scholarly journals Effects of Controlled Irrigation and Drainage on Nitrogen and Phosphorus Concentrations in Paddy Water

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Shi-kai Gao ◽  
Shuang-en Yu ◽  
Guang-cheng Shao ◽  
Dong-li She ◽  
Mei Wang ◽  
...  
Keyword(s):  
Water Stress ◽  
Growth Stage ◽  
Stage Iv ◽  
Growing Season ◽  
Growth Stages ◽  
Nitrogen And Phosphorus ◽  
Paddy Water ◽  
Controlled Irrigation ◽  
Different Growth Stages ◽  
Percolation Water

Controlled irrigation and drainage (CID) has received attention for improving water quality. Under CID condition, water stress is frequently experienced in two contexts: first drought and then flooding (FDTF) and first flooding and then drought (FFTD). This study aimed to investigate the effects of FDTF and FFTD on nitrogen (N) and phosphorus (P) dynamics in paddy water at different growth stages. The effects of water stress on the migration and transformation of N and P were also investigated. Results showed that CID can decrease N and P concentrations in surface water.NH4+-Nwas the major form of N in surface drainage and percolation water. Mean total phosphorus (TP),NH4+-N, andNO3--Nconcentrations were significantly higher than in FFTD during the growth stage. MeanNH4+-N,NO3--N, and TP concentrations were significantly higher in percolation water under flooding stress than those under drought stress at growth stage, except for mean TP concentrations at milky stage (stage IV). Meanwhile, flooding can sharply increase theNH4+-N,NO3--N, and TP concentrations in percolation water after drought. Thus, without CID, the considerably highNH4+-N,NO3--N, and TP concentrations via runoff and leaching can be responsible for the eutrophication of water bodies in the vicinity of paddy fields during the rice growing season when water stress transforms from drought into flooding.

scholarly journals Evaluation of Rice Responses to the Blast Fungus Magnaporthe oryzae at Different Growth Stages

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Xinglong Chen ◽  
Yulin Jia ◽  
Bo Ming Wu
Keyword(s):  
Disease Severity ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Stage ◽  
Disease Index ◽  
Blast Disease ◽  
Growth Stages ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Different Growth Stages

Rice blast, caused by the fungus Magnaporthe oryzae, is the most damaging disease for rice worldwide. However, the reactions of rice to M. oryzae at different growth stages are largely unknown. In the present study, two temperate japonica rice cultivars, M-202 and Nipponbare, were inoculated synchronously at different vegetative growth stages, V1 to V10. Plants of M-202 at each stage from V1 to reproductive stage R8 were inoculated with M. oryzae race (isolate) IB-49 (ZN61) under controlled conditions. Disease reactions were recorded 7 days postinoculation by measuring the percentage of diseased area of all leaves, excluding the youngest leaf. The results showed that the plants were significantly susceptible at the V1 to V4 stages with a disease severity of 26.7 to 46.8% and disease index of 18.62 to 37.76 for M-202. At the V1 to V2 stages, the plants were significantly susceptible with a disease a severity of 28.6 to 39.3% and disease index of 23.65 to 29.82 for Nipponbare. Similar results were observed when plants of M-202 were inoculated at each growth stage with a disease severity of 29.7 to 60.6% and disease index of 21.93 to 59.25 from V1 to V4. Susceptibility decreased after the V5 stage (severity 4.6% and index 2.17) and became completely resistant at the V9 to V10 stages and after the reproductive stages, suggesting that plants have enhanced disease resistance at later growth stages. These findings are useful for managing rice blast disease in commercial rice production worldwide.

scholarly journals Effect of water stress at different growth stages on quantity and quality traits of Virginia (flue-cured) tobacco type

2010 ◽  
Vol 56 (No. 2) ◽  
pp. 67-75 ◽  
Author(s):  
M.H. Biglouei ◽  
M.H. Assimi ◽  
A. Akbarzadeh
Keyword(s):  
Water Stress ◽  
Block Design ◽  
Water Volume ◽  
Growth Stages ◽  
Research Station ◽  
Quality Traits ◽  
Effect Of Water ◽  
Leaf Yield ◽  
Number Of Leaves ◽  
Different Growth Stages

