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2010 - 20197
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Start date: 2010 × End date: 2019 × Subject: Agricultural Statistics and Informatics ×
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Now showing 1 - 7 of 7
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    ThesisItemOpen Access
    STATISTICAL EVALUATION OF DIFFERENT METHODS FOR PREHARVEST FORECASTING OF GROUNDNUT YIELD IN JUNAGADH DISTRICT OF GUJARAT 2899
    (JAU, JUNAGADH, 2019-08) SATHEES KUMAR K; M. S. Shitap
    A timely and reliable forecast of crop yield needs more emphasis for monsoon dependent country like India where, the economy is mainly based on agricultural production. Weather is a major factor affecting crop production in advanced agricultural systems. The large variation in yield from year to year and place to place is dominated by the weather parameters. In view of fluctuating weather effects, a timely and reliable forecast of crop productivity could help in deciding the policies. A proper forecast of production of commercial crops is very important in an economic system. There is close association between crop productions with prices. An unexpected decrease in production reduces marketable surplus and income of the farmers and leads to prices rise. An efficient forecasting is thus a pre-requisite for food supply information system at district and state level. The present study has been taken up to, (1) To identify the nature of effect of weather variables and time period on groundnut yield in Junagadh district of Gujarat, (2) To explore the possibility of suggesting suitable statistical method for pre-harvest forecasting of the groundnut yield in Junagadh district of Gujarat and (3) To compare the efficiency of MLR and ARIMA models. To estimate the effect of weather variables and time period, yield and weather data for 31 years (1985 to 2015) were used. The weekly averages of weather variables viz., maximum temperature (MAX T), minimum temperature (MIN T), morning ABSTRACTrelative humidity (RH1), afternoon relative humidity (RH2) and weekly total rainfall (RF) from 24th to 37th standard meteorological week of the respective year were considered in the study. In all five approaches were used in the study. Out of these, four approaches used weather variables which were further categorized as based on generated weather variables (correlation coefficient as weight and week number as weight) and based on original weather variables (week wise approach and crop stage wise approach). Three sets of multiple linear regression equations consisting of 23, 24 and 25 years data considering the data up to 10, 12 and 14 weeks for each model were fitted. In addition to this, ARIMA model which used only time series yield data was also used. Similarly, three sets of ARIMA model consisting 23, 24 and 25 years data for each model were fitted. The models based on 10 weeks with 25 years data using correlation coefficient as weight with generated weather variables and model based on 10 weeks with 23 years data using week-wise approach using original weather variables were recommended as pre-harvest forecast models for groundnut productivity of Junagadh district which can predict the groundnut yield 6 weeks before harvest. In case of ARIMA model, ARIMA (1, 1, 1) with 25 years data can be considered as the forecasting model for groundnut productivity in Junagadh district of Gujarat. The comparison between the selected regression models and ARIMA model on the basis of R2 , R̅2 , RMSE and MAE values showed that regression models were superior as compared to ARIMA models. The proposed models are Model based on correlation coefficient as weight using generated weather variables Y= -3536.86 + 1.24Z141 + 5.95Z121 + 15.27Z51 + 1.37Z131 – 41.73Z31 (R̅2 =86.30%) Model based on week-wise approach using original weather variables Y = -6605.93 + 105.81 X45 + 456.09 X25 + 2.94 X38 -27.27 X510 - 456.42 X210 (R̅2=85.70%)
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    ThesisItemOpen Access
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    ThesisItemOpen Access
    ESTIMATION OF THE EFFECT OF WEATHER PARAMETERS ON CASTOR YIELD IN GUJARAT
    (JAU,JUNAGADH, 2016-07) Sabhaya A. G.; Dr. N. J. Rankja
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    ThesisItemOpen Access
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    ThesisItemOpen Access
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    ThesisItemOpen Access
    “DEVELOPMENT OF STATISTICAL MODELS FOR FORECASTING OF CHICKPEA CROP IN GUJARAT STATE”
    (jau,junagadh, 2013-06) Marviya P. B.; Dr. N. J. Rankja
    Weather is a major factor affecting crop production in advanced agricultural systems in our country. The large variation in yield is predominantly due to weather parameters. In view of fluctuating prices and weather effects a timely and reliable forecast of crop yield could help the planners in deciding the policies. Chickpea is an important pulse in the country and abroad. Therefore, an attempt has been made to identify the nature of the effect of weather parameters and technological advancement on chickpea crop and thereby to suggest suitable preharvest forecast models for major chickpea producing and growing districts of Gujarat state. Timely and reliable forecast of crop yield is of great importance for monsoon dependent country like India, where the economy is mainly based on agricultural production. Chickpea crop grown mainly under irrigated as well as rainfed condition, the fluctuations in yield levels over the years are due to weather behavior. The present investigation entitled “Development of statistical models for forecasting of chickpea crop in Gujarat state” was undertaken to develop pre-harvest forecasting models for chickpea yield based on weekly average data of weather parameters (maximum and minimum temperature, morning and afternoon relative humidity, sunshine hours and past year total rainfall) over a period of 30 years (1981 to 2010) covering five selected chickpea growing districts of Gujarat state. The time period used for chickpea crop was from 42nd meteorological standard week (MSW) to 7th standard week of next year. The weekly average of weather variables used were maximum and minimum temperature, morning and afternoon relative humidity, sunshine hours and total annual rainfall of past year. The weather data were collected from respective observatories of each district. The data of area, production and productivity of chickpea from 1981 to 2010 were collected from Department of Economics, J.A.U., Junagadh. The approach used for forecasting yield was original weather variables and week wise approach. The time trend was included as an explanatory variable in this approach. For early forecast, 4, 3, 2 and 1 weeks intervals were considered. The stepwise regression procedure was adopted using 30 years data for selection of variables. The prediction equations and forecasts of subsequent years were obtained separately for 25, 26, 27 and 28 years data set. The influence of the time trend on chickpea yield was observed positive and significant in all the districts and each of the models fitted. It could be also observed from the results that the advances in chickpea production technology during last few years. The effects of all the weather variables, in relation to their quantum and direction, differed over the district. However, they were found important for prediction point of view in chickpea productivity. In case of Jamnagar, Amreli and Valsad districts, the model of 14 week crop period (Using original weather variables, week wise approach) where as in Junagadh and Rajkot districts, the model of 13 and 12 week period (week wise approach) respectively were selected. These models for respective districts can be used for providing pre-harvest forecasts, 2 weeks before expected harvest in case of Jamnagar, Amreli and Valsad districts, while 3 and 4 weeks before expected harvest in case of Junagadh and Rajkot district respectively. These models explained highest predictability in yield and the forecasted yields were close to the observed values. The result of the study showed that models selected for pre-harvest forecasts explained more than 60% variation for Junagadh district, more than 86% for Jamnagar and Rajkot districts, more than 83% for Amreli district and more than 49% for Valsad district. The errors of simulated forecasts were less than 1, 7, 6, 3 and 1 percent in respective models.
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    ThesisItemOpen Access
    COMPARISON OF NORTH CAROLINA DESIGNS IN OKRA (Abelmoschus esculentus (L.) Moench)
    (jau,junagadh, 2010-12) Shri A.D. Kalola; Dr. H.R. Pandya
    The present investigation entitled “Comparison of North Carolina Designs in Okra (Abelmoschus esculentus (L.) Moench)” was undertaken at the Vegetable Research Station, Junagadh Agricultural University, Juanagdh. F2 generation was obtained by selfing the Fl generation at the same place during kharif 2006. The plants of F2 generation of the crosses were used to generate the experimental materials for NCD I, II and III during summer 2007. The experimental progenies developed in NCD I, II and III were evaluated alongwith their selfed progenies of parent plants in a compact family block design with two replications for designs I & II and three replications for design III at the Instructional Farm, College of Agriculture, Junagadh Agricultural University, Junagadh during kharif 2007. The progenies developed through NCD I, II and III in F2 populations of two cross viz., HRB-55 x Kamini and BO-13 x Parbhani Kranti of okra were used to study the genetic variances. The mean performance of the progenies of all the NCDs and their selfed progenies were studied. The major findings are as under.