Components of Error in Field Experiments with Cotton, Groundnuts, Kenaf and Sesame in the Central Sudan Rainlands. II . Variation in Plant Measurements Through the Season and a Discussion of Surface Drainage as a Source of Variation

1976 ◽  
Vol 12 (3) ◽  
pp. 225-240 ◽  
Author(s):  
H. R. B. Hack
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Branch Length ◽  
Dry Weight ◽  
Mean Square ◽  
Node Number ◽  
Surface Drainage ◽  
Central Sudan ◽  
Main Components ◽  
Uncontrolled Variation

Dry weight, stem and branch length and node number, and flower and fruit number where appropriate, were recorded through the season on cotton, groundnuts, kenaf and sesame in the central rainlands of the Sudan in 1965. For each sampling date variationwithin plotsandbetweenreplicate plots within blocksandtreatmentxblockinteraction have been studied, together with the effect of these components on the magnitude of the residual root mean square in the analysis oftreatmentsxblocks.The main components were usuallywithin plotandbetween replicate plots within blockerrors. Uncontrolled variation was unacceptably great, and was thought to be in large part the result of irregular surface drainage conditions. It seems more likely to be useful to include surface drainage contrasts in field experiments subject to high intensity rainfall on this impermeable clay soil than to attempt to increase precision alone.

scholarly journals Evaluation by grafting technique of changes in the contribution of root-to-shoot development and biomass production in soybean (Glycine max) cultivars released from 1929 to 2006 in China

2019 ◽  
Vol 70 (7) ◽  
pp. 585 ◽  
Author(s):  
Xiaoning Cao ◽  
Tingting Wu ◽  
Shi Sun ◽  
Cunxiang Wu ◽  
Caijie Wang ◽  
...  
Keyword(s):  
Glycine Max ◽  
Shoot Growth ◽  
Field Experiments ◽  
Root Traits ◽  
Dry Weight ◽  
Shoot Development ◽  
Node Number ◽  
Grafting Technique ◽  
Glycine Max L ◽  
Soybean Roots

Root traits are essential for optimising nutrient and water absorption and anchorage. However, changes in root traits and the contribution of root-to-shoot growth and development of soybean (Glycine max (L.) Merr.) across a century of breeding are poorly documented. In this study, we adopted a grafting technique, using 55 cultivars released in the three main soybean-production regions in China as rootstocks in a pot experiment and 24 cultivars from the Yellow-Huai-Hai Valley (YHH) region as rootstocks in a field experiment, with cv. Zigongdongdou as the common scion. Changes in soybean roots, including dry weight (DW) of roots, lateral root number (LRN) and taproot length (TRL), and their contribution to shoot development and biomass formation, including shoot DW, plant height and node number, were evaluated under optimal conditions in 2011. Aboveground traits declined with year of release in the YHH region and did not vary over time in the northern Heilongjiang province and mid-south Heilongjiang region except for shoot DW. The root traits root DW, LRN and TRL were similar over years of release in the pot and field experiments. The results suggest that the newer cultivars have lesser shoot growth and root capacity but the same amount of root growth as older cultivars. Root traits did not change during selection, suggesting that improvement in soybean root traits should be an aim in future breeding.

Investigations in crop husbandry. III. Effect of time of application of sulphate of ammonia to wheat

1936 ◽  
Vol 26 (2) ◽  
pp. 316-327 ◽  
Author(s):  
F. H. Garner ◽  
H. G. Sanders
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Foot Rot ◽  
Plant Establishment ◽  
Poor Condition ◽  
Time Of Application ◽  
Gravelly Soil ◽  
Heavy Clay ◽  
Crop Husbandry

1. Over a period of six years seven field experiments were carried out to study the effect of the time of application of sulphate of ammonia to autumn-sown wheat.2. Three experiments were located on light gravelly soil which had been farmed highly for some years, and in those three cases sulphate of ammonia decreased yield, irrespective of time of application; the reduction in yield was of the order of 10 per cent. and is ascribed to more lodging and greater incidence of “foot-rot”.3. Three experiments were located on heavy clay soil in poor condition; in these sulphate of ammonia gave percentage increases in yield of 18, 20 and 7.4. Evidence is produced that early dressings of sulphate of ammonia do not affect germination or plant establishment, but that they tend to increase tiller formation by the end of February.

