Growth and Reproduction of Junglerice (Echinochloa colona) in Response to Water Stress

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.

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.


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.


Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 277-282 ◽  
Author(s):  
M. S. Ahmadi ◽  
L. C. Haderlie ◽  
G. A. Wicks

Under greenhouse conditions, postemergence herbicide effectiveness was greater when barnyardgrass [Echinochloa crus-galli(L.) Beauv.] plants were 5-or 10-cm tall as compared to 15-or 20-cm tall. Absorption of14C-glyphosate [N-(phosphonomethyl)glycine] decreased from 58% of applied to 47% as plant height increased from 5 to 15 cm, and an additional reduction (to 32% of applied at 5 cm) occurred when terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] was added to glyphosate. Translocation of14C-glyphosate was reduced in older plants or when terbutryn was added to glyphosate. Water stress studies included soil moisture levels of 10, 20, 30, and 40% moisture (PW). Herbicide treatments were less effective at soil moisture levels below field capacity (30 PW). When soil moisture was 10 PW (-37 bar) absorption of14C-glyphosate was greatly reduced in plants treated at both 7.5-and 15-cm heights with or without terbutryn. At 10 PW only 15 to 20% of applied14C was absorbed whereas at 40 PW, absorption was over 45% and 62% with and without terbutryn, respectively. The addition of terbutryn to glyphosate resulted in decreased translocation for all soil moisture levels except the 20 PW treatment at the 15-cm height. Translocation of14C was greatly reduced for plants in soils at 10 PW for both herbicide treatments.


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.


Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Debalin Sarangi ◽  
Suat Irmak ◽  
John L. Lindquist ◽  
Stevan Z. Knezevic ◽  
Amit J. Jhala

Common waterhemp is one of the most commonly encountered and troublesome weeds in the midwestern United States. It is well known that water stress adversely affects crop growth and yield; however, the effects of water stress on weed growth and seed production are poorly understood. The objective of this study was to determine the effects of degree and duration of water stress on growth, development, and fecundity of two common waterhemp biotypes in greenhouse experiments conducted at the University of Nebraska–Lincoln. No difference was observed in growth, development, and seed production between two biotypes in response to degree and duration of water stress; therefore, data were combined. The degree of water stress study included five treatments, where the amount of water applied to each pot at 2-d interval was equivalent to 100, 75, 50, 25, and 12.5% of pot (soil) water content. The highest plant height (163 cm), number of leaves (231 plant−1), and growth index (4.4 × 105cm3) were recorded at 100% of pot water content (no water stress). Similarly, aboveground biomass, total leaf area, and seed production reached their maximum at 100% of pot water content treatment, whereas they were reduced as degree of water stress increased. The study of water stress duration included five treatments, where amount of water applied to each pot at 2-, 4-, 6-, 8-, and 10-d intervals was equivalent to 100% of pot water content. The highest plant height (150 cm), number of leaves (210 plant−1), and growth index (3.8 × 105cm3) were observed at 2-d interval of water stress, whereas seed production was similar at 2-d (36,549 seeds plant−1) and 4-d (34,176 seeds plant−1) intervals. This study shows that common waterhemp has capacity to survive and reproduce even under a higher degree and duration of water stress.


1970 ◽  
pp. 10-15
Author(s):  
ARUNKUMAR K

Aim of this study to screened the root morphology and root characters of different cocoa types at 100 and 50 percent field capacity under water deficit condition at seedling stage. A survey was conducted at Idukki region of Kerala and twenty seven plus trees were identified. These twenty seven plus trees were screened for water stress tolerance under glasshouse condition by gravimetric method. With respect to the performance of plus trees, root length under 50% field capacity got increased to 21.15 cm as against 20.51 cm in 100 per cent field capacity. Fresh root weight and dry root weight substantially got increased under water stress. The average root girth of 27 plus trees got increased in stressed condition from 3.70 cm to 3.88 cm. The root volume also followed the same trend (47.28 as against 45.96). The percent of nitrogen is 1.37 in 50 per cent field capacity as against 1.63 in 100 per cent field capacity. The percentage of phosphorous decreased to 0.16 under 50 per cent field capacity as against 0.37 in 100 per cent field capacity. Similarly the percentage of potassium also showed a decreasing trend (1.27 % under 100 % field capacity to 1.06 % under 50 % field capacity). In the present investigation, under water stress condition the root length, number of roots, fresh weight of root and dry weight of root tends to increase compared to the 100 per cent field capacity, indicating the morphological adaptations of roots to survive under water stress condition. Furthermore, under water stress condition, root nutrients tend to get depleted.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Alemayehu Tefera ◽  
Mulugeta Kebede ◽  
Kassu Tadesse ◽  
Tsegaye Getahun

Wheat is one of the most important cereal crops and extensively cultivated in wide ranges of altitudes in Ethiopia. With an alarming population growth in the era of climatic change, there is a need for further crop improvement for sustainable production. In this regard, the study was carried out at the Kulumsa Agricultural Research Center (KARC) in a rainout shelter to investigate the responses of durum and bread wheat varieties to soil water stress in terms of selected morphological, physiological, and biochemical parameters. The 2 factors were combined factorially and arranged in a randomized complete block design with 3 replications. The 12 wheat varieties, 6 bread wheat and other 6 durum wheat, were sown in pots under well-watered (100% field capacity) and water-stressed (30% field capacity) conditions. Results revealed that water stress resulted in 26%, 9%, 23%, 16%, and 11% reductions in plant height, spike length, number of spikelets spike−1, relative water, and chlorophyll contents, respectively. The tested wheat varieties under water stress produced 28% and 6% more proline content and total soluble sugar, respectively, as mitigation strategies against drought. Results further exhibited that wheat varieties significantly differed in all of the measured traits except for the plant height and relative water content. The present study verified that the biochemical parameters needs to be considered as better traits to select wheat (Triticum spp.) varieties for drought tolerance under water stress conditions.


