G. NAVEEN*, V. UMAMAHESH, A. R. NIRMAL KUMAR and Y. REDDI RAMU

Department of Crop physiology, S.V. Agricultural College, ANGRAU, Tirupati – 517502, Chittoor Dt., A.P., India

ABSTRACT

A field experiment was carried out during kharif, 2018 on sandy clay loam soils of wet land farm of S. V. Agricultural College, Tirupati, Acharya, N. G. Ranga Agricultural University. The experiment was laid out in factorial randomized block design with three dates of sowings (1st fortnight of June, 1st fortnight of July, 1st fortnight of August), four varieties (MTU-1010, NLR-34449, BPT-5204 and NLR-3041) and replicated thrice. More number of days taken to attain 50% flowering 1st fortnight of June sowing (108) followed by 1st fortnight of July sowing and 1st fortnight of August sowing. Among varieties more number of days taken to attain 50% flowering in NLR- 3041 (107) followed by BPT-5204, NLR-34449 and MTU-1010. With every delay in sowing there was a decline in accumulation of growing degree days and photothermal units, this leads to decrease the time taken to attain 50% flowering. The highest accumulation of growing degree days (2218.38oC day) and photothermal units (26098.71oC day hr) in 1st fortnight of June sowing from sowing to harvest followed by 1st fortnight of July sowing and 1st fortnight of August sowing. Among the varieties highest accumulation of growing degree days (2136.83oC day) and photothermal units (25830.56oC day hr) in NLR- 3041 from sowing to harvest followed by BPT-5204, NLR-34449 and MTU-1010.

KEYWORDS:

Growing Degree Days and Photothermal Units