SIXTY-SIX-YEAR TRENDS IN IRRIGATED CROP YIELDS—BARLEY, WHEAT, AND OATS

1979 ◽  
Vol 59 (3) ◽  
pp. 685-689
Author(s):  
S. DUBETZ ◽  
M. OOSTERVELD
Keyword(s):  
Crop Yields ◽  
Weight Basis ◽  
Climatic Variables ◽  
Regression Coefficients ◽  
Unit Weight ◽  
Effect On Yield ◽  
Yield Trends ◽  
New Cultivars

The regression coefficients of barley, wheat, and oat yields on advancing years were calculated to be 0.061, 0.020, and 0.034 t/ha/yr based on 66 yr of data from an irrigated rotation. Yield increases with time were attributed mainly to the introduction of new cultivars. These yield trends can be useful for predictive purposes. In recent years, barley has outyielded oats and wheat (utility wheat excluded) on a unit-weight basis even though barley yields were the lowest of the three cereals when the rotation began in 1911. The climatic variables measured and date of harvest had virtually no effect on yield. Wheat yields were enhanced when seeding took place during the last 113 days of April compared to those when the crop was seeded during the first 13 days of May.

A LONG-TERM FIELD EXPERIMENT WITH COMMERCIAL FERTILIZERS AND MANURE.: II. FERTILITY LEVELS AND CROP YIELDS IN A ROTATION OF POTATOES, OATS AND HAY

1962 ◽  
Vol 42 (1) ◽  
pp. 49-60 ◽  
Author(s):  
R. F. Bishop ◽  
L. B. MacLeod ◽  
L. P. Jackson ◽  
C. R. MacEachern ◽  
E. T. Goring
Keyword(s):  
Field Experiment ◽  
Crop Yields ◽  
Fertilizer Application ◽  
Regression Coefficients ◽  
Residual Effects ◽  
Commercial Fertilizer ◽  
Phosphatic Fertilizer ◽  
Yield Trends ◽  
Term Field

Treatments in a field experiment, conducted from 1936 to 1957, included commercial fertilizers and manure. A rotation of potatoes, oats and hay was followed.Application of manure at 30 tons per acre every third year practically maintained initial levels of total nitrogen and soil organic matter. Marked decreases occurred with lower rates of manure and various commercial fertilizers applied at 1 ton per acre. Increases and decreases in adsorbed and easily acid-soluble phosphorus were directly related to the amounts of phosphatic fertilizer applied. Although the situation with respect to exchangeable potassium was not comparable there was some evidence that final values were influenced by the amounts of potassium applied.All treatments were applied for potatoes, and yield differences were much greater for this crop than for either oats or hay. Rate of fertilizer application was of primary importance for potatoes, and residual effects on the oat and hay crops from 500 or 1000 pounds of commercial fertilizer per acre were generally slight. They were much more marked from manure and where commercial fertilizer was applied at a ton per acre. Irrespective of the treatment applied, linear regression coefficients, showing yield trends with advancing rotation cycles, were positive for potatoes and negative for hay. In the case of oats they were generally negative for the lowest rates of fertilizer used and positive for the highest.

Weight differences in rat embryos prior to sexual differentiation

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 259-263
Author(s):  
William J. Scott ◽  
Joseph F. Holson
Keyword(s):  
Sexual Differentiation ◽  
Thymidine Incorporation ◽  
Weight Basis ◽  
Unit Weight ◽  
Gonadal Differentiation ◽  
Barr Body ◽  
Endocrine Activity ◽  
Rat Embryos ◽  
Weight Protein ◽  
Amniotic Membranes

Sex of day-12 rat embryos was determined using Barr body counts made on spreads of amniotic membranes examined histologically. Embryonic weight, protein content and rate of thymidine incorporation were compared in male and female embryos. Male embryos were found to be heavier and accordingly to contain more protein on absolute but not on per unit weight basis. The rate of thymidine incorporation did not differ in the two sexes. Since gonadogenesis in day-12 rat embryos is rudimentary, with gonadal differentiation of sex not yet apparent, the increased weight suggests that sex-linked genes exist which influence body growth prior to gonadal endocrine activity.

Temporal changes in climatic variables and their impact on crop yields in southwestern China

2013 ◽  
Vol 58 (6) ◽  
pp. 1021-1030 ◽  
Author(s):  
Hong-Bin Liu ◽  
Yu Gou ◽  
Hong-Ye Wang ◽  
Hong-Mei Li ◽  
Wei Wu
Keyword(s):  
Crop Yields ◽  
Temporal Changes ◽  
Climatic Variables ◽  
Southwestern China

Observations on the proteins of pasturage. Phosphorus and protoplasm

1938 ◽  
Vol 28 (1) ◽  
pp. 135-173 ◽  
Author(s):  
F. W. Foreman
Keyword(s):  
Amino Acids ◽  
Weight Basis ◽  
New Method ◽  
Unit Weight ◽  
Rye Grass ◽  
Mineral Acids ◽  
The Right ◽  
Made In