A field research was carried out in the years of 2005, 2006 and 2007 in order to determine the effect of irrigation and water stress imposed at different growth stages on quantity and quality traits of Virginia tobacco plants. A randomized complete block design with four treatments and three replications was applied at the Rasht tobacco research station. Treatments were: no irrigation (dryland farming) as the complete water stress (WS<sub>0</sub>), water stress till the end of flower bud forming stage (WS<sub>1</sub>), water stress till the end of flowering stage (WS<sub>2</sub>) and full irrigation (WS<sub>3</sub>) as control in each cropping season. The combined analysis of variance showed that the effect of water stress on all the traits related to yield, quality traits and all the traits related to yield components except number of leaves, was significant (<i>P</i> < 0.01). The interaction between year and water stress showed that the treatment of WS0 in all three experimental years significantly (<i>P</i> < 0.05) affected the fresh and dry leaf yield, plant height and sugar and nicotine percentage. The comparison of means of three years (average of three years) also revealed that the treatment of WS<sub>0</sub> significantly (<i>P</i> < 0.05) affected all of the traits which were related to tobacco quantity and quality except for the number of leaves. Moreover, the level of water productivity in recognition of each water volume unit for three experimental years for the treatments of WS<sub>1</sub>, WS<sub>2</sub> and WS<sub>3</sub> were 1.223, 0.873 and 0.594 kg/m<sup>3</sup>, respectively, in the case of average dry leaf yield. Consequently, the results indicate that with optimizing irrigation application we can reach the higher level of productivity.

Irrigation of field peas (Pisum sativum): response to timing at different crop growth stages

1999 ◽  
Vol 132 (4) ◽  
pp. 417-424 ◽  
Author(s):  
C. M. KNOTT
Keyword(s):  
Pisum Sativum ◽  
Vegetative Growth ◽  
Growth Stage ◽  
Crop Growth ◽  
Yield Response ◽  
Growth Stages ◽  
Field Peas ◽  
Crop Growth Stages ◽  
Different Growth Stages

The response of two cultivars of dry harvest field peas (Pisum sativum), Solara and Bohatyr, to irrigation at different growth stages was studied on light soils overlying sand in Nottinghamshire, England in 1990, when the spring was particularly dry, in 1991 which had a dry spring and summer and in contrast, 1992, when rainfall was greater compared with the long-term (40 year) mean.Solara, short haulmed and semi-leafless was more sensitive to drought than the tall conventional-leaved cultivar Bohatyr and gave a greater yield response to irrigation, particularly at the vegetative growth stage in the first two dry years 1990 and 1991, of 108% and 55% respectively, compared with unirrigated plots. Bohatyr was less sensitive to the timing of single applications.In all years, peas irrigated throughout on several occasions produced the highest yields, but this was the least efficient use of water.

Nutrient digestibility of alfalfa at different growth stages on sheep and goat

2003 ◽  
Vol 2003 ◽  
pp. 193-193
Author(s):  
M. M. Moeini ◽  
M. Souri ◽  
F. Hozabri ◽  
M. R. Sanjabi
Keyword(s):  
Dry Matter ◽  
Growth Stage ◽  
Animal Feed ◽  
Maximum Yield ◽  
Nutrient Digestibility ◽  
Growth Stages ◽  
Preparation Methods ◽  
Nutritive Values ◽  
High Forage ◽  
Different Growth Stages

The nutritive values of animal feed are dependents on plant species, stages of maturity, harvesting and preparation methods. Legumes provide maximum yield, high forage quality (protein, mineral and digestible energy). Legumes decrease in protein and digestible dry matter and increase in fibre as they increase in growth or in maturity (Hochensmith et al., 1997). Alfalfa (medica sativa) is world unique forage in livestock food. This study was conducted to examine the chemical composition and nutrient digestibility of Hamadanian alfalfa forage at different growth stage on two local Iranian sheep and goat breeds.

scholarly journals Wheat response to water stress condition at different growth stages in Amibara, Ethiopia

2019 ◽  
Vol 14 (32) ◽  
pp. 1493-1498
Author(s):  
M. Hassen Jemal ◽  
T. Wondimu ◽  
R. Borena Fikadu ◽  
N. Kebede ◽  
A. Niguse ◽  
...  
Keyword(s):  
Water Stress ◽  
Stress Condition ◽  
Growth Stages ◽  
Water Stress Condition ◽  
Response To Water ◽  
Different Growth Stages

SENSITIVITY OF CROP PLANTS TO WATER STRESS AT SPECIFIC DEVELOPMENTAL STAGES: REEVALUATION OF EXPERIMENTAL FINDINGS

1995 ◽  
Vol 43 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Zvi Plaut
Keyword(s):  
Water Stress ◽  
Irrigation Water ◽  
Field Experiments ◽  
Developmental Stages ◽  
Growth Period ◽  
Soluble Solids ◽  
Growth Stages ◽  
Mild Stress ◽  
Uniform Reduction ◽  
Different Growth Stages

