Runner Tips Research Articles

Plugging Date and Cold Storage Affect Strawberry Transplant Production and Performance in Annual Plasticulture

`Chandler' strawberry plants were propagated in tissue culture and grown from April to August in a protected environment to produce stolons. July-harvested daughter plants were stuck in cell packs with rooting media and placed under mist sprinklers, or cold stored at 2 °C for 42 days. Among the July transplants, some were kept in the greenhouse until field planting (14 Sept.) and others were moved into a cold room on 14 August. Daughter plant size and position on the stolon affected rooting and quality of transplants. July-harvested daughter plants that were plugged and misted after being cold stored for 42 days developed fewer roots than daughter plants plugged immediately after detaching from mother plants in July or August. In the field, transplants produced from daughter plants harvested in July and cold stored for 42 days developed more stolons than transplants from July- and August-harvested daughters that were not exposed to cold storage treatments. Larger daughter plants produced more branch crowns than did smaller daughter plants during the fall. All transplants from daughter plants harvested in July and propagated without cold treatment bloomed by November. Fruit production ranged from 521 to 703 g per plant. `Chandler' plants from daughter plants that weighed 10 g produced 10% greater yield than those that weighed <1.0 g. Plants generated from daughter plants plugged in July produced 26% more fruit than those plants plugged in August. Greenhouse soilless systems can be used to grow `Chandler' mother plants for generating runner tips and transplants for the annual plasticulture in colder climates. `Chandler' plants produced in July can yield a late fall crop under high tunnels and more fruit in the spring than August-plugged transplants

COMPARISON OF STRAWBERRY PLUGS FROM DORMANT PLANTS TO CANADIAN TIP CUTTINGS

New Jersey strawberry plantings on plastic mulch are normally planted with plug plants from Canadian tip culture in the month of September. In order to utilize new cultivars, we evaluated the technique of growing plug plants from dormant plants out of cold storage (28°C). These plants were dug in April and placed in storage until mid-July. The dormant plants were transplanted into a 36-cell tray containing a peat-lite mix and grown over the summer months outdoors in full sunlight. Blooms were removed from the dormant plugs twice during August before planting. Runner tips from Canada were grown in a 50-cell tray containing a peat-lite mix during August in a nearby greenhouse and set out on September 9 in the field alongside the dormant plug plants in a randomized block design. The cultivars Chandler, Northeastern, Seneca, and Sweet Charlie were included in this study. Marketable yield of the dormant plants was 12579 kg/ha as compared to 15015 kg/ha from the Canadian tip plugs. Fruit size was 17.2 g/berry for the dormant plugs vs. 17.6 g/berry for the tip cuttings. Chandler remains the standard cultivar for commercial growers in New Jersey.

Produção de frutos e estolhos do morangueiro em diferentes sistemas de cultivo em ambiente protegido

Este trabalho teve por objetivo comparar a produção de frutos e de estolhos do morangueiro (Fragariaxananassa Duch.) cv. Campinas IAC-2712, em função de três sistemas de condução em ambiente protegido (solo, hidropônico-NFT e hidroponia em casca de arroz carbonizada em colunas verticais). O experimento foi realizado no período de junho de 2000 a fevereiro de 2001, na Estação Experimental de Agronomia de Jundiaí (latitude: 23:06'S, longitude: 46:55'W, altitude média: 715 m, clima Cwa), do Instituto Agronômico, seguindo-se o delineamento de parcelas subdivididas com três repetições, em casa de vegetação modelo semi-arco com abertura zenital superior. Nos dois sistemas hidropônicos foram usadas duas composições de soluções nutritivas, respectivamente, para a fase de crescimento vegetativo e para a produção de frutos. Os resultados obtidos permitiram concluir que no sistema vertical, embora as produções de frutos e de estolhos por planta tenham sido menores que nos demais sistemas estudados, há possibilidade de melhor aproveitamento interno do ambiente protegido, com reflexos positivos no aumento do rendimento por área e maior facilidade de manejo da cultura, incluindo as operações de transplante, limpeza das plantas e colheitas de frutos e remoção de estolhos. Essas vantagens também se aplicam ao sistema hidropônico-NFT mesmo não tendo apresentado diferenças de produção em relação ao cultivo convencional.

