Thumbnail Image

Thesis

Browse

20191
Reset filters
Subject: Agricultural Meteorology × Author: Anand, Shubham × End date: 2022 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Role of meteorological parameters in incidence of rice brown planthopper
    (Punjab Agricultural University, Ludhiana, 2019) Anand, Shubham; Dhaliwal, L. K.
    A field experiment was conducted at the Research Farm, Department of Climate Change and Agricultural Meteorology, PAU, Ludhiana during kharif 2018. Two rice varieties (PR 121 and PR 126) were transplanted on 20th June and 30th June. Variety Pusa Basmati 1121 was transplanted on 5th July and 15th July under three spacings (25 cm x 12 cm, 20 cm x 15 cm and 30 cm x 10 cm). The experiment was laid out in Split-Split Plot Design for rice crop and Factorial-RCBD Design for basmati rice in four replications. The micrometeorological data on photosynthetically active radiation (PAR) and relative humidity were recorded at different phenological stages. The periodic biometric observations on leaf area index were recorded. At harvesting, the yield and yield contributing characters (number of effective tillers, number of grains/panicle, 1000-grain weight, grain yield etc.) were recorded. The results indicate that PAR interception was higher under wider spacing (30 cm x 10 cm) followed by closer spacings (20 cm x 15 cm and 25 cm x 12 cm). The higher relative humidity was recorded in closer spacing (25 cm x 12 cm) than wider spacing (20 cm x 15 cm and 30 cm x 10 cm). Leaf area index was higher in 30 cm x 10 cm spacing followed by 20 cm x 15 cm and 25 cm x 12 cm spacing. The higher grain yield (58.65 q/ha) was recorded in rice varieties transplanted under wider spacing (30 cm x 10 cm) in comparison to closer spacings of 20 cm x 15 cm (55.70 q/ha) and 25 cm x 12 cm (53.40 q/ha). In Pusa Basmati 1121, grain yield was higher (30.57 q/ha) in 30 cm x 10 cm spacing followed by 20 cm x 15 cm (29.25 q/ha) and 25 cm x 12 cm (26.89 q/ha) spacings. The peak incidence of brown planthopper incidence was observed in 25 cm x 12 cm spacing (3.1 brown planthopper population/hill) as compared to 20 cm x 15 cm spacing (2.9 brown planthopper population/hill) and 30 cm x 10 cm (2.4 brown planthopper population/hill).The brown planthopper incidence data from 2014 to 2016 and 2018 indicated that the highest incidence at Ludhiana was observed in 2016 and the lowest in 2018. Correlation and regression analysis were carried out between different meteorological parameters and brown planthopper incidence. Using brown planthopper data (in field) of different years stepwise regression models were developed. Minimum temperature and relative humidity (morning and evening) were found to be important parameters in incidence of brown planthopper. Agroclimatic indices viz. growing degree days (GDD) and humid-thermal ratio (HTR) were calculated for brown planthopper. Agroclimatic indices based model was developed using brown planthopper incidence data from 2014 to 2016. RHe/Tmax and RHe/Tmin based model gave lowest error (%) when validated with 2018 brown planthopper data. According to present study, the favourable temperature for brown planthopper incidence was 30.2-33.4 oC (maximum temperature) and 20.6-22.5 oC (minimum temperature) while relative humidity was 86-90 per cent in the morning and 48-60 per cent in the evening. Hot, cloudy and humid conditions are conducive for brown planthopper multiplication. The crop-weather-brown planthopper-calendar was prepared on the basis of four-year brown planthopper data. This calendar can be used in agro-advisory for giving forewarning of brown planthopper to the farmers.