It has been suggested that in many crops differences in sensitivity to water stress occur at different growth stages. Since identical amounts of water may be applied, irrespective of whether a crop is exposed to relatively severe and short periods of stress or to extended periods of mild stress, the responses to such differing conditions should be compared. Unfortunately, such a comparison has not been conducted in most studies on sensitivity to water stress at different growth stages. In the present study, based on three field experiments conducted for different purposes, such a comparison was made for three crops: corn, sunflower, and tomato. In corn, distinct responses of ear and kernel yields to the timing of water stress were found. Withdrawal of irrigation water during flowering and cob formation resulted in greater yield losses than during other stages, indicating that this is a critical growth stage. However, slight and uniform reduction of water during the entire growth period resulted in significantly less damage to kernel or ear production, although the total amount of water applied was similar to that under staged withdrawal. In sunflowers, the withdrawal of irrigation water even at noncritical growth stages caused a more marked reduction in grain yield than did a uniform reduction throughout the entire season. In tomatoes, on the other hand, the withdrawal of irrigation water during specific growth stages caused minimal damage to fruit and total soluble solids yield as compared with fully irrigated control; reduction of irrigation water throughout the season brought about a significant decrease in yield. The difference between these crops is interpreted on the basis of the determinance of their floral meristems.

Relative effectiveness of various sources, methods, times and rates of copper fertilizers in improving grain yield of wheat on a Cu-deficient soil

2005 ◽  
Vol 85 (1) ◽  
pp. 59-65 ◽  
Author(s):  
S. S. Malhi ◽  
L. Cowell ◽  
H. R. Kutcher
Keyword(s):  
Grain Yield ◽  
Protein Concentration ◽  
Growth Stage ◽  
Foliar Application ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Relative Effectiveness ◽  
Growing Season ◽  
Growth Stages ◽  
Cu Deficiency

A field experiment was conducted to determine the relative effectiveness of various sources, methods, times and rates of Cu fertilizers on grain yield, protein concentration in grain, concentration of Cu in grain and uptake of Cu in grain of wheat (Triticum aestivum L.), and residual concentration of DTPA-extractable Cu in soil on a Cu-deficient soil near Porcupine Plain in northeastern Saskatchewan. The experiment was conducted from 1999 to 2002 on the same site, but the results for 2002 were not presented because of very low grain yield due to drought in the growing season. The 25 treatments included soil application of four granular Cu fertilizers (Cu lignosulphonate, Cu sulphate, Cu oxysulphate I and Cu oxysulphate II) as soil-incorporated (at 0.5 and 2.0 kg Cu ha-1), seedrow-placed (at 0.25 and 1.0 kg Cu ha-1) and foliar application of four solution Cu fertilizers (Cu chelate-EDTA, Cu sequestered I, Cu sulphate/chelate and Cu sequestered II at 0.25 kg Cu ha-1) at the four-leaf and flag-leaf growth stages, plus a zero-Cu check. Soil was tilled only once to incorporate all designated Cu and blanket fertilizers into the soil a few days prior to seeding. Wheat plants in the zero-Cu treatment exhibited Cu deficiency in all years. For foliar application at the flag-leaf stage, grain yield increased with all four of the Cu fertilizers in 2000 and 2001, and in all but Cu sequestered II in 1999. Foliar application at the four-leaf growth stage of three Cu fertilizers (Cu chelate-EDTA, Cu sequestered I and Cu sulphate/chelate), soil incorporation of all Cu fertilizers at 2 kg Cu ha-1 and two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 0.5 kg Cu ha-1 rate, and seedrow placement of two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 1 kg Cu ha-1 increased grain yield of wheat only in 2001. There was no effect of Cu fertilization on protein concentration in grain. The increase in concentration and uptake of Cu in grain from Cu fertilization usually showed a trend similar to grain yield. There was some increase in residual DTPA-extractable Cu in the 0–60 cm soil in Cu lignosulphonate, Cu sulphate and Cu oxysulphate II soil incorporation treatments, particularly at the 2 kg Cu ha-1 rate. In summary, the results indicate that foliar application of Cu fertilizers at the flag-leaf growth stage can be used for immediate correction of Cu deficiency in wheat. Because Cu deficiency in crops often occurs in irregular patches within fields, foliar application may be the most practical and economical way to correct Cu deficiency during the growing season, as lower Cu rates can correct Cu deficiency. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation

scholarly journals Salmonella in healthy pigs: prevalence, serotype diversity and antimicrobial resistance observed during 1998–1999 and 2004–2005 in Japan

