South Texas Pecan Field Days a success
By MONETTE TAYLOR | Country World South Central
May 3, 2001 -- At recent pecan field days in counties across South Texas, Dr. Larry Stein, extension horticulturist for Texas A&M University out of Uvalde, and Dr. Bill Ree, extension entomologist from College Station, presented information and demonstrations to pecan producers.
Stein spoke on four major areas: the potential crop outlook for this year, the need for zinc and nitrogen and crop land management.
"One of the things that most of y'all have noticed when driving around is...when you go by all these different pecan trees...the good catkin crop that we have. You've got to have catkins before you can set pecans," said Stein.
After the dry weather and stress on the trees, last year, the winter and spring rains have brought new hope for the 2001 growing season, according to Stein. The trees can store a lot of nutrients during stress, and with the right conditions can produce a good crop the next season.
"The two key management things we need to be aware of here are zinc and nitrogen. Zinc is very important as far as leaves go. What we want to do is try and grow as many leaves as we can and as big of leaves as we can. The one thing we can do to help influence that is zinc. Zinc is fairly cheap and zinc pays big dividends," said Stein.
While there is not a lot of changes in pecan production over the years, one of the recent changes involves the nitrogen timing for application to the trees. Spacing remains very important and the need for sunlight, zinc and nitrogen is paramount.
"One of the things that has changed concerns nitrogen timing, as far as timing of the nitrogen fertilizer. I know a lot of you have heard about fall fertilization of pecans, and a lot of people have done some of that. The big question is what is the optimum time to apply nitrogen fertilizer to get the best out of it...to get the most out of the money you're spending on this nitrogen.
"The latest research shows us trees that are in an 'on' mode...that will have a big crop this year...use nitrogen at two critical times. The first is about right now, at about one-half to three-fourths leaf expansion. Trees in an 'on' situation have a lot of stored nitrogen and so if you apply it really early, your trees are not taking it up because they're growing off the stored nitrogen. We used to say apply at bud-break, but now we say three to four weeks after bud-break," said Stein.
The other time trees need nitrogen is when the nuts start to fill, usually around July or August, according to Stein.
If you can get the nitrogen into the ground at that time, with the right amount of water, you should have an ideal opportunity for a good crop.
"What we're looking at is about half of what you'd normally apply, if you apply 100 units per acre per year. Then you'd do half in the early spring and half in early summer," said Stein.
He encouraged producers to go into their orchards to evaluate terminals on the trees to determine how many nuts are on the trees and make a decision as to how many to leave and how many should be removed for optimum production. For most varieties of pecans, the fewer nuts, the larger and better the pecans will be, according to Stein.
Ree spoke concerning the control of the pecan nut casebearer and other insect pests.
He suggested using pheromone traps to help determine when to begin scouting for the first generation casebearer eggs.
"The purpose or intent of these traps is to alert producers to casebearer activity," said Ree. "We know that from your trap catches from the initial trap catch to the time of egg laying is about 7-10 days. The time from trap catch to nut entry is around 12-16 days."
Scouting can assist the producer in deciding when and if to apply insecticides.
In some cases, the loss may contribute to the correct amount of set nuts, and in other cases, the casebearer can completely destroy a crop.
"I highly recommend, after you've done your scouting, you sprayed and made a good application, that you continue to come back, afterwards, and look. Looking over your shoulder is pretty cheap," said Ree.
If producers have questions concerning their individual locations and varieties of pecans, they can contact their local Texas Agricultural Extension Service representative.
