Effects of Preemergence Herbicides on the Competitiveness of Selected Weeds

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 54-56 ◽  
Author(s):  
Timothy E. Adcock ◽  
Philip A. Banks
Keyword(s):  
Leaf Area ◽  
Water Use ◽  
Field Experiments ◽  
Dry Weight ◽  
Growth Characteristics ◽  
Preemergence Herbicides

Experiments were conducted to evaluate the effects of preemergence herbicides on the growth characteristics and competitiveness of sicklepod and common cocklebur to soybean. Alachlor was applied at 1.1 or 2.2 kg ai ha–1and metribuzin at 0.2 or 0.4 kg ai ha–1in glasshouse and field experiments. Alachlor at 2.2 kg ha–1reduced sicklepod dry weight and leaf area 4 weeks after planting. Sicklepod water use was initially lowered by both rates of alachlor while soybean and common cocklebur water use was initially lowered by metribuzin at 0.4 kg ha–1. Sicklepod and common cocklebur fresh weights were reduced at soybean harvest by the high rates of alachlor and metribuzin. Soybean competing with sicklepod injured by 1.1 or 2.2 kg ha–1of alachlor produced yields greater than soybean competing with untreated sicklepod. Soybean yields were not improved when metribuzin was used on common cocklebur.

Water use efficiency of wheat in a Mediterranean-type environment. II. some limitations to efficiency

1984 ◽  
Vol 35 (6) ◽  
pp. 765 ◽  
Author(s):  
RJ French ◽  
JE Schultz
Keyword(s):  
Water Use Efficiency ◽  
Leaf Area ◽  
Water Use ◽  
Harvest Index ◽  
Field Experiments ◽  
Field Trials ◽  
Growth Yields ◽  
Potential Yield ◽  
Use Efficiency ◽  
Factorial Treatments

Evidence is presented that water use efficiency and yield of wheat are reduced by insufficient leaf area and by inadequate content of nutrients in the top growth. Yields from field trials are compared with the potential yield, and a review is made of the limitations caused by weeds, the incidence of diseases and the harvest index. The data highlight the need for field experiments to define the evaporation and transpiration components of water use in each environment. They also indicate the need for multi-factorial treatments to overcome all yield limitations and thereby attain the potential yield.

scholarly journals Comparison of an Antitranspirant Spray, a Polyacrylamide Gel, and Wind Protection on Early Growth of Muskmelon

HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Laurie Hodges ◽  
Entin Daningsih ◽  
James R. Brandle
Keyword(s):  
Plant Growth ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Field Experiments ◽  
Block Design ◽  
Dry Weight ◽  
Early Growth ◽  
Polyacrylamide Gel ◽  
Fresh Weight ◽  
Area Index

Field experiments were conducted over 4 years to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc., Paulsboro, N.J.) and polyacrylamide gel (SuperSorb, Aquatrol Inc., Paulsboro, N.J.) on early growth of transplanted muskmelon grown either protected by tree windbreaks or exposed to seasonal winds. A randomized complete block design (RCBD) with split plot arrangement was used with wind protection (sheltered and exposed) areas as the main treatment and use of an antitranspirant spray or gel dip as subtreatments. Based on destructive harvests in the field, treatments and subtreatments did not affect dry weight or leaf area index in the first 2 years. Specific contrasts, however, showed that gel application significantly increased fresh weight, dry weight, and leaf area index over that of the untreated transplants whereas the spray application tended to reduce these factors during the first 3 weeks after transplanting. Significant differences between gel and spray subtreatments disappeared by 5 weeks after transplanting. Shelterbelts ameliorated crop microclimate thereby enhancing plant growth. Significantly, wind velocity at canopy height was reduced 40% on average and soil temperatures were about 4% warmer in the sheltered plots compared to the exposed plots during the first 5 weeks post-transplant. Muskmelon plants in the sheltered areas grew significantly faster than the plants in the exposed areas in 2 of the 3 years reported, with the 3-year average fresh weight increased by 168% due to wind protection. Overall transplanting success and early growth were enhanced the most by wind protection, followed by the polyacrylamide gel root dip, and least by the antitranspirant foliar spray. We conclude that microclimate modification by wind speed reduction can increase early muskmelon plant growth more consistently than the use of polyacrylamide gel as a root dip at transplanting or the use of an antitranspirant spray. A polyacrylamide gel root dip generally will provide more benefit during early muskmelon growth than the use of an antitranspirant spray.

