Diagnosis needed for my mango neighbor

[zands]

I think his tree is Keitt. It is a late mango
He is unhappy with the way his fruits have been the last few years. Here are some  photos from today

[Cookie Monster]

Mango Bacterial Black Spot aka MBBS. Keitt are especially prone due to the fact that they hang fruit throughout the rainy season.

As for treatment, I've found that a religious fortnightly spray of copper works during the rainy season. If not controlled from the get go, it can multiply and get to the point where 90% of crop is destroyed every year. Once under control, copper spraying regimen can be scaled back.

I've also heard that pruning and discarding of infected fruits keeps MBBS from spreading.

[cotter pin]

Mango Bacterial Black Spot aka MBBS. Keitt are especially prone due to the fact that they hang fruit throughout the rainy season.

As for treatment, I've found that a religious fortnightly spray of copper works during the rainy season. If not controlled from the get go, it can multiply and get to the point where 90% of crop is destroyed every year. Once under control, copper spraying regimen can be scaled back.

I've also heard that pruning and discarding of infected fruits keeps MBBS from spreading.

 What is your recommended mixture percentage of copper and which copper product do you recommend for blackspot? When do you spray it and how often do you spray it? ex. nightly, every other night, once a week.

[Cookie Monster]

I've settled on Nordox 75. One tablespoon per gallon, applied with a blower / mister. I tend to prefer dusk application to prevent burn, cause I usually mix it with other stuff.

The drawback is that Nordox 75 does stain the fruit.

Nordox (also Brandt) 30/30 (copper zinc) is great and doesn't stain. However, I haven't been able to find a supplier in many years.

There usually talk about copper toxicity, but I've typically struggled with copper deficiency, so it's served as a micro nutrient. And I've sprayed about 20 pounds of the stuff over a 1/2 acre orchard through the years.