Bare Root Research Articles

599 PB 205 THE INFLUENCE OF COASTAL BERMUDAGRASS AND CHEMICAL MOWING ON THE GROWTH, DEVELOPMENT, AND WATER UTILIZATION OF YOUNG PECAN TREES AS MEASURED IN NON-WEIGHING LYSIMETERS

Budded, bare root, `Wichita' pecan trees were planted and grown in inexpensive, 2m X.75m, non-weighing lysimeters for three growing seasons. Metered water was applied automatically through microirrigation systems as called for by switching tensiometers. Soil moisture tension was not allowed to exceed 25 Kpa. All tree/sod combinations received 336 kg N per hectare from 1-1-1 ratio commercial fertilizer. Water use, tree growth, and nutrient status of trees grown under the following orchard floor management practices were measured: 1)Unmowed coastal bermudagrass. 2)Mechanically mowed bermudagrass, 3)Chemically mowed bermudagrass, and 4)Bare soil. Water use by trees with chemical or mechanically mowed sod were intermediate in water use between unmowed and fallow soil treatments. In spite of the fact that water was never limiting for any treatment, fallow trees grew significantly larger than trees in any of the sodded treatments. A significantly lower level of foliar potassium was noted in trees growing in sod systems.

1045 IMPACT OF SEED VIGOR ON PRODUCTIVITY OF VEGETABLE TRANSPLANT NURSERIES AND MECHANICAL TRANSPLANTING OPERATIONS.

Seed vigor has a very subtle effect on the productivity of greenhouses producing vegetable transplants, celery, cauliflower, lettuce, etc. and on todays highly mechanized automatic or semi-automatic transplanting operations. As greenhouse production technology moves from traditional bare root to plug/tray growing systems and as automatic and semi-automatic transplanting operations increase in number, the impact of poor seed vigor is realized. Measures to mitigate the impact of poor seed vigor in the nursery are: Seed density grading; increased growing cycle in the nursery, hand culling or replanting. Measures to mitigate the impact of poor seed vigor in automatic transplanting operations: increase the number of people following the planter to replace poor vigor plants; use hand fed transplanters.

Phytopathological aspects of closed irrigation systems

European and in particular German growers have to struggle with environmental programs, public concern, drastical decrease in the number of available pesticides and high costs for manpower and energy. Some of these problems may be solved by soilless cultivation and/or recirculating irrigation systems. For pot plant cultivation closed subirrigation systems (troughs, flooding benches) are widely used in European greenhouses. In Germany in an increasing extent also for the outdoor production of pot plants and woody container plants. As far as soilless cultivation is concerned open system are still predominant in cut flower and stock plant production. The hesitant introduction of soilless, closed irrigation systems may be due to high investments and growers fear of spreading diseases. A closed irrigation system is defined as one in which losses of water, nutrients and pesticides are widely avoided thus preventing pollution of soil or ground water. Depending on the path of water movement, recirculating irrigation systems can be classified as demonstrated in figure 1 (Molitor and Wohanka, 1992). Case A describes systems in which nutrient solution is applied to the top and drain water is collected after passing through the roots and the substrate, e. g. rockwool culture with trickle irrigation. Case B demonstrates subirrigation systems in which the nutrient solution is applied to the bottom and soaks up into the root zone while the rest of the nutrient solution remains in the circulating system, e. g. subirrigation with pot plants. Case C represents substrate free cultivation such as NFT, plant plane hydrponic or aeroponics in which the bare root system is continually in contact with the circulating solution. The risk of disease dispersal depends to great extent on the type of irrigation system and on the water movement is the root zone in particular.

Handling and planting methods influence field performance of red pine ten years after planting

In 1976 several plantings were established to compare the post-planting performance of 3 + 0 Red pine (Pinus resinosa Ait.) bare root stock planted by operational planting crews with those planted by research planting crews. Ten-year results show that field performance is directly influenced by the handling and planting methods employed by the two groups. Extra care in the handling and planting of bare root stock by research crews has led to improved survival, total height and diameter growth, resulting in a 27% overall increase in basal area. Key words: Red pine, handling and planting, plantation assessment, survival, total height, diameter and basal area

FERTILIZATION OF TWO WOODY SPECIES WITH FISH HYDROLYZATE FERTILIZER

The effect of a fish hydrolyzate fertilizer product on growth of Acer rubrum and Pseudotsuga menzeisii was studied. Bare root plants were fertilized at a rate of 90, 180, and 270 kilograms of N/hectare. Soil samples were collected every two weeks throughout the summer and were analyzed for nutrient content. In addition, August leaf samples were collected and analyzed for N, P, and K content. Growth measurements on Acer rubrum indicate that stem caliper was significantly increased by all fertilizer treatments over the control trees. The granular fertilizer produced a significant linear increase in caliper growth with respect to fertilizer rate. Shoot growth was also significantly increased by all fertilizer treatments; however, as with caliper growth, the granular fertilizer treatments resulted in the greatest and most consistent response. The response of Pseudotsuga menzeisii showed significant increases in shoot growth and stem caliper but results were not as consistent as in the case of the maple.