The effect of a common date of either anthesis or planting on the rate of development and grain yield of wheat

1983 ◽  
Vol 34 (1) ◽  
pp. 13 ◽  
Author(s):  
DR Woodruff
Keyword(s):  
Grain Yield ◽  
Soil Water ◽  
Water Use ◽  
Field Experiments ◽  
Dry Weight ◽  
Developmental Rate ◽  
Rate Of Development ◽  
Kernel Weights ◽  
Total Dry Weight ◽  
Faster Development

In field experiments in southern Queensland comparisons were made, for a given wheat genotype, of the influence on grain yield of varying the rate of development while maintaining common dates either of anthesis or of planting. Rates of development were varied by the use of extended photoperiods or of isogenic lines of Triple Dirk varying in developmental rate. Hastened development lowered spikelet numbers and total dry weight at anthesis in all the genotypes tested, under highly stressed dryland and fully irrigated conditions. The saving in water use due to fast development rate, measured as available water at anthesis, was not proportional to the difference in total dry weight. This could be due to additional effective rainfall in the longer growing season wheats, to a high rainfall event just prior to anthesis reducing differences in available soil water, or to the complete use of soil water reserves in all treatments. With a common anthesis date, the saving in water use by the quicker developing crops (i.e. later planted) did not offset their lower dry weights and spikelet numbers at anthesis, so that there was either no yield difference or a yield decline with faster development rates. Where common dates of planting were compared the faster developing treatment (i.e. earlier flowering) still showed a trend to reduction in grain number per unit area, but this was usually offset by higher kernel weights. The yield outcome in this case was dominated by the prevailing environmental conditions at the differing anthesis dates.

scholarly journals Relations Between Leaf Area Index and Growth Characteristics of Florunner, Southern Runner, and Sunrunner Peanut1

1991 ◽  
Vol 18 (1) ◽  
pp. 30-37 ◽  
Author(s):  
David P. Davis ◽  
Timothy P. Mack
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Fungal Pathogens ◽  
Dry Weight ◽  
Growth Characteristics ◽  
Vegetative Stage ◽  
Height Range ◽  
Area Index ◽  
Number Of Leaves ◽  
Leaf Dry Weight

Abstract Growth characteristics of three commonly planted peanut cultivars were measured during the 1988 and 1989 growing seasons at the Wiregrass Substation in Headland, Ala., to develop equations for predicting leaf area index (LAI) from other growth varibales. These equations were needed to allow rapid estimation of leaf area loss from foliar-feeding insects or foliar-fungal pathogens. Conventionally planted and tilled fields of Florunner, Sunrunner and Southern Runner peanut (Arachis hypogaea L.) were sampled for plant vegetative stage, reproductive stage, height, number of leaves, leaf area, leaf dry weight, number of pods, pod dry weight, stem dry weight, and stand density. Most growth characteristics increased linearly (p<0.05) with time in both years. LAI was significantly correlated (P<0.05) with most growth variables for each cultivar. Linear regression was used to create equations for prediction of LAI from leaf dry weight (range of R2 = 0.93 to 0.97) and number of leaves (range of R2 = 0.74 to 0.95) for each cultivar, and all cultivars combined. Equations were also developed to predict LAI from plant height (range of R2 = 0.85 to 0.96) and plant vegetative stage (range of R2 = 0.81 to 0.83). These equations should be useful to those who wish to estimate LAI from other growth variables.

scholarly journals Water use estimation and growth of container grown tatarian dogwood (Cornus alba L. ‘Sibirica’) and cherry laurel (Prunus laurocerasus L. ‘Novita’)

2020 ◽  
Vol 48 (2) ◽  
pp. 1027-1042
Author(s):  
Éva ÓNODY ◽  
Károly HROTKÓ ◽  
Magdolna SÜTÖRINÉ DIÓSZEGI
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Dry Weight ◽  
Plant Size ◽  
Area Measurement ◽  
Evergreen Species ◽  
Significant Difference ◽  
Cherry Laurel

The pot in pot (PIP) system is a new alternative to container above ground (CAG) cultivation in nurseries. Our study estimates plant water usage of plants in CAG and PIP. Main variables as plant species, nursery container type and year effect on morphological parameters (plant size, leaf area, fresh and dry weight), on daily water use (weighed DWU), transpiration of leaves (DT) supplemented with species effect were analysed. Twenty plants grown in 5 L plastic pots of each combination were investigated. For leaf area measurement by AM350 we sampled 30 leaves from each plant. Fourty plants were weighed by a digital scale (Dyras, KSCL-300), morning and evening on each sampling day. Leaf gas exchange was measured on the same days by using leaf gas exchange analyzer (LCi, ADC Scientific Ltd.). From the two investigated deciduous (tatarian dogwood) and evergreen species (cherry laurel), only the tatarian dogwood showed improved quality in the PIP system (enhanced canopy increment, fresh and dry weight).  Significant difference showed the two species in DWU, and in DT. The tatarian dogwood used 626 g day-1 water (194 %) compared to the cherry laurel’s 341 g day-1 water use in 2015, while in 2016 this ratio was 144% in favor of tatarian dogwood. We measured higher initial morning weight (IWC) in PIP system. The transpiration measurements on single selected leaves overestimated the real transpiration compared to DWU. The DT of the deciduous tatarian dogwood responses more sensitive to environmental conditions than the evergreen cherry laurel.

