scholarly journals Estimation of Rice Yield Loss Using a Simple Linear Regression Model for Bacterial Blight Disease

2020 ◽  
Vol 23 (1) ◽  
pp. 73-79
Author(s):  
T H Ansari ◽  
M Ahmed ◽  
S Akter ◽  
M S Mian ◽  
M A Latif ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Yield Loss ◽  
Rice Variety ◽  
Severity Index ◽  
Susceptible Variety ◽  
Crop Growth ◽  
Grain Weight ◽  
Growth Stages ◽  
Crop Growth Stages ◽  
1000 Grain Weight

Field experiment was carried out in hot and humid summer (Transplanted Aus) season to realize the yield loss of a susceptible rice variety Purbachi inoculated with bacterial blight (BB). Treatments consist of BB inoculations at different crop growth stages like maximum tillering (MT), panicle initiation (PI), booting (Bt), flowering and heading stages differently including a control (no BB inoculation). Disease severity index (DSI) was measured at 14 days after inoculation (DAI) and harvest. Data on 1000-grain-weight and yield was recorded at harvest. Significant variation on DSI was observed among different BB inoculated crop growth stages. MT, PI and Boot stage inoculations showed similar (DSI 7.1-8.0) but higher DSI than flowering and heading stages inoculation (3.2-5.3) even control (0.00) at 14 DAI. However, all the treatments showed similar DSI 9.0 at harvest. Bacterial blight can affect the grain weight to some extent although it was insignificant among the treatments (0.1-4.5%). DSI showed negative correlation with 1000-grain weight (r=-0.77*) and similarly with the yield (r=-0.97**). The yield ranged from 2.4-3.4 t/ha among the treatments. The yield loss was observed 5.8-30.4% in the BB inoculated treatments. MT, PI and Boot stages inoculation affected the yield much resulting 21-30.4% yield loss. It could be concluded that a susceptible variety can be affected with significant yield loss up to 30.4% with severe outbreak of B B. A simple regression equation = 4.09-0.211X( = Yield, X = BB severity score) is suggested for the prediction of yield loss in susceptible variety in summer season. Bangladesh Rice j. 2019, 23(1): 73-79

scholarly journals Integrating Economics in the Critical Period for Weed Control Concept in Corn

Weed Science ◽  
2014 ◽  
Vol 62 (4) ◽  
pp. 608-618 ◽  
Author(s):  
Martina Keller ◽  
Geoffroy Gantoli ◽  
Jens Möhring ◽  
Christoph Gutjahr ◽  
Roland Gerhards ◽  
...  
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Logistic Models ◽  
Crop Growth ◽  
Growth Stages ◽  
Corn Yield ◽  
Leaf Stage ◽  
Weed Interference ◽  
Free Interval ◽  
Crop Growth Stages

The effect of weed interference on corn yield and the critical period for weed control (CPWC) were determined in Germany and Benin. Treatments with weed control starting at different crop growth stages and continuously kept weed-free until harvest represented the “weed-infested interval.” Treatments that were kept weed-free from sowing until different crop growth stages represented the “weed-free interval.” Michaelis–Menten, Gompertz, logistic and log–logistic models were employed to model the weed interference on yield. Cross-validation revealed that the log–logistic model fitted the weed-infested interval data equally well as the logistic and slightly better than the Gompertz model fitted the weed-free interval. For Benin, economic calculations considered yield revenue and cost increase due to mechanical weeding operations. Weeding once at the ten-leaf stage of corn resulted already profitable in three out of four cases. One additional weeding operation may optimize and assure profit. Economic calculations for Germany determined a CPWC starting earlier than the four-leaf stage, challenging the decade-long propagated CPWC for corn. Differences between Germany and Benin are probably due to the higher yields and high costs in Germany. This study provides a straightforward method to implement economic data in the determination of the CPWC for chemical and nonchemical weed control strategies.

scholarly journals TIME SERIES ANALYSIS OF REMOTE SENSING OBSERVATIONS FOR CITRUS CROP GROWTH STAGE AND EVAPOTRANSPIRATION ESTIMATION