Weed Science ◽  
2019 ◽  
Vol 67 (05) ◽  
pp. 552-559 ◽  
Author(s):  
Gulshan Mahajan ◽  
Navneet Kaur Mutti ◽  
Michael Walsh ◽  
Bhagirath S. Chauhan

AbstractJunglerice [Echinochloa colona (L.) Link] is a problematic weed in the northern grain region of Australia. Two pot experiments (Experiment 1 and Experiment 2) were conducted in a screen house to evaluate the growth and reproductive behavior of two biotypes (A, collected from a cotton (Gossypium hirsutum L.)–fallow; B, collected from a fence near a water channel) of E. colona in response to water stress (100%, 75%, 50%, and 25% water holding capacity [WHC]). Averaged across both biotypes, the plant height, biomass, and seed production of E. colona were reduced at 25% WHC compared with 100% WHC. However, E. colona still produced a considerable amount of seeds at 25% WHC (at least 365 seeds plant−1). Biotype A produced more seeds in the second experiment, while biotype B produced more seeds in the first experiment. In Experiment 2, at 100% WHC, biotype A produced more seeds (17,618 seeds plant−1) than biotype B (4,378 seeds plant−1), and similar observations were noticed for root biomass. Growth and seed production of E. colona at all moisture levels and environmental conditions ensure survival in an unpredictable environment and contribute to the weedy nature of this species. Results indicate that biotype A is more invasive than biotype B under favorable environmental conditions (100% WHC). This study suggests an enhanced competitive ability of some biotypes of E. colona in response to a range of environmental and soil moisture conditions in Australia. Under favorable environmental conditions, biotype A could be more problematic, as it has higher seed production than biotype B. Therefore, it is important to implement sustainable weed control methods for such biotypes in the early stages of crop growth to prevent loss of stored moisture.


1970 ◽  
Vol 44 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tanjia Shormin ◽  
M Akhter Hossain Khan ◽  
M Alamgir

The response of mint (Mentha arvensis L.) to different levels of nitrogen and different levels of water stress were investigated. Relative performances of different growth and yield parameters such as plant height and fresh weight of shoot as influenced by N-fertilizer and water stress were investigated. Pot experiment was conducted with five levels of N treatments- 0, 60, 120, 180, and 240 kg N ha-1 and four levels of water conditions 100, 75%, 50 and 25% field capacity. Plant growth (height and fresh herb (product) was affected by water stress and different N levels. At 100% field capacity, the highest dose of N- (240kg N/ha) Produced maximum plant height (46.33 cm) and fresh herb product. Lower dose of N treatment decreased the plant height and herb product. Compared to 100% field capacity the fresh herb product was drastically decreased from 103.54 -31.67 g pot -1 at 25% field capacity. Key words: Mentha arvensis, Water stress, N-fertilization, Yield of mint.   doi: 10.3329/bjsir.v44i1.2723 Bangladesh J. Sci. Ind. Res. 44(1), 137-145, 2009


Author(s):  
Philippe Bayen ◽  
Anne Mette Lykke ◽  
François Wenemi Kagambèga ◽  
Fidèle Bognounou ◽  
Adjima Thiombiano

Abstract Water stress is the most important factor limiting early survival and growth of seedlings in arid and semi-arid zones. Many woody species develop adaptive mechanisms in response to water stress. This study assesses survival rate, growth and dry matter distribution in response to water stress in four dryland species (Senegalia dudgeonii, Senegalia gourmaensis, Vachellia nilotica and Vachellia tortilis). A total of 240 seedlings (60 per species) were grown using a completely randomized block design with three replicates in each of three water treatments (control = 100 percent of field capacity; moderate water stress = 50 percent of field capacity; severe water stress = 25 percent of field capacity) with a 7 day watering frequency. Data were collected on seedling survival, height, collar diameter, leaf production and dry matter distribution. Survival rate of the four species was not affected by water stress. However, the morphological responses to water stress were significantly different between species. Water stress resulted in significant reductions in height and collar diameter, higher below-ground biomass and significant increase in shedding of leaves. Under water stress, S. dudgeonii, S. gourmaensis and V. tortilis invested more in root growth. The allocation pattern from above-ground to below-ground parts was found to be the main adaption to drought. In contrast, V. nilotica gave preference to above-ground development, which could be an indication that the seedlings are adapted to grow under severe water stress. The results confirm the interspecific genetic differences in growth and dry matter distribution among species. These variations in water stress response may be used as criteria for species selection for degraded land reforestation.


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