nutrient to be applied. Predicting such amount is not simple. The performance of leaf analysis annually may reflect the response to fertilizer application ( Fernández-Escobar et al., 2009b ) and provide a good approach to determine the amount of nutrient to
Ricardo Fernández-Escobar, Miguel A. Sánchez-Zamora, Jorge M. García-Novelo, and Concepción Molina-Soria
The nuts of 10 pecan cultivars were used to produce rootstock trees for the propagation of two scion cultivars—Posey and Pawnee. Seed sources included: `Chickasaw', `Colby', `Dooley', `Giles', `Greenriver', `Major', `Mohawk', `Peruque', `Posey', and `Shoshoni'. Leaf analysis performed in 1994 and 1996 revealed that rootstock influenced K and Zn concentrations. Scions propagated on `Posey' seedlings contained the greatest amount of K, while scions propagated on `Greenriver' seedlings contained the least. Zn levels were highest in trees with `Chickasaw' seedling rootstocks and the least in `Major' seedlings. Yield and nut quality was influenced by a major drought during the late summer and fall of 1995. Nuts produced by trees with `Chickasaw' and `Colby' rootstocks had the highest kernel percentage, while trees grown on `Major' and `Posey' had the lowest. The greatest yields, during the drought year, were produced from scion cultivars grafted on `Giles' and `Chickasaw' seedling rootstocks. `Major' and `Greenriver' seedlings produced trees with the smallest yields.
Ray E. Worley
Ray E. Worley and Benjamin G. Mullinix
Yield and quality of pecan nuts were as high when 50 pounds N/acre was applied through a dripirrigation system as with 100 pounds/acre (112 kg·ha−1) applied either all broadcast or half broadcast-half fertigated. All N treatments kept leaf N well above the 2.50% (dry weight) lower threshold recommended for pecans. The 50 pounds N/acre-all-fertigated treatment resulted in less soil pH reduction and less loss of K, Ca, and Mg from soil in the nonwetted zone underneath the tree canopy than broadcast treatments. Soil pH, K, and Mg were slightly lowered in the 6- to 12-inch (15 to 30 cm) soil layer when all of the N was fertigated. Higher leaf Ca and Mg from the low rate of N fertigated reflected the higher concentrations of these elements in the soil in the nonwetted zone rather than the lower concentrations in the wetted zone. There was no evidence of a detrimental effect on the tree from lowering the N application to only 50 pounds/acre and applying it in four monthly applications through the drip irrigation system beginning 1 Apr.
Shirin Shahkoomahally, Jose X. Chaparro, Thomas G. Beckman, and Ali Sarkhosh
concentrations, and to interpret the leaf analysis, orchard nutritional status, and the amount of soil nutrient removal ( Nachtigall and Dechen, 2006 ) as it relates to the physiological status of the tree. The results are essential for the accurate application
M. Lenny Wells
is of value to recognize the status of pecan tree and orchard soil nutrition typical of a region. Leaf analysis is widely regarded as a reliable index for many of the nutrient elements of pecan trees. Critical ranges for leaf nutrients have been
M. Leonard Wells and Bruce W. Wood
growth, and leaf analysis of pecan J. Amer. Soc. Hort. Sci. 99 49 57 Worley, R.E. 1990 Pecan leaf scorch in response to various combinations of nitrogen and potassium fertilization HortScience 25 422 423 Worley, R.E. 1994 Long-term performance of pecan
Michael W. Smith, Becky Cheary, and Becky Carroll
March vs. October N applications in factorial combination with two P rates were evaluated on two pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars. Leaf N concentrations were not affected by N application time. However, yield of `Hayes' was increased during 4 of 7 years and cumulative yield was increased 37% when N was applied during October compared to March. Yield of `Patrick' and individual nut weight and kernel percentage of `Hayes' and `Patrick' were not affected by N application time. Phosphorus application increased leaf P concentration 5 of 7 years during the study. Shoot growth, yield, individual nut weight, and kernel percentage were not affected by P application.
Michael W. Smith, Becky S. Cheary, and B. Scott Landgraf
A low leaf Mn concentration was detected in bearing pecan (Carya illinoinensis Wangenh. C. Koch) trees growing in an alluvial soil with an alkaline pH. Trees lacked vigor and leaves were pale in color, but there was no discernible leaf chlorosis or necrosis. Three foliar applications of MnSO4 beginning at budbreak, then twice more at 3-week intervals at rates of 0 to 3.3 kg·ha-1 of Mn increased leaf Mn concentration curvilinearly, and alleviated leaf symptoms. Results indicated that three foliar applications of MnSO4 at 2.15 kg·ha-1 of Mn plus a surfactant were adequate to correct the deficiency.
Esmaeil Fallahi, Bahman Shafii, Jeffrey C. Stark, Bahar Fallahi, and Saad L. Hafez
Cane growth, leaf blade area, blade and petiole fresh and dry weights and mineral nutrients of six grape (Vitis vinifera) cultivars were evaluated in 2000 and 2001 under climatic conditions of southwestern Idaho. The cultivars were: `Barbera 02', `Cabernet Sauvignon 02', `Cabernet Sauvignon 04', `Chardonnay 29', `Merlot 01', and `Sangiovese 04'. No differences were found in cane growth of different cultivars. `Sangiovese 04' and `Merlot 01' had larger leaf area and heavier leaves (both blades and petioles) and higher concentrations of blade nitrogen (N), while `Merlot 01' and `Chardonnay 29' had higher petiole nitrate-N than all other cultivars. `Merlot 01' had relatively the highest potassium (K) concentrations in both blade and petiole tissues. `Chardonnay 29' had lower concentration of calcium (Ca) and `Sangiovese 04' had lower concentrations of magnesium (Mg) in both blade and petiole tissues than other cultivars although differences were not always significant. `Barbera 02' had higher blade iron (Fe) and tended to have higher blade copper (Cu) than other cultivars. However, `Chardonnay 29' had higher petiole Fe than `Barbera 02', `Cabernet Sauvignon 04', and `Sangiovese 04'. `Merlot 01' had higher blade manganese (Mn) than `Sangiovese 04'.