Growth Response of Itchgrass (Rottboellia cochinchinensis) to Water Stress

Weed Science ◽  
2013 ◽  
Vol 61 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Bhagirath S. Chauhan

Greenhouse studies were conducted to evaluate the growth response of itchgrass to water stress. Itchgrass plants produced the greatest aboveground biomass and seeds at 75% of field capacity and these parameters at 50 and 100% of field capacity were similar. With further increase in water stress, seed production was sharply reduced, but itchgrass was still able to produce an average of 63 and 9 seeds plant−1at 25 and 12.5% of field capacity, respectively. Itchgrass plants responded to increasing water stress with increased leaf weight ratio; it was 2.5 times greater at 12.5% of field capacity than at 100% of field capacity. In another study, compared with daily irrigation, intervals of 9 d between irrigations reduced aboveground biomass of itchgrass by 27% and 12-d intervals reduced aboveground biomass by 67%. Compared with the daily irrigation regime, itchgrass seed production was reduced by 61% at intervals of 12 d between irrigations; however, the weed plants produced a considerable number of seeds (153 seeds plant−1) at the 12-d intervals. The ability of itchgrass to produce biomass and seeds under water stressed conditions necessitates strategies that minimize weed survival while maximizing irrigation efficiency for the crop at the same time.

2020 ◽  
Author(s):  
Wenhui Zhao ◽  
Jianjun Wu ◽  
Leizhen Liu ◽  
Jianhua Yang ◽  
Xinyi Han ◽  
...  

<p>Drought has become one of the major constraints on agricultural development, particularly in areas lacking water. By studying the effects of different water stresses on photosynthesis, growth, yield, water use efficiency (WUE) and other indicators of winter wheat, this study provides scientific irrigation strategies for developing water-saving agriculture. According to the size of the water field capacity, four different water stress levels were set, i.e., 30–40% water field capacity (severe stress), 40–50% (moderate stress), 50–60% (mild stress) and 60–80% (well-watered irrigation), through an automatic irrigation system to create different water stress gradients by controlling the irrigation amount. The results showed that the diurnal and seasonal changes in photosynthetic parameters such as net photosynthetic rate (Pn), intercellular carbon concentration (Ci), stomatal conductance (Gs), and transpiration (E) significantly decreased with water stress intensification. The Pn of mild stress only slightly decreased compared to that of well-watered irrigation and was even higher than after May 16th, resulting in an increase in the dry biomass and 1000-grain weight under mild stress. Under all water stresses, the heights and stem weights of the winter wheat significantly decreased. Moderate and severe stress also significantly reduced the fresh weight of the aboveground biomass, dry weight, spike weight, grain weight, WUE and irrigation water productivity (IWP), while mild stress only slightly decreased the fresh weight of aboveground biomass, spike weight and grain weight. Mild stress increased the WUE and IWP. Thus, mild stress results in the optimal use of water resources without a significant reduction in yield. Therefore, mild stress can be considered as a suitable environment for winter wheat growth in arid areas.</p>


Weed Science ◽  
2010 ◽  
Vol 58 (2) ◽  
pp. 132-135 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
David E. Johnson

Junglerice is one of the most serious grass weeds of rice in the tropics. Greenhouse studies were conducted to evaluate growth and reproduction of junglerice in response to water stress. Plant height, biomass, and seed production of junglerice grown alone were reduced with increasing water stress. However, most stressed plants (irrigated at 12.5% of field capacity) still produced considerable biomass (8.5 g plant−1) and seeds (>1,600 seeds plant−1). When junglerice and rice were grown together under water-stressed condition, junglerice was taller than rice. The junglerice-to-rice biomass ratio also increased from 4.7 at 100% of field capacity to 7.6 at 12.5% of field capacity, indicating the greater junglerice vigor in water-stress conditions. In another study, the influence of the duration of water stress at intervals between 3 and 15 d on growth and seed production of junglerice was evaluated. Plant height, biomass, and seed production decreased with increasing water-stress duration. However, the weed produced an average of 400 seeds plant−1 in the most stressed treatment (i.e., when irrigation was applied at 15-d intervals). Water-stressed treatments did not affect germination of junglerice seeds in the laboratory. Growth and seed production of junglerice at all moisture levels ensures survival of the population in an unpredictable environment and contributes to the weedy nature of this species. The joint effect of enhanced weed competition and drought stress could severely harm crop yield; therefore, it is important to control such weeds in the early stages of crops and save stored moisture for the crops.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M.R.R. PEREIRA ◽  
C.C. MARTINS ◽  
A.C. SILVA JR. ◽  
D. MARTINS

