Abstract

Currently, predicting species responses to climate change is a major challenge in agriculture. Nowadays Chile is positioned as one of the main producers of kiwifruit in the southern hemisphere, although it is also classified as highly vulnerable to the effects of climate change. This study looks at the potential impact of climate change (considering temperature changes only) on total yield and fruit size in kiwifruit cultivars, focusing on the principal growing area of Chile. Kiwifruit is a crop highly dependent on optimum pollination and with a long fruit growth period (more than 4 months) during the summer, therefore, increased temperatures during flowering and pre-harvest can have a negative impact on final fruit size and yield. Several trials were conducted in 'Hayward' and 'Jintao' orchards in the Central Valley of Chile. Fruit length and equatorial diameter (maximum and minimum) were measured throughout the growing season. Fruit quality parameters were evaluated at harvest. The thermal time was calculated using temperature sensor records available in each orchard. The dynamic model was built with Stella® software and estimates the yield and average fruit weight as a function of thermal time, fruit set, flowering and harvest date. The size distribution is estimated from the average fruit weight considering the commercial categories. Preliminary results indicate that fruit weight and yield are reduced by approximately 8% and 2% when the average temperature during pollination is increased by 1.5°C and 2.4°C in 'Jintao' and ‘Hayward’, respectively.