326 High Root-zone Temperature Inhibits Strawberry Reproductive and Vegetative Growth and Development

High temperatures are reported to promote day-neutral strawberry (Fragaria ×ananassa) vegetative growth and development and inhibit floral and fruit development, thereby imposing geographic and temporal limitations on fruit production. Day-neutral strawberry response to air temperature has been researched, but specific responses to temperature in the root zone have not. In a 1998 greenhouse experiment, 60 `Tristar' plants were grown hydroponically in a system of individual, temperature-controlled pots. A randomized complete-block design with constant root-zone treatments of 11, 17, 23, 29, and 35 °C and 12 replications were used. Stomatal conductance and transpiration rate were significantly lower for plants at 35 °C, compared with plants at all other temperatures. Leaf area and leaf dry mass of plants at 35 °C were five and four times smaller, respectively, than the combined mean for plants in all other treatments. Leaf area of runner tips was 450 and 44.5 cm2 at 11 and 35 °C, respectively, compared with that of plants at all other temperatures, 1552.1 cm2. Fruit dry mass was 14.5, 21.6, 25.5, 29.0, and 3.96 g per plant at 11, 17, 23, 29, and 35 °C, respectively. Root dry mass was highest at 11 and 17 °C and lowest for plants at 35 °C. The number of flowers, fruit, and inflorescences per plant was reduced at 35 °C, as were individual berry fresh mass and diameter. Overall, `Tristar' growth and development were near optimal at 17, 23, and 29 °C.

Herbicide Tolerance Of Transgenic `Stevens' Cranberry Plants Depends on the Test Environment

`Stevens' cranberry was genetically engineered to confer tolerance to the broad spectrum herbicide glufosinate. Initially, herbicide tolerance was verified by spraying greenhouse plants with the commercial formulation Liberty. Although one transformant showed significant tolerance, the tolerance level was below that required to kill goldenrod, a common weed of cranberry beds. This transformant was propagated and the plants established outdoors in a coldframe, yielding a growth form more typical of field-grown plants than that of greenhouse-grown plants. These plants, as well as untransformed cranberry and goldenrod plants, were sprayed with various levels of the herbicide. The transformed plants were not killed at glufosinate concentrations up to 1000 ppm, although delayed growth did occur. Some runner tip injury was observed at 500 ppm as well as widespread shoot tip death at higher levels. The above-ground parts of goldenrod plants were killed at 400 ppm with significant injury at 200 ppm. Untransformed cranberry plants were killed at 300 ppm and had extensive tip death even at 100 ppm. Transformed cranberry plants with confirmed “field” tolerance were re-established in the greenhouse and new vegetative growth was forced. When these plants were sprayed with glufosinate, significant shoot tip injury was observed at levels as low as 100 ppm. The degree of herbicide tolerance of transformed cranberry appears to be modulated by the growth environment, which may affect the expression of the inserted genes or the physiological sensitivity of the impacted tissues.

Factors Influencing Strawberry Plug Plant Performance

Three studies evaluating production of strawberry (Fragaria × ananassa Duch.) plug plants were conducted. The influence of runner tip plantlet size, container size, and chilling on the field performance of `Chandler' plug plants were evaluated over a 2-year period in central and southern Alabama. Plantlet size did not significantly influence yield following transplanting; therefore, grading of plantlets prior to propagation appears to be an unnecessary expense for successful yields from plug plants. There were no significant differences in yields of plug plants from 60-cell vs. 72-cell packs; therefore, growers could produce more plug plants in the same area without compromising total yield, early yield, or berry size when propagating plug plants in 72-cell packs. The influence of 1, 2 or 3 months of runner tip cold storage prior to rooting in cell packs was also investigated.

168 EFFECT OF PLANTING DATE AND ROW COVER UTILIZATION ON YIELD OF `CHANDLER' IN A HIGH-DENSITY ANNUAL SYSTEM

An RCB (4 replicates - 4 m plots) planting of `Chandler' was established to test the effects of planting date and floating row covers (FRC) in a high density strawberry planting system under NJ conditions. Transplant “plugs” from runner tips were planted on a double row (0.5 m × 0.3 m) on a raised plastic mulch bed (1.5 m centers), with trickle irrigation. Treatments included: plant 9/18/91 w/FRC on 10/7/92; plant 9/18/91 w/FRC on 12/2/92; plant 9/18/91 w/noFRC; plant 10/7/91 w/noFRC; plant 9/14/92 w/FRC on 10/7/92; plant 9/14/92 w/noFRC. In 1992, `Chandler' yield increased with earlier planting date and earlier FRC application (range: 8,600 to 13,400 kg/ha). There were no significant differences in cull or fruit weight. In 1993, there were no significant differences in 2nd year yield for 1991 treatments (range: 19,198 to 20,531 kg/ha). However, the 1992 treatments again showed the benefit of FRC (range: 13,437 to 20,531 kg/ha) for improved first year production. One year old plots had significantly larger average fruit weight than two year plots (range: 10.3 to 13.7 g). Early planting date with early applied FRC was the best treatment, combining high yield and good fruit weight.