Effect of applying nitrogen to cereals in the spring or at ear emergence

1962 ◽  
Vol 58 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Gillian N. Thorne
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Field Experiments ◽  
Spring Barley ◽  
Dry Weight ◽  
Early Application ◽  
Low Efficiency ◽  
Total Dry Weight ◽  
Effect On Yield ◽  
Ear Number

Nitrogen applied at ear emergence to winter wheat or spring barley grown in pots with various levels of basal nitrogen fertilizer, increased grain and total dry weight much less than similar amounts of nitrogen applied in March or April. No nitrogen was absorbed after ear emergence from unfertilized soil, or from the early application, and at maturity equal amounts of nitrogen had been absorbed from early and late applications.Early nitrogen increased final ear number by increasing the number at emergence and also increased grain size. Late nitrogen had negligible effect on yield of ears present when it was applied and caused the production of new shoots with small ears. Nitrogen applied at both times increased leaf area duration after ear emergence similarly; early nitrogen by increasing area at ear emergence and late nitrogen by delaying senescence of existing shoots and causing production of new shoots. The efficiency in grain production of the leaf area present after ear emergence was less with late than with early nitrogen, mainly because of the low efficiency of the shoots produced after ear emergence.These results differed from those of field experiments in which early and late nitrogen usually increased grain yield similarly, probably because in the field there were no late unproductive tillers and all the late nitrogen was utilized in increasing grain yield of existing shoots. Another difference was that nitrogen uptake from soil in the field continued until maturity.

scholarly journals CO2 enrichment and increasing light intensity till a threshold level, enhance growth and water use efficiency of lettuce plants in controlled environment

2020 ◽  
Vol 48 (4) ◽  
pp. 2244-2262
Author(s):  
Maryam ESMAILI ◽  
Sasan ALINIAEIFARD ◽  
Mahmoud MASHAL ◽  
Parisa GHORBANZADEH ◽  
Mehdi SEIF ◽  
...  
Keyword(s):  
Light Intensity ◽  
Water Use Efficiency ◽  
Leaf Area ◽  
Water Use ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Photon Flux ◽  
Fresh Weight ◽  
Co2 Concentrations ◽  
Use Efficiency

Carbon dioxide (CO2) and light intensity are the two main environmental drivers known to play important roles in crop growth and yield. In the current study, lettuce seedlings were exposed to four different light intensities [(75, 150, 300 and 600 Photosynthetic Photon Flux Density (PPFD)] and four different concentrations of CO2 (400, 800, 1200 and 1600 ppm). By increasing light intensity and CO2 concentration growth parameters such as fresh weight, dry weight and leaf area were stepwise increased from 75 to 300 PPFD and from 400 ppm to 1200 ppm CO2 concentration. Maximum fresh weight was observed in 300 PPFD under both 1200 ppm and 1600 ppm CO2 concentrations. Highest dry weight was obtained in plants exposed to 300 and 600 PPFD under both 1200 and 1600 ppm CO2 concentrations. Highest leaf area was detected in 300 PPFD under both 1200 and 1600 ppm CO2 concentrations. Widest stomatal pore aperture was detected in 600 PPFD under 400 ppm and 800 ppm CO2 concentrations. Evapotranspiration increased in a light intensity and CO2 concentration-dependent manner; higher light intensity or higher CO2 concentration, more evapotranspiration. Highest water use efficiency (WUE) was achieved in plants exposed to 300 PPFD under 1200 ppm CO2 concentration. In conclusion, to achieve best growth performance and WUE, lettuce should be produced under 300 PPFD light intensity and 1200 ppm CO2.

