PHENOLOGICAL RESPONSE OF POTATO CULTIVARS TO AGROMETEOROLOGICAL INDICES ACROSS DIVERSE GROWING ENVIRONMENTS IN NORTH-WESTERN PLAINS OF INDIA

Abstract

The study was conducted during the Rabi season of 2019–20 and 2020–21 at Chaudhary Charan Singh Haryana Agricultural University, Haryana Agricultural University, Hisar, to evaluate the thermal indices such as Growing Degree Days (GDD), Helio-thermal Units (HTU), Photo-thermal Units (PTU), thermal use efficiency (TUE) and radiation use efficiency (RUE) of different potato varieties viz. V1- Kufri Bahar, V2- Kufri Pushkar and V3- Kufri Lima under different planting dates viz. D1- 10th October, D2- 25th October, D3- 10th November and D4- 25th November. The results revealed that D1 sown crop recorded highest AGDD (1237.1°C days), AHTU (5833.3°C day hours), APTU (13646.4°C day hours), D4 sown crop recorded highest TUE (0.16 gm-2 °C days) and the maximum RUE was found in D2 sown crop i.e. 0.65 g MJ-1during crop season 2019-20 whereas, in 2020-21, D1 recorded highest AGDD (1130.9°C days), APTU (12420.6°C day hours), D4 recorded highest AHTU (5978.8°C day hours), D2 sown crop recorded highest TUE (0.23 gm-2 °C days) and RUE (1.59 g MJ-1). Among different varieties, Kufri Lima accumulated maximum AGDD (1002.5°C day and 1068.5°C days), AHTU (4062.1°C day hours and 5806.7°C day hours), APTU (11003.6°C day hours and 11716.9°C day hours), the maximum TUE and RUE was observed in Kufri Pushkar (0.16 gm-2 °C days and 0.21 gm-2 °C days) and (0.54 g MJ-1 and 1.37 g MJ-1) respectively, during both the crop seasons. The findings show the importance of selecting an optimum planting time and variety for maximizing potato yield. This becomes especially relevant in the context of increasing climate variability in semi-arid regions and north-western plains of India.