2007 ◽  
Vol 136 (8) ◽  
pp. 1118-1123 ◽  
Author(s):  
K. FUTAGAWA-SAITO ◽  
S. HIRATSUKA ◽  
M. KAMIBEPPU ◽  
T. HIROSAWA ◽  
K. OYABU ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Growth Stage ◽  
Growth Stages ◽  
Finishing Pigs ◽  
Weaned Pigs ◽  
Farm Level ◽  
Faecal Samples ◽  
National Estimates ◽  
Fattening Pigs ◽  
Different Growth Stages

SUMMARYTo determine prevalence, serotype diversity and antimicrobial resistance of Salmonella in healthy pigs, faecal samples from 6771 pigs on 73 farms collected during 1998–1999 and 2004–2005 were examined. Salmonella isolates were serotyped and tested for susceptibility to 22 antimicrobials: benzylpenicillin, ampicillin, amoxicillin, cefazolin, cephaloridine, gentamicin, kanamycin, streptomycin, fradiomycin, colistin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol, thiamphenicol, sulfadimethoxine, sulfamethoxazole, sulfamethoxypyridazine, trimethoprim, sulfamethoxazole/trimethoprim, norfloxacin and ofloxacin. Farm-level and pig-level Salmonella prevalences were 35·5% and 2·2% in 1998–1999, and 35·7% and 3·3% in 2004–2005. Prevalence by growth stage was 2·4% for sows, 3·3% for weaned pigs, 2·7% for fattening pigs and 3·8% for finishing pigs. The predominant serotypes identified were Agona (28·4%), Typhimurium (17·9%) and Infantis (16·4%) in 1998–1999, and Typhimurium (32·5%), Anatum (24·6%) and Infantis (13·5%) in 2004–2005. Compared with the 1998–1999 isolates, the 2004–2005 isolates showed significantly higher rates of resistance to all the antimicrobials except tetracyclines (P<0·01 to P<0·05) and resistance to ⩾2 antimicrobials [19·4% (13/67) vs. 39·7% (50/126), P<0·01]. This study provides national estimates of Salmonella prevalence in healthy pigs of different growth stages in Japan.

scholarly journals Effect of Irrigation and Soil Water Stress on Densities of Macrophomina phaseolina in Soil and Roots of Two Soybean Cultivars

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 895-900 ◽  
Author(s):  
S. R. Kendig ◽  
J. C. Rupe ◽  
H. D. Scott
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Soil Water ◽  
Growth Stage ◽  
Root Colonization ◽  
Growing Season ◽  
Moisture Stress ◽  
Macrophomina Phaseolina ◽  
Soil Moisture Stress ◽  
Soil Water Stress

The effects of irrigation and soil water stress on Macrophomina phaseolina microsclerotial (MS) densities in the soil and roots of soybean were studied in 1988, 1989, and 1990. Soybean cvs. Davis and Lloyd received irrigation until flowering (TAR2), after flowering (IAR2), full season (FSI), or not at all (NI). Soil water matric potentials at 15- and 30-cm depths were recorded throughout the growing season and used to schedule irrigation. Soil MS densities were determined at the beginning of each season. Root MS densities were determined periodically throughout the growing season. Microsclerotia were present in the roots of irrigated as well as nonirrigated soybean within 6 weeks after planting. By vegetative growth stage V13, these densities reached relatively stable levels in the NI and FSI treatments (2.23 to 2.35 and 1.35 to 1.63 log [microsclerotia per gram of dry root], respectively) through reproductive growth stage R6. After R6, irrigation was discontinued and root densities of microsclerotia increased in all treatments. Initiation (IAR2) or termination (TAR2) of irrigation at R2 resulted in significant changes in root MS densities, with densities reaching levels intermediate between those of FSI and NI treatments. Year to year differences in root colonization reflected differences in soil moisture due to rainfall. The rate of root colonization in response to soil moisture stress decreased with plant age. Root colonization was significantly greater in Davis than Lloyd at R5 and R8. This was reflected in a trend toward higher soil densities of M. phaseolina at planting in plots planted with Davis than in plots planted with Lloyd. Although no charcoal rot symptoms in the plant were observed in this study, these results indicated that water management can limit, but not prevent, colonization of soybean by M. phaseolina, that cultivars differ in colonization, and that these differences may affect soil densities of the fungus.

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