scholarly journals EFFECT OF HARDENING TO DROUGHT TOLERANCE ON THE MOISTURE CONTENT OF SUNFLOWER PLANT. I. MOISTURE PERCENTAGEIN ROOT AND STEM

2008 ◽  
Vol 5 (4) ◽  
pp. 513-521
Author(s):  
Baghdad Science Journal

Two field experiments were conducted during the spring seasons of 2000,2001.The aim was to study the effect of hardening to drought tolerance on moisture percentage in root and stem of sunflower plant during growth stages . Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available soil water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments :Control(unsoaked),soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature until they regained their original weight. Amount of water for each irrigation were calculated to satisfy water depletion in soil using a neutron meter. . Results indicated that stress at 800 Kp reduced moisture percentage in the root by 15.96% compared with full irrigation after86 days from planting,and in the stem by 9.64 and 11.99%compared with full irrigation and stress 600 Kp, respectively after 72 days from planting in the season 2001.Also stress 600 Kp reduced moisture percentage in the root after 58 days from planting by 5.81 and 5.97% compared with full irrigation and stress 800 Kp as a mean of seasons. Euroflor was superior over Flame after30 days from planting in the moisture percentage of its roots by 6.78 in the season of 2000 and by 3.10% as a mean of seasons..While Flame was superior in the moisture percentage of its stems by 4.62 and 2.51% after 58 days from planting in the season of 2000 and as a mean of seasons, respectively.Unsoaked treatment gave highest moisture percentage in the root, the percentage of increase reached to 5.05 and 9.63% than soaking in water and paclobutrazol after 30 days from planting and by 11.43 and 10.65% than soaked in water and pix solution after 86 days from planting as a mean of seasons. soaking in paclobutrazol solution decreased moisture percentage in the stem after 30 days from planting by 4.43 and 8.31% in the season 2000 and by 2.82 and 3.23% as a mean of seasons compared with soaking in water and pix solution , respectively. On the other hand paclobutrazol increased the percentage of moisture in the stems during the next stages of growth. The study suggest that it could improve water relations specially during the stages which increased water requirement (flowering and seeds filling), and increased drought tolerance by soaking the seeds presowing in water or plant growth regulators

2010 ◽  
Vol 7 (2) ◽  
pp. 888-894
Author(s):  
Baghdad Science Journal

The study was conducted during spring seasons of 2000 and 2001.The aim was to study the changes in the moisture content of sunflower plants during growth stages under hardening conditions to drought tolerance .Agricultural practices were made according to recommendation. Asplit-split plots design was used with three replications. The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water. The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments: Control (unsoaked), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature until they regained their original weight. Amount of water for each irrigation were calculated to satisfy water depletion in soil using a neutron meter. Results indicated that plant moisture content was not affected by irrigation treatments in both seasons and as a mean of seasons ,except after 72 days from planting in the season 2000.when stress 800 Kp caused a decreased in moisture content by 4.55and 5.18% compared with full irrigation and stress 600 Kp, respectively. Euroflor was superior over Flame after 30 days from planting by 13.64% in the season of 2000 and by 6.23% as a mean of seasons , and by 2.80% after 86 days from planting in the season of 2001.While Flame was superior by 2.75% after 58 days from planting in the season of 2001. Soaking in water , paclobutrazol and pix solutions increased plant moisture content by 4.56,3.92 and 3.82% after 86 days from planting in the season 2000 , soaking in water and paclobutrazol solution increased plant moisture content by 2.61 and 2.62% as amean of seasons compared with unsoaked treatment. In conclusion, soaking the seeds presowing in water or plant growth regulators could improve water relations of plants , and increase moisture content in plants tissues especially during flowering and seed filling , when the water requirements increased and associated with high temperature in spring season in Iraq.


2009 ◽  
Vol 6 (3) ◽  
pp. 470-479
Author(s):  
Baghdad Science Journal

The study was conducted during the spring season of 2000 and2001. The objective was to study the changes in leaves number of sunflower plants and its leaf area during growth stages under hardening conditions to drought tolerance. Agricultural practices were made according to recommendations.Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments:Control(unsoaking), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature until they regained their original weight. Amount of water for each irrigation were calculated to satisfy water depletion in soil using a neutron moisture meter. Results indicated that stress 800Kp reduced leaves number after 72 days from Planting by 5.29% compared with full irrigation as a mean of seasons.Increased stress to 600 and 800 Kp caused decreasing in leaf area at physiological maturation by 36.10 and 44.32% than full irrigation as a mean of seasons. Flame was superior over Euroflor after 58 days from planting in leaves number by 12.30 % in the season of 2001, while Euroflor was superior by 4.87% after58 days from planting in the season of 2000 ,and in leaf area by 58.25% after 44 days from planting in the season of 2001, and by 34.72% as a mean of seasons.Soaking the seeds presowing in paclobutrazol and pix solutions enhanced leaf formation , the percentage of increase reached to 5.57 and 7.49% after 86 days from planting as a mean of seasons, and leaf area by 35.9 and 36.95% respectively, compared with unsoaked as a mean of seasons. This study suggest that it could improve plant growth and kept sutable leaf area during seeds filling and drought tolerance by soaking the seeds presowing in water or plant growth regulators.


2009 ◽  
Vol 6 (2) ◽  
pp. 290-297
Author(s):  
Baghdad Science Journal

The objective of the work was to study the changes in height and stem diameter of sunflower plants during growth stages under hardening conditions to drought tolerance. Field experiments were carried out during the spring season of 2000 and2001. Agricultural practices were made according to recommendations.Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments:Control(unsoaking), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature until they regained their original weight. Amount of water for each irrigation were calculated to satisfy water depletion in soil using a neutron moisture meter. Results showed that stress 600 and 800Kp caused asignificant decreasing in plan height and stem diameter at most growth stages in both seasons and as a mean of seasons.The decrease in plant height at physiological maturation as a mean of seasons were 12.62 and 14.29%, and stem diameter 11.94 and 9.41%, respectively compared with full irrigation.Euroflor was superior over Flame in plant height at most growth stages during spring season of 2000, while Flame was superior in plant height at most growth stages during spring season of 2001 ,and in stem diameter after 30 days from planting.Soaking the seeds presowing in paclobutrazol and pix solutions decreased plant height at most growth stages in both seasons and as a mean of seasons. The decrease at physiological maturation as amean of seasons were 4.49 and 2.78%compared with unsoaked , and 5.27 and 3.57% compared with soaking in water, respectively.On the other hand,soaking in paclobutrazol and pix solutions increased stem diameter at physiological maturation by 9.78 and 12.18% compared with unsoaked as a mean of seasons. In conclusion, that it could reduce plant height and increase stem diameter to support the plants to drought tolerance by soaking the seeds presowing in water or plant growth regulator


Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 291-296 ◽  
Author(s):  
N. K. Rogers ◽  
R. E. Talbert ◽  
L. R. Oliver

Field experiments were conducted in 1977 and 1978 to determine susceptibility of rhizome johnsongrass [Sorghum halepense(L.) Pers.] to metriflufen3{2-[4-(4-trifluoromethylphenoxy) phenoxy] propanoic acid, methyl ester} applied as preplant-incorporated, preemergence, or postemergence treatments. Rates of metriflufen applied preplant incorporated and preemergence were 1.12, 2.24, and 3.36 kg/ha. Postemergence treatments consisted of 0.56, 1.12, and 1.68 kg/ha of metriflufen plus a non-ionic polyethylene glycol alkyl ester, each applied to johnsongrass at growth stages of 30 to 38 cm, 60 to 75 cm, and heading. Johnsongrass control increased with each increase in rate of soil-applied metriflufen with no differences in control between preplant incorporated and preemergence treatments. Johnsongrass density was reduced by increased rates of metriflufen, and 1978 soil-applied treatments reduced densities by 62%. Preplant-incorporated and preemergence applications of 3.36 kg/ha of metriflufen resulted in higher soybean yields than did the two lower rates. Results from treatments with trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) were similar to those with metriflufen at the same rate. Metriflufen applied to 30-to 38-cm johnsongrass reduced stands by 60% in 1978, but stands increased by 51 and 71% in plots treated at the 60- to 75-cm or heading stages of growth. Soybean tolerance to postemergence applications of metriflufen was excellent for all stages of growth and rates of metriflufen.


