Studies were conducted in 1988 and 1989 to evaluate the influence of planting time and method on plant establishment and yield of fall broccoli. In 1988, plant establishment of direct-seeded broccoli was not improved with application of vermiculite (63 kg/ha). a cross-linked polyacrylamide polymer (17 kg/ha), or both as anti-crustants over the untreated check (37.6%, 32.2%, 24.6%, and 31% of target population, respectively). In 1989, transplants were compared with double-seeding (planting two seeds 25 mm apart). With seed. germination of 55% in the early planting (8 Aug.). plant populations of double-seeding and transplants were similar, but 42% germination of double-seeding in the late planting (28 Aug.) resulted in lower plant populations than from transplants. While yield reflected differences in plant populations, the percentage of marketable heads from transplants was significantly greater (90.6%) than from seedlings (78.9%). These data suggest that broccoli transplants are a viable option when high soil temperatures may be detrimental to seed germination.
S. B. Sterrett, C. P. Savage Jr., and K. M. McManus
Raul I. Cabrera and Diana Devereaux
Ilex opaca and Lagerstroemia indica plants were grown over 9 months using complete nutrient solutions differing in N concentration [(N)A: 15, 30, 60, 120, 210 and 300 mg·L–1]. Biomass production increased as (N)A were raised from 15 to 60 mg·L–1, but was depressed by higher concentrations. Increases in (N)A produced higher shoot: root ratios. Maximum leaf N concentration was observed at 60 mg·L–1, with similar values at higher (N)A. Plant survival, establishment and performance was evaluated over 15 weeks following transplant (15 WAT) to a landscape with minimum management conditions. Despite the initial significant differences in growth, shoot: root ratios and plant N status, plant establishment was not affected following transplant. Plant characteristics changed significantly over time, and by 15 WAT, all of the measured variables were statistically the same across all treatments. Flowering was, however, delayed over several weeks for Lagerstroemia indica plants grown at the higher (N)A. Analysis of these results indicate that plant production under relatively low N levels in the nursery maximizes N fertilizer use efficiency without affecting landscape establishment and performance.
David L. Trinka and Marvin P. Pritts
Micropropagated (MP) raspberries (Rubus idaeus L. var. idaeus) are sensitive to moisture and temperature extremes and to certain preemergent herbicides used at transplanting. We examined fertilizer placement and row covers in conjunction with various weed management strategies to identify beneficial practices for newly planted, MP primocane-fruiting `Heritage' raspberries. Uncontrolled weed growth during plant establishment inhibited raspberry cane growth and production into the second and third growing seasons. Handweeding and herbicide treatments successfully controlled weeds, but soil moisture was apparently insufficient for optimum growth of the MP raspberries when these treatments were imposed, even with normal rainfall in early summer and drip irrigation in late summer. Polyethylene and straw mulches during the establishment year provided both weed control and adequate soil moisture, resulting in more cane growth in the first and 2nd year, and higher yields the 2nd year. Primocane density after the third growing season still was influenced by first-year weed management practices. Raspberry plants responded best to straw mulch without row covers as plant growth was better in both years. Canes were thicker, yields were higher, and a larger portion of the total crop was harvested early. Row covers were beneficial only in bare-soil treatments, and method of fertilizer placement had no effect on any measured variable. Mulching newly transplanted MP raspberries is an alternative to herbicide use that also provides physiological benefits to the plant through microclimate modification.
David Trinka and Marvin Pritts
Tissue-cultured (TC) plantlets are becoming the preferred planting stock for raspberry growers because of their uniformity, ease of handling, general vigor and disease status. However, previous studies have shown that TC plants are sensitive to many preemergent herbicides and to cultivation within several weeks after planting. ln addition, little is unknown about handling practices for TC plants relative to conventionally propagated plants during the establishment year. We subjected TC raspberries cv. Heritage to different management practices during the establishment year and monitored plant performance over two years to determine if better recommendations could be made for TC plantlets. One set of management practices examined weed control, and treatments included straw mulch, black polyethylene mulch, white on black polyethylene match, napropamide herbicide, simazine herbicide, hand weeding, and an untreated control. A second factor was fertilizer placement, with calcium nitrate applied on the soil surface around the plant or placed in the planting hole. A third factor was row cover application during the first six weeks of growth. Significant differences in soil moisture, soil temperature, plant growth, and yield occurred among the 22 treatments, and results suggested that TC plants require a different set of management practices than conventional propagules.
George Hochmuth, Dan Cantliffe, Craig Chandler, Craig Stanley, Eric Bish, Eric Waldo, Dan Legard, and John Duval
Strawberry (Fragaria ×ananassa) crops were transplanted in two seasons in central Florida with bare-root and containerized (plug) plants under three transplant establishment-period irrigation methods to evaluate crop fruiting responses and production economics associated with the various establishment systems. Irrigation was not required to establish plug transplants in the field. Early (first 2 months) fruit yield with nonirrigated plug plants was greater than early yield with sprinkler-irrigated bare-root plants (the current commercial system) in one of two seasons and equal in a second season. Total-season yields were similar in each season between the two establishment systems. Large or medium plug plants led to greatest early fruit yields in one season while large plug plants resulted in greatest early yield in a second season. Total yield was greatest with medium plants in one season and large plants in another season. The extra cost for the plug plant system was $1853/acre. In one out of two seasons there was increased net income amounting to $1142/acre due to greater early yield associated with the plug plant cultural system. Strawberry plug transplants showed promise for earlier and more profitable crops in addition to substantial savings in water used for plant establishment in the field. The ability to establish strawberry crops without irrigation will be important in areas where growers are required to reduce farm water consumption.