Effect of Light, Watering Frequency, and Chlorsulfuron on Canada Thistle (Cirsium arvense)

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 590-594 ◽  
Author(s):  
Robert L. Zimdahl ◽  
Jingzhu Lin ◽  
Armando A. Dall'Armellina
Keyword(s):  
Leaf Area ◽  
Field Experiments ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Water Levels ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Canada Thistle ◽  
Root Dry Weight ◽  
Effect Of Light

Greenhouse and field experiments were conducted to determine effects of light, water, and chlorsulfuron on growth of Canada thistle. In the greenhouse, shoot and root dry weight, leaf area, and number of inflorescences decreased as light and water levels decreased. In the field, shoot and root dry weight, leaf area, and number of Canada thistle inflorescences were positively correlated with light intensity from 1832 to 30 μmol m−2s−1photosynthetic photon flux density (PPFD). The greatest effect of light was on inflorescence production which was eliminated at 30 μmol m−2s−1(PPFD). The combined effect of water stress and chlorsulfuron decreased root and shoot growth but did not eliminate it.

Response of Soybean to Combinations of Clomazone, Metribuzin, Linuron, Alachlor, and Atrazine

1992 ◽  
Vol 6 (4) ◽  
pp. 922-929 ◽  
Author(s):  
Frederick P. Salzman ◽  
Karen A. Renner
Keyword(s):  
Organic Matter ◽  
Leaf Area ◽  
Field Experiments ◽  
Soybean Seed ◽  
Dry Weight ◽  
Application Rate ◽  
Shoot Dry Weight ◽  
Temperature Regimes ◽  
Chamber Studies ◽  
Growth Chamber Studies

Field observations in 1986 indicated that increased injury to soybean could occur from clomazone plus metribuzin and clomazone plus linuron compared with metribuzin or linuron alone. Field experiments to measure this response were conducted in 1988, 1989, and 1990 at two locations in Michigan. Atrazine at 0, 1120, 2240, and 3360 g ha-1was applied the year previous to soybean planting to determine if atrazine residues in the soil influenced soybean response. Herbicide treatments in soybean included clomazone, metribuzin, linuron, alachlor, clomazone plus metribuzin or linuron, alachlor plus metribuzin or linuron, and an untreated control. Additive and synergistic responses in soybean to clomazone plus linuron and clomazone plus metribuzin, regardless of atrazine application rate, occurred in some field environments. Experiments in the greenhouse demonstrated that soybean shoot weight was reduced synergistically from clomazone plus metribuzin compared with either herbicide alone, and the response was greater on a soil with 2.5% organic matter compared with a soil with 4.4% organic matter. Clomazone plus metribuzin reduced leaf area and shoot dry weight, regardless of placement, while leaf area and shoot dry weight were reduced more when clomazone plus linuron- and atrazine plus metribuzin-treated soil was placed in the same zone as the soybean seed. The synergistic interaction in soybean to clomazone plus metribuzin occurred under both cool and warm temperature regimes in growth chamber studies.

Competition between maize and Rottboellia exaltata

1975 ◽  
Vol 84 (2) ◽  
pp. 305-312 ◽  
Author(s):  
P. E. L. Thomas ◽  
J. C. S. Allison
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Field Experiments ◽  
Plant Density ◽  
Seedling Emergence ◽  
Total Yield ◽  
Dry Weight ◽  
Maize Yield ◽  
One Pot ◽  
Maize Grain

SUMMARYOne pot and five field experiments were made to study different aspects of the competition between R. exaltata and maize.The growth of young maize plants was not inhibited by being grown together in pots with young R. exaltata plants. In the field the soil tended to be somewhat wetter when the two species were grown together than when maize was grown alone, and was wettest with R. exaltata grown alone. Maize grain and total yield decreased and shoot yield of R. exaltata increased with R. exaltata plant density on both irrigated and unirrigated blocks of land, but yields were not much affected on either block by increase in plant density of maize or in nitrogen supply; maize yield was increased by irrigation but that of R. exaltata was not. Maize plant arrangement did not greatly affect maize grain and total yield or R. exaltata shoot yield, nor did arrangement of R. exaltata plants have much influence on their depression of maize yield, but R. exaltata caused a greater decrease in the grain yield of a short than of a tall maize cultivar.R. exaltata plants germinating at the same time as the crop plants did not have much effect on maize grain yield if they were removed by 8 weeks after the seedlings emerged, but decreased it considerably if allowed to remain for 12 weeks or more; weeds sown 2 or more weeks after the maize emerged hardly grew and had little effect on maize yield. When maize and R. exaltata were grown together leaf area of the maize was little affected up to the time of flowering, but was decreased after flowering, while leaf area of the weed was greatly depressed. Up to 7–8 weeks after seedling emergence more of the ground area was covered by foliage when maize was grown with R. exaltata than when it was grown alone, but later the ground was completely covered by foliage in both cases. Dry weight of grain and shoot of maize increased and that of shoot of R. exaltata decreased when the weed plants were shortened with growth regulators.

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