2016 ◽  
Vol XLI-B8 ◽  
pp. 1037-1042 ◽  
Author(s):  
S. A. Sawant ◽  
M. Chakraborty ◽  
S. Suradhaniwar ◽  
J. Adinarayana ◽  
S. S. Durbha
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Growth Stage ◽  
Crop Growth ◽  
Water Requirement ◽  
Growth Stages ◽  
Crop Water ◽  
Horticultural Crops ◽  
Crop Growth Stages ◽  
Crop Growth Stage

Satellite based earth observation (EO) platforms have proved capability to spatio-temporally monitor changes on the earth's surface. Long term satellite missions have provided huge repository of optical remote sensing datasets, and United States Geological Survey (USGS) Landsat program is one of the oldest sources of optical EO datasets. This historical and near real time EO archive is a rich source of information to understand the seasonal changes in the horticultural crops. Citrus (Mandarin / Nagpur Orange) is one of the major horticultural crops cultivated in central India. Erratic behaviour of rainfall and dependency on groundwater for irrigation has wide impact on the citrus crop yield. Also, wide variations are reported in temperature and relative humidity causing early fruit onset and increase in crop water requirement. Therefore, there is need to study the crop growth stages and crop evapotranspiration at spatio-temporal scale for managing the scarce resources. In this study, an attempt has been made to understand the citrus crop growth stages using Normalized Difference Time Series (NDVI) time series data obtained from Landsat archives (<a href="http://earthexplorer.usgs.gov/"target="_blank">http://earthexplorer.usgs.gov/</a>). Total 388 Landsat 4, 5, 7 and 8 scenes (from year 1990 to Aug. 2015) for Worldwide Reference System (WRS) 2, path 145 and row 45 were selected to understand seasonal variations in citrus crop growth. Considering Landsat 30 meter spatial resolution to obtain homogeneous pixels with crop cover orchards larger than 2 hectare area was selected. To consider change in wavelength bandwidth (radiometric resolution) with Landsat sensors (i.e. 4, 5, 7 and 8) NDVI has been selected to obtain continuous sensor independent time series. The obtained crop growth stage information has been used to estimate citrus basal crop coefficient information (Kcb). Satellite based Kcb estimates were used with proximal agrometeorological sensing system observed relevant weather parameters for crop ET estimation. The results show that time series EO based crop growth stage estimates provide better information about geographically separated citrus orchards. Attempts are being made to estimate regional variations in citrus crop water requirement for effective irrigation planning. In future high resolution Sentinel 2 observations from European Space Agency (ESA) will be used to fill the time gaps and to get better understanding about citrus crop canopy parameters.

scholarly journals Comparative study of different organic mulches for increased wheat productivity district Faisalabad, Punjab, Pakistan

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Ahmad Raza ◽  
Muhammad Nawaz ◽  
Muhammad U. Chattha ◽  
Imran Khan ◽  
Muhammad B. Chattha ◽  
...  
Keyword(s):  
Grain Yield ◽  
Crop Growth ◽  
Grain Weight ◽  
Growth And Yield ◽  
Straw Mulch ◽  
Nitrogen Levels ◽  
Major Threat ◽  
Biological Yield ◽  
1000 Grain Weight ◽  
Sorghum Straw

