Department of Plant Breeding, Haryana Agricultural University, Hissar-125 004, India
**Present address: R.R.S., H.A.U., Banval (M. Garh) 123 501, India.
*A part of the M.Sc. Thesis submitted by the Senior author to the Haryana Agricultural University, Hissar-125 004.
Growth pattern of parents and hybrids has been investigated for seven developmental traits at various stages of plant growth in upland cotton. Analysis of variance revealed that significant differences existed among parents and hybrids for all the attributes at different stages. Most rapid growth for plant height occurred between 60 to 90 day intervals. ‘J 34 × 152 F’ was found to be the tallest hybrid. ‘Reba × Stoneville’ showed heterotic response throughout the growth period. Dry matter accumulation in stem and floral parts increased linearly, whereas in leaves a steep fall was observed in dry matter production at S8. This stage appeared to be the most important of all the stages of plant growth as it influenced all the seven attributes substantially. The parents and hybrids showed almost similar pattern of dry matter production. The total dry matter production was a reflection of the collective dry matter accumulation in its components, stem, leaves and floral parts. Heterobeltiosis for dry matter traits was exhibited by ‘A218 × Lankart’ and ‘Reba × Stoneville’. ‘J34’ and CA218’ were at the top in the dry matter production. The results on NAR and RGR for parents and hybrids did not fall into any set pattern. In general, the mannitude of heterobeltiosis for physiological traits was low; thus hybrid breeding programme could not be suggested. Exploitation of crosses (A 218 × Lankart, Reba × Stoneville) and varieties (J 34, A218) in the varietal breeding programme has been advocated.
