Optimising rootstock age and propagation methods in avocado (Persea americana) under naturally ventilated polyhouse conditions

Avocado (Persea americana Mill.), renowned for its exceptional nutritional and medicinal benefits, has seen a surge in popularity. There has been a huge demand for quality planting material for commercial cultivation. Hence, there is an urgent need for identification of successful propagation methods in avocado. Therefore, the present study was carried out during 2021–23 at ICAR-Central Horticultural Experiment Station, Chettalli, Karnataka to assess the suitability of different propagation methods (soft wood grafting, chip budding and patch budding) on rootstocks of varied age (2–8 months old) of avocado for growth and success at sub humid tropics of Coorg region. Softwood grafting on two months old rootstocks recorded the highest success (94.67%), when compared with other treatments, while it was the lowest in patch budding on two months old rootstocks (3.67%). Among different propagation methods, softwood grafting was found superior (61.43%) compared to chip (32.62%) and patch budding (32.67%). Rootstock age significantly impacted on sprouting and success rates, with eight-month-old rootstocks showing the quickest initial sprouting and seven-month-old rootstocks exhibiting the highest success rates. Additionally, rootstock age and girth were analysed through linear regression, revealing varying impacts on success rates across propagation methods. The success of softwood grafting decreased with increasing rootstock girth and age while chip and patch budding success increased as the rootstock age and girth advanced up to seven months. In conclusion, softwood grafting using two months old rootstocks is ideal for large scale multiplication of quality planting material. The chip and patch budding can also be utilised on 7–8 months old rootstocks and where there is shortage of scion.