Trace element uptake by two British Columbia forages as affected by poultry manure application

1991 ◽  
Vol 71 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. A. Bomke ◽  
L. E. Lowe
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Clay Soil ◽  
Poultry Manure ◽  
Yield Response ◽  
Silty Clay ◽  
Manure Application ◽  
Deep Pit ◽  
Loam Soil ◽  
Trace Element Uptake

Field experiments evaluated yield response to deep-pit poultry manure application to barley on a clay soil near Prince George and a grass-legume forage on a silty clay loam soil near Chilliwack, B.C. Substantial dry matter yield increases were measured at manure applications up to 20 t ha−1. Subsamples of both crops and the poultry manure were analyzed for Cu, Zn, Mn, Ba, Pb, Ni, Cr, Cd, B and Co. Selenium analyses were made on selected crop samples. There were no indications of toxicity problems even at 40 t ha−1, the highest application. Copper and Zn concentrations in forages were increased by the poultry manure and the Mn/Cu ratio tended to decrease with manure application. Key words: Orchardgrass, ladino clover, barley, micronutrients

scholarly journals Effects of Cover Methods and Nitrogen Levels on the Growth and Yield of Tomato

2021 ◽  
Vol 4 (2) ◽  
pp. 1021-1033
Author(s):  
Nguyen Thi Loan ◽  
Tran Thi My Can
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Block Design ◽  
Tomato Fruit ◽  
Dry Weight ◽  
Fruit Yield ◽  
Growth And Yield ◽  
Plastic Mulch ◽  
Yield Attributes ◽  
Black Plastic

To study the effects of cover methods and nitrogen (N) levels on the growth and yield components of tomato Cv. Pear F1, field experiments with a 4x3 factorial design were conducted in the 2019 spring and winter seasons using a randomized complete block design with three replications. The cover methods included four treatments: bare soil (BS), black plastic mulch (BPM), transparent polypropylene row cover (RC), and a combination of BPM and RC (BPMRC) with the RC removed approximately 30 days after transplanting. Nitrogen (N) was applied at three levels (150, 180, and 210 kg N ha-1). Using BPM and RC generally led to an increased air temperature, air humidity, soil moisture, and soil temperature compared to the BS treatment. Higher N rates (180 and 210 kg N ha-1) did not result  in different tomato fruit sizes and fruit weights but positively increased fruit yield and quality (Brix values and fruit dry weight) as compared to the 150 kg N ha-1 addition. The cover methods positively affected the yield components and fruit yield of tomato as well as the fruit characteristics compared to the BS treatment. Using cover materials (BPM and RC) combined with a higher N application significantly increased the yield attributes and fruit yield. The highest fruit yield was achieved under the mulching treatment by black plastic (BPM treatment) combined with a 210 kg N ha-1 application, resulting in 50.90 tons ha-1 in the spring and 58.27 tons ha-1 in the winter.

Investigation of a chlorsulfuron-resistant chickweed [Stellaria media (L.) Vill.] population

1994 ◽  
Vol 74 (4) ◽  
pp. 693-697 ◽  
Author(s):  
J. T. O'Donovan ◽  
G. M. Jeffers ◽  
M. P. Sharma ◽  
D. Maurice
Keyword(s):  
Field Experiments ◽  
Dry Weight ◽  
Sulfonylurea Herbicides ◽  
Percentage Germination ◽  
Flower Number ◽  
Stellaria Media ◽  
Shoot Dry Weight ◽  
Excellent Control ◽  
Two Populations ◽  
Growth Analyses

A chickweed population (R) from a farm near Stony Plain, Alberta, was more resistant to chlorsulfuron than a population (S) collected near Vegreville, Alberta. In greenhouse experiments, the S population was controlled completely by chlorsulfuron applied at 5 g ha−1, whereas 22 g ha−1 was required to reduce dry weight of the R population by 50%. Experiments conducted in a germinator indicated that percentage germination of the R population was higher than that of the S population up to ~ 60 h. Growth analyses in the greenhouse indicated that leaf number, leaf area, shoot dry weight, days to flowering, flower number, seed weight and relative yields differed little between the two populations. In field experiments, control of the R population was poor with the sulfonylurea herbicides, chlorsulfuron, metsulfuron methyl, triasulfuron, amidosulfuron and thifensulfuron. Good to excellent control was obtained with cyanazine/MCPA, linuron, metribuzin, mecoprop, bentazon, metribuzin + MCPA, linuron + MCPA, and mecoprop + bentazon. Key words: Sulfonylurea herbicides, chlorsulfuron, herbicide resistance, relative competitiveness