Weeds are major threat to global wheat production and cause serious threat to food security. Likewise, water scarcity is also a major threat to food production and its intensity is continuously soaring up across the globe. Organic mulches have potential to reduce weeds growth and conserve the soil moisture thus ensures the better crop growth and yield. Therefore, present study was conducted to compare the performance of different organic mulches in improving wheat growth and productivity. The study was comprised of different organic mulches; M1= No mulch (control) M2= maize straw mulch, M3= wheat straw mulch, M4= sorghum straw mulch and M5= rice straw mulch and three nitrogen levels N1 = 90 kg, N2 = 120 kg and N3= 150 kg/ha. The results indicated that both organic mulches and N rates had significant impact on growth, and yield traits. The maximum leaf area index (LAI), crop growth rate (CGR), productive tillers (307 m-2), grains/spike (46.22), 1000 grain weight (42.33 g) biological yield (13.76 t/ha) and grain yield 4.75 t/ha was obtained with sorghum straw mulch and minimum productive tillers (255.33 m-2), grains/spike (36.22), biological yield (11.46 t/ha) and grain yield (3.59 t/ha) was recorded in no mulch (control). Among nitrogen levels maximum productive tillers (290.6 m-2), grains/spike (42.80), 1000 grain weight (40.65 g), biological yield (13.44 t/ha) and grain yield (4.32 t/ha) was obtained with 150 kg/ha N and minimum productive tillers (274 m-2), grains/spike (38.13), 1000 grain weight (36.94 g) biological yield (11.98 t/ha) and grain yield (3.90 t/ha) was obtained with 90 N kg/ha. Thus, farmers can use sorghum straw mulch and N (150 kg ha-1) to improve the wheat productivity. However, farmers must be educated by government institute and adoptive research farms in order to understand and adaption of this approach.

scholarly journals Genetic Diversity of Bacterial Blight Resistant Rice (Oryza sativa L.) Genotypes from INGER

2020 ◽  
Vol 23 (2) ◽  
pp. 59-64
Author(s):  
F Akter ◽  
MZ Islam ◽  
A Akter ◽  
SK Debsharma ◽  
A Shama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Bacterial Blight ◽  
Oryza Sativa L ◽  
Mean Value ◽  
Grain Weight ◽  
Yield Potential ◽  
Growth Duration ◽  
Panicle Number ◽  
Cluster Distance ◽  
1000 Grain Weight

Genetic diversity of 65 rice genotypes was studied from IRBBN (International Rice Bacterial Blight Nursery) of INGER (International Network for Genetic Evaluation of Rice) materials through Mahalanobis D2 statistic for grain yield and yield contributing characters. The genotypes were grouped into five clusters. The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the genotypes of different clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. The cluster III contained the highest number of genotypes (23) and the clusterv contained the lowest (8). The highest intra-cluster distance was noticed for the cluster I and lowest for cluster III. The highest inter-cluster distance was observed between cluster I and V, followed by cluster IV and V, cluster II andV and the lowest between cluster I and IV. Regarding inter-cluster distance, the genotypes of cluster V showed high genetic distance from all other clusters. The genotypes from cluster V could be hybridized with the genotypes of other clusters for producing transgressive segregants. Based on canonical vector analysis, panicle number per plant had maximum contribution towards genetic divergence. The highest cluster means for yield, grain/panicle and spikelet fertility were obtained from cluster V. The highest means for 1000 grain weight, second higher yield and the lowest growth duration were found in cluster II, while the lowest mean value for yield and 1000 grain weight and higher mean value for growth duration were found in cluster IV. The crosses between the genotypes/parents of cluster V and cluster II, cluster V and cluster I would exhibit high heterosis as well as higher level of yield potential. Therefore, more emphasis should be given for selection of the genotypes from clusters II and V for future breeding programme. Bangladesh Rice j. 2019, 23(2): 59-64

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.

scholarly journals Assessment of Yield Loss in Maize due to Attack by the Maize Borer, Chilo partellus (Swinhoe)

1970 ◽  
Vol 11 ◽  
pp. 25-30
Author(s):  
Prem Nidhi Sharma ◽  
Purushottam Gautam
Keyword(s):  
Chilo Partellus ◽  
Yield Loss ◽  
Plant Protection ◽  
Grain Weight ◽  
Summer Maize ◽  
Maize Productivity ◽  
Stem Breakage ◽  
Maize Borer ◽  
Yield Difference ◽  
1000 Grain Weight

