BAWEJA, P KHAMIDULLAH, SAYED2019-09-212019-09-212019-08http://krishikosh.egranth.ac.in/handle/1/5810128849ABSTRACT Research work entitled, “Evaluation of potato cultivars (Solanum tuberosum L.) under different environmental conditions in Himachal Pradesh” with 3 sowing dates (mid February to mid March), four cultivars (Kufri Himalini, Kufri Kanchan, Kufri Girdhari and Kufri Jyoti) was carried out at Experimental Farm in the department of Environmental Science, Dr. Yashwant Singh Parmar University of Horticulture and Forestry Nauni, Solan, Himachal Pradesh. Various thermal indices viz., GDD, HTU, PTU, PTI and HUE were evaluated to study the impact of varied environments on pheno-phases of potato cultivars. Several quality attributes were also analysed to test the potato tuber quality in terms of weight, size, skin colour, moisture percent, dry matter, starch contents, total sugars, reducing sugars, ash contents, ascorbic acid, TSS and crude fibre. Results revealed that early and midsown potato cultivar K. Kanchan adjudged the best in terms of marketable yield (18.2 t ha-1 and 16.00 t ha-1) which significantly took 123 and 114 days to mature. It accumulated 1654 o C days and 1453 oC days of growing degree days, 615,183 oC days hrs and 510,812 oC days hrs of helio-thermal units and 20,138 oC days hrs and 20,380 oC days hrs of photo-thermal units, respectively. Heat use efficiency was significantly higher in K. Kanchan (0.949 g m-2 o C-1 days-1) with Pheno-thermal Index of 12.90 as compared to 12.93 in K.Girdhari and 12.78 in K. Himalini. Furthermore, the processing quality attributes in K. Kanchan and K. Jyoti evaluated high Vitamin C (18.56 mg 100 g-1) and (17.44 mg 100 g-1), TSS (4.31 oBrix) and (4.92 oBrix), ash contents (1.21%) and (1.14) with high crude fibre of 1.56% and 1.73% respectively. The best time for sowing of potato cultivars in mid hills of Himachal Pradesh was second fortnight of February month for attaining high marketable yield as well as good processing quality attributes, which could improve potato adaptation to climate change.ennullThesis