STRAWBERRY PERFORMANCE USING THE ANNUAL HILL PLASTICULTURE SYSTEM IN ALABAMA

A number of strawberry cultivars and breeding line selections have been tested in the annual plasticulture system. The only two cultivars currently recommended based on cultural and economic performance ate 'Chandler' and 'Oso Grande'. Plant type (fresh dug, plug, etc.) and nursery source have also been evaluated. Fresh dug plants with leaves intact generally perform better than those with leaves removed. Rooted runner tips in cell packs (plug plants) look very promising and outperform fresh dug plants in most situations. Plastic mulch treatments included clear (CLR), black (BLK), laminated white on black (W/B), laminated black on white (B/W), IRT-76 (IRT), AL-OR brown (ALOR), and a bare ground (BG) check. In the first season the highest yields for 'Chandler' were obtained on IRT, followed by CLR, ALOR, B/W, BLK, W/B, and BG. The highest yields for 'Selva' were on CLR followed by BLK, ALOR, IRT, B/W, W/B, and BG. In the second season the highest yields for 'Chandler' were on W/B followed by BLK. ALOR, IRT, B/W, CLR, and BG. In the case of 'Selva' ALOR was the top performing treatment followed by IRT, W/B, BLK, B/W, BG, and CLR.

EFFECT OF PLANT SPACING AND PLANTING DATE ON YIELD OF ANNUAL STRAWBERRY SYSTEM IN NEW JERSEY

High density strawberry planting systems have increased yield and fruit quality, and allow greater production on small acreage. To adapt the system to New Jersey conditions, replicated plantings of `Chandler', `Tribute', and `Tristar' were established at 3 spacings and two planting dates (9/9, 9/15) in 1989, and two plant spacings and two planting dates (8/14, 9/7) in 1990. Plants were propagated as plugs from runner tips. The plantings were covered with floating row covers (polypropylene) in December, covers were removed in early April at 5% bloom. In 1990, `Chandler' yield increased as density increased, and decreased with later planting date. Fruit quality was very good; saleable % was over 90%. Size ranged from 8 to 21 g., and averaged from 12 to 17 g. for the various treatments. `Tribute' responded similar to `Chandler' but `Tristar' yield at 12″ was not significantly different than 6″, but greater than 9″. Size ranged from 9 to 19 g., and averaged from 10 to 14 g.; saleable % was over 85%. In 1991, 2 spacings (6″, 12″) and 2 planting dates (8/24, 9/7) were tested. The earlier planting date was superior to later; yields were not different between the 6″ and 12″ treatments (yield range: 3.8-5.4 T/A). Size was superior at wider spacing; day-neutral fruit size was small (avg fruit size range: 7.7-11.2g; high range: 10.1-17.4g).

The effect of temperature, daylength and irradiance on the growth of mother plants of Nephrolepis exaltata (L.) Schott and on the subsequent growth in vitro of runner tip explants

Plants of Nephrolepis exaltata cultivar ‘Bostoniensis’ were grown at different temperatures, both constant and fluctuating day/night temperature, at long or short days, and at different irradiances. At the lowest temperature, constant 15°C, the growth of the plants stagnated and death occurred after 4 months of exposure. The best growth was obtained at the highest temperature, constant 27°C. At this temperature, the highest number of explants (runner tips) for in vitro culture was obtained and the plants produced had the most vigorous growth. At 18°C, the mother plants produced runners which gave slightly more shoots in vitro than when mother plants were held at 27°C. However, this was more than compensated for by the higher number of runners produced at 27 than at 18°C. Increased light level caused an increase in plant growth and runner production. The highest mother plant irradiances (120 μmol m −2 s −1) gave a high number of shoots in vitro. Daylength affected plant shape. In short days, plants became flat shaped, in long days growth was more upright. Runner tips from plants in long days gave significantly more shoots in vitro than runners from plants in short days.

TISSUE CULTURE PRODUCED STRAWBERRY PLANTS ARE DEFICIENT IN ABSCISIC ACID (ABA).

In previous abstracts (HortScience 23:707;24:121), ABA when added throughout the in vitro production cycle, reversed the tissue culture-induced rejuvenation of the day neutral strawberry `Fern'. Compared to benzyl adenine (BA) proliferated plants, ABA treated tissue culture-produced plants flowered earlier and had more adult leaf patterns. In the present study, we analysed endogenous ABA concentrations in the apices and unexpanded leaves of BA treated tissue culture-propagated plants, selved seedlings and propagated adult runner tip plants at 3, 7 and 15 weeks ex vitro, after germination or after runner tip propagation. Using pentadeuterated standards and single ion monitoring, ABA concentrations in tissue culture produced and juvenile seedling plants were significantly lower than adult plants at 3 and 7 weeks. By 7 weeks, only the adult plants were flowering. At 15 weeks, no differences in ABA concentration were significant and all three types flowered.