Functional growth analysis of conifer seedling responses to competing vegetation

A modification of functional growth analysis is proposed for investigating the responses of conifer seedlings to vegetative competition. The approach permits detailed comparisons of the absolute growth and relative growth rate with respect to competition level between crop species and between stock types. In this study, jack pine (Pinus banksiana Lamb.) demonstrated greater height and diameter growth than black spruce (Picea mariana (Mill.) B.S.P.) across the range of competition. However, competition had a larger negative impact on relative growth rate for jack pine. The absolute growth and relative growth rate were greater for bare root stock than for container stock, indicating that the effects of initial size differences between the stock types remained four years after planting. In all cases, the negative effect on seedling growth of each unit of competition diminished as the competition intensity increased.A practical application of functional growth analysis is suggested to assist free-to-grow assessments in plantations. The underlying functions would be developed separately for each ecological site type encountered, and would use root collar diameter increment to assess seedling potential. With the functions entered into a programmable calculator, field crews could rapidly obtain the required competition measurements, apply the functions, and make tending decisions. Key words: Relative growth rate, competition threshold, vegetation management, free-to-grow, plantation, tending, weeding, black spruce, jack pine

LATE PLANTING OF STRAWBERRIES IN THE HILL SYSTEM USING PLUG OR DORMANT BARE ROOT PLANTS

Plug or bare root strawberry plants were planted on raised beds with black plastic mulch from mid-June to early-August. The early plantings gave the most developped and productive plants but these required several derunnerings to avoid overcrowding. Due to the unavailability of runners, it was not possible to establish plug plants before mid-July. Field losses of dormant bare root plants were high for the July planting. The use of a perforated polyethylene rowcover from October to May increased yield and fruit size.

The use of fertilizer to enhance growth of transplanted seagrasses Zostera marina L. and Halodule wrightii Aschers

The effect of two slow release fertilizers on the survival and growth of transplants of two seagrasses, Zostera marina L. and Halodule wrightii Aschers was examined. The two fertilizers, an unbalanced nitrogen, phosphorus, and potassium formulation (18-0-0) and a balanced (14-14-14) formulation, were applied to bare root transplant units (PU) of each seagrass at three doses, 10, 90, and 170 g per PU. Survival and growth of the transplants, nutrient release from the fertilizers, and several environmental characteristics of the study sites were examined. Nitrogen enrichment vegetative reproduction, the rate of area covered and leaf growth in a fall transplant of Z. marina, but only moderately stimulated growth in the spring, confirming that nitrogen may limit the rate of development of newly established populations of Z. marina. There was no effect of nitrogen on survival of Z. marina nor on the growth and survival of H. wrightit transplants. No phosphorus was released from the balanced fertilizers in the spring and fall experiments and no nitrogen was released from the unbalanced formulation in the spring Z. marina experiment. Therefore, it was not possible to examine the effect of nitrogen and phosphorus interactions on plant growth and vegetative reproduction. Nitrogen enrichment may be used to stimulate shoot growth of Z. marina transplants, and we suggest alternative procedures of fertilizer application to overcome problems of nutrient release.

Product and Service Attributes Related to Marketing Nursery Stock

Survey data from 3 11 garden centers, landscapers, and combined garden center/landscaping firms in selected western United States trade centers were analyzed. Results identified important product and service attributes used in respondent decisions to purchase nursery stock. In general, product characteristics were ranked higher than supplier services. The highest-ranked product characteristics included plants free of insects and disease, properly dug and handled container or balled and burlapped stock, properly dug and handled bare root stock, and plants available when needed. However, several additional product characteristics received high rankings. The highest-ranked service was supplier knowledgeable about plant materials. A χ2 analysis was conducted to segment this market on the basis of firm size, business type, and geographic location. Results indicated there were limited between-group differences to use in segmenting the market on the basis of size, business type, or location.

