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1964 - 197912000 - 20182
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Subject: Agricultural Entomology × Start date: 1960 × Type: Thesis ×
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    The Pattern of volatile fatty acids production during the digestion of common indian feeds in cattle and Buffalo
    (Punjab Agricultural University, Ludhiana, 1964) Verma, Manohar Lal; Sindu, G. S
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    ThesisItemOpen Access
    Population dynamics, distribution and rind disorder of mites and thrips on citrus in Punjab
    (Punjab Agricultural University, Ludhiana, 2018) Rajwinder Kaur; Bhullar, Manmeet Brar
    The studies on “Population dynamics, distribution and rind disorder of mites and thrips on citrus in Punjab” were conducted at three locations namely Fruit Research Farm, Punjab Agricultural University, Ludhiana; Regional Research Station, Abohar and Department of Horticulture (Punjab), Hoshiarpur (Bhunga). During the present study eight mite species namely Brevipalpus phoenicis (Geijskes), B. californicus (Banks), Tetranychus urticae Koch, Eutetranychus orientalis (Klein), Polyphagotarsonemus latus (Banks), Amblyseius (Euseius) alstoniae Gupta, A. (Euseius) finlandicus (Oudemans) and Cunaxa setirostris (Hermann) were observed on leaves, B. phoenicis was also observed on fruits from May onwards with maximum population in November - December. There was a negative correlation between mite abundance and rainfall at all locations. The mite families viz. Tenuipalpidae, Tarsonemidae and Cunaxidae had negative correlation with temperature and positive correlation with maximum R.H. but Tetranychidae had positive correlation with temperature and negative with maximum relative humidity. Citrus thrips, Scirtothrips citri (Moulton), started appearing in first week of March with the initiation of flowering and their attack continued up to last week of May. The population of citrus thrips increased progressively with increase in temperature and decrease in relative humidity. Maximum population of citrus thrips and mite species was observed in the arid zone (Abohar) followed by central zone (Ludhiana) and submontane zone (Hoshiarpur) of Punjab. Among all the mite species, E. orientalis and Amblyseius spp. were found to be widely distributed and recorded on all sampled fruit crops in Kinnow orchards. The study of alpha diversity indices showed that diversity and evenness indices were highest in Hoshiarpur (H’ = 1.32, Dmg = 1.42, E = 0.83), followed by Ludhiana (H’ = 1.27, Dmg = 1.32, E = 0.77) whereas lowest were observed in Abohar (H’ = 1.23, Dmg = 1.22, E = 0.73). The highest dominance indices were observed in Abohar (Simpson index = 0.37, d = 0.54). Results also indicated the dominance of B. phoenicis during November month at all the three locations. The experiments to study the impacts of rind disorder caused by mites, thrips and wind on various quality and biochemical parameters were conducted in the laboratory of Punjab Horticultural Postharvest Technology Center (PHPTC), Punjab Agricultural University, Ludhiana. The results showed that damaged fruits (rind scarring by mites and thrips) had less fruit firmness and lesser amount of ascorbic acid, phenols, pectin and carotenoids. But acidity, reducing sugar, total sugar and non reducing sugars were not affected due to rind scarring. However, TSS was higher in fruits having 50 per cent rind scarring as compared to healthy fruits but fully damaged fruits (75 - 100%) had less TSS. Wind damaged fruits had nonsignificant results or negligible differences between values of all physiochemical parameters of healthy fruits and wind scarred fruits. So it was concluded that these losses might be due to deterioration caused by only thrips and mites but not wind.
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    ThesisItemOpen Access
    Population Dynamics and Management of Insect Pests of Chilli
    (Punjab Agricultural University, Ludhiana, 2014) Gurlaz Kaur; Sangha, K. S.
    India is the largest producer and exporter of chilli (Capsicum annuum) in the world and attack of insect pests is a major constraint in its production. Present study was conducted during kharif 2013 at Bharti Field Fresh Farm, Ladhowal, Ludhiana and during rabi 2014 at Department of Forestry and Natural Resources Research Farm, PAU, Ludhiana. In the present study population dynamics of insect pests of chilli, efficiency of sticky traps for monitoring alate insects in chilli ecosystem and effectiveness of various insecticides in managing the insect pest population was worked out. Forty one arthropod species were found to be associated with the chilli crop among which fourteen species were each of pests and natural enemies, twelve species of casual visitors and one species of pollinator. Order coleoptera occupied the maximum share (26.83%) in arthropod fauna recorded on chilli ecosystem. Diversity indices represented a highly diverse arthropod fauna which was evenly distributed and without dominance of any species during both the seasons. Peak activity period for aphid and thrips was recorded during October and May, for whitefly it was September and June, for mite peak population was during October and fruit borer demonstrated highest activity during May. Rectangular yellow sticky traps proved to be better in capturing alate insect pests of chilli as compared to the cylindrical traps. Among the various insecticide treatments tested Thiocloprid 21.7 % SC @ 200 ml/acre proved to be best for management of aphid and whitefly whereas Buprofenzin 25 EC @ 240 ml/acre was the best for managing thrips and mite. In case of fruit borer, Chlorantraniliprole 18.5 SL @ 50 ml/acre performed better than the other treatments.