Tree growth and nutrition were unaffected by orchard floor management system (OFMS) treatments except for foliar nitrogen concentration, which was higher with alfalfa mulch. Trees grafted on Supporter 4 were the most vigorous. There was a
Dario Stefanelli, Roberto J. Zoppolo, Ronald L. Perry and Franco Weibel
Dan TerAvest, Jeffrey L. Smith, Lynne Carpenter-Boggs, Lori Hoagland, David Granatstein and John P. Reganold
. (2008) reported that leguminous cover crops resulted in greater soil N availability and microbial activity than other orchard floor management strategies, including cultivation and wood chip mulch. Numerous studies, however, have reported reduced tree
M.L Parker, J. Hull and R.L. Perry
The root distribution of peach trees [Prunus persica (L.) Batsch cv. Redhaven/Halford] as affected by six orchard floor management treatments was evaluated after 3 years of growth. Two treatments were maintained vegetation-free and four had vegetative covers in the alleyway with a 1.2-m-wide herbicide strip in the tree row. The profile wall method was used to determine root distribution. Trees maintained vegetation-free with herbicide had the most roots. Trees in the vegetation-free plots, maintained with herbicide or cultivation, produced more roots 1.2 m from the tree than trees in the vegetative covers. The number of roots, 1.2 m from the tree, was lowest in the tall fescue treatment. The number of roots were higher in the Kentucky bluegrass (Poa pratensis L.) or alfalfa (Medicago sativa L.) than with tall fescue (Festuca arundinacea, Schreb.).
William D. Goff, Michael G. Patterson and Mark S. West
Nutrient status of young pecan [Carya illinoensis (Wangenh.) C. Koch] trees grown under eight combinations of orchard floor management and irrigation was determined by leaf and soil analyses. Orchard floor management practices were weedy-unmowed, weedy-mowed, weed control with herbicides, and weed control by disking, with trees either irrigated or nonirrigated. The element most affected by treatment was K. Mean leaf K for the two sample years was significantly (P < 0.01) lower in the weedy plots (0.56% K) than in those where weeds were controlled (0.76% K), suggesting a highly competitive effect of weeds for K with young pecan trees. Weed competition also suppressed leaf Ca and Mg, but presence of weeds or sod resulted in higher soil pH and higher leaf Zn. Leaf concentrations of N, P, B, Cu, and Fe were not significantly affected by the treatments.
Danielle R. Ellis and Gregory L. Reighard.
Trees of `Redhaven' peach [Prunus persica (L.) Batsch] budded to `Lovell', `Bailey', and `Nemaguard' rootstocks were grown with bahiagrass or cultivated orchard middles. Terminal shoots were collected once a month through the dormant season. `Redhaven' on `Lovell' had significantly higher levels of sucrose, sorbitol, total soluble sugars, starch and total non-structural carbohydrates than `Redhaven' on `Nemaguard'. However, there were no significant differences in any carbohydrate fraction between `Redhaven' on `Bailey' and the other rootstocks. Orchard floor management system had no significant effect on carbohydrate levels.
Michael L. Parker and John R. Meyer
Peach (Prunus persica L. Batsch. `Biscoe'/Lovell) trees were grown in a sandy loam soil under six orchard floor management systems, including five vegetative covers (continuous under the tree) and a vegetation-free control (bare ground). At the end of the fifth year, trees grown in bare ground and nimblewill grass (Muhlenbergia schreberi J.F. Gmel.) had a significantly larger trunk cross-sectional area (TCSA) than trees grown in weedy plots, centipedegrass [Eremochloa ophiuroides (Munro) Hack.], or bahiagrass (Paspalum notatum Flugge). Trees grown in brome (Bromus mollis L.) did not differ significantly in TCSA from any other treatment. Soil profile excavations of the root system revealed that trees grown in bare ground or with nimblewill had significantly higher root densities than those in the weedy plots or grown with bahiagrass. Vector analysis of root distribution indicated that trees grown in bare ground or nimblewill rooted deeper than trees in all other treatments. The greatest reduction in deep rooting occurred with bahiagrass.
G.C. Wright, W.B. McCloskey and K.C. Taylor
Four orchard floor management strategies—disking, mowing, chemical mow, and clean culture using herbicides—were evaluated in a `Limoneira 8A Lisbon' lemon orchard in Southern Arizona, starting in the fall of 1993. Disking was the cultural practice used to manage the orchard floor before the start of the experiment. Although disking the orchard floor may have injured shallow tree roots, it provided satisfactory weed control except underneath the tree canopies where bermudagrass, purple nutsedge, and other weed species survived. Chemical mowing with Roundup at 1.168 L/ha did not provide satisfactory control of many weed species and required too many applications to be commercially feasible. This treatment was converted to a combination clean culture and disk treatment (clean and disk) in Summer 1995. Mowing the orchard suppressed broadleaf weed species, allowing the spread and establishment of grasses, primarily bermudagrass, and to a lesser extent, southern sandburr. A fall application of Solicam and Surflan followed by a summer spot treatment application of Roundup was used to control the weed flora in the clean culture treatment. Spot treatment applications of sethoxydim (Poast and Torpedo) were also made to control bermudagrass growing under the tree canopies in the clean culture treatment. Total 1995 yield of the mow, clean & disk, disk, and clean culture treatments were 4867, 5112, 5216, and 6042 kg of fruit, respectively. For the first harvest of 1995, the trees under clean culture also had significantly greater numbers of large fruit than did the trees under the other treatments.
