Although irrigation is a common practice in pecan (Carya illinoinensis) orchards, the effects of different methods of irrigation on young tree growth, nut quality, and nutrient uptake have not been estimated. Five irrigation systems and one nonirrigated control system were established. Tree performance was characterized by change in trunk diameter, weight per nut, average kernel percentage, and total trunk diameter growth. Nutrient uptake was determined by foliar levels. The five irrigation systems were a microsprinkler with a 35-ft diameter, a microsprinkler with a 70-ft diameter, two subsurface driplines irrigating for 2 days/week alternating between water for 2 hours and no water for 2 hours, two subsurface driplines irrigating 1 day/week for 20 hours continuously (LI2), and four subsurface driplines irrigating for 10 hours continuously for 1 day/week (LI4). Irrigation systems affected foliar levels of potassium (K), boron (B), and manganese (Mn) levels. Irrigation system did not affect change in trunk diameter or kernel percentage. A spatial Durbin error model was estimated to use trunk diameter estimates from all trees in the orchard. This model found the trunk diameters of nonirrigated and LI4 system trees to be significantly less than those trees that were irrigated by the LI2 system. When observations were pooled over all years, LI4 trees had individual pecan nut weights that were significantly less than all other systems.
Abby ShalekBriski, B. Wade Brorsen, Jon T. Biermacher, Charles T. Rohla and Will Chaney
Clyde L. Elmore, Lawrence R. Costello and W. Douglas Hamilton
Cider gum (Eucalyptus gunnii Hook. F.), Monterey pine (Pinus radiata D. Don), and camphor tree [Cinnamonium camphora (L.) J. Presl] were evaluated in a field study comparing the effects of herbicides on tree growth. Trees were planted on 13 May 1983 and treated on 20 May 1983, 10 Apr. 1984, and 4 Oct. 1984 with simazine, oryzalin, napropamide, and oxyfluorfen. Glyphosate was applied as a postemergence treatment in all basins on 20 Mar. 1984. None of the herbicides injured the trees. Trunk circumferencesin treated plots increased as much as 553% over untreated plots. All species showed a positive response to increasing weed control. Chemical names used: 6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine (simazine); 3,5-dinitro-N4,N4-dipropylsulfanilamide (oryzalin); N,N-diethyl-2-(1-naphthalenyloxy)-propanamide (napropamide); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); N-(phosphonomethyl)glycine (glyphosate).
Michael W. Smith, Becky S. Cheary and Becky L. Carroll
Newly planted pecan (Carya illinoinensis Wangenh. C. Koch) trees were grown for 3 years in a tall fescue (Festuca arundinacea Shreb. CV. Kentucky 31) sod with vegetation-free circles 0, 0.91, 1.83, 3.66, or 7.32 m in diameter. Trees were irrigated to minimize growth differences associated with water competition from fescue. There were no differences among treatments in total shoot growth after 1 year, but trunk growth was increased by vegetation-free areas. During the second year, trees with a 0.91-m-wide vegetation-free area had twice as much shoot growth, and trunks were twice the size of those without a vegetation-free zone. The third year, trees with a 0.91-m-wide vegetation-free circle had 403% more new shoot growth, and trunks were 202% larger than those without a vegetation-free zone. Cumulative shoot growth was up to 559% greater with vegetation control. Tree growth was similar with a 1.83- or 3.66-m-wide vegetation-free circle, and trees in both treatments were larger than trees with 0- or 0.91-m-wide vegetation-free zones. Extending the vegetation-free zone to 7.32 m wide was not advantageous.
Connie L. Fisk, Michael L. Parker and Wayne Mitchem
Management of orchard floor vegetation is directly related to subsequent peach [ Prunus persica (L.) Batsch] tree growth and yield ( Arnold and Aldrich, 1980 ; Belding et al., 2004 ; Buckelew, 2009 ; Foy et al., 1994 ; Liverani et al., 1992
Mark A. Williams, John G. Strang, Ricardo T. Bessin, Derek Law, Delia Scott, Neil Wilson, Sarah Witt and Douglas D. Archbold
materials for fertility, and disease, insect, and weed control, to assess tree growth, tree and fruit injury from insect pests and diseases, and yield. In Phase 2, beginning in 2014, strategies to address major limitations and/or problems identified in Phase
Ken Kupperman and Curt R. Rom
The effect of soil preplant strategies winter solarization and methyl bromide fumigation were compared to a non-treated control on apple tree growth. Treatments were applied in the fall after removal of an existing orchard with spring planting of 'Jonee' and 'Smoothee Golden Delicious' on M.26 EMLA rootstock. Soil fumigation significantly increased shoot length in first year, trunk cross-sectional area increase during two seasons, and bloom and set in second year. The control and winter solarization treatments were similar in all responses. Foliar Mn concentrations were significantly lower with fumigated trees in second years compared to other two treatments, which were similar.
Richard C. Beeson Jr.
Pulsing consists of applying subvolumes of a normal daily irrigation volume several times per day. Previous studies have shown splitting overhead irrigation into two subapplications increased growth of container-grown landscape ornamentals in the southeastern U.S. In Florida, water restrictions prohibit overhead irrigation during the critical mid-afternoon when irrigation is most beneficial. Using individual microirrigation spray stakes, only 25% of the water required for overhead irrigation per bed area was necessary to produce similar plants if irrigated once per day. When the same daily volume was pulsed as 2 or 3 subvolumes, tree growth was significantly increased. Data suggest 2 pulses are sufficient for trees with a xeric nature while mesic trees prefer 3 pulses per day. Root:shoot ratios were unchanged by pulsing. Lower cumulative diurnal water stress was measured on pulsed trees.
Michael W. Smith, Becky S. Cheary and Becky L. Carroll
Newly planted pecan (Carya illinoinensis Wangenh. C. Koch cv. Kanza) trees were grown for 5 years in a bermudagrass [Cynodon dactylon (L.) Pers.] sod with vegetation-free circles 0, 0.91, 1.83, 3.66, or 7.32 m in diameter. Trees were irrigated and fertilized to minimize growth differences associated with competition from the bermudagrass. There were no differences in trunk diameter among treatments the first 2 years of the study. During the next 3 years, trunk diameter increased curvilinearly as the vegetation-free circle increased. A vegetation-free circle diameter of 1.83 m produced near maximum tree growth. Although trunk diameter improved slightly as the vegetation-free diameter was increased up to 7.32 m, it was not sufficient to justify the additional expense for herbicides nor exposure of unprotected soil to erosion.
Esmaeil Fallahi, Bahar Fallahi and Bahman Shafii
; Neilsen et al., 1994 , 2010 ; Yao et al., 2001 ; Zydlik and Pacholak, 2001 ), information on tree growth, yield, and fruit quality for new apple cultivars and rootstocks under various regimes of drip or microjet sprinkler irrigation systems in the
Dongyan Hu and Ralph Scorza
’ ( Hansche, 1989 ) as a dwarf (DW) peach tree reference. Sixteen ST trees from open pollination of ‘Bounty’ were included as a standard peach tree growth habit reference. The ST trees were transferred from the greenhouse to the field in May 2006. Due to