My idea is not applying any chemicals to mature trees in the future, as a rule for extensive almond production. It is just a matter of costs. However, applying chemicals with a manual sprayer is very cheap when trees are young. I apply two winter treatments:
- An spray of copper and oil (0.5% of copper sulphate, 2% of vegetable oil with washing up liquid) after pruning in November or December. Its goal is to prevent fungus from developing, reduce insect populations and provide the tree with copper, which is an important micro nutrient.
- A broad spectrum fungicide (my favourite is Captan) at bloom time. That is aimed at preventing fungal diseases such as brown rot. I share a good post about this bellow:
These treatments may save a good harvest and its profit. Nonetheless, I do agriculture as something I love, not something to exploit. I work the other side of the equation: costs. My experience shows that chemicals are often ineffective. I think that they are not a worthy effort. But when the effort is small I just do that. That is the case of young trees: