scholarly journals Drought Resistance Strategies of Seashore Paspalum Cultivars at Different Mowing Heights

HortScience ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Mohamed A. Shahba ◽  
Mohamed S. Abbas ◽  
Saad F. Alshammary
Keyword(s):  
Soil Moisture ◽  
Drought Tolerance ◽  
Drought Resistance ◽  
Water Regime ◽  
Proline Content ◽  
Root Production ◽  
Root Mass ◽  
Seashore Paspalum ◽  
Water Regimes ◽  
Turf Quality

Understanding how mowing height and soil moisture influence drought resistance mechanisms may lead to better management of seashore paspalum. This research was conducted to evaluate the effect of mowing height and soil moisture replacement on drought tolerance strategies in three seashore paspalum cultivars. In a greenhouse, clear polyvinyl chloride (PVC) root tubes were placed in a black PVC sleeve with a bottom cap drilled with holes for drainage. Sod pieces (10 cm in diameter) of seashore paspalum (Paspalum vaginatum Swartz) cultivars Salam, Excalibur, and Adalayd were planted into these tubes after roots were trimmed. In a split-split experimental design, water regimes applied included control [100% of the total evapotranspiration (ET)] as well as 75%, 50%, and 25% of the total ET. Mowing heights were 45.0, 35, and 25 mm. Visual turf quality, maximum root extension (MRE), root length densities (RLD), total nonstructural carbohydrate content (TNC), shoot reducing sugar content (RSC), and proline content were determined. Turf quality decreased linearly with the decrease in irrigation water applied under the three mowing heights with higher slope at 25.0 mm than at either 35.0 or 45.0 mm. ‘Salam’ turf quality declined only to the unacceptable rating of 5.5 and 4.5 when mowed to 35 and 25 mm, respectively, whereas quality was 6.5 at the mowing height of 45 mm under the water regime of 25% of total ET. ‘Excalibur’ did not show acceptable turf quality at the 25% treatment, whereas ‘Adalayd’ did not show such quality at both 50% and 25% water regimes under all mowing heights. Regression analysis indicated a significant negative association between RLD and drought levels at all mowing heights and soil depths. In ‘Salam’, as drought levels increased from control to 25%, average RLD decreased by 76%, 75%, and 76% at 25-, 35-, and 45-mm mowing heights, respectively, at the top 30 cm of soil in the column. The change was 93%, 85%, and 83% at 25-, 35-, and 45-mm mowing heights, respectively, at the deeper soil (90 to 120 cm). In ‘Salam’, on average overall water regimes, MRE at 45 mm was ≈10% to 17% greater than that of 35-mm mowing height and 28% to 36% greater than that of 25-mm mowing height. The highest root mass (810 mg) was obtained when ‘Salam’ was mowed to 45 mm and subjected to the drought level of 50% of the total ET. The lowest root mass (320 mg) was obtained when ‘Salam’ was mowed to 25 mm and the water regime was not limiting. In ‘Salam’, as drought increased from control to 25% of the total ET, average TNC decreased by 43.5%, 26.0%, and 29.0% and the average TNC decrease in ‘Excalibur’ shoots was 48.0%, 30.0%, and 32.0%, whereas the decrease in ‘Adalayd’ was 51.3%, 42.3%, and 35.4% at 25-, 35-, and 45-mm mowing heights, respectively. As drought levels increased from control to 25% of the total ET, average RSC increased by 57.3%, 57.1%, and 53.0% in ‘Salam’ and by 59.4%, 57.0%, and 51.5% in ‘Excalibur’ and 61.2%, 58.1%, and 61.0% in ‘Adalayd’ at 25-, 35-, and 45-mm mowing height, respectively. When drought increased to 25%, average proline content in shoots increased by 435%, 432%, and 431% in ‘Salam’; 404%, 376%, and 324% in ‘Excalibur’; and 257%, 278%, and 302% in ‘Adalayd’, at 25-, 35-, and 45-mm mowing heights. The resistance of paspalum cultivars to moderate to high drought stress can be enhanced by increasing the mowing height that may be related to increased carbon fixation, which favors increased root production. Proline accumulation could add to the drought tolerance through osmoregulation or by acting as a carbon and nitrogen sink for stress recovery.

scholarly journals Effects of Mowing and Trinexapac-Ethyl on St. Augustinegrass Sod Establishment during a Simulated Water Variance Period

2016 ◽  
Vol 26 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Daniel Hargey ◽  
Benjamin Wherley ◽  
Andrew Malis ◽  
James Thomas ◽  
Ambika Chandra
Keyword(s):  
Root Development ◽  
Drought Resistance ◽  
Water Conservation ◽  
Root Length ◽  
Rapid Development ◽  
Embryo Rescue ◽  
Root Production ◽  
Extension Rate ◽  
Root Weight ◽  
Turf Quality

During water conservation periods, municipal water purveyors often limit irrigation for established lawns to once every 7 to 14 days, although a 4- to 6-week variance to these restrictions is often permitted for turfgrass establishment. Therefore, establishment practices promoting rapid development of a deep and expansive root system during this time may support long-term success of the turf once irrigation is scaled back. Sod producers and turf managers could benefit from information on the influence of mowing practices and plant growth regulator (PGR) applications on turf root development during this initial establishment period. The objectives of this greenhouse study were to 1) evaluate the effects of mowing and trinexapac-ethyl (TE) application on final turf quality and root development characteristics (weight, total length, and extension rate) of st. augustinegrass (Stenotaphrum secundatum) sod during a 35-day establishment period, and 2) compare the quality and rooting potential of ‘TamStar’, a newly released, embryo-rescue-derived cultivar possessing good drought resistance, with ‘Floratam’, the current industry standard for drought resistance. Weekly mowing reduced both total (2.5 to 90 cm) and deep (45 to 90 cm) root weight and root length in both cultivars. TE had no effect on visual quality of ‘TamStar’, but decreased turf quality in ‘Floratam’. TE reduced clipping yields of both cultivars but did not improve root development for either cultivar. Depth of maximal root extension during establishment was unaffected by cultivar, mowing, or TE treatment. At the conclusion of the 35-day establishment period, ‘TamStar’ exhibited superior turf quality and root weight relative to ‘Floratam’, but also produced higher rates of shoot growth. Results emphasize the importance of withholding mowing during st. augustinegrass establishment, particularly for improving total root length and deep root production, and also show that TE does not improve root development of st. augustinegrass during establishment.

scholarly journals The regularities of water regime, growth and longevity of artificial forest stands in dry conditions

2017 ◽  
Author(s):  
А.С. Манаенков
Keyword(s):  
Soil Moisture ◽  
Pinus Sylvestris ◽  
Drought Resistance ◽  
Quercus Robur ◽  
Water Regime ◽  
Life Support ◽  
Average Density ◽  
Forest Steppe ◽  
Forest Stands ◽  
Forest Condition

Исследования проводились на юге Восточно-Европейской равнины в зональном поясе лесостепь-полупустыня. Изучались водный режим, рост и состояние древостоя Pinus sylvestris L. и Quercus robur L. на математических, лизиметрических моделях насаждений и в натуре. Установлено, что главная причина безлесья степных равнин и недолговечности лесонасаждений – чрезмерная динамичность атмосферного увлажнения по годам, критическое снижение запаса почвенной влаги и влагообеспе- ченности древостоя в засушливые годы. Динамичность увлажнения и периодичность обезвоживания его корнеобитаемого слоя увеличиваются с ростом континентальности климата и потребности насаждений (интенсивности десукции). Наиболее напряженные условия жизнеобеспечения складываются в сомкнувшихся молодняках. С возрастом их засухоустойчивость повышается благодаря развитию корней, ранней кульминации и уменьшению прироста. Плодородные почвогрунты повышают порог устойчивости полнотных древостоев к дефициту почвенной влаги, но провоцируют их чрезмерное развитие, снижают засухоустойчивость. Однако при высокой влагоемкости их зоны аэрации можно накапливать большой старто- вый запас почвенной влаги, который демпфирует опасное снижение влагообеспеченности, ускоряет рост, усиливает дифференциацию и изреживание молодых древостоев. В целом, техника культивирования долговечных лесонасаждений на влагоемких песках и зональных комплексных почвах засушливой зоны должна включать выбор наиболее лесопригодных участков и (или) многолетнюю основ- ную обработку почвы; создание чистых по составу древостоев из относительно теневыносливых (плотнокронных) засухоустойчивых пород средней густоты; агротехнические уходы до смыкания крон; частое низкоинтенсивное изреживание молодняка; содействие появлению отеняющего яруса под пологом редеющих древостоев старшего возраста. The studies were conducted in the South of Eastern European plain in the zone of the zonal forest-steppe semi-desert. The water regime, growth and the forest condition of Pinus sylvestris L. and Quercus robur L. on mathematical models lysimetrics plantations and in natural conditions were studied. The main reason for the treeless steppe of the plains and the disappearance of forest is excessive dynamic of atmospheric moisture over the years, the critical reduction in stored soil moisture and moisture of forest stand in droughty years. The dynamics of hydration and frequency of dehydration of its root layer increases with the continentality of the climate and the needs of plants (intensity of absorption). The most intense of conditions of life support are formed in dense young plantings. Drought resistance of plantings increases thanks to development of roots, the early culmination and decrease of growth with age. Fertile soils raise a threshold of resistance of forest stands to deficit of soil moisture, but provoke their excessive development and reduce drought resistance. But in case of a high moisture capacity of their zone of aeration of deposits there is an opportunity to accumulate a large starting supply of soil moisture which reduce dangerous decrease in moisture security accelerates growth, strengthens differentiation and reduces death of young forest stands. Generally, the technology of cultivation of durable afforestations on moisture capacious sands and zone complex soils of a droughty zone has to include: choice most woodable of sites and (or), long-term main processing of the soil; creation of forest stands, pure on structure, from rather shade-enduring (densely located) drought-resistant breeds of average density; agrotechnical care until a close arrangement of kroner; frequent low-intensive thinning of young growth; assistance to emergence of the shading tier under a rare curtain of forest stands of advanced age.