Controlled-temperature effects on cotton growth and development

1998 ◽  
Vol 130 (4) ◽  
pp. 451-462 ◽  
Author(s):  
D. ROUSSOPOULOS ◽  
A. LIAKATAS ◽  
W. J. WHITTINGTON
Keyword(s):  
Leaf Area ◽  
Temperature Variation ◽  
Vegetative Growth ◽  
Growth And Development ◽  
Dry Weight ◽  
Maximum Temperature ◽  
Node Number ◽  
Mean Temperature ◽  
Fruiting Branch ◽  
Threshold Temperatures

The growth and development of cotton was studied on cotton plants grown in pots in growth rooms under constant day/night temperature (C) and varying temperature regimes throughout the day and/or night (V) The V-treatments had a common mean temperature of 22°C. The objectives were to determine the thermal requirements of three cultivars and to observe the extent of genotype×thermal environment interactions throughout the entire growth period.Vegetative growth was found to be almost exclusively time and temperature dependent, varietal differences being largely insignificant. Plant material was found to accumulate four times faster under the warmest C-regime, which was 7°C warmer than the coolest. The C-treatments caused variation in the number and size of lateral shoots and leaves, causing leaf area to be larger at the squaring stage in cool environments but at maturity in warm regimes. Relatively cool nights lowered the position of the first floral or fruiting branch, whereas warm days shortened flowering intervals and thus promoted earliness. However, the effect of temperature in altering the position of the first floral branch seems to be less important than its effect on the shedding of early squares.The effects of fluctuating temperature (V) on vegetative growth and earliness were similar to those from constant temperature environments. Growth and development rates were low in the low minimum V-regimes, especially when the maximum temperature was also low. Temperature variation affected vegetative growth to a greater extent in the early than in the later stages of development. At squaring, leaf area and dry weight were lowest under the regime with the highest minimum and maximum temperatures. Later on, only leaf area at flowering and total dry weight at maturity significantly differed between treatments. High maximum or minimum temperatures produced effects similar to a higher or lower mean temperature, respectively. The low minimum raised the node number of the first floral or fruiting branch, whereas in the case of boll dry weight it acted in the same way as a further drop in temperature, decreasing the weight, regardless of the maximum temperature. Boll period was affected mainly by the temperature variation itself rather by than the type of variation.The inverse of time to a certain stage and the corresponding mean temperature were linearly related and allowed threshold temperatures (T0) and thermal time requirements to be estimated. T0=12°C, except for the initial stage, when it was lower. A cotton growing season cooler on average by only 1°C will considerably delay maturity.

Components of Error in Field Experiments with Cotton, Groundnuts, Kenaf and Sesame in the Central Sudan Rainlands. I. Field and Statistical Methods; Increasing Precision by Replication and its Cost

1976 ◽  
Vol 12 (3) ◽  
pp. 209-224 ◽  
Author(s):  
H.R.B. Hack
Keyword(s):  
Statistical Methods ◽  
Field Experiments ◽  
Sources Of Error ◽  
Central Sudan ◽  
Standard Procedures ◽  
Different Levels

The layout of experiments for the study of the growth of four crops in the central rainlands of the Sudan in 1965 is described. The treatments, different levels of flooding prior to sowing, were replicated within blocks. Standard procedures for estimating within plot, between replicate plotswithin block and treatment x block components of error are set out and an example is given of the analysis employing data on kenaf. Using typical values for components of error found in these experiments, increases in precision obtainable by varying the number of plants sampled per plot, and the number of replicate plots per treatment, are considered in relation to their costs. It is concluded that excessive replication would be required to establish differences of interest and that attention should be given to sources of error variation when such large errors are found.

scholarly journals Genetic diversity among Asparagus species using morphological characteristics and RAPD markers in Pakistan

2019 ◽  
Vol 5 (1) ◽  
pp. 13-24
Author(s):  
M Irshad ◽  
M Idrees ◽  
A Tariq ◽  
ML Pathak ◽  
M Hanif ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Field Experiments ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Phenotypic Variance ◽  
Neighbor Joining ◽  
Comparative Performance ◽  
Shoot Height

