Int.J.Curr.Microbiol.App.Sci (2020) 9(10): 704-711 704 Original Research Article https://doi.org/10.20546/ijcmas.2020.910.084 Influence of Farmyard Manure and Nitrogen on Performance of Bt Cotton (Gossypium hirsutum L.) Harkirat Singh * , Balwinder Singh Dhillon and Sudhir Yadav College of Agriculture, Guru Kashi University, Talwandi Sabo, Punjab, India *Corresponding author ABSTRACT Introduction American cotton (Gossypium hirsutum L.) is an important fibre crop of global significance and cultivated in tropical and subtropical regions of more than seventy countries in the world of which the top five producers are China, USA, India, Pakistan and Uzbekistan. It is a cash crop of India and the most important foreign exchange earner through export of raw cotton, garments and cotton seed by products in the form of edible oils and oilcakes. It plays a key role in national economy in terms of both employment generation and foreign exchange earnings. Cotton impacts the lives of estimated 60 million people in India. The area under cotton in India was 122.4 lakh ha with an annual production of 361 lakh bales (1 bale =170 kg) and the productivity was 501.5 kg lint ha -1 . It International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 10 (2020) Journal homepage: http://www.ijcmas.com A field experiment entitled influence of farmyard manure and nitrogen on growth and yield of Bt cotton (Gossypium hirsutum L.) was conducted at Research Farm of University College of Agriculture, Guru Kashi University, Talwandi Sabo, Bathinda to study the effect of different levels of farmyard manure (FYM) and nitrogen on growth and yield of Bt cotton during kharif season in 2019. The trial was laid out in split plot design with three levels of FYM (0, 15 and 30 t ha -1 ) in main plots and four nitrogen levels (0, 75, 100 and 125% of recommended dose of Nitrogen) in sub plots, replicated thrice. Farmyard manure @ 30 t ha -1 recorded significantly higher plant height (181.1 cm), dry matter accumulation plant -1 (306.1 g), number of monopodial branches plant -1 (2.4), number of sympodial branches plant -1 (35.2), number of bolls plant -1 (54.6), boll weight (15.4 g ), seed cotton yield (36.8 q ha -1 ), stick yield (55.7 q ha -1 ) and biological yield (92.5 q ha -1 ) than other control and 15 t ha -1 . FYM @ 30 t ha -1 (36.8 q ha -1 ) resulted in 15.0 and 5.4% higher seed cotton yield than 0 and 15 t ha -1 , respectively. Plant height (181.3 cm), dry matter accumulation plant -1 (321.1 g), number of monopodial branches plant -1 (2.6), number of sympodial branches plant -1 (38.3), number of bolls plant -1 (56.4), boll weight (16 g), seed cotton yield (37.5 q ha -1 ), stick yield (57 q ha -1 ) and biological yield (94.5 q ha -1 ) was recorded significantly higher in 125% RDN but it was statistically at par with the application of 100% RDN. The application of 125% RDN resulted in 21.8, 10.3 and 3.9% higher seed cotton yield than 0, 75 and 100% RDN, respectively. Keywords Bt cotton, farmyard manure, Monopodial, nitrogen, Seed cotton yield and Sympodial Accepted: 07 September 2020 Available Online: 10 October 2020 Article Info