ABSTRACT: Plants in soils with low water availability may present a reduction of their leaf area and photosynthetic rate, as well as lower assimilated compound supply for seeds. Knowing the physiological quality and seed production of weeds generated under water deficit conditions can help understanding the survival and competition strategies of species. The objective of this work was to evaluate the effect of water stress on the production and germination of Bidens pilosa and Raphanus raphanistrum seeds. Plants were maintained in soils with different water potentials (-0.03, -0.07 and -1.5 MPa) throughout their cycle, until seed production, when they were harvested. Then, evaluations were performed to find out the number of seeds per plant and number of seeds per pod (Raphanus raphanistrum). The evaluation on the germination of these seeds was performed on moistened paper, with four replications, at 20-35 oC and 8 hours of light per day, weekly, until 28 days after seeding. The experimental design was completely randomized with three treatments (soil water potential: -0.03 MPa, -0.07 MPa and -1.5 MPa). The results were submitted to analysis of variance by F test, and the means of the treatments were compared by Tukey’s test at 5% probability. It was concluded that Bidens pilosa is more adapted to water deficit conditions than Raphanus raphanistrum, due to the higher production of seeds, better germination and seedlings with greater vigor.


Weed Science ◽  
2019 ◽  
pp. 1-7
Author(s):  
Navneet Kaur Mutti ◽  
Gulshan Mahajan ◽  
Prashant Jha ◽  
Bhagirath S. Chauhan

AbstractGlyphosate-resistant junglerice [Echinochloa colona(L.) Link] is a problematic weed in mungbean [Vigna radiata(L.) R. Wilczek] crops in Australia. Due to limited herbicide options in mungbean, there is an increased interest in developing integrated management strategies for the sustainable control ofE. colona. Pot experiments were conducted in a screenhouse in 2017 and 2018 by growingE. colonaplants (glyphosate-resistant [GR] and glyphosate-susceptible [GS] biotypes) alone (1 plant pot−1) and in competition with 4 and 8 mungbean plants pot−1. Both biotypes were developed from a single population using the clone method. The growth and seed production of both GR and GS biotypes were similar in response to mungbean competition. Averaged over biotypes, there was a reduction in the growth and seed production ofE. colonaas crop plants increased. Compared with the weed plants grown alone, crop interference reducedE. colonaheight by 17% to 19%, tiller numbers by 69% to 82%, total shoot biomass by 85% to 91%, and inflorescence numbers by 74% to 91%. WhenE. colonawas grown with 8 mungbean plants pot−1, leaf weight ratio increased by 42% compared with plants grown alone. Compared with weed plants grown alone, mungbean interference (4 and 8 plants pot−1) reduced weed seed production by 85% to 95%. These reductions were similar for both biotypes (GR and GS), suggesting that there was no fitness penalty associated with resistance. The results of this study suggest that mungbean interference can reduceE. colonagrowth and seed production, but it should not be considered as a stand-alone strategy to manageE. colonaand similar species in mungbean. These results also highlight the need for integrating crop competition with other management strategies to achieve complete and sustainable management of this weed.


2016 ◽  
Vol 96 (5) ◽  
pp. 828-836 ◽  
Author(s):  
Simranpreet Kaur ◽  
Jatinder Aulakh ◽  
Amit J. Jhala

The objectives of this study were to determine the effects of degree and duration of water stress on growth and seed production of glyphosate-resistant (GR) giant ragweed. The degree of water stress included giant ragweed response to 100%, 75%, 50%, 25%, and 12.5% of field capacity. The highest growth index (588 cm3) was achieved at 75% of field capacity with plants typically ≥125 cm tall and ≥57 leaves plant−1. Giant ragweed seed production was ≥55, 35, 20, and 5 seeds plant−1 at ≥75%, 50%, 25%, and 12.5% of field capacity, respectively. The study of duration of water stress included the response of giant ragweed to withholding water for 2, 4, 6, 8, and 10 d following 100% of field capacity. Water stress of 4 d or longer reduced giant ragweed plant height ≥20%, root and shoot biomass ≥66%, number of leaves ≥36%, growth index ≥54%, and seed production by 36% compared with 2 d of water stress. Results from this study indicate that giant ragweed can survive and produce seeds at 12.5% of field capacity or 10 d of water stress.


Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Navneet Kaur Mutti ◽  
Gulshan Mahajan ◽  
Prashant Jha ◽  
Bhagirath S. Chauhan

AbstractGlyphosate-resistant junglerice [Echinochloa colona (L.) Link] is a problematic weed in mungbean [Vigna radiata (L.) R. Wilczek] crops in Australia. Due to limited herbicide options in mungbean, there is an increased interest in developing integrated management strategies for the sustainable control of E. colona. Pot experiments were conducted in a screenhouse in 2017 and 2018 by growing E. colona plants (glyphosate-resistant [GR] and glyphosate-susceptible [GS] biotypes) alone (1 plant pot−1) and in competition with 4 and 8 mungbean plants pot−1. Both biotypes were developed from a single population using the clone method. The growth and seed production of both GR and GS biotypes were similar in response to mungbean competition. Averaged over biotypes, there was a reduction in the growth and seed production of E. colona as crop plants increased. Compared with the weed plants grown alone, crop interference reduced E. colona height by 17% to 19%, tiller numbers by 69% to 82%, total shoot biomass by 85% to 91%, and inflorescence numbers by 74% to 91%. When E. colona was grown with 8 mungbean plants pot−1, leaf weight ratio increased by 42% compared with plants grown alone. Compared with weed plants grown alone, mungbean interference (4 and 8 plants pot−1) reduced weed seed production by 85% to 95%. These reductions were similar for both biotypes (GR and GS), suggesting that there was no fitness penalty associated with resistance. The results of this study suggest that mungbean interference can reduce E. colona growth and seed production, but it should not be considered as a stand-alone strategy to manage E. colona and similar species in mungbean. These results also highlight the need for integrating crop competition with other management strategies to achieve complete and sustainable management of this weed.


2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1316
Author(s):  
Abida Parveen ◽  
Muhammad Arslan Ashraf ◽  
Iqbal Hussain ◽  
Shagufta Perveen ◽  
Rizwan Rasheed ◽  
...  

The present work reports the assessment of the effectiveness of a foliar-spray of salicylic acid (SA) on growth attributes, biochemical characteristics, antioxidant activities and osmolytes accumulation in wheat grown under control (100% field capacity) and water stressed (60% field capacity) conditions. The total available water (TAW), calculated for a rooting depth of 1.65 m was 8.45 inches and readily available water (RAW), considering a depletion factor of 0.55, was 4.65 inches. The water contents corresponding to 100 and 60% field capacity were 5.70 and 1.66 inches, respectively. For this purpose, seeds of two wheat cultivars (Fsd-2008 and S-24) were grown in pots subjected to water stress. Water stress at 60% field capacity markedly reduced the growth attributes, photosynthetic pigments, total soluble proteins (TSP) and total phenolic contents (TPC) compared with control. However, cv. Fsd-2008 was recorded as strongly drought-tolerant and performed better compared to cv. S-24, which was moderately drought tolerant. However, water stress enhanced the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and membrane electrolyte leakage (EL) and modulated the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as accumulation of ascorbic acid (AsA), proline (Pro) and glycine betaine (GB) contents. Foliar-spray with salicylic acid (SA; 0, 3 mM and 6 mM) effectively mitigated the adverse effects of water stress on both cultivars. SA application at 6 mM enhanced the shoot and root length, as well as their fresh and dry weights, and improved photosynthetic pigments. SA foliage application further enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) and nonenzymatic antioxidants such as ascorbic acid and phenolics contents. However, foliar-spray of SA reduced MDA, H2O2 and membrane permeability in both cultivars under stress conditions. The results of the present study suggest that foliar-spray of salicylic acid was effective in increasing the tolerance of wheat plants under drought stress in terms of growth attributes, antioxidant defense mechanisms, accumulation of osmolytes, and by reducing membrane lipid peroxidation.


Author(s):  
MUHAMMAD ASLAM ALI ◽  
SANJIT CHANDRA BARMAN ◽  
MD. ASHRAFUL ISLAM KHAN ◽  
MD. BADIUZZAMAN KHAN ◽  
HAFSA JAHAN HIYA

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.


2006 ◽  
Vol 28 (2) ◽  
pp. 45-52 ◽  
Author(s):  
Armando Martins dos Santos ◽  
Luis Mauro Gonçalves Rosa ◽  
Lucia Brandão Franke ◽  
Carlos Nabinger

The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well-watered plants, with no statistically significant effect of leaf movements.


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