Help me help my vintage pear tree (apple trees, spring, north)

[SLDerry]

Arborists have told me this tree is a hopeless case. It has suffered the scourge of pear rust for years on end and I lost every pear last year to June drop.

But it seems to be making a comeback. I woodchipped around the base. I have scrupulously removed any rust-infected leaves as soon as I see them and the leaves are very clean this year. I removed a Grand Fir that was shading it out. I rented Mason bees. There is plenty of fruit on the tree right now.

My questions:

1. Would thinning the new pears now in May help to reduce June drop? If so, what percent should I thin?

2. How long is rust a danger? Does rust spread from leaf to leaf OR is each rust spot due to airborne fungus from the juniper/cedar host? I live in the Pacific Northwest.

3. How often should I water an established tree that is probably 40+ years old?

[Hemlock140]

When a kid in California we had 30 Bartlett pear trees.

1.We never did any thinning, but sometimes had to prop up branches with sticks when the weight bent them over. On a tree recovering from stress some thinning is a good idea, you will get bigger fruit, and I would start by removing those in a bunch, if there are 2-3 that would eventually be hitting each other, reduce to just 1.

2. Pear rust was typically a big problem every 2-3 years, very little the other years. There was no chemical treatment that would allow the fruit to be eaten, so we would remove the leaves and thin branches, and put them in the trash. The airborne fungus spores are also spread by water, so late spring/early summer rain will spread it as well as the wind.

3. Our trees were that age, the house was built on former orchards, and we never watered. That was in a place where we got only 24" of rain annually, and in late August-early September it averaged 105F. Here in Sammamish I never water our two apple trees, and they do fine, but the root area is completely shaded by a nearby fence and another tree.

Soil, and sun exposure, and stress can affect watering needs, and in your case I might water every other week during July and August. If we have a typical year, we will get more rain in the next few weeks, despite this unusual early summer heat.

[gemstone1]

Are you describing Fire Blight ? This is the most common problem with pear trees, and difficult to manage.

[Hemlock140]

Originally Posted by gemstone1

Are you describing Fire Blight ? This is the most common problem with pear trees, and difficult to manage.

Two different problems. Rust rarely kills a tree, but fire blight can destroy an entire orchard as it spreads from tree to tree. When you see that affecting a branch you have to cut it off and get it into the garbage.
One of my neighbors cut down a whole tree (apple) to save his others.