1. Studies lead to the conclusion that Chibnall-preparations of pasturage proteins, in spite of their small amounts of carbohydrate impurity, may yet yield, on hydrolysis by mineral acids, practically the right amounts even of most of those amino-acids which are adversely affected by carbohydrates to some extent when tested singly under the conditions.2. Preparations made in another way after treating the pasturage with ether as in the original Chibnall-method showed features of interest in the problem of attaining very pure proteins now much needed for purposes of comparison.3. A new method is introduced by which it is possible to compare what may be extracted from the protoplasm of fresh unpulverized pasturages with the composition of the natural saps on a unit weight basis.4. Production and breakdown of protoplasmic protein in perennial rye-grass during growth consistently appeared related to variations in the content of “nitrogen” and phosphates in the saps and the supplies of “nitrogen” and phosphates from the soil.

scholarly journals Proteine als Schutzstoffe gegenüber dem Gefriertod der Zelle

1970 ◽  
Vol 25 (8) ◽  
pp. 834-842 ◽  
Author(s):  
U. Heber ◽  
M. Kempfle
Keyword(s):  
Molecular Weight ◽  
Frost Tolerance ◽  
Thylakoid Membranes ◽  
Weight Basis ◽  
Unit Weight ◽  
Low Molecular Weight ◽  
Complete Protection ◽  
Highly Active ◽  
Heat Stable ◽  
Better Than

Two protein factors from hardy leaves were highly active in preventing the inactivation of photophosphorylation of washed thylakoid membranes which takes place during freezing of thylakoids in the absence of protective compounds. Non-hardy leaves did not yield protective protein material. On a unit weight basis, protection by the protein factors was 10 to 100 times better than protection by compounds of low molecular weight such as sucrose, glycerol or dimethylsulfoxide. Very low amounts of the protein factors, which alone were scarcely protective, considerably reduced the concentration of sucrose required for the complete protection of thylakoids during freezing. The protein factors were heat-stable and had a molecular weight between 10 000 and 20 000 daltons. It is assumed that they contribute to and are in part responsible for the frost tolerance of hardy plant material.

scholarly journals Assessing Multiple Years’ Spatial Variability of Crop Yields Using Satellite Vegetation Indices

2019 ◽  
Vol 11 (20) ◽  
pp. 2384 ◽  
Author(s):  
Abid Ali ◽  
Roberta Martelli ◽  
Flavio Lupia ◽  
Lorenzo Barbanti
Keyword(s):  
Spatial Variability ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Crop Yields ◽  
Landsat Imagery ◽  
Vegetation Indices ◽  
Good Potential ◽  
Yield Trends ◽  
Final Agreement ◽  
Simple Ratio

Assessing crop yield trends over years is a key step in site specific management, in view of improving the economic and environmental profile of agriculture. This study was conducted in a 11.07 ha area under Mediterranean climate in Northern Italy to evaluate the spatial variability and the relationships between six remotely sensed vegetation indices (VIs) and grain yield (GY) in five consecutive years. A total of 25 satellite (Landsat 5, 7, and 8) images were downloaded during crop growth to obtain the following VIs: Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Soil Adjusted Vegetation Index (SAVI), Green Normalized Difference Vegetation Index (GNDVI), Green Chlorophyll Index (GCI), and Simple Ratio (SR). The surveyed crops were durum wheat in 2010, sunflower in 2011, bread wheat in 2012 and 2014, and coriander in 2013. Geo-referenced GY and VI data were used to generate spatial trend maps across the experimental field through geostatistical analysis. Crop stages featuring the best correlations between VIs and GY at the same spatial resolution (30 m) were acknowledged as the best periods for GY prediction. Based on this, 2–4 VIs were selected each year, totalling 15 VIs in the five years with r values with GY between 0.729** and 0.935**. SR and NDVI were most frequently chosen (six and four times, respectively) across stages from mid vegetative to mid reproductive growth. Conversely, SAVI never had correlations high enough to be selected. Correspondence analysis between remote VIs and GY based on quantile ranking in the 126 (30 m size) pixels exhibited a final agreement between 64% and 86%. Therefore, Landsat imagery with its spatial and temporal resolution proved a good potential for estimating final GY over different crops in a rotation, at a relatively small field scale.

Investigation of Properties of Low Thermal Conductivity Pozzolanics Soil Bricks Towards Sustainable Development

2011 ◽  
Vol 261-263 ◽  
pp. 469-479 ◽  
Author(s):  
Weerapol Namboonruang ◽  
Rattanakorn Rawangkul ◽  
Wanchai Yodsudjai ◽  
Joseph Khedari
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Physical Properties ◽  
Adsorption Property ◽  
Weight Basis ◽  
Modulus Of Rupture ◽  
Unit Weight ◽  
Commercial Development ◽  
Load Bearing ◽  
Alternative Type