An approach to performance improvement of existing Kaplan turbines with runner updating.

Flow analyses which were performed to design a new runner for upgrading existing Kaplan turbines are presented. The reliability of quasi-three dimensional flow analysis is confirmed by comparison with the measured flow pattern using a two focus laser velocimeter. Then the flow distribution at the runner inlet is investigated numerically at the best efficiency point and at the full load point. The strong effect of flow distortion due to the curvature of the meridional flow channel are discussed. The design concepts of a new runner adaptable to the existing turbines are presented and indicate that the new runner should generate the pertinent swirl flow to the existing draft tube and that the leakage through the runner tip clearance should be decreased. The performance of the new runner designed with the concept concerned is shown to be a great improvement on the existing one.

In vitro propagation of Nephrolepis cordifolia Prsel

Rapid propagation of Nephrolepis cordifolia was achieved by means of runner tip culture in vitro. Runner tips produced green globular bodies (GGB) when quarter-strength Murashige and Skoog medium supplemented with 0.5 mg 1 −1 of benzylaminopurine (BA) was used. GGB easily regenerated plantlets by culturing on BA-free medium, and GGB were rapidly multiplied on BA medium. The multiplication rates were 4–41 times per month expressed as increment of fresh weight, depending on the size of the segment for sub-culture. Consequently, using GGB for the multiplication stage, 160 000 plantlets could be obtained from one runner tip in 6 months.

Histogenic Instability in Tissue Culture-proliferated Strawberry Plants

Abstract A phenotypic and sexual analysis of Fragaria vesca ‘Albo-Marginata’ determined that the leaf variegation was of chimeral origin. Stable periclinal chimeras were established in vitro from runner tips. Plants were transferred to proliferation media containing 0.5 μm IBA, 0.3 μm GA3, and BA at either 0, 1.3, 4.4, or 13.2 μm. Whereas the histogens of field-grown runner plants remained stable, more than 90% of the plantlets propagated in vitro varied from the original explants. Most variants were albino or were green, but some were mericlinal chimeras. Histological evidence indicated that many shoots were adventitious, arising from basal callus tissue or petioles. Chemical names used: 1H-indole-3-butanoic acid (IBA); gibberellic acid (GA3); N-(phenylmethyl)-1H-purin-6-amine (BA).

Recherche expérimentale et numérique sur le comportement d'une roue réversible au point de tracé

Object of this paper is the comparison of actual flow configurations in a turbomachine with flow configurations estimated by numerical procedures. Blade-to-blade solutions of the differential equation of motion are generally referred to an isolated runner, and in fixing the boundary conditions at the impeller periphery the influence of the casing or of the stationary system is completely disregarded. While this may be acceptable for centripetal turbine runners, it gives unsatisfactory results in pumps and compressors, where flow pattern at the runner outlet changes considerably with the discharge rate because of the influence of the volute and/or the diffuser. The present investigation has been conducted on a model reversible pump-turbine stage fitted with a fully bladed diffuser-conveyor. The runner tip clearance has been traversed in pump operation in order to examine the distorsion of the flow induced by the stationary system. The averaged values of flow angle, velocity and total pressure better agreed with theoretical estimates only at the matching point of runner and diffuser, which occurred at a discharge different from the b.e.p. rate. At lower or higher rates the averaged value of the meridional component of the absolute velocity differed considerably from actual through-flow. And also, the runner input head obtained from the averaged values of the tangential component of the velocity , which on account of the impeller losses was expected to be always greater than the total head rise through the runner, appeared to be smaller than the latter at flows below the design rate and greater at higher flows. The discrepancies have been ascribed to the interaction of runner and stationary vanes, which distorted the flowlines in the clearance annulus. It is also shown that fewer interference problems are present in turbine operation. The stationary vanes were then removed from the diffuser channel so as to obtain an unobstructed annulus where freeflow conditions would set up comparable to those existing outside an isolated runner. Flow measurements showed now better consistency with theoretical estimates. It could also be appreciated that the ratio of slip velocity to runner tangential velocity did not change appreciably with the rate of flow. Axial distribution of velocity and pressure in the clearance annulus was also considerably affected by the presence of the diffuser vanes. Known numerical solutions of the equation of motion may yield satisfactory results provided no external action is exerted on the runner flow other than the pressure forces exchanged by the runner itself. For pump runner with volute or vaned diffuser casing, the boundaryconditions at the impeller exit should be defined by an equation expressing the distorting effects of the stationary system on the flow.