Establishment of Three Emergent Macrophytes Under Different Water Regimes

1999 ◽  
Vol 40 (3) ◽  
pp. 233-240 ◽  
Author(s):  
S. G. T. Giovannini ◽  
D. M. L. da Motta Marques
Keyword(s):  
Water Level ◽  
Aquatic Macrophytes ◽  
Water Regime ◽  
Emergent Macrophytes ◽  
Morphological Response ◽  
Water Regimes ◽  
Wetland Construction ◽  
Scirpus Californicus ◽  
Level 3 ◽  
Plot Design

The behavior of three emergent aquatic macrophytes under different water regimes was studied with the aim of achieving reconvertion of degraded wetlands and wetland construction for water quality improvement. Scirpus californicus, Typha subulata and Zizaniopsis bonariensis establishment was evaluated under a split plot design, in a factorial experiment with three levels of a water regime factor over a subsoil substratum. The stagnant 10±2 cm water level was best suited to T. subulata and Z. bonariensis development and S. californicus developed better at oscillating water level (3±2 cm) with flooding at 48 hour intervals. The morphological response variables (thickness and width at half length of the tallest leaf or stem per plant, height of tallest leaf or stem per plant, number of green leaves or stems and number of shoots per plant, and survival of propagules' original leaves or stems) were satisfactory descriptors to differentiate (p<0.1%) growth of above ground parts as related to water regimes and species. The three species did survive satisfactory in subsoil-like substratum under the tested water regimes. Mortality was in the worse case, 17.2%, 36.7%, and 9.4% for S. californicus, T. subulata, and Z. bonariensis, respectively. Although Z. bonariensis growth was very poor, only S. californicus and T. subulata could be indicated for planting under similar limiting conditions.

Penconazole and calcium ameliorate drought stress in canola by upregulating the antioxidative enzymes

2020 ◽  
Vol 47 (9) ◽  
pp. 825 ◽  
Author(s):  
Maryam Rezayian ◽  
Vahid Niknam ◽  
Hassan Ebrahimzadeh
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Antioxidative Enzymes ◽  
Proline Content ◽  
Fresh Weight ◽  
Negative Effects ◽  
Mda Content ◽  
Effects Of Drought

The aim of this research was to gauge the alternations in the lipid peroxidation and antioxidative enzyme activity in two cultivars (cv. RGS003 and cv. Sarigol) of canola under drought stress and drought tolerance amelioration by penconazole (PEN) and calcium (Ca). Plants were treated with different polyethylene glycol (PEG) concentrations (0, 5, 10 and 15%) without or with PEN (15 mg L–1) and Ca (15 mM). The Ca treatment prevented the negative effects of drought on fresh weight (FW) in RGS003 and Sarigol at 5 and 15% PEG respectively. Ca and PEN/Ca treatments caused significant induction in the proline content in Sarigol at 15% PEG; the latter treatment was accompanied by higher glycine betaine (GB), lower malondialdehyde (MDA) and growth recovery. Hydrogen peroxide (HO2) content in Sarigol was proportional to the severity of drought stress and all PEN, Ca and PEN/Ca treatments significantly reduced the H2O2 content. PEN and PEN/Ca caused alleviation of the drought-induced oxidative stress in RGS003. RGS003 cultivar exhibited significantly higher antioxidative enzymes activity at most levels of drought, which could lead to its drought tolerance and lower MDA content. In contrast to that of Sarigol, the activity of catalase and superoxide dismutase (SOD) increased with Ca and PEN/Ca treatments in RGS003 under low stress. The application of PEN and Ca induced significantly P5CS and SOD expression in RGS003 under drought stress after 24 h. Overall, these data demonstrated that PEN and Ca have the ability to enhance the tolerance against the drought stress in canola plants.

