽  
Botanical Composition ◽  
Grazing Experiment ◽  
Ewe Lamb ◽  
The Relationship ◽  
Over Time ◽  
Block Experiment

A five-year dryland grazing experiment explored the relationship between sheep liveweight (LWt) production and dry matter (DM) yield of lucerne-based pastures in spring. In 2011, a randomised complete block experiment with a lucerne monoculture, a lucerne/brome mix and a lucerne/cocksfoot mix were established at Ashley Dene, Canterbury and replicated six times. Pastures were managed under dryland conditions. Ewes with twin lambs at foot grazed in spring and LWt production, DM yield and botanical composition were quantified.Regression analysis showed total DM feed on offer accounted for only 11% of the observed variation in spring LWt production. Subsequent analysis of the botanical composition of the three pastures showed total feed on offer in spring was unaffected by pasture treatment in four out of five years. However, yield of the lucerne component on offer was 77–230% greater in the monoculture than the mixes in Years 3–5. Brome yields declined from Year 3 and did not recover. By Year 5, weeds accounted for 41% of the feed on offer in spring in the lucerne/brome mix. Net spring ewe + lamb liveweight production increased at a rate equivalent to 246 kg LWt +71 kg LWt per tonne of lucerne DM on offer (R2 = 0.83). There was no effect of pasture type. Where possible lucerne should be established as a monoculture to maximise liveweight gain. A runout stand was overdrilled with a companion grass to extend the productive stand life. The loss of lucerne over time indicated renewal should be initiated within 2–3 years of oversowing to ensure LWt production is not compromised.

scholarly journals A paddock survey of on-farm plantain use

2019 ◽  
pp. 125-130 ◽  
Author(s):  
Michael B. Dodd ◽  
Ray A. Moss ◽  
Ina J.B. Pinxterhuis
Keyword(s):  
Dry Matter ◽  
Critical Level ◽  
Plantago Lanceolata ◽  
Visual Assessment ◽  
N Cycling ◽  
N Leaching ◽  
Visual Estimation ◽  
Successful Establishment ◽  
Direct Drilling ◽  
On Farm

The use of narrow-leaved plantain (Plantago lanceolata) in pasture sowing mixtures has recently increased following research demonstrating the value of the ‘Tonic’ cultivar in reducing cattle urinary N concentration, with likely benefits for reducing N leaching from pasture systems. The purpose of this study was to document the ways in which farmers are using plantain, investigate the factors that enhance successful establishment and persistence, and to test a method of visual estimation of plantain content in paddocks. This information will support verification of animal intake, given that there is evidence that a critical level of plantain is required in the diet to achieve significant effects on N cycling. In grass-based pastures, plantain content declined with age since sowing and few paddocks had more than 20% of their available dry matter as plantain after three years. A systematic visual assessment of plantain cover correlated well with a formal visual dry matter assessment and could be used to establish when plantain content at a paddock scale is  >20–30%. Plantain content tended to be highest when sown without grass, when established by direct drilling and on clay soils, but optimal sowing rates have yet to be determined.

scholarly journals Connection between Nutrient Content and Resistance to Selected Pests Analyzed in Brassicaceae Hybrids

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 94
Author(s):  
Justyna Szwarc ◽  
Janetta Niemann ◽  
Jan Bocianowski ◽  
Monika Jakubus ◽  
Marek Mrówczyński
Keyword(s):  
Positive Association ◽  
Nutrient Content ◽  
Mineral Elements ◽  
Delia Radicum ◽  
Growth Stages ◽  
Flowering Stage ◽  
Brassica Napus L ◽  
Wide Range ◽  
Cultivated Species ◽  
The Relationship

Rapeseed (Brassica napus L. ssp. oleifera Metzg) is attacked by a wide range of pests. Breeding of resistant cultivars is one of the best methods of protecting crops against insects, and non-cultivated species of Brassicaceae can be used as resistance donors. In this study, we investigated the relationship between nutrient content and resistance to two commonly occurring pests (Delia radicum and Brevicoryne brassicae) in 12 Brassicaceae hybrid combinations. The experiment was conducted at Poznań University of Life Sciences Experimental Station located in Dłoń. The assessment was carried out for three years (2017, 2018, and 2019) on randomly chosen individuals in two growth stages: vegetative stage and flowering stage. The resistance to B. brassicae and D. radicum was observed in all three years, however, macronutrient and micronutrient contents as well as total nitrogen, total sulfur, and sulfur sulfate were observed only in 2019. Statistically significant negative association between Ca and resistance to B. brassicae and D. radicum was discovered. Additionally, positive association between Cu and resistance to B. brassicae was observed. The importance of selected mineral elements in plant resistance is widely discussed.

