Mulch may affect soil chemistry, soil microclimate, biological communities, and tree performance. The trial was conducted to evaluate the effects of different orchard mulches on leaf nutrition, soil moisture, bulk density, root density, and water infiltration for understanding potential use in organic orchards for weed control and as a nutrient resource. Black plastic, hardwood chips, and shredded white paper were applied to three apple cultivars, `Gala', `Jonagold', and `Braeburn' on M.9 rootstocks. A control was sprayed with contact herbicide. Trees grown in hardwood mulch had the highest foliar P and K in year 3. Trees in other mulches showed no difference of leaf nutrition in year 5. All treatments had consistently higher soil moisture than control in year 1, 2, and 4. Mulch did not affect soil bulk density in year 2. The root density was lowest under black plastic mulch in year 2, but was similar in all treatments in year 3. In year 2, water infiltration was fastest in hardwood mulch and control treatments.
Hyun-Sug Choi, Curt Rom, and Jason McAfee
Gerry Neilsen and Frank Kappel
Leaf nutrient concentration of `Bing' sweet cherry (Prunus avium L.) was affected by rootstock over 4 years in the Pacific Northwest. Trees on GM 79, GI 148/1, GI 195/1, and GI 196/4, which had higher yields than Mazzard, also had lower leaf K and, excepting GM 79, lower leaf Mg concentration. Use of GI 195/1 and 196/4 resulted in lower leaf N than use of Mazzard. These higher-yielding rootstocks will require greater attention to these macronutrients, especially on infertile soil sites. Micronutrient nutrition was little affected by rootstocks, which tended to have the low leaf Zn concentrations typical of irrigated Pacific Northwest orchards. GM 9 and GM 61/1 rootstocks were more dwarfing than Mazzard, with GM 9 leaves having lower K, but higher P, Mg, and Mn concentrations. GM 61/1 had lower leaf concentrations of most nutrients relative to Mazzard.
Xinhua Yin, Clark F. Seavert, Janet Turner, Roberto Núñez-Elisea, and Helen Cahn
. 2003 Mulches and biosolids affect vigor, yield, and leaf nutrition of fertigated high density apple HortScience 38 41 45 Núñez-Elisea, R. Cahn, H. Caldeira, L. Seavert, C. 2004 Effect of a
G.H. Neilsen, E.J. Hogue, T. Forge, and D. Neilsen
`Spartan' apple (Malus×domestica Borkh.) trees on M.9 (T337) rootstock were planted in April 1994 at 1.25 m × 3.5 m spacing. Seven soil management treatments were applied within a 2-m-wide strip centered on the tree row and arranged in a randomized complete-block experimental design. Treatments included a weed-free strip (check) maintained with four annual applications of glyphosate; surface application of 45 t·ha-1 of Greater Vancouver Regional District (GVRD) biosolids applied in 1994 and again in 1997; mulches of shredded office paper; alfalfa (Medicago sativa L.) hay; black woven polypropylene; and shredded paper applied over 45 t·ha-1 GVRD-and Kelowna-biosolids applied in 1994 and 1997. All experimental trees were fertigated with phosphorus (P) in the first year and with nitrogen (N) annually. Cumulative yield for the first five harvests was higher for trees subjected to any soil management treatment relative to check trees. Maximum cumulative yield, exceeding check trees by 80%, was measured for trees grown with a shredded paper mulch with or without biosolids application. Trees from the three shredded paper treatments were the only ones significantly larger than check trees after six growing seasons. No increases in leaf nutrient concentration were consistently as sociated with improved tree performance. Notable effects included increased leaf P concentration associated with biosolids application, increased leaf K concentration after alfalfa mulch application and temporary increases in leaf Zn and Cu concentration associated with application of biosolids high in Zn and Cu. Use of both mulches and biosolids amendments benefits growth of trees in high density plantings despite daily drip irrigation and annual fertigation.
