VALIDATION OF COTTAM MODEL UNDER DIFFERENT SOWING DATES, ORIENTATION AND METHOD OF PLANTING CUM IRRIGATION APPLICATION

R.P. YADAV¹, S.S. MATHAUDA²*
¹Department of Agronomy and Agro Meteorology Punjab Agricultural University, Ludhiana 141 004, Punjab, India
²Department of Agronomy and Agro Meteorology Punjab Agricultural University, Ludhiana 141 004, Punjab, India
* Corresponding Author : raghu_mam@rediffmail.com

Received : 21-06-2018     Accepted : 27-06-2018     Published : 30-06-2018
Volume : 10     Issue : 12       Pages : 6477 - 6480
Int J Agr Sci 10.12 (2018):6477-6480

Keywords : Model, COTTAM, Validation, Sowing date, Orientation, Planting method
Conflict of Interest : None declared
Acknowledgements/Funding : Author thankful to Punjab Agricultural University, Ludhaina, 141004, Punjab
Author Contribution : All author equally contributed

A field experiment was conducted on cotton (F-846) with two sowing dates (April 26 and May 20) in main plot and combinations of two orientations (66.5cm x 30cm and 100cm x 20cm) and two methods of planting cum irrigation application (ridge-furrow and flat) in sub-plot during kharif 2000 at Punjab Agricultural University, Ludhiana. The ancillary and yield parameters were compared with the simulated output of COTTAM model for validation. The COTTAM model underestimated the maximum LAI by 2 to 8 percent under April 26 sowing and overestimated by 8 to 12 percent under May 20 sowing. The model estimated number of open bolls per plant within 69 to 86 percent of field observed values. The model predicted maximum boll size very close (97 to 100 percent) to that of field observed maximum boll size under all treatments. The model simulated seed cotton and lint yield within 100 to 121 percent of the actual seed cotton and lint yield observed in the field. The COTTAM model showed 100 percent agreement in predicting the seed cotton yield under May 20 sowing with wider row spacing and ridge-furrow method of planting cum irrigation application under Punjab conditions.

1. Bishnoi O.P. (1993) Personal communications. Deptt of Agricultural Meteorology Chaudhary Charan Singh Haryana Agricultural University, Hissar, India.
2. Ehlig C.F. and Lamert R.D. (1973) Crop Science 13, 168-71.
3. Jackson B.S., Arkin G.F. and Hearn A.B. (1988) Transactions ASAE 31, 846-54
4. Jackson B.S., Arkin G.F. and Hearn A.B. (1989) COTTAM: a cotton plant simulation model. Texas A&M University system. Temple, Texas 76583, 1-240.