O. P. ChaudharyNarendra Kumar2024-07-032024-07-032023-07-05https://krishikosh.egranth.ac.in/handle/1/5810211402The present study was conducted at Chaudhary Charan Singh Haryana Agricultural University, Krishi Vigyan Kendra, Sadalpur, Hisar, Haryana (India) during kharif 2018 and 2019 with three objectives i.e. evaluation of the status of major insect pests, determination of beneficial organisms and economics of cotton under natural organic and inorganic production and protection systems. Results revealed that whitefly and leafhopper were active from 25th to 41st standard meteorological weeks (SMW) while, thrips from 25th to 37th SMW and natural enemies from 25th to 40th SMW. The population of whitefly, leafhopper and infestation by spotted bollworms was not influenced by the source of nutrients in 2018 season, however in 2019 its effect were significant. Insect pest management strategies significantly influenced the population of whitefly, leafhopper and spotted bollworm (SBW). Overall highest population of whitefly (4.25 adults/leaf) was recorded in 2018 as compared to 2.36 adults/leaf in 2019 with peak (16.44 adults/leaf and 7.06 adults/leaf, respectively) during 2018 and 2019 in 36th SMW. In kharif 2019 significantly low but statistically similar whitefly population was recorded in natural and organic control treatments (2.17 and 2.19 adults/leaf, respectively) as compared to untreated control (2.62 adults/leaf). SBW infestation on square basis was 6.16% and 5.78% during 2018 and 2019, respectively. In 2018 relatively highest SBW infestation was recorded (11.49%) in 38th SMW and (12.71%) in 34th SMW of 2019. Very less population (1.25 and 0.78 larvae/plant, respectively) was recorded of SBW in 2018 and 2019. Pink bollworm infestation in cotton was 1.04% and 1.27% on locule basis during 2018 and 2019, respectively. Mean population of natural enemies (Spiders, Chrysoperla, coccinellids and yellow wasp) was in the range of 0.04 to 0.60 adults/plant and were not influenced by the source of nutrients, however pest management strategies influences population of spiders and Chrysoperla. Wide diversity of 48 insect visitors and pollinators belonging to eight orders viz., Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, Odonata, Orthoptera and Neuroptera were recorded. Continuous build up of bacterium counts over their initial level (4.22 cfu/g soil) was observed during 2018 (4.77) that further increased (5.96 of Azotobacter cfu/g) in 2019. In case of whitefly, natural control treatment provided highest population reduction (37.00%) followed by organic (32.10%) and chemical control treatments (31.18%). In year 2018 maximum (63.08%) reduction in leahopper population was recorded in chemical control treatment followed by organic (27.72%) and natural (17.38%) control strategies. SBW were most efficiently managed by chemical control (44.53 % reduction in population) followed by natural (38.84%) and organic control (33.84%), the two were comparable in efficacy. In the first year, lower yield (422 kg/ha) was obtained in natural sources as compare to organic (495 kg/ha) and inorganic treatment (912 kg/ha). In 2019, highest yield (2563 kg/ha) was obtained in organic sources followed by inorganic (2128 kg/ha) and natural sources (1864 kg/ha). Highest net returns (Rs. 96407/ha) was recorded in organic followed by inorganic (Rs. 80739/ha) and natural production system (Rs. 70907/ha) during 2019. The results clearly indicated the effectiveness on natural farming in second year with increase in net return and significant gains in microbial count also.EnglishThesis