Progress 01/31/14 to 01/31/19
Outputs
Target Audience:Commercial pecan producers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Results were presented at industry conferences such as the Georgia Pecan Growers Association Conference, Southeastern Pecan Growers Association Conference, Western Pecan Growers Conference, and Texas Pecan Growers Association Conference. Results were also presented at county production meetings throughout Georgia (approx 15 meetings annually) How have the results been disseminated to communities of interest?Results were presented at industry conferences such as the Georgia Pecan Growers Association Conference, Southeastern Pecan Growers Association Conference, Western Pecan Growers Conference, and Texas Pecan Growers Association Conference. Results were also presented at county production meetings throughout Georgia (approx 15 meetings annually) What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Nutritional, Cultural, and Irrigation Studies of Pecan to Enhance Profitability and Stewardship Lenny Wells, UGA Horticulture Foliar Sulfur Trials Many commercial pecan [Carya illinoinensis (Wangenh.) K. Koch] producers routinely spray foliar urea and sulfur (S) in combination with their fungicide sprays, despite very little information available in the scientific literature regarding the effects of these practices on pecan production. The objectives of this study were to investigate the effects of foliar application of elemental S and urea, alone and in combination, on pecan leaf tissue nitrogen (N) and S concentration, pecan nut quality, leaf chlorophyll index (LCI), and pecan scab control. Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop. Young Pecan Tree Fertilization Trials The prolonged period from tree planting to first commercial harvest of pecan [Carya illinoinensis (Wangenh.) K. Koch] provides incentive for many growers to intensively manage young trees to induce commercial production as soon as possible. This management includes high nitrogen (N) application rates with or without fertigation. However, there remains little data regarding the effect of N fertilization or fertigation on young pecan trees grown under Southeastern U.S. orchard conditions. The objectives of this study were to compare the effects of fertigation with more commonly recommended forms of fertilization on growth and leaf N, phosphorous (P), potassium (K), and zinc (Zn) concentrations of 1st through 3rd leaf pecan trees irrigated with microsprinklers. An optimal growth rate of young pecan trees was obtained as easily with a balanced granular fertilizer application using significantly less N compared with fertigation applications. The minimal treatment differences observed along with the fact that leaf N concentration never fell below the minimum recommended level in any treatment throughout the study supports the supposition that first-year pecan trees require no N fertilizer during the year of establishment. Only modest N application rates are required during the second and third growing seasons. This practice helps to promote optimal tree growth while minimizing excessive losses of N to the environment. Reduced Rate Irrigation Schedule for Pecans Pecan [Carya illinoinensis (Wangenh.) K. Koch] tree stem water potential (?), shoot length, nut yield, and nut quality for the following treatments were evaluated in a commercial pecan orchard in Berrien County, Georgia; 1) Current recommended irrigation schedule; 2) A reduced early-season irrigation schedule, and 3) Non-irrigated control. Water Stress on pecan occurred at about -0.78 MPa using the pressure chamber to measure stem water potential. Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel filling period is a function of nut development and/or crop load in addition to soil moisture. The reduced early-season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early-season water stress with no effect on pecan yield or quality under Southeastern U.S. environmental conditions. Hedging of Pecan Recent extensive pecan [Carya illinoinensis (Wangenh.) K. Koch] plantings coincided with a shift toward the planting of pecan trees at higher density by Georgia pecan producers in anticipation of maintaining these densities through hedge pruning. Initial studies of mechanical hedge pruning in the low-light environment of the southeastern U.S have failed to show significant benefits to pecan production. The objectives of this study were to compare the effects of hedge pruning on pecan nut quality, yield, and mid-day stem water potential (ψ) of pecan trees in the temperate climate of the southeastern U.S. and to evaluate the effect of hedge pruning on wind-storm damage to pecan trees. Treatments were arranged in a randomized complete block design with three blocks. Two treatments were evaluated; 1) Hedge-pruned; 2) Non-Hedge pruned (control). Mid-day stem ψ was 8.5%, 17.6%, and 16.6% higher (P<0.05), indicating less water stress, on hedged trees than on non-hedged trees during 2015, 2016, and 2017, respectively. Nut weight and percent kernel were increased (P<0.05) by hedge-pruning two out of three years of the study. While no direct positive effect of hedge pruning on in-shell nut yield was observed, hedge pruning was not detrimental to pecan yield in the short term. Hurricane/Tropical Storm Irma brought damaging winds to the entire pecan producing region of Georgia on 11 September 2017, resulting in blown down trees, broken branches, and immature nuts blown from the trees. Hedged trees had 60% less wind damage in the form of major limb breakage and tree loss than did non-hedged trees.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Wells, M.L., J. Brock, and T. Brenneman. 2014. Effects of foliar sulfur sprays on pecan independent of pecan scab control. HortScience 49:434-437.
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Wells, M.L. 2018. Mechanical hedge pruning affects nut size, nut quality, wind damage, and stem water potential of pecan in humid conditions. HortScience 53:1203-
1207.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Wells, M.L. 2015. Irrigation water management for pecans in humid climates. HortScience 50:1070-1074.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Wells, M.L. 2015. Growth and nitrogen status of young pecan trees using fertigation. HortScience 50: 904-908.