IMPORTING PLANT GERMPLASM INTO THE UNITED STATES

International plant germplasm resources are an invaluable source of information, and bringing viable plant materials into the United States is a necessity for many researchers. Quarantine regulations vary based on the plant pests and pathogens occurring in the country of origin to prevent the introduction of injurious plant pests and diseases. These regulations also depend on the type of germplasm (such as live plant, cuttings, or seeds), size and age of specimen, and the media grown in. Plants in soil are prohibited, while those in agar, or bare root may be allowed to enter. Procedures to follow for bringing plant germplasm of international origin (including CITES species), forms and permits, ports of entry, delays to expect or avoid along with other information on successfully bringing plant germplasm resources into the United States will be discussed.

The Effects of Cold Storage and Dormant Pruning on Growth of Radiant Crabapple

The effects of different durations of cold storage and bare root pruning treatments on two-year-old Radiant crabapple (Malus 'Radiant') were examined for one to three growing seasons after planting. Six pruning treatments, applied by length, were as follow: 1) 50% top (shoot) removal, 2) 30% root removal, 3) 60% root removal, 4) 50% top and 30% root removal, 5) 50% top and 60% root removal and 6) control (no pruning). Planting dates of March 15 and May 1, 1987 were selected to allow a six week difference in cold storage and planting dates. Leaf area, shoot regrowth, new root dry weights, total plant dry weights, leaf :new root ratios and total shoot:root ratios were determined. Virtually no statistically significant differences between treatments were noted until the third year. Shoot regrowth was then significantly greater for the 50% shoot pruning treatment than for all other treatments. Overall, this research indicated that the various pruning treatments applied to the roots or shoots of Radiant crabapple did not have major effects on their short or long term growth response.

Planting survival of selected street tree taxa: R. H. Miller & R. W. Miller, Journal of Arboriculture, 17(7), 1991, pp 185–191

Planting survival of selected street tree taxa: R. H. Miller & R. W. Miller, Journal of Arboriculture, 17(7), 1991, pp 185–191

Root Rot ofBrachychiton populneusSeedlings Caused byLasiodiplodia theobromae

Lasiodiplodia theobromae was the causal agent in the death of several hundred 18-mo-old Australian bottle trees (Brachychiton populneus) at a nursery in southern California. Disease became apparent after the plants, which had been shipped bare root from Israel, were reported in California. The fungus infects the taproot, causing maceration and collapse of tissue and the eventual wilting and death of the plant (.)

MECHANICAL BUD DAMAGE TO BRANCHED AND UNBRANCHED `BRADFORD' PEAR TREES DURING POST HARVEST HANDLING

Branched (B) and unbranched (UB) one-year-old `Bradford'/`OHFx97' trees were examined at intervals between preparation for bare root harvest and long term storage to determine the extent of mechanical bud damage caused by the various handling steps. After hand stripping of leaves, digging, transportation to the storage facility, and grading, and tying of bundles, there was a marked difference in the percentage of damaged buds between branched (26%) and unbranched (53%) trees. The B/UB live bud ratio before and after harvest was 1:0.45 and 1:0.26, respectively. This difference may have been due to a various morphological growth pattern which both types of trees had produced.

Development of a competition index for young conifer plantations established on boreal mixedwood sites

A competition index was developed, and then used to examine the relationships between perennial competition and plantation performance. Species included were white spruce, black spruce, and jack pine for both over-wintered containers and bare root stock. A total of fifteen four-year-old plantations were used in this study representing a range of soil textures located on boreal mixedwood sites in northern Ontario.Effective canopy cover, derived from vertical hemispherical photographs taken at the base of seedling leaders, provided an accurate estimate of the perennial woody competition affecting seedling diameter growth. Initial seedling size, defined by the stem volume at time of planting, proved to be an important covariate in the analysis.Using the relationship between effective canopy cover and seedling root collar diameter, the following questions regarding vegetation control decision-making were addressed: 1) jack pine was more sensitive to increased levels of competition, 2) over-wintered container stock were more sensitive than their larger bare root counterparts, 3) minimal differences occurred in the pattern of growth response to competition across the range of soil textures studied, and 4) early tending treatments should be concentrated on jack pine plantations or on spruce plantations with an effective canopy cover in excess of 60. Key Words: competition index, hemispherical photographs, boreal plantations, white spruce, black spruce, jack pine, tending guidelines.