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 637-639 ◽  
Author(s):  
Mark U. Magnusson ◽  
Donald L. Wyse ◽  
Joseph M. Spitzmueller

Field experiments were conducted to determine whether aerial and subterranean stem sections taken from Canada thistle [Cirsium arvense (L.) Scop. # CIRAR] plants in four stages of development (spring-vegetative, bud, postbloom, and fall-vegetative) could survive and produce infestations the following year. Partially buried aerial stem sections from all stages of development had greater survival 28 days after planting than completely buried aerial stem sections. Few completely buried aerial stem sections survived. Partially or completely buried subterranean stem sections from Canada thistle at the postbloom stage had the highest survival rate. Few partially or completely buried subterranean stem sections from the other three growth stages survived. Surviving stem sections from spring-vegetative, bud, and postbloom stages of Canada thistle produced adventitious roots that overwintered and produced new infestations the following spring. Surviving stem sections from Canada thistle at the fall-vegetative stage did not develop an adequate root system for winter survival.


2006 ◽  
Vol 20 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Zacharria A. Deeds ◽  
Kassim Al-Khatib ◽  
Dallas E. Peterson ◽  
Phillip W. Stahlman

Field experiments were conducted at Hays and Manhattan, KS, in 2002 and 2003 to determine winter wheat response to simulated drift rates of glyphosate and imazamox. Glyphosate and imazamox at 1/100×, 1/33×, 1/10×, and 1/3× of usage rates of 840 g ae/ha glyphosate and 35 g/ha imzamox were applied individually to wheat in the early jointing or the early flower stages of growth. Wheat injury and yield loss increased as herbicide rate was increased, with minimal effect from either herbicide at the 1/100× rate, and nearly complete kill and yield loss of wheat from both herbicides applied at the 1/3× rate, regardless of growth stage at application. In general, wheat injury and yield reduction were greater from glyphosate than from imazamox. In addition, wheat injury and yield loss were greater from herbicide treatment at the jointing stage than at the flowering stage of development. Correlation analysis suggests that visual injury is an accurate indicator of yield reductions. Germination tests of harvested grain showed that the viability of the wheat seed was not reduced if plants survived the herbicide treatment and produced a harvestable seed.


Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 521 ◽  
Author(s):  
Abdelsattar Abdelkhalik ◽  
Bernardo Pascual ◽  
Inmaculada Nájera ◽  
Carlos Baixauli ◽  
Nuria Pascual-Seva

Field experiments were performed for two growing seasons in Spain under Mediterranean conditions to evaluate the response of onion growth, plant water status, bulb yield, irrigation water use efficiency (IWUE), and gross revenue to regulated deficit irrigation strategies (RDI). Seven irrigation treatments were utilized, including the application of 100% irrigation water requirements (IWR) during the entire growing season and the application of 75% or 50% of the IWR during one of the following growth stages: the vegetative growth, bulbing, and bulb ripening stages. The deficit irrigation strategies tested decreased marketable yields to greater or lesser extents; therefore, if water is readily available, full irrigation would be recommended. The RDI with 50% of the IWR during the bulb ripening stage led to important water savings (22%) and to slight decreases in yield (9%), improving IWUE (20%) compared with full irrigation, and this strategy can be recommended under a severe water shortage. A satisfactory bulb yield was obtained with RDI with 75% of the IWR during the bulb ripening stages, resulting in a lower reduction in yield (4%) and in an increased IWUE (9%); this strategy is an advisable strategy for onion production under a mild water shortage in Mediterranean conditions.