Esmaeil Fallahi, W. Michael Colt, Bahar Fallahi, and Ik-Jo Chun
Tree fruit rootstocks are used to influence precocity, tree size, fruit quality, yield efficiency, mineral uptake, and to withstand adverse environmental conditions. In this paper, we will briefly discuss the history and literature of apple (Malus domestica) rootstocks and their effects on scion tree growth, yield, fruit quality, leaf mineral nutrition, and photosynthesis. Then, the results of our long-term study on the effects of rootstocks on tree growth, yield, fruit quality and leaf mineral nutrition, and one season of photosynthesis measurement in `BC-2 Fuji' will be presented and discussed. In this study, `Fuji' trees on `Malling 9 NAKBAT337' (M.9) rootstock had the smallest trunk cross-sectional area (TCA), highest yield efficiency, and were the most precocious followed by those on `East Malling-Long Ashton 26' (M.26 EMLA) and `East Malling-Long Ashton 7' (M.7 EMLA). Trees on M.7 EMLA often had larger fruit with less color than those on M.9 and M.26 EMLA. Trees on M.7 EMLA frequently had greater leaf K than those on other rootstocks. Trees on M.26 EMLA always had greater leaf Mg than those on other rootstocks. Leaves from the current terminal shoots (CTS) of trees on M.9 had higher net photosynthesis and transpiration than those on M.7 EMLA rootstock during 1998 growing season.
G.H. Neilsen, P. Parchomchuk, D. Neilsen, R. Berard, and E.J. Hague
`Gala' apple (Malus domestica Borkh) on M.26 rootstock was subjected, in the first five growing seasons, to NP-fertigation and a factorial combination of treatments involving method and frequency of irrigation. Two types of emitters (drip or microjet) were used to apply the same quantity of water at high (daily), intermediate (about weekly) and low (about bi-weekly) irrigation frequencies. Although initial tree vigor and yield were higher for drip-fertigated trees, by the end of the study microjet fertigation produced larger trees of similar yield. These microjet fertigated trees had higher leaf P, K and Cu but lower leaf N, Mg, and Mn than drip-fertigated trees. Soil pH and extractable Mg and K concentrations were higher and extractable-P concentrations lower directly beneath microjet-emitters as a result of the larger fertigated soil volume relative to drip-emitters. High frequency irrigation improved tree growth but had less effect on leaf nutrient concentrations or soil chemical changes than lower frequency irrigation. Leaf N concentration was most affected by irrigation frequency, tending to decrease with daily irrigation.
Xinhua Yin, Jinhe Bai, and Clark F. Seavert
Single broadcast application of nitrogen (N) and phosphorus (P) on the soil surface results in low use efficiency of applied N and P in pear (Pyrus communis) production systems in Oregon and the Pacific northwestern United States. A field experiment was conducted from 2005 through 2006 to evaluate the effects of split fertigation and band placement as alternate N and P management practices in ‘Anjou’ pears growing on a Parkdale loam soil near Parkdale, OR. Measurement and analysis of tree nutrition, fruit yield, quality, and storability, as well as indigenous soil nutrient supply was the scope of the experiment. To evaluate fertilizer management practices on pear growth and productivity, the following four treatments were tested with a randomized complete block design replicated four times: 1) broadcast application of N and P on the soil surface in a 10-ft-wide, weed-free strip centered on the tree row, 2) band placement of N and P on both sides of tree rows in 1 × 1-ft ditches (width × depth), 3) 1 × 1-ft ditches were dug using the band placement equipment, the dug soil was completed returned to the ditch without any fertilizer, and the broadcast application of N and P on the soil surface was applied on a 10-ft-wide, weed-free strip centered on the tree row, and 4) fertigation of N and P split into five equal applications throughout the growing season. Nitrogen and P fertilizers were applied to treatments 1, 2, and 3 at 100 lb/acre N and 55 lb/acre P, while treatment 4 received only 80 lb/acre N and 44 lb/acre P. The 2-year average results show leaf N and P concentrations in the fall were increased by 10.0% and 10.6%, respectively, with split fertigation compared with broadcast application on the soil surface. Band placement increased leaf N by 7.1% relative to broadcast application on the soil surface with soil disturbance caused by band placement. Split fertigation and band placement slightly increased fruit yield, but increased marketable fruit (the total of excellent and very slightly scalded fruit) by 20.9% and 11.1% (absolute value) when compared with broadcast application of N and P and broadcast application of N and P with soil disturbance caused by band placement, respectively, and after 3 months of cold storage. No detrimental effects on fruit weight or reduction in soil amino sugar N were observed from lowering the N and P application rates by 20% with split fertigation. Overall, split fertigation and band placement of N and P can be used to replace single broadcast application on the soil surface on pear orchards to reduce fruit superficial scald during cold storage and improve the use efficiency of applied N and P in the mid-Columbia region of Oregon.