Ian Merwin, Dave Rosenberger and Cathy Engle
In several northeastern USDA Low-Input Sustainable Agriculture (LISA) projects, we compared natural (hay-straw, wood-chips, recycled newspaper pulp) and synthetic (polypropylene films and polyester fabrics) mulch materials with mowed sodgrass, tillage, and residual herbicides, as orchard groundcover management systems (GMS). Treatments were applied in 2m-wide strips under newly planted apple (Malus domestica cvs. Liberty, Empire, Freedom. and others) trees on MARK rootstock, planted at 3 by 5m spacing, in 1990. Edaphic, economic, tree nutritional and fruit yield impacts of these GMS were evaluated for four years in five Hudson Valley orchards. All the mulches cost more to establish and maintain ($450 to 4500/ha) than mowed sod ($150/ha), tillage ($120/ha), or residual herbicide ($50/ha) systems. There were few differences in soil water or nutrient availability, leaf nutrient content, tree growth or fruit yield in the mulch systems compared with herbicide or tillage GMS. Meadow voles (Microtus spp.) caused considerable damage to trees in the synthetic and straw mulches, despite the use of trunk guards. Wood-chips were the most enduring, least expensive, and most effective natural mulch. There were insufficient short-term benefits to offset the greater costs of synthetic mulch fabrics or films, in comparison with conventional herbicide snip systems for orchard floor management.
Sarah F. McDonald, Anita Nina Azarenko, Annie Chozinski and Tim Righetti
The percentage of N from fertilizer removed from the field by fruit trees is low. Overapplication of N in orchards has been a common practice and is a concern due to environmental and tree growth problems caused by excess N. Orchard floor management practices (OFMP) can improve the physical and chemical properties of the soil and may alter the soil biological community. Biological activity can affect mineralization rate and thus nutrient availability. The purpose of this study was to determine the effect of alternative OFMP on fertilizer N uptake. Research plots were located in Corvallis, Ore. (COR) (7-year-old `Fuji'), and Hood River, Ore. (HR) (3-year-old `Red Delicious'). Treatments were begun in 2001 in a split-plot completely randomized design with three replications. Main plot treatments were herbicide or cultivation. Subplot treatments were no amendment, bark mulch, compost, and barley/vetch mown and blown into the tree row. Depleted NH3SO4 was applied to single-tree replicates at budbreak. Trees were destructively harvested at harvest of 2003. At HR, the percentage of N derived from fertilizer (NDFF) was significantly lower in the whole tree, leaves, new wood, old wood, spurs, and roots of trees from compost than from unamended plots (P < 0.05). At COR, the NDFF in the leaves, fruit, new wood, spurs and roots was significantly lower in trees from compost plots than unamended plots (P < 0.05). The NDFF also tended to be lower in trees from bark mulch-treated plots than control plots, although differences were not always significant. Vetch/barley amendment resulted in NDFF similar to no amendment. There were no significant differences between the total N of trees from unamended and compost plots. Trees from compost-treated plots appear to be acquiring N from sources other than fertilizer.
J.D. Willmott, E.T. Foster, R. Pavis and J.L. Frecon
Various turfgrass species and cultivars are utilized for orchard floor management. Selection and establishment of low-maintenance species compatible with site conditions results in less need for mowing, fertilizing, and pesticide applications. Koelaria macrantha (Ledeb.) J.A. Schultes is a new turfgrass species that has demonstrated outstanding low-maintenance characteristics. This study evaluated the only commercially available cultivar `Barkoel' and three other species, including Festuca arundinacea Schreb (tall fescue), Festuca rubra L. ssp. falax Thuill (chewings fescue), and Festuca longifolia auct. non Thuill (hard fescue). Turf was seeded in a commercial peach orchard in Oct. 1996 and evaluated through Oct. 1999. After 3 years, the hard fescue cultivars had the best quality, with excellent density and low weed populations. Chewings fescue also had good density and few weeds. Tall fescue had good density, but more weeds than the hard and chewings fescues. Koelaria macrantha `Barkoel' had unacceptable quality, with poor density and the highest weed populations. The fine fescues, hard and chewings, suffered damage from orchard maintenance equipment. Damage was most severe during heat and drought stress in Summer 1999. Growers should limit equipment traffic on hard and chewings fescues during heat and drought stress. Tall fescue showed no significant damage from equipment, but it demonstrated a faster vertical growth rate. This increases the need for mowing. Koelaria macrantha `Barkoel' was not damaged by equipment. While Koelaria had the least density and most weeds after 3 years, it has performed well in our other tests. Higher seeding rates or modifications in seedbed preparation may improve density and reduce weed infestations.