The maize borer, Chilo partellus (Swinhoe), is one of the major biotic constrains reducing maize productivity in Nepal. Summer maize is infested mainly by it rather than by other insect species in Nepal. National Maize Research Program (NMRP)-Rampur farm was considered as a potential spot for this study where summer maize is highly infested every year by this pest. This study was conducted during the summers of 2004 and 2005 with an objective of assessing the loss by it in maize. A maize variety, Arun-2, was used in this study. Yield loss by this pest was estimated by obtaining the yield difference between the chemically protected and unprotected maize plants. Number of plant stands, number of stem breakage, number of ears harvested, number of poor cobs, 1000 grain weight, and stem tunneling were also recorded as the yield affecting factors. The yield difference was significantly less (by 28%) in unprotected maize as compared to protected maize. Number of plant stands, number of ears harvested and 1000 grain weight were found less (by 8.5, 14, and 6%, respectively) whereas number of stem breakage, number of poor cobs, length of tunnels per plant and per tunnel length were found higher (by 16, 6, 30, and 24%, respectively) in unprotected maize. This study has suggested that application of plant protection measures against C. patellus can significantly increase maize productivity and hence can greatly contribute in poverty alleviation in Nepal. Key words: maize borer; Chilo partellus; yield loss assessment; maize DOI: 10.3126/njst.v11i0.4085Nepal Journal of Science and Technology 11 (2010) 25-30 The maize borer, Chilo partellus (Swinhoe), is one of the major biotic constrains reducing maize productivity in Nepal. Summer maize is infested mainly by it rather than by other insect species in Nepal. National Maize Research Program (NMRP)-Rampur farm was considered as a potential spot for this study where summer maize is highly infested every year by this pest. This study was conducted during the summers of 2004 and 2005 with an objective of assessing the loss by it in maize. A maize variety, Arun-2, was used in this study. Yield loss by this pest was estimated by obtaining the yield difference between the chemically protected and unprotected maize plants. Number of plant stands, number of stem breakage, number of ears harvested, number of poor cobs, 1000 grain weight, and stem tunneling were also recorded as the yield affecting factors. The yield difference was significantly less (by 28%) in unprotected maize as compared to protected maize. Number of plant stands, number of ears harvested and 1000 grain weight were found less (by 8.5, 14, and 6%, respectively) whereas number of stem breakage, number of poor cobs, length of tunnels per plant and per tunnel length were found higher (by 16, 6, 30, and 24%, respectively) in unprotected maize. This study has suggested that application of plant protection measures against C. patellus can significantly increase maize productivity and hence can greatly contribute in poverty alleviation in Nepal. Key words: maize borer, Chilo partellus, yield loss assessment, maize

Evaluation of cellular thermotolerance and associated heat tolerance in wheat (Triticum aestivum L.) under late sown condition

2015 ◽  
Vol 49 (6) ◽  
Author(s):  
Chubasenla Aochen ◽  
Pravin Prakash
Keyword(s):  
Heat Stress ◽  
Grain Filling ◽  
Grain Weight ◽  
Growth Stages ◽  
Wheat Genotypes ◽  
Grain Filling Rate ◽  
Grain Filling Duration ◽  
Membrane Thermostability ◽  
Heat Susceptibility Index ◽  
1000 Grain Weight

Fifty wheat genotypes were evaluated at the seedling stage of growth, for genetic variation in cellular thermotolerance by cell membrane thermostability (CMS) and Triphenyl tetrazolium choride (TTC) assays. A subset of eight genotypes was also evaluated at the anthesis stage using the same assays. Large and significant differences existed among wheat genotypes for TTC and CMS at the seedling and anthesis stages. Average thermotolerance declined from seedling to anthesis stage. Thermotolerance was well-correlated between growth stages among the eight genotypes for both CMS (r=0.95; p= 0.01) and TTC (r=0.92; p= 0.01). The correlation between TTC and CMS among the eight genotypes at seedling and anthesis stages was significant (r=0.95; p=0.01 and r =0.93; p= 0.01, respectively). The effect of heat stress on wheat genotypes selected on the basis of TTC and CMS thermotolerance ratings were evaluated. 1000-grain weight, grain filling duration (GFD) and grain filling rate (GFR) reduced under heat stress. The heat susceptibility index (S) revealed K-65 and Yangmai6 to be susceptible and NW-1014 and DBW-14 to be moderately tolerant to heat stress. GFR and 1000-grain weight were found to have highly significant positive correlation with CMS and TTC ratings at both seedling and anthesis stages.

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