J.P. Syvertsen, L.S. Lee, and J.W Grosser
Diploid (2x) and autotetraploid (4x) Citrus L. rootstock cultivars were grown at elevated CO2 to obtain insights into limitations on growth and net gas exchange that have been associated with tetraploidy. Well-nourished 2x and 4x seedlings of `Volkamer' lemon (Volk, C. volkameriana Ten & Pasq.), `Troyer' citrange [Troy, C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] and `Cleopatra' mandarin (Cleo, C. reticulata Blanco.), were grown in greenhouses at either ambient or twice ambient CO2 for 4 months. Plant growth, water relations, mineral nutrition, and net gas exchange characteristics of leaves were measured. Most 4x plants were smaller and had lower rates of whole plant transpiration but shorter fibrous roots than 2x plants. Fibrous roots of 4x were thicker than 2x roots as indicated by a lower specific root length (SRL) in 4x than in 2x roots. Root hydraulic conductivity was correlated to total plant growth but there were no effects of CO2 or ploidy on root conductivity. Tetraploid leaves had lower N concentrations than 2x leaves when expressed on a dry weight basis but these differences disappeared when N concentration was expressed on an leaf area basis because 4x leaves had more leaf dry weight per area (LDW/a) than 2x leaves. Plant growth was greater and SRL was lower at elevated CO2 than at ambient CO2. LDW concentrations of N, P, and K were lower at elevated CO2 than at ambient apparently due to a growth dilution effect. LDW/a, net CO2 assimilation (ACO2), and leaf water use efficiency were greater at elevated CO2 than at ambient. Overall, there was no effect of ploidy on ACO2 but 4x Volk and Troy had lower rates of ACO2 than their 2x at elevated CO2. Net gas exchange of tetraploid leaves was less responsive to elevated CO2 than 2x leaves. The low SRL of tetraploids was correlated with low whole plant transpiration rates and low leaf area-based N concentrations, which may be operative in determining the growth characteristics associated with tetraploidy.
M. Lenny Wells
orchard soils typical of the southeastern portion of the U.S. pecan belt. Materials and methods A leaf nutrition and soil fertility survey of pecan orchards was conducted from 18 July to 5 Aug. 2005 and from 17 July to 3 Aug. 2008. In 2005, 29 orchards in
Dámaris L. Ojeda-Barrios, Eloísa Perea-Portillo, O. Adriana Hernández-Rodríguez, Graciela Ávila-Quezada, Javier Abadía, and Leonardo Lombardini
The objective of this study was to assess the changes in leaflet zinc (Zn), leaf nutritional state, vegetative and physiological parameters, and yield quality in pecan trees sprayed with different Zn compounds. Eight-year-old ‘Western Schley’ pecan trees grafted to native seedlings were treated with ZnNO3 (100 mg·L−1 Zn), Zn-EDTA (50, 100, and 150 mg·L−1 Zn), and Zn-DTPA (100 mg·L−1 Zn) and compared with the Zn-untreated control. After 3 years of evaluation, the trees with the best appearance were those treated with ZnNO3 (100 mg·L−1 Zn) and Zn-DTPA (100 mg·L−1 Zn), which showed leaf Zn concentration increases of 73% and 69%, respectively, when compared with the controls. The chlorophyll values of the Zn-treated trees reached 46 SPAD units, equivalent to 43 mg·kg−1 dry weight (DW) of chlorophyll compared with values of 22 mg·kg−1 DW in Zn-deficient leaves. On a leaf area basis, chlorophyll value was 37% lower under Zn deficiency conditions than that of Zn-treated trees. Nut quality was unaffected by the Zn treatments. Data suggest that Zn-DTPA and Zn-NO3 are good options to carry out foliar Zn fertilization in pecan trees.