scholarly journals Genetic Basis of Drought Resistance at Reproductive Stage in Rice: Separation of Drought Tolerance From Drought Avoidance

Genetics ◽  
2005 ◽  
Vol 172 (2) ◽  
pp. 1213-1228 ◽  
Author(s):  
Bing Yue ◽  
Weiya Xue ◽  
Lizhong Xiong ◽  
Xinqiao Yu ◽  
Lijun Luo ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Drought Resistance ◽  
Genetic Basis ◽  
Reproductive Stage ◽  
Drought Avoidance

EFFECT OF DEFICIT IRRIGATION ON YIELD, RELATIVE LEAF WATER CONTENT, LEAF PROLINE ACCUMULATION AND CHLOROPHYLL STABILITY INDEX OF COTTON–MAIZE CROPPING SEQUENCE

2013 ◽  
Vol 50 (3) ◽  
pp. 407-425 ◽  
Author(s):  
T. SAMPATHKUMAR ◽  
B. J. PANDIAN ◽  
P. JEYAKUMAR ◽  
P. MANICKASUNDARAM
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Water Content ◽  
Deficit Irrigation ◽  
Stability Index ◽  
Moisture Gradient ◽  
Proline Content ◽  
Leaf Water Content ◽  
Chlorophyll Stability Index ◽  
Soil Moisture Gradient

SUMMARYWater stress induces some physiological changes in plants and has cumulative effects on crop growth and yield. Field experiments were conducted to study the effect of deficit irrigation (DI) on yield and some physiological parameters in cotton and maize in a sequential cropping system. Creation of soil moisture gradient is indispensable to explore the beneficial effects of partial root zone drying (PRD) irrigation and it could be possible only through alternate deficit irrigation (ADI) practice in paired row system of drip layout that is commonly practiced in India. In the present study, PRD and DI concepts (creation of soil moisture gradient) were implemented through ADI at two levels of irrigation using drip system. Maize was sown after cotton under no till condition without disturbing the raised bed and drip layout. Relative leaf water content (RLWC) and chlorophyll stability index (CSI) of cotton and maize were reduced under water stress. A higher level of leaf proline content was observed under severe water-stressed treatments in cotton and maize. RLWC and CSI were highest and leaf proline content was lowest in mild water deficit (ADI at 100% crop evapotranspiration once in three days) irrigation in cotton and maize. The same treatments registered higher values for crop yields, net income and benefit cost ratio for both the crops.

scholarly journals Morphological and Physiological Responses of Seashore Paspalum and Bermudagrass to Waterlogging Stress

2019 ◽  
Vol 144 (5) ◽  
pp. 305-313
Author(s):  
Bo Xiao ◽  
David Jespersen
Keyword(s):  
Lipid Peroxidation ◽  
Root Respiration ◽  
Morphological Changes ◽  
Physiological Responses ◽  
Specific Root Length ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Seashore Paspalum ◽  
Waterlogging Stress ◽  
Turf Quality

Turfgrasses have varying tolerance to waterlogging conditions. The objective of this study was to identify important root traits and physiological responses to waterlogging stress in seashore paspalum (Paspalum vaginatum) and bermudagrass (Cynodon sp.). After being exposed to waterlogging conditions for 28 days, turf quality, leaf photosynthesis, transpiration rate, stomatal conductance (gS), and root fresh weight were significantly decreased in bermudagrass, and root lipid peroxidation was significantly increased. However, seashore paspalum was found to be more tolerant to waterlogging conditions and changes in turf quality, photosynthesis, or lipid peroxidation were not seen. The waterlogging treatments increased specific root length (SRL), surface area, and volume and decreased root respiration and diameter to a greater extent in seashore paspalum compared with bermudagrass. Under waterlogging conditions, root aerenchyma formation was found in both seashore paspalum and bermudagrass, but to a greater extent in seashore paspalum. Both grasses exhibited significant increases in root water-soluble carbohydrate (WSC) but to a lesser extent in seashore paspalum than in bermudagrass. Shoot WSC remained unchanged in seashore paspalum but was significantly increased in bermudagrass. These results indicate greater root morphological changes such as root volume, SRL, and root porosity, as well as lower root respiration may be important contributors to waterlogging tolerance for seashore paspalum.

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