Jassid Resistance and Hairiness of the Cotton Plant

1949 ◽  
Vol 39 (4) ◽  
pp. 539-575 ◽  
Author(s):  
F. R. Parnell ◽  
H. E. King ◽  
D. F. Ruston
Keyword(s):  
Cotton Plant ◽  
Visual Assessment ◽  
Stages Of Growth ◽  
Wide Range ◽  
Leaf Hairiness ◽  
Resistant Strains ◽  
High Degree ◽  
The Relationship ◽  
Very High ◽  
Continuous Range

A wide range of material has been studied in an investigation of the relationship between “resistance” to attack by Empoasca facialis and “hairiness” of the cotton plant.A continuous range has been found between full susceptibility and very high resistance.In general relative susceptibility, as gauged by visual assessment of symptoms, has been found to correspond closely with relative infestation, determined by counts of nymphs.With attention confined to grown plants, the relative susceptibility of varieties has been found substantially constant under varying levels of exposure to infestation.Hairiness of the cotton plant has been found to show an extremely wide range in degree, style and distribution. A method has been devised for expressing hairiness numerically, taking into account both length and density of hairs.A very close and consistent relationship has been found between degree of hairiness of the under surface of the leaf, and degree of resistance to Jassid. Without exception, all thoroughly hairy types have been found highly resistant, and all non-hairy types fully susceptible. Intermediate degrees of hairiness ate associated with intermediate degrees of resistance.The relationship has been found to hold good between varieties and between plants within varieties, of the species G. hirsutum; also between plants of G. barbadense, and in segregating progenies of hybrids between these two species.The hairiness of resistant strains of cotton has been found to develop gradually with the growth of the plant; the first few leaves on the seedlings being virtually non-hairy. This lack of hairiness in the early stages of growth is associated with a lack of resistance. Hairiness and resistance to Jassid develop concurrently.The conclusion is reached that hairiness of the leaf confers resistance to Jassid and that degree of leaf hairiness, measured in an appropriate manner, is a thoroughly reliable guide to degree of resistance.Length of hairs is shown to be of prime importance, and high densities without adequate length are ineffective.The relative importance of hairs on lamina and midrib has not been conclusively determined. Both have an influence on resistance but a high degree of midrib hairiness is not essential if the lamina is hairy.Hairs on stem and petiole are shown to be of very little direct importance.

Assessment of tolerance in wheat and barley to common root rot (Cochliobolus sativus)

1993 ◽  
Vol 73 (4) ◽  
pp. 1177-1187 ◽  
Author(s):  
L. J. Duczek ◽  
G. B. Wildermuth
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Dry Matter ◽  
Field Tests ◽  
Cochliobolus Sativus ◽  
Disease Assessment ◽  
Growth Stages ◽  
Common Root ◽  
Common Root Rot ◽  
The Relationship

Field tests at Saskatoon, Saskatchewan, Canada indicated no evidence of tolerance to common root rot in four spring wheat cultivars. There was a relationship between increased yield losses and increasing disease. In barley, the relationship was inconsistent in four cultivars and there was evidence of tolerance or recovery in Melvin with the number of seeds per head increasing with the level of disease. In Queensland, Australia there was evidence of tolerance in the wheat cultivar Banks across two locations, but the response was not consistent in all cultivars. Dry matter loss at immature growth stages was not related to grain yield loss. The inconsistent expression of tolerance in wheat, the difficulty of assessing it, and the difficulty of distinguishing tolerance from recovery suggest that the assessment of tolerance is not a reliable method of determining the reaction to common root rot. The relationship between loss in dry matter and grain yield, as disease increased, indicates that disease assessment should continue to be based on severity of symptoms. The evidence of tolerance to common root rot in barley suggests research on tolerance should concentrate on barley instead of wheat. Key words: Cochliobolus sativus, common root rot, tolerance, wheat, barley

Evaluation of techniques for estimating the yield of irrigated pastures intensively grazed by dairy cows. 2. The rising plate meter

1984 ◽  
Vol 24 (126) ◽  
pp. 305 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Visual Assessment ◽  
Matter Content ◽  
Dry Matter Content ◽  
Botanical Composition ◽  
Assessment Technique ◽  
Grazed Pastures ◽  
Number Of Factors ◽  
Short Period

A semi-automatic rising plate meter, the Ellinbank Pasture Meter (EPM) was used to estimate herbage yields of the three most common types of irrigated pasture intensively grazed by dairy cows in northern Victoria. While there were only small differences in precision between the pasture types, yields of pre-grazed pastures were measured more precisely than yields of post-grazed pastures. The EPM also estimated pre-grazing yield more precisely than a visual assessment technique, while the two techniques were similar for estimating post-grazed herbage. A number of factors, including dry matter content of the herbage, botanical composition, season, and lodging due to trampling were shown to influence pre- and post-grazing regressions. It was concluded that pooled regressions were therefore unsuitable for research purposes unless the pooling was for a relatively short period only. Pre- and post-grazing data can be pooled for periods of up to two months to allow the estimation of pasture growth rates at various points of time between grazings. An alternative method of obtaining yield estimates has been proposed in which it is not necessary to develop a regression. This method relies on cutting quadrats in each plot that are representative of the yield and composition of the plot. While this method can circumvent some of the problems associated with the factors that influence the yield-height relationship, severe lodging due to trampling of the sward may preclude the use of the EPM regardless of method.

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