In-transit Neem Insecticide Treatment of Rooted Chrysanthemum Cuttings Controls Leafminer

Abstract Environmental concerns and disadvantages of synthetic insecticides have stimulated interest in natural chemicals derived from plants for insect control. Extracts from seeds of the neem tree (Azidirachta indica A. Juss) have attracted attention as an insecticide not only because of its broad spectrum action, but also because it has demonstrated uncommon safety to man and warm-blooded animals and the environment (Henkes, 1986). Furthermore, neem extract has been reported to act systemically to effectively control serpentine leafminer (Liromyza trifolii Burgess), a serious pest on ornamentals and vegetables due mainly to pesticide resistance (Larew et al., 1984; Lindquist et al., 1986; Stein and Parrella, 1985; Webb et al., 1983). Larew et al. (1984) demonstrated that neem soil drenches provided systemic control of L. trifolii for up to 3 weeks. Lindquist et al. (1986) investigated the use of neem insecticide (Margosan-O) as a preshipping crop treatment by soaking bare root cuttings in neem solutions. Their 2- to 4-hr soaks (3.0% Margosan-O) effectively controlled leafminers for 4 weeks. The objective of this study was to determine if a simple in-transit application method could provide control of serpentine leafminers on chrysanthemum.

Root System Configuration Affects Transplanting of Honeylocust and English Oak

Eight cm (approximately 3 inch) diameter Gleditsia triacanthos Inermis 'Imperial', Imperial honeylocust, and Quercus robur, English oak, were spring dug bare root and root pruned to one of four root configurations, standard, wide-deep, narrow-deep or wide-shallow, to simulate different ball sizes and shapes had the plants been balled and burlaped. The plants were placed in a healing-in area. Survival, leaf and shoot growth were followed for 18 months. All 40 honeylocust trees survived transplanting while three English oaks died. Honeylocust trees given the narrow-deep and wide-shallow root configurations had larger leaves and longer lateral shoots 18 months after transplanting than trees given standard and wide-deep configurations. English oak trees given wide-deep and wide-shallow root configurations had more shoot and leaf growth than did trees given standard or narrow-deep configurations. English oak recovered from transplanting more rapidly than did honeylocust. For both species, shoot and leaf growth during 1 986 were not significantly correlated with shoot and leaf growth in 1987.

Puddled Soil and Rice Seedling Characteristics Affecting Rice Seedling Withdrawal Force

ABSTRACT THE effect of puddled soil and rice seedling characteristics on the rice seedling withdrawal force was determined in a laboratory study. Rice seedling withdrawal force is a good index of seedling anchorage in puddled soil. The goal of this study was to obtain fundamental information on rice seedling and puddled soil characteristics needed for the rational design and development of bare root rice transplanters. The seedling withdrawal force was found to increase with soil aging. The effect of planting speed (strain rate) was found inconsistent on the withdrawal force. A minimum of 3 days of puddled soil aging and rice seedlings with 2 cm root lengths were found necessary for evaluating the performance of a root washed paddy transplanter.

Bare Root Dip Treatment of Tomato Transplants with Paecilomyces lilacinus for the Control of Meloidogyne incognita

Results on the evaluation of bare root dip treatment of tomato seedlings in a spore suspension of Paecilomycis lilacinus for the control of Meloidogyne incognita is reported in this paper.

Inhibitory Effects of Two Organocarbamates Nematocides on Growth and Yield of Capsicum annuum, NP 46A, and Their Reversion by Gibberellic Acid

Summary Results have shown that two nematocides aldicarb and carbofuran at all the concentrations were inhibitory to the plant growth as well as for seed germination in Capsicum annuum. But the extent of toxicity was very low when applied as bare root dip treatment at lower concentrations (1-2 · 106ppm). Results on the effect od GA3 alone showed that 100ppm of GA3 was the optimum concentration for plant growth and seed germination. A combination of 100ppm of GA3 with graded concentrations (1-10 · 106 ppm) of aldicarb and carbofuran could reverse the inhibitory effects of both the nematocides on chilli plant. However, higher dosages of nematocides were able to nullify the stimulatory effect of GA3. An analysis of residual nematocides in plants after treating with graded concentration of nematocides indicated a linear increase in the amount of toxic residues as the concentration of nematocides was increased. But application of an optimum concentration of GA3 (100 ppm) along with graded concentration of nematocide (1-10 · 106 ppm) could significantly reduce the level of toxic residues in plants. thus, the results showed an antagonistic nature of GA3 against nematocide toxicity which might base upon its property to prevent the accumulation of toxic residues of nematocides in plants.