2007 ◽  
Vol 47 (12) ◽  
pp. 1460 ◽  
Author(s):  
A. Datta ◽  
B. M. Sindel ◽  
R. S. Jessop ◽  
P. Kristiansen ◽  
W. L. Felton

Balance® (75% a.i. isoxaflutole) at 100 g/ha is registered in Australia for the control of several broadleaf weeds in chickpea. Polyhouse and field experiments were carried out to examine the tolerance of chickpea genotypes to isoxaflutole. Seven rates of isoxaflutole [0, 18.75, 37.5, 75 (recommended rate), 150, 300 and 600 g a.i./ha] were applied to 20 genotypes in the first polyhouse experiment while in the second experiment, 16 genotypes were tested. In the field, six genotypes were treated with five herbicide rates (0, 37.5, 75, 150 and 300 g a.i./ha). There was a strong dose response in the polyhouse experiments in visual injury ratings, plant height, and shoot and root dry weight. In general, there was less herbicide injury to the kabuli genotypes than in the desi chickpea genotypes. Chickpea genotypes Yorker, Howzat, Amethyst, Gully, 91025-3021, Jimbour, S 95425 and FLIP 94-92C exhibited higher overall mean injury rating in experiment 1. Among these genotypes, shoot dry matter was reduced significantly in Amethyst, Jimbour, 91025-3021 and S 95425. Root dry matter in Amethyst, Jimbour, Yorker, 91025-3021 and S 95425 was also reduced significantly. Height was reduced significantly in all of the above eight genotypes. Although there was less overall injury level in the second polyhouse experiment, which was at lower temperatures, Howzat, Yorker, 91025-3021, FLIP 94-92C and S 95425 again recorded high overall mean injury ratings and should be regarded as more susceptible to isoxaflutole than the other strains. In comparison, 97039-1275 and Kyabra recorded very minor injury symptoms in all the experiments and can be regarded as the most tolerant. The herbicide injury to the genotypes in the field was less than in the polyhouse although Yorker and 91025-3021 showed injury symptoms at early stages of growth. The injury symptoms were temporary and did not produce significant effects on the overall crop growth and yield. It is suggested that plant breeding programs take into account the relative susceptibility of new chickpea genotypes to isoxaflutole.


1979 ◽  
Vol 92 (2) ◽  
pp. 375-381 ◽  
Author(s):  
Joyce R. A. Steckel ◽  
D. Gray

SummaryIn field experiments made over 3 years Pentland Crown and Majestic gave, in general, higher total and dry matter yields from plots given no supplementary water and protected from rainfall throughout growth than King Edward or Maris Piper. However, on plots kept at or near to field capacity all varieties gave similar yields. Pentland Crown and Majestic were deeper rooting than the other two varieties at the time of tuber formation (when the production of new roots ceased) but the differences in rooting depth (ca. 100 mm) between the varieties were small. Except for the top 150 mm of soil, differences in water extraction between the varieties throughout the profile were also small. Neither these differences in water extraction nor the differences in rooting depth could be related consistently to the differences in varietal yield response between ‘wet’ and ‘dry’ plots.


HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1170d-1170
Author(s):  
Donald J. Merhaut ◽  
Rebecca L. Darnell

The influence of stage of vegetative flush development on NH4NO3-N uptake and carbon and nitrogen partitioning was evaluated in two-year-old 'Climax' rabbiteye blueberries using dual labeling with 15N and14C. Plants were grown in sand and fertilized with a modified Hoagland's solution. Plants were pruned to induce three stages of vegetative development: flush initiation, mid -flush, and flush maturity. Total nitrogen uptake did not differ for the different stages of growth. However, N allocation to leaves was greatest at mid-flush, possibly due to higher transpiration rates of developing leaves. Total 14C partitioning to roots was reduced at mid-flush, compared to the other growth stages, reflecting the increased demand for carbon by growing shoots. Although less carbon was allocated to roots at mid-flush,this did not limit N uptake.


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