Gardening: Pecans have holes and tomatoes are sprouting

Q: I was wondering about an increasing problem with this year’s pecan crop. The tree is producing great but every nut has worm holes. Is there some way to treat the tree and at what time? Could the last year’s or probably this year’s weather affect the tree?

A: The problem you described is caused by either the hickory shuckworm (Cydia caryana) or pecan weevil (Curculio caryae). The shuckworm starts feeding on the shell before it begins to harden. This causes the nut to fall off the tree. There are three to five generations per year. The overwintering generation emerges from the fallen nut in spring before fruit set.

A good cleanup of the fallen nuts will prevent the next genarations from forming.

The pecan weevil is generally the worst insect attacking the pecan. This snot beetle drills holes through both the shuck and the shell to lay eggs on the pecan kernel, where the larvae will hatch and devour kernels. Infested nuts drop from the tree and the larvae will remain in the soil for one to two years. Again, a good clean-up of fallen nuts will help to control them.

They pupate and remain in the soil for another year before they turn into adults and then mate. They usually lay eggs on the same tree that they ate the nuts from as larvae. Certain trees will be infested year after year and other pecan trees are not affected at all. Spray the infected trees with Sevin insecticide in spring when the adult weevils appear. A second spray should be made 10 to 14 days later.

This year’s wet spring could have controlled some of the problem, but because the weevil spends one to two years as a pupa, some will always make it through this period.

Q: My mom purchased these tomatoes from a grocery store the other day. She did not use them right away, so she left them sit on the counter. A few days later, they started sprouting from the inside and split it open. I’ve never seen anything like this before. I pick home grown tomatoes all summer long and they ripen on my window sill and never do this. What caused this to happen?

A: There are possibly two different agents causing the seeds to germinate. The first could be the tomatoes had been refrigerated and the warmup on the counter could have given a temperature signal for the seeds to germinate.

Another agent could have been a plant hormone known as gibberellic acid. This hormone acts upon the embryo to break down starch stored in the endosperm, releasing sugar. This sugar nourishes the embryo and promotes the germination of the seed.

This actually happens in the home garden when we experience cooler temperatures for a longer period but the gardener picks the fruit before the seeds are fully formed and cannot germinate. A few gardeners have seen this, but it is quite a rarity. Speaking of a rarity, who thought I would discussing tomato growing in my last two columns — in December?

This story was originally published December 10, 2015 at 3:45 AM with the headline "Gardening: Pecans have holes and tomatoes are sprouting."