Implications of variable environments on phenology of apple (Malus × domestica Borkh.) in Northwestern Himalayan region.

Apple phenology is greatly influenced by temperature. For quality apple production in the orchards, knowledge of the real timing of phenological stages is essential for scientific management decisions. In the Kashmir region, the year 2017 had a normal weather phenomenon, whereas the year 2018 had an erratic weather phenomenon wherein unusually high temperatures prevailed in the winter months and may be a clear sign of climate change effect. Due to this higher temperature in winter months of the year 2018 before bud break, earliness of phenological stages happened as compared to the year 2017, viz. silver tip stage by 5.67 days, green tip stage by 6.61 days, pink bud stage by 10.09 days, initial bloom by 10.43 days, full bloom by 9.70 days, and petal fall by 8.00 days. The flowering duration was overall recorded 2.43 days more in 2018 as compared to that in 2017. Due to the earliness of phenological stages in 2018, all twenty-five cultivars of the apple remained at high risk of spring frost and scientific apple orchard interventions were badly hit as growers were surprised and unprepared. The information generated will be very useful for growers, students, researchers, policy makers, and all the concerned stakeholders to understand how apple phenology responds to normal and extreme erratic weather conditions and may happen more frequently in the future due to climate change.