The MGS Forum

Plants for mediterranean gardens => Fruit and Vegetables => Topic started by: John J on August 29, 2012, 07:24:08 AM

Title: Pecan
Post by: John J on August 29, 2012, 07:24:08 AM
I have a mature pecan tree that produces large quantities of nuts every year. That is until this year. It does not appear to have set a single nut. Could the unusual weather pattern we've experienced this year be to blame? We had a very wet winter, an unusually prolongued and mild spring followed by a, so far, blisteringly hot summer. Anyone any ideas?
Title: Re: Pecan
Post by: MikeHardman on August 29, 2012, 07:41:30 AM
You could be right - just a consequence of the weather.
But also...
...pecans need/prefer particular co-pollinator trees, as shown by this chart (http://www.texaspecannursery.com/chart.htm), for instance.
If your cultivar (or non-selected form) happens not to be receptive at the time co-pollinators are shedding pollen, seed would not get set. And maybe the other co-pollinator(s) that have done the trick in past years have been felled or heavily pruned? That is to say, some co-pollinator trees may persist, bu they could be out-of-sync with yours and hence not useful for setting seed.
The flaw in that argument is that pecans are self-fertile, so they should set fruit even if there are no co-pollinators around, albeit perhaps of lesser quality.
But also, it has been written that the female flowers are not always produced annually (eg. http://wiki.answers.com/Q/How_do_pecan_trees_pollinate).
There's a good account of what goes on here - 'Flowering Habits of Pecan Trees', by College of Agriculture, Consumer and Environmental Sciences New Mexico State University (http://aces.nmsu.edu/pubs/_h/h-622.html), which hints at some other possible issues, eg. low carbohydrate levels.
Title: Re: Pecan
Post by: John J on August 29, 2012, 09:39:10 AM
Thanks for that info, Mike, some interesting stuff. We bought our tree about 25 years ago from what was then a government experimental farm at Saittas. I believe the variety is Mohawk. I can't remember at what age it began to produce nuts but it has never failed to give a good crop every year, until this one. I know it is self-fertile as it is the only one in this area, the nearest ones being way over the other side of the village, probably a couple of miles away. The only suggestion I can come up with is similar to what you say, that the unusual weather pattern has somehow thrown its pollen shedding and pollen receptivity out of sync. We'll just have to wait and see what happens next year. In the meantime no nuts for Christmas!!