~ 222 ~ Journal of Pharmacognosy and Phytochemistry 2021; 10(3): 222-230 E-ISSN: 2278-4136 P-ISSN: 2349-8234 www.phytojournal.com JPP 2021; 10(3): 222-230 Received: 13-05-2021 Accepted: 15-06-2021 Gauswami Jyoti J Department of Genetics and Plant Breeding College of Agriculture Junagadh Agricultural University Junagadh, Gujarat, India Valu MG Department of Genetics and Plant Breeding College of Agriculture Junagadh Agricultural University Junagadh, Gujarat, India Odedara Geeta N Department of Genetics and Plant Breeding College of Agriculture Junagadh Agricultural University Junagadh, Gujarat, India Corresponding Author: Gauswami Jyoti J Department of Genetics and Plant Breeding College of Agriculture Junagadh Agricultural University Junagadh, Gujarat, India Correlation, path coefficient and D 2 analysis study of seed cotton yield and fibre quality traits in American cotton ( Gossypium hirsutum L.) Gauswami Jyoti J, Valu MG and Odedara Geeta N Abstract The present Investigation was carried out to study the correlation, path coefficient and D 2 analysis in American cotton. The material was evaluated in a Randomized Block Design (RBD) with three replications during kharif 2019. In this experiment association analysis revealed significant positive correlation for seed cotton yield per plant with number of bolls per plant. The path analysis revealed that the days to boll opening, number of bolls per plant, boll weight, ginning percentage, and 2.5% span length and fibre fineness exhibited high direct effect on seed cotton yield per plant. D 2 analysis indicated wider genetic diversity among fifty genotypes of cotton which were grouped into twelve clusters. Maximum genetic divergence was observed between cluster XI and cluster XII followed by cluster VI and cluster XII. Keywords: correlation, path coefficient, D 2 analysis and genetic divergence Introduction Cotton (Gossypium hirsutum L.) (2n=52), is one of the most important fiber and cash crop of India and plays a dominant role in the industrial and agricultural economy of the country. It provides the basic raw material (cotton fibre) to cotton textile industry. Cotton in India provides direct livelihood to 6 million farmers and about 40-50 million people are employed in cotton trade and its processing. It is an important fibre and oilseed crop of nearly 80 countries with India, China, United States, Pakistan and Brazil being five of the largest producers of cotton. Cotton, a semi-xerophyte, is grown in tropical and sub-tropical conditions. A minimum temperature of 1 5℃ is required for better germination at field conditions. The optimum temperature for vegetative growth is 21-27 ℃ and it can tolerate temperature to the extent of 43 ℃ but temperature below 21 ℃ is detrimental to the crop. Warm days of cool nights with large diurnal variations during the period of fruiting are conducive to good boll and fibre development. Cotton is grown on a variety of soils ranging from well drained deep alluvial soils in the north to black clayey soils of varying depth in central region and in black and mixed black and red soils in south zone. Cotton is semi-tolerant to salinity and sensitive to water logging and thus prefers well drained soils. There are four cultivated species of cotton viz., Gossypium arboreum, G. herbaceum, G. hirsutum and G. barbadense. The first two species are diploid (2n=26) and are native to old world. They are also known as Asiatic cottons because they are grown in Asia. The last two species are tetraploid (2n=52) and are also known as New world cottons. G. hirsutum is also known as American cotton or upland cotton and G. barbadense as Egyptian cotton or Sea Island cotton or Peruvian cotton or Tanguish cotton or Quality cotton. Materials and Methods Plant material The present investigation carried out at Cotton Research Station, Junagadh Agricultural University, Junagadh during kharif 2019. The experimental material consisted of fifty diverse genotype of cotton (Gossypium hirsutum L.). The pure seeds of these genotypes were obtained from the Cotton Research Station, Junagadh Agricultural University, Junagadh. Field trial Fifty genotypes of cotton were sown on 26 th June, 2019 in a Randomized Block Design (RBD) with three replications at Cotton Research Station, Junagadh Agricultural University, Junagadh. Each line was sown in a single row plot of 6.3 × 1.2 m length with each row spaced 120 cm apart and plant to plant distance within row was 45 cm. The genotypes were randomly allotted to the plots in each replication.