Jeffrey G. Williamson and D. Scott NeSmith
; Williamson and Lyrene, 2004 ). This projected increase in acreage suggests that many growers will be planting new orchards with the goal of rapid, uniform plant establishment. One concern with the establishment of blueberry plantings is fruit set and
Daniel I. Leskovar and Daniel J. Cantliffe
Transplants produced with overhead or subirrigation and plants from direct seeding using primed or nontreated `Jupiter' bell pepper (Capsicum annuum L.) seeds were evaluated for growth and yield in the field for 3 years. Early in development, overhead-irrigated (01) transplants had more basal root elongation than subirrigated (SI) transplants; however, root growth differences caused by irrigation systems in the greenhouse were minimized during late ontogeny in the field. Basal, lateral, and taproot dry weights accounted for 81%, 15%, and 4% of the total for transplants and 25%, 57%, and 18% of the total for direct-seeded plants. Direct-seeded plants maintained a more-balanced root, stem, leaf, and fruit dry matter partitioning than transplants, which allocated more dry weight (per unit of root growth) to stems, leaves, and fruits. Over all seasons, transplants exhibited significantly higher and earlier yields than direct-seeded pepper plants, and total yields were similar between SI and OI transplants and between primed and nontreated seeds.
Peter J. Dittmar, David W. Monks, and Jonathan R. Schultheis
An experiment was conducted during 2005 and 2006 in Kinston, NC, with the objective of maximizing triploid watermelon [Citrullus lanatus (Thunb.) Matsum. and Nak.] fruit yield and quality by optimizing the choice and use of pollenizers. Treatments were pollenizer cultivars planted singly [‘Companion’, ‘Super Pollenizer 1’ (‘SP1’), ‘Summer Flavor 800’ (‘SF800’), and ‘Mickylee’] or in pairs (‘Companion’ + ‘SP1’, ‘Companion’ + ‘SF800’, and ‘SP1’ + ‘SF800’). All pollenizers from these seven treatments were interplanted with the triploid cultivar Tri-X-313. Planting arrangement was compared by establishing ‘SF800’ in a hill versus an interplanted field arrangement. Effect of pollenizer establishment timing on triploid fruit yields and quality was evaluated by establishing ‘SP1’ 3 weeks after planting and comparing it with the establishment of ‘SP1’ at the time of triploid plant establishment. Finally, a triploid planting with no pollenizer (control) was included to determine pollen movement. Fruit yield from the control was 22% or less of yield of the other treatments containing a pollenizer and less than 10% in the initial or early harvests. Pollen movement was minimal among plots and differences in yield and fruit quality could be attributed to pollenizer treatment. In 2005, the use of ‘Companion’, ‘SP1’, or ‘Mickylee’ as pollenizers produced similar total yields, whereas ‘SF800’ produced the lowest yield. In 2005, ‘Companion’ produced more large fruit than the other individual pollenizer treatments. Combining the pollenizers generally did not enhance triploid yields or quality. Interplanting of pollenizers consistently resulted in greater yield compared with the hill system. Late planting of ‘SP1’ increased the incidence of hollow heart in the marketable fruit and decreased yield compared with simultaneously planting ‘SP1’ and triploid plants. Thus, selection of pollenizer, planting arrangement, and time of pollenizer establishment are all important considerations to optimizing triploid yield and quality.
Several biological control agents for the control of fungal diseases have recently been commercialized. Do the claims of pest control meet the expectations of the growers? Do the biocontrol agents perform consistently? How do they compare to chemicals? These questions have yet to be answered but recent trials indicate mixed results. In Massachusetts, Mycostop worked well against fusarium stem rot but not against fusarium wilt. Deny (Burkholderia cepacia) did not perform well against Rhizoctonia or Pythium root rot of poinsettia. The following information was taken from the 1997 and 1998 Biological and Cultural Tests for Control of Plant Diseases. In Maryland, zinnia damping-off was controlled by both SoilGard (Gliocladium virens) and Bio-Trek (Trichoderma harzianum). The biocontrols performed as well as the conventional fungicide. In North Carolina, GlioGard (Gliocladium virens) and SoilGard gave only partial control against Pythium and Rhizoctonia damping-off of bedding plants. In Pennsylvania, Greygold (mixture of four microorganisms) did not provide adequate control of Botrytis on geranium. In Georgia, Pythium and Rhizoctonia diseases of a variety of plants were evaluated with SoilGard and RootShield (Trichoderma harzianum). Disease pressure was low and the results varied from inconclusive to both positive and negative. In addition, SoilGard apparently reduced fresh weight of several plant species. RootShield was reported to both increase root weight in one case and decrease root weight in another. In Connecticut, Rhizoctonia root rot of poinsettia was not significantly suppressed with SoilGard, RootShield, or Earthgro, a suppressive growing medium. However, the authors stated that the results indicated that the biocontrols had promise. Results of additional trials will be presented.
Joyce G. Latimer
Seeds of marigold (Tagetes erects L. `Janie') were sown in flats of three cell sizes (inverted pyramids, Todd 