The development of new alternative type of pozzolanics soil bricks using the locally available clay from Ratchaburi province were mixed with fly ash from Kanchanaburi province, where both source in western of Thailand, is the main purpose of this study. These are compared to the local clay cement bricks without the mixing of flyash in different proportions. In the present work, the physical properties of the specimens are presented namely, compressive strength, modulus of rupture, thermal conductivity and unit weight. Tests were also conducted to study the influence of time of curing on the increase in physical properties of the bricks. It was concluded that the addition of fly ash reduces the thermal conductivity and unit weight, while increases the water adsorption property of the specimen. The compressive and flexural strength are decreased when the ratio of fly ash is more than 30 percentages. However, when considering the various factors it can be said that, appropriately ingredient toward produce to commercial of the good pozzolanics soil bricks is portland cement constant was 5 percentages and 30 percentages of fly ash by weight basis of soil at water per total powder, W/P 0.3525. The compositions of fly ash more than 25 percentages by weight basis of soil and since up to 14 days of curing time proved to be economical mixtures for load bearing panels or brick type structural elements according to the Thai Industrial Standard(TIS) for structural clay load-bearing tile. Therefore, commercial development is highly promising.

scholarly journals Production Trends in Mature Macadamia Orchards and the Effects of Selective Limb Removal, Side-hedging, and Topping on Yield, Nut Characteristics, Tree Size, and Economics

2013 ◽  
Vol 23 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Lisa McFadyen ◽  
David Robertson ◽  
Margaret Sedgley ◽  
Paul Kristiansen ◽  
Trevor Olesen
Keyword(s):  
Substantial Reduction ◽  
Size Control ◽  
Cost Effective ◽  
Tree Size ◽  
Macadamia Integrifolia ◽  
Effective Removal ◽  
Effect On Yield ◽  
Yield Trends ◽  
Disease Pressure

Yields of macadamia (Macadamia integrifolia, M. tetraphylla, and hybrids) orchards tend to increase with increasing tree size up to ≈94% light interception. Beyond this, there is some indication that crowding leads to yield decline, but the evidence is limited to one site. Increasing tree size and orchard crowding also present numerous management problems, including soil erosion, harvest delays, and increased pest and disease pressure. The aim of this study was to better characterize long-term yield trends in mature orchards and to assess the effects of manual and mechanical pruning strategies on yield, nut characteristics, tree size, and economics. We monitored yield at four sites in mature ‘344’ and ‘246’ orchards for up to seven years and confirmed a decline in yield with crowding for three of the sites. There was a small increase in yield over time at the fourth site, which may reflect the lower initial level of crowding and shorter monitoring period compared with the other sites, and highlights the need for long-term records to establish yield trends. Pruning to remove several large limbs from ‘246’ trees to improve light penetration into the canopy increased yield relative to control trees but the effect was short-lived and not cost-effective. Removal of a codominant leader from ‘344’ trees reduced yield by 21%. Annual side-hedging of ‘246’ trees reduced yield by 12% and mechanical topping of ‘344’ trees caused a substantial reduction in yield of up to 50%. Removal of limbs in the upper canopy to reduce the height of ‘344’ trees had less effect on yield than topping but re-pruning was not practical because of the extensive regrowth around the pruning cuts. Tree size control is necessary for efficient orchard management, but in this study, pruning strategies that controlled tree size also reduced yield. Research into the physiological response to pruning in macadamia is required to improve outcomes.

Response of New Cultivars to Early Postemergence Chlorimuron Applications1

2004 ◽  
Vol 31 (2) ◽  
pp. 119-123 ◽  
Author(s):  
G. Wehtje ◽  
T. L. Grey
Keyword(s):  
Field Studies ◽  
Yield Reduction ◽  
Clear Indication ◽  
Application Timing ◽  
Main Effect ◽  
Effect On Yield ◽  
New Cultivars

Abstract Field studies were conducted in Alabama and Georgia in 2002 and 2003 to determine whether the peanut cultivar that replaced the cultivar Florunner can tolerate earlier applications of the herbicide chlorimuron than what is registered. The application timing restriction of chlorimuron on peanut had been established in the late 1980s with Florunner. In a factorial treatment arrangement, the cultivars AT201, Georgia Green, Viragard, C99R, and Florunner were treated with chlorimuron at 8.75 g ai/ha at 5, 7, 9, or 11 wk after planting. Only the later two application timings are covered by the current registration. Across all 4 yr-location replications, yield was influenced by the main effect of peanut cultivar. C99R was consistently the highest yielding cultivar. Chlorimuron had no effect on yield, regardless of application timing when compared to the nontreated entries in three of the four repetitions (i.e. Plains 2002, Plains 2003, and Headland 2002). Cultivar-based chlorimuron tolerance differences were detected only at Headland in 2003. For this location, chlorimuron applied at 5 wk after planting reduced yield across all cultivars, while application at 7, 9, and 11 WAP had no effect on yield. Results indicate that chlorimuron possesses a yield-reducing risk only when the crop has been stressed by other factors. Assuming that the crop has been stressed, the potential of yield reduction can be avoided only by observing the currently registered application timing. No clear indication was obtained that one cultivar was more tolerant to chlorimuron than another cultivar.

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