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:Commercial pecan producers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Information presented to county extension agents at various agent updates, blog posts, and county meetings and field days How have the results been disseminated to communities of interest?County production meetings, industry conferences, field days, industry magazines, blog posts What do you plan to do during the next reporting period to accomplish the goals?Continue as above
Impacts
What was accomplished under these goals?
1)Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop. 2) An optimal growth rate of young pecan trees was obtained as easily with a balanced granular fertilizer application using significantly less N compared with fertigation applications. The minimal treatment differences observed along with the fact that leaf N concentration never fell below the minimum recommended level in any treatment throughout the study supports the supposition that first-year pecan trees require no N fertilizer during the year of establishment. Only modest N application rates are required during the second and third growing seasons. This practice helps to promote optimal tree growth while minimizing excessive losses of N to the environment. 3) Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel filling period is a function of nut development and/or crop load in addition to soil moisture. The reduced early-season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early-season water stress with no effect on pecan yield or quality under Southeastern U.S. environmental conditions.
Publications
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Commercial pecan producers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Information presented to county extension agents at various agent updates, blog posts, and county meetings and field days How have the results been disseminated to communities of interest?County production meetings, industry conferences, field days, industry magazines, blog posts What do you plan to do during the next reporting period to accomplish the goals?Continue as above
Impacts
What was accomplished under these goals?
1)Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop. 2) An optimal growth rate of young pecan trees was obtained as easily with a balanced granular fertilizer application using significantly less N compared with fertigation applications. The minimal treatment differences observed along with the fact that leaf N concentration never fell below the minimum recommended level in any treatment throughout the study supports the supposition that first-year pecan trees require no N fertilizer during the year of establishment. Only modest N application rates are required during the second and third growing seasons. This practice helps to promote optimal tree growth while minimizing excessive losses of N to the environment. 3) Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel filling period is a function of nut development and/or crop load in addition to soil moisture. The reduced early-season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early-season water stress with no effect on pecan yield or quality under Southeastern U.S. environmental conditions.
Publications
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:Commercial pecan producers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Information presented to county extension agents at various agent updates, blog posts, and county meetings and field days How have the results been disseminated to communities of interest?County production meetings, industry conferences, field days, industry magazines, blog posts What do you plan to do during the next reporting period to accomplish the goals?Continue as above
Impacts
What was accomplished under these goals?
1)Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop. 2) An optimal growth rate of young pecan trees was obtained as easily with a balanced granular fertilizer application using significantly less N compared with fertigation applications. The minimal treatment differences observed along with the fact that leaf N concentration never fell below the minimum recommended level in any treatment throughout the study supports the supposition that first-year pecan trees require no N fertilizer during the year of establishment. Only modest N application rates are required during the second and third growing seasons. This practice helps to promote optimal tree growth while minimizing excessive losses of N to the environment. 3) Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel filling period is a function of nut development and/or crop load in addition to soil moisture. The reduced early-season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early-season water stress with no effect on pecan yield or quality under Southeastern U.S. environmental conditions.
Publications
|
Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Commercial pecan producers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Information presented to county extension agents at various agent updates, blog posts, and county meetings and field days How have the results been disseminated to communities of interest?County production meetings, industry conferences, field days, industry magazines, blog posts What do you plan to do during the next reporting period to accomplish the goals?Continue as above
Impacts
What was accomplished under these goals?
1)Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop. 2) An optimal growth rate of young pecan trees was obtained as easily with a balanced granular fertilizer application using significantly less N compared with fertigation applications. The minimal treatment differences observed along with the fact that leaf N concentration never fell below the minimum recommended level in any treatment throughout the study supports the supposition that first-year pecan trees require no N fertilizer during the year of establishment. Only modest N application rates are required during the second and third growing seasons. This practice helps to promote optimal tree growth while minimizing excessive losses of N to the environment. 3) Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel filling period is a function of nut development and/or crop load in addition to soil moisture. The reduced early-season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early-season water stress with no effect on pecan yield or quality under Southeastern U.S. environmental conditions.
Publications
|
Progress 01/31/14 to 09/30/14
Outputs
Target Audience:commercial pecan growers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?State, Regional, and national Industry and county production meetings How have the results been disseminated to communities of interest?State, Regional, and nationalIndustry and county production meetings What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Many commercial pecan [Carya illinoinensis (Wangenh.) K. Koch] producers routinely spray foliar urea and sulfur (S) in combination with their fungicide sprays, despite very little information available in the scientific literature regarding the effects of these practices on pecan production. The objectives of this study were to investigate the effects of foliar application of elemental S and urea, alone and in combination, on pecan leaf tissue nitrogen (N) and S concentration, pecan nut quality, leaf chlorophyll index (LCI), and pecan scab control. Foliar S sprays increased pecan nut weight over the control in two out of three years of study. Pecan nut weight was not affected by foliar urea sprays compared to the control, but nut weight was lower for foliar urea sprays compared to foliar S sprays in the first two years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea following year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Wells, M.L., J. Brock, and T. Brenneman. 2014. Effects of foliar sulfur sprays on pecan independent of pecan scab control. HortScience 49:434-437.
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