The Use of an Agar Substitute in the Initial Growth of Boston Ferns in Vitro1

Abstract There was no significant difference in growth (fresh weight) of runner tips of Nephrolepis exaltata (L.) Schott var. bostoniensis Davenport cultured on a modified Murashige and Skoog medium solidified by either agar or a new starch co-polymer agar substitute. The agar substitute requires no boiling to dissolve and appears to promote more shoot initiation than agar solidified medium.

Soil Moisture Effects on the Rooting and Early Development of Strawberry Runners1

Abstract The rooting of strawberry runner tips was studied in relation to soil moisture tension in the rooting medium and soil moisture supplies to the mother plants. In the first weeks of runner establishment the rate and amount of top growth was controlled largely by the moisture supply to the mother plant. Growth was decreased as moisture stress on the mother plant was increased. For the most part, root habit of the runner was independent of influence from the mother plant. Variations in soil moisture tension in the rooting medium had little influence on top growth of the runner except for leaf area but did influence root growth significantly. Secondary root growth was restricted by both very wet and very dry soil conditions. The results confirmed that the initial number of main roots formed and their penetration was independent of moisture tension in the rooting medium. Organic matter additions to the rooting medium did not influence moisture effects appreciably.

STUDIES OF VIRUS DISEASES OF STRAWBERRIES IN BRITISH COLUMBIA: I. THE REACTION OF THE BRITISH SOVEREIGN VARIETY AND THE INDICATOR FRAGARIA VESCA TO YELLOWS

British Sovereign, the commercial strawberry variety of British Columbia, has shown no field evidence of degeneration from the virus disease, yellows, that is attacking the Marshall variety in the Pacific Northwest. However, experimental inoculation of British Sovereign by stolon grafting to a yellows-infected Marshall plant proved the British Sovereign to be susceptible to yellows. As with the Marshall, infected plants were reduced in size and the foliage tended to flatten towards the grounds but, unlike the Marshall, there was no pronounced yellowing. When Fragaria vesca was grafted to a yellows-infected Marshall plant the reaction was rapid and severe. The older leaves flattened to the ground, the young runner tips hooked back, the newly developing leaves, though relatively well proportioned, were minute and yellow at the margins, and the plants eventually died.

SECTORIAL POLYPLOIDY AND PHYLLOTAXY IN THE CRANBERRY (VACCINIUM MACROCARPON AIT.)

INTRODUCTION.-DERMEN AND Bain (1944) reported that colchicine treatments applied to runner tips or to meristematic lateral buds of the cranberry resulted in the development of polyploid stem sectors much more frequently than in the development of completely polyploid stems. Stem sectors were utilized as sources of completely polyploid material, however, by forcing lateral buds located on the sectors to develop into branches. The presence of sectors was indicated by the simultaneous occurrence of diploid and polyploid types of leaves on the treated branches. The order in which the two types of leaves alternated along the stems was obviously controlled by the interaction between width of the sector and phyllotaxy of the stem. The present paper reports an analysis of the mathematical and anatomical principles underlying the relations between sectors and phyllotaxy. CHARACTERISTICS OF SECTORS.-Sectors as a rule were either totally tetraploid, epidermally tetraploid, or internally tetraploid (Dermen and Bain, 1944), and were usually laid down continuously as long as the stem elongated. Narrow sectors occasionally disappeared completely, particularly after resumption of growth following a period of dormancy. In two instances epidermal and internal sectors occurred on opposite sides of the same runner stem. The most conspicuous feature of sector-bearing stems was the peculiar alternation of diploid and tetraploid leaves along the stems. To understand better the phenomenon of alternation, the stem may be visualized as a long slender cylinder having a br.oad strip, the sector, marked along one side, while the phyllotactic arrangement is thought of as a spiral line winding around the cylinder and bearing nodes at regular angular intervals. Tetraploid leaves would then appear at those node positions which happened to fall within the limits of the marked strip, and diploid leaves at all positions outside of it. But since cranberry runner leaves are spaced relatively far apart on very slender stems, the spiral arrangement of leaves is not readily apparent, the leaves instead appearing to follow one another in simple linear succession. In the linear direction, diploid leaf would succeed diploid leaf until the phyllotactic spiral crossed the tetraploid sector, when there would follow as many successive tetraploid leaves as there were adjacent nodes within its limits; after this, diploid leaves would again appear until the sector is reached once more. Thus as long