The aim of present research was to study the genetic diversity among Asparagus species and its cultivars using morphological characteristics and RAPD markers. In-vitro and field experiments of 14 germplasm sources of Asparagus species and its cultivars were conducted at the Kohat University of Science and Technology to estimate the comparative performance. Highest genotypic variance, phenotypic variance, genotypic and phenotypic coefficient of variance were observed in shoot height in shoot related traits were 318.40, 320.30, 939.34 and 944.96, respectively, whereas highest values for root related traits were observed in root length that were 21.84, 22.35, 141.60 and 144.91 respectively. Among the shoot related traits maximum heritability, genetic advance and genetic gain were calculated for shoot length, while in root related traits these characters were highest for root dry weight. RAPD markers were used to evaluate genetic diversity analysis of 14 germplasm sources of Asparagus species and its cultivars. RAPD markers generated a total of 247 bands, of these 239 bands were polymorphic with average of 34.1 bands per primer. Cluster analysis based on Neighbor Joining methods showed that wild species (A. adsendens, A. densiflorus, A. capitatus, A. gracelus, A. plumosus, A. racemosus and A. setaceus) were genetically distant from A. officinalis and its cultivars (Abril, Apollo, Gersengum, Huchel, Para seletion and Taranga). The results of the present investigations could be particularly used for authentic identification and would be useful for evaluation of genetic improvement of Asparagus species and its cultivars. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(1): 13-24

Compensatory Responses of Common Cocklebur (Xanthium strumarium) and Velvetleaf (Abutilon theophrasti) to Partial Shading

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 541-547 ◽  
Author(s):  
Emilie E. Regnier ◽  
S. Kent Harrison
Keyword(s):  
Leaf Area ◽  
Shade Tolerance ◽  
Shoot Growth ◽  
Branch Length ◽  
Dry Weight ◽  
Xanthium Strumarium ◽  
Leaf Angle ◽  
Petiole Length ◽  
Partial Shading ◽  
Total Plant

Lower leaves of greenhouse-grown common cocklebur and velvetleaf were shaded to 5% of full light over a 12-d period while upper leaves remained exposed to full light to determine weed foliar and branching responses to partial shading similar to that encountered in soybean crops. Shading increased lower leaf senescence and specific leaf area, and decreased branch length and number of second-order leaves in both species compared to unshaded controls. Common cocklebur branched more extensively along the lower portion of its stem than velvetleaf under both shaded and unshaded conditions. Upper leaves of partially shaded velvetleaf were held in a more perpendicular position to the light source beginning 3 days after treatment (DAT) compared to upper leaves of unshaded plants. Shading of lower leaves caused an increase in upper (unshaded) leaf area beginning 3 and 6 DAT in velvetleaf and common cocklebur, respectively. Petiole length of upper leaves also increased in response to shading in both species. Total plant dry weight at 12 DAT was unaffected by shading in velvetleaf but was reduced 10% by shading in common cocklebur. While common cocklebur maintained greater lower shoot growth in the presence of shade than velvetleaf, there was a greater change in upper leaf angle by velvetleaf in response to shading than by common cocklebur. These results support previous field observations of apparent greater shade tolerance of common cocklebur compared to velvetleaf and indicate that both species have the ability to compensate for shading of lower leaves by altering upper shoot growth.

Foliar and Root Absorption of Atrazine Applied Postemergence to Giant Foxtail

Weed Science ◽  
1969 ◽  
Vol 17 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Lafayette Thompson ◽  
F. W. Slife
Keyword(s):  
Field Experiments ◽  
Soil Surface ◽  
Dry Weight ◽  
Field Studies ◽  
Simulated Rainfall ◽  
Root Absorption ◽  
Giant Foxtail ◽  
Setaria Faberii ◽  
Chamber Studies ◽  
Growth Chamber Studies

In growth chamber studies, high relative humidity and rewetting crystalline spray deposits of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) increased absorption by and phytotoxicity to giant foxtail (Setaria faberii Herrm.), but phytotoxicity was restricted to expanded (unrolled) leaves unless some atrazine was absorbed by the roots. Though phytotoxicity was increased by simulated rainfall when root absorption was prevented, an appreciable number of the plants were killed only when atrazine residues were washed into the soil. In field studies, atrazine applied to a wet soil surface was as effective as the same rate of atrazine foliarly applied. In other field experiments, atrazine applied to giant foxtail on a wet soil and followed by simulated rainfall reduced stand and dry weight, but on a dry soil and not followed by simulated rainfall, atrazine reduced dry weight less and did not reduce stand. These results are due to root absorption of atrazine from wet soil. Spray additives increased phytotoxicity.

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