Winter Effects on Avocado

‘Hass' avocado fruit set, January 12, 2024.

I was looking for ‘Fuerte' fruit for harvest this winter and came across a grower who said that there was no fruit from last spring, but the tree is loaded with newly set fruit right now. This is in Santa Paula, 15 miles for the ocean. In the same grove there is also ‘Hass' fruit set going on. What is going on? It's too cold – day and night. Almost too cold for honeybees to fly and maybe too cold for pollen tube growth, even if there were pollination. Pollination is the movement of pollen from male to female stage flowers by a bug agent. Too cold for fertilization, pollen tube growth from the stigma down through the pistil to the ovule to start fruit formation.

Cold weather fruit set is often the condition for formation of ‘cukes', especially along the coast.

These little bullet shaped fruit that are seedless can often form doubled fruit.

We are sure of the actual cause of this occurrence but some varieties like ‘Fuerte' and in in some places like New Zealand have a greater occurrence of the fruit.

Stenospermocarpy is the formation of fruit after pollination and fertilization, but in absence of the seed, which has aborted for some reason. Somehow, the endocarp (the fleshy part of the fruit) continues to supply the necessary carbohydrates and hormones necessary for fruit development. So, there might be a lot of these cukes forming from this early set, or it may just not stick. The avocado is pretty clever, it keeps flowering through winter and spring until it has had a really good chance to set fruit that will hold to maturation.

Even the ‘Gordon' apple tree in my Ventura backyard is confused; it hasn't dropped its leaves this winter.  This is not the winter that i was expecting.

 

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