Wednesday, May 27, 2015

Recharging the water supply

   
     Over the last few weeks, we have received an abundant amount of rainfall. So much rain fell over southeastern Kansas last weekend that the Neosho River spilled out of its banks and flooded our pecan grove (photo above).
   There are positive and negatives when it comes to flooding. On the plus side, a low level flood, like the one we are experiencing now, is serving to recharge the subsoil water supply. Every since the extreme droughts of 2011 and 2012, we have never received the surplus rains needed to completely recharge the system. This flood should get us back to full water supply.
    The downside of flooding is a loss of soil nitrogen due to the actions of denitrifying bacterial that flourish in flooded soils.  Based on predictions from the National Weather Service, this flood should last about five days. That's long enough to recharge the soil moisture supply but not long enough to throw our trees into nitrogen deficiency.

Friday, May 22, 2015

Pruning off sprouts under new grafts

   Between all the rain showers we've been having this week, I've had some time to inspect the grafts I made late last month. All of my scions have sprouted and I'm hoping for a 99.9% grafting success rate (100% would be bragging!). Below the graft unions, I'm also seeing a profusion of rapidly growing sprouts that threaten to out-compete the scion for sunlight (photo at right). These stock sprouts have a reddish coloration, a characteristic of  juvenile pecan seedlings. The sprouts growing from the scion are fully green, the color of sexually mature pecan tissue.
   To make sure all the tree's root energy is focused on growing the scion, I use my pocket knife to cut off all the sprouts below the graft union. The photo at left shows a 3-flap graft before and after all stock sprouts were removed. The photo below shows a bark graft that was pruned to promote scion growth.
   The faster you get out in the field to prune off  competing stock sprouts, the more growth you'll push to your scion. Left unpruned, stock sprouts can over-grow a scion, shade out emerging buds, and eventually kill the graft.
    This week was been so wet its been hard to get anything done out on the farm. However, between rain storms, I'll pull on my rubber boots, hop in my 4WD utility vehicle, and head to the field to trim up some grafts.

  

Wednesday, May 20, 2015

Our pecan seeds are up!

   Last fall we acquired an old Truax tree seed planter in need of repair and re-engineering. This simple machine reminds me of a larger version of a single row corn planter but capable of handling much larger seeds such pecan. We worked on a redesign of the nut metering system and gave the planter a test run last fall (photo at right).
   The planter works best in a well prepared seed bed as shown at right. To make sure we planted the nuts in a strait row, we stretched a string across the field and planted following the string with the front right tractor tire.
   To establish this planting, we harvested early-ripening Peruque nuts, cleaned the seeds, then planted in late October. After planting the pecan seed, we planted a cover crop of winter wheat between the tree rows to hold the soil during the winter and following spring.

    This week, a well defined row of pecan seedlings have popped out of the ground (photo at left). Prior to pecan seedling emergence and before the wheat started to joint, we marked the tree row with a string and sprayed a mixture of roundup and pendimethalin (pre-emergence herbicide) over the top to suppress weeds.
    We plan on leaving the wheat in place throughout the spring flooding season to hold the soil.  Over the summer, we'll spot treat weeds in the tree row with herbicides and clean till the area between rows.
    In using the tree seed planter last fall, we discovered that the furrow closing system currently on the machine does not work in our heavy textured soils. Soil becomes compacted around the shoe of the planter and seeds back up in the drop tube. To plant last year, we removed this ineffective furrow closing system and planted the seed without it. Look at the photo at the top of this post and note that the planter left a V-shaped trench in the soil. This summer we'll be installing two discs on the machine to close this furrow.
    Once we get all the bugs worked out on the planter, we will be leasing the planter to area growers interested in direct seedling new pecan orchards.

Friday, May 15, 2015

June beetles cut off new growth

   Last week, we experienced several days when early evening hour temperatures remained in the low 70's. That's when I heard the familiar sound of large "June" beetles crashing into the windows of my house starting shortly after sunset.  I looked through the window glass and spotted a European chafer crawling on the sill. After spotting this insect, I knew that I could go outside the next morning and find new leaves and shoots chewed off young pecan trees (photo at right). I've written about this pest in an earlier post, but this week I wanted to talk further about the adult beetle behavior and why they only damage young pecan trees.

    The European chafer produces one generation per year. Female beetles lay their eggs in the turf  and C-shaped grubs that hatch from these eggs spend all year feeding on the roots of grasses. Each spring larvae pupate and become adult beetles. These beetles emerge from the turf during early evening hours and swarm to low lying tree branches or shrubs. By cutting off tender leaves and shoots, the European chafer creates an ideal place for additional beetles to land facilitating the search for a suitable mate.
   European chafers are ground dwelling insects so when then fly onto young pecan trees they generally migrate to lower limbs. In the photo at left, you can see that the lowest two limbs of this tree have been attacked by beetles while the upper portion of the tree is untouched. As pecan trees grow larger and lower limbs are pruned off, European chafers will no longer present a problem because these insect can't stand heights.  
    Spring emergence of adult beetles lasts about 2 weeks. At my location, emergence is trailing off and will be over soon.