- Nuts: chestnuts
- Crop Production: agroforestry, cover crops, intercropping
- Education and Training: demonstration, workshop, youth education
- Production Systems: general crop production
The objective of this grant was to measure the grafting success and potential increase in chestnut yields that can be gained by grafting scion wood selected from improved chestnut cultivars to young Chinese chestnut trees. The chestnut trees are part of an agroforestry operation using alley cropping to produce chestnuts in rows of trees and to produce hay in the 28-foot-wide alleyways between rows of trees. In 2011 and 2012 we successfully completed grafting three selected Chinese chestnut cultivars (Qing, Gideon, and Peach, with an ungrafted control) in a statistically designed field experiment (a replicated complete block design). We also included demonstration areas for two other cultivars: Kohr and Auburn Super. A total of 199 trees were grafted. Despite the fact that the summer of 2012 delivered a severe drought, graft success was slightly more than 90 percent. The grafted trees were not expected to produce nuts in 2012, but the ungrafted control trees were. They had been gradually increasing nut production in the preceding years. However, due to the drought, none of the ungrafted control trees produced marketable chestnuts in 2012. That was typical for other producers who did not water aggressively. We conducted outreach with a one-day grafting workshop in April of 2012 that was attended by four people from Central Missouri.
In May 2012 we got one cutting of mixed grass and legume hay from between the trees, roughly 0.75 tons of hay per acre of mixed trees and forage. The drought precluded further cuttings. Nevertheless the mixed grass and legumes continued to provide effective erosion control and appear to have rebounded sufficiently to produce hay in 2013, weather permitting. In March of 2013 we pruned trees and collected scion wood from the grafted trees for grafting later in 2013. We sent some of the scion wood to a grower in Arkansas who wrote seeking the cultivars we were working with. In subsequent years we will continue to fertilize and prune the grafted and ungrafted (control) trees and measure the mean nut yield per tree for each of the cultivars and the controls. The orchard will continue to be available for field tours by other interested growers or potential growers.
In 2007 we established an agroforestry operation on 7 acres of our small farm in central Missouri. We planted Chinese chestnut trees for nut production. Between the trees planted at a 28-foot spacing we are growing hay, some of which we use for our horses and some of which we sell. This is an alley cropping system with hay produced in the “alleyways” between rows of trees. It takes 8 years or more for the chestnut trees to grow large enough to produce commercial crops of chestnuts. During that time the mixed grass and legume forage crop protects the soil and provides some income. As the trees become larger, they will increasingly shade the forage crop and reduce hay production. But the loss of forage should more than be offset by the value of the chestnut crop.
Training from the chestnut experts at The Center for Agroforestry at the University of Missouri taught me that grafting chestnut trees with scion wood from chestnut cultivars with proven high productivity is necessary to ensure large crops of high-quality nuts in the future. (Virtually all fruit and nut trees in commercial orchard operations are grafted in this way.) I set up an experimental design to conduct an operational comparison of the success of three different Chinese chestnut cultivars. Experts (current and recently retired) from The Center for Agroforestry at the University of Missouri helped me identify three promising chestnut cultivars for the experiment. I used funds from the SARE grant to hire an expert grafter to graft scion wood from the selected cultivars to chestnut trees that were already established in my agroforestry system.
This report describes the field experiment and the early results in detail. Results are complete for evaluating the survival (success) of the three selected cultivars. This project is set up for long-term monitoring of chestnut yields in future years as the trees grow large enough for commercial-scale nut production.
Project objectives:div style="margin-left:1em;">
The objective of this grant was to measure the increase in chestnut yields that can be gained by grafting scion wood selected from improved chestnut cultivars to young Chinese chestnut trees established in an agroforestry operation designed to simultaneously produce chestnuts and forage.
Performance was measure by:
1. Establishment of an experimental design to test outplanting of three improved Chinese chestnut cultivars
2. Grafting trees according to the experimental design
3. Measuring graft success rates
4. Maintaining grafted trees
5. Measuring chestnut yield by cultivar for 5 subsequent years
6. Reporting results of the analysis
7. Providing demonstrations or other outreach activities