in Florida uses bare-root transplants, with three to four intact leaves ( Bish et al., 2002 ), which are established by overhead irrigation during daylight hours for up to 10 d. Bare-root transplants for Florida are usually grown in southern Canada
Emmanuel A. Torres-Quezada, Lincoln Zotarelli, Vance M. Whitaker, Bielinski M. Santos and Ixchel Hernandez-Ochoa
Commercially produced bare-root onion (Allium cepa L.) transplants may not be uniform in size and require a period following planting in which to begin regrowth. There is little information on how, when established in the field, plants developed from greenhouse grown onion transplants differ from those that develop from bare-root transplants. Development and yield for onions grown from bare-root transplants were compared to plants produced from transplants grown in single cells with volumes of 36 or 58 cm3 in seedling production trays in a greenhouse. `Texas Grano 1015Y' and `Walla Walla' onions were established in the field with commercially available bare-root transplants or with greenhouse grown transplants produced in trays. Bare-root transplants were heavier than 8-week-old greenhouse grown transplants. Fresh weights of transplants produced in 58-cm3 cells were heavier than those from 36-cm3 cells, but dry weights were similar. From when about 20% of onion tops were broken over, onion bulb diameters did not increase sufficiently to justify delaying harvest until 50% of tops had broken over. Yields of `Walla Walla' were better than those of `Texas 1015 Y' and yields from plants developed from seedlings grown in 58-cm3 cells were similar to those from plants developed from bare-root transplants and better than those from plants developed from seedlings grown in 36-cm3 cells. Individual bulb weights of `Texas 1015 Y' were not affected by transplant type and averaged 162 g. Individual bulbs for `Walla Walla' from plants developed from bare-root transplants and those produced in 58-cm3 cells were similar in weight (averaged 300 g) and were heavier than those from plants developed from transplants grown in 36-cm3 cells (240 g). Greenhouse transplants produced in trays with the larger cells may provide an alternative to the use of bare-root transplants, if transplant production costs are comparable.
James P. Gilreath, Bielinski M. Santos, Joseph W. Noling, Salvadore J. Locascio, Donald W. Dickson, Erin N. Rosskopf and Steven M. Olson
Field studies were conducted in three Florida locations (Bradenton, Gainesville, and Quincy) during 1998-99 and 1999-2000 to: 1) compare the performance of two transplant systems under diverse MBr alternative programs in `Chandler' strawberry (Fragaria ×ananassa), and 2) determine the efficacy of these treatments on soilborne pest control in strawberry. Fumigant treatments were: 1) nonfumigated control, 2) methyl bromide plus chloropicrin (MBr + Pic) at a rate of 350 lb/acre, 3) Pic at 300 lb/acre and napropamide at 4 lb/acre, 4) 1,3-dichloropropene (1,3-D) plus Pic at 35 gal/acre and napropamide at 4 lb/acre, 5) metam sodium (MNa) at 60 gal/acre and napropamide at 4 lb/acre, and 6) MNa followed by 1,3-D at 60 and 12 gal/acre and napropamide at 4 lb/acre, respectively. Strawberry transplants were either bare-root or containerized plugs. There were no significant fumigant by transplant type interactions for strawberry plant vigor and root weight per plant, whereas ring nematode (Criconema spp.) and nutsedge (Cyperus rotundus and C. esculentus) populations, and total marketable fruit weight were only infl uenced by fumigant application. The nonfumigated plots had the lowest strawberry plant vigor and root weight per plant in all three locations. In most cases, plant vigor and root biomass per plant increased as a response to any fumigant application. With regard to the transplant type, bare-root transplants had similar plant vigor as plugs in two of the three locations. Fumigation improved nutsedge and ring nematode control. All fumigants had higher early and total marketable yield than the nonfumigated control, whereas transplant type had no effect on total fruit weight.
John R. Duval and Elizabeth Golden
Emmanuel A. Torres-Quezada, Lincoln Zotarelli, Vance M. Whitaker, Rebecca L. Darnell, Bielinski M. Santos and Kelly T. Morgan
dissemination and leaching nutrients out of the rooting zone ( Bish et al., 1997 ; Hochmuth et al., 2006b ). Lack of uniformity of bare-root transplants combined with plant damage created by sprinkler irrigation can contribute to reduction of early yield ( Bish
Michael A. Arnold and W. Edgar Davis
Growth and post-transplant establishment of half-sib seedlings from two elite sycamore (Platanus occidentalis L.) mother trees (Westvaco Corp.) and seedlings from a bulk seed lot from elite sweetgum (Liquidambar styraciflua L.) trees (Scott Paper Co.) were compared to that of seedlings from a native (Cookeville, TN) sycamore tree and a commercial source of sweetgum seeds. Seedlings were grown under standard field nursery conditions for two years, dug hare-root in autumn, and transplanted to another site to simulate landscape planting. Growth of elite seedlings during production was increased by 11 to 22% in height and 10 to 118 in caliper compared to that of conventional seed sources. Growth differences were maintained following transplanting. The primary lateral root number at transplanting was increased by 2 to 3 on elite sycamore seedlings compared to conventional seedlings. The number of pruning cuts required to eliminate multiple leaders tended to be less for elite seed sources. Survival did not differ among seed sources within a species.
Monika Walter, Cath Snelling, Kirsty S.H. Boyd-Wilson, Geoff I. Langford and Graeme Williams
System requirements for organic strawberry (Fragaria × ananassa) runner production under cover were determined during the 2001-02 and 2002-03 seasons. In the field, yield and fruit quality were assessed for organically produced runners (plug and bare-rooted transplant) in comparison with barerooted conventionally produced runners under organic, BioGro certified production conditions. The preferred organic production system was the enhanced suspended system, where mother plants grew on benches in the tunnel house and the first two runners were potted into growth substrate. This system produced approximately 50 plug transplants/mother plant or 200 plug transplants/m2. The least preferred system was the nursery bed, where mother plants were allowed to produce runners that yielded approximately 100 bare-rooted runners or 100 transplants/m2. Tunnel house production of runners (plug transplants and bare-rooted) allowed earlier planting (March vs. May) compared to field-produced bare-rooted runner plants. The earlier planting date increased yield by approximately 181 g/plant. Under organic production conditions, organically produced runners (plug and bare-rooted transplants) performed at least as well as bare-rooted conventionally produced runners. Our results show that indoor production of organic strawberry runners is possible. We also showed that organically produced runners (bare-rooted and plug transplants) perform similarly in the field compared to bare-rooted conventionally produced runners. Generally, there were no differences in yield or fruit quality among runner sources.
Eric B. Bish, Daniel J. Cantliffe and Craig K. Chandler
Containerized strawberry transplants offer an alternative to problematic bare-root transplants, which often have variability in flowering and vegetative vigor. Containerized transplants were propagated in three different container cell sizes (75, 150, and 300 cm3) and grown at two different temperature regimes for 2 weeks prior to planting (25/15 and 35/25°C day/night). Bare-root transplants from Massachusetts and Florida were graded into small, medium, and large plants based on crown size (8, 12, and 16 mm respectively). Plug transplants grown at 25/15°C had greater root dry weights than transplants grown at 35/25°C. Root imaging analysis (MacRHIZO) showed that the differences in dry weight were due to root area, not root tissue density. Crown dry weight increased with increasing cell size. Plug transplants grown at 25/15°C flowered earlier and had greater production than any other treatment. The 75 cm3 cell size grown at 35/25°C produced greater December strawberry production than larger cell sizes at the same temperature regime; however, the 75 cm3 cell size had decreased January strawberry production while the larger cell sizes had increased production. Larger plug cell sizes had significantly greater production than smaller plugs throughout the season, whereas larger bare-roots had greater production only early in the season. Containerized plug transplants therefore offers a viable alternative to problematic bare-root transplants.
John R. Duval*, Elizabeth Golden, Julia Reekie and Peter Hicklenton
Bare-root transplants received from high latitude nurseries for Florida production have limited root systems, very long petioles and wilt soon after planting. Further dessication occurs when leaves come in contact with black plastic mulch used in the annual production system. Conventional irrigation practices for the establishment of bare-root transplants of strawberry consist of overhead water application for at least 8 hours/day for 10-14 days after planting. Plant growth regulators (PGRs) have been used to modify the growth characteristics of many plants species. A split-block experiment was implemented at the GCREC-Dover, Dover Fla., to determine the effect of the use Prohexidione-Ca (PC) and IBA [(indole-3) butyric acid] on growth, yield and establishment of strawberry. Main blocks consisted of over head establishment irrigation for 4, 8, and 12 days, and sub-plots consisted of treatments of PC applied in the nursery at a rate of 62.5 mg·L-1 2, 4, or 6 weeks before digging, PC applied in the nursery at 31.25 mg·L-1 2 weeks before digging, a root dip of transplants in 100 mg·L-1 IBA just prior to transplanting. The experiment was conducted for four growing seasons. Data were recorded for marketable yield, number of marketable berries (>10g), and disease incidence. Significant differences were detected for duration of establishment irrigation and growth regulator treatment. No interaction was shown between establishment irrigation and growth regulator treatment.
George Hochmuth, Dan Cantliffe, Craig Chandler, Craig Stanley, Eric Bish, Eric Waldo, Dan Legard and John Duval
Experiments were conducted in two seasons in Dover, Fla. (central Florida), with bare-root and containerized (plug) strawberry (Fragaria ×ananassa) transplants to evaluate transplant establishment-period water use, plant growth, and flowering responses in the 3-week transplant establishment period. Strawberry plug plants were established with 290 gal/acre water applied only with the transplant at planting time, while 200,000 gal/acre from microjet or 1 million gal/acre of water from sprinkler irrigation were used to establish bare-root transplants. Root, shoot, and crown dry matter of plug plants rapidly increased during the establishment period, while there was a decline in leaf area and root and crown mass of bare-root plants, even with sprinkler or microjet irrigation. Water applied with the bare-root transplant only at planting was not enough to keep the plant alive during the establishment period. Large plug plants, but not irrigated bare-root plants, began flowering at 3 weeks after planting. Plug plants were used to successfully establish strawberry crops with low water inputs.