Impact of Low Temperature on Subtropical Fruit Species in the Foothills of Uttarakhand

The occurrence of subzero temperature during winter season (December to February) once in 4-5 years is a common phenomenon in the valley portion of foot hills of Uttarakhand in Indian sub-Himalaya. The frequency of extreme climatic events, their magnitude and extend are increasingly common in recent years. Extremes of temperature, un-seasonal rains and high intensity storms have also increased the risk of damage in agriculture and farming practices. But the frequency of occurring subzero temperature is now changing and it is happening twice or thrice in a five years duration keeping in view of climate change. Among these months, January is considered as coldest one, so the study the effect of Mean January Temperature (MJT) on plant survival (<2 years of age) and foliage dam age in fruit bearing orchards on 9 subtropical fruit species (mango, litchi, guava, papaya, aonla, mandarin, jackfruit, anar and lemon. The study was conducted during 1999 to 2010 on survival % and foliage damage in bearing orchard in common fruit plants in the region. Minimum survival in aonla (39%), jackfruit (45%), papaya (49%) and mango plants (50%) which were below 2 years whereas these plant were the worst affected crops with nearly 100% mortality in young (< 2 years old) plants during 2003 and 2008, while litchi, anar, mandarin and guava plants were relatively un affected. Altitude and frost impact on plant survival was positively correlated (r=0.98). Orchards at higher elevations (>600 masl) were significantly less affected than orchards at 600 m asl. Maximum survival 95%, 82% and 65% were recorded at > 900, 600-800 and 600 m altitude, respectively among all the fruit species. Correlation between foliage damage in fruit bearing plant species and available soil moisture recorded was negative (r= -0.93), which indicated that high available soil moisture in the root zone have reduced the foliage dam age in all fruit bearing orchard. Maximum foliage burning was observed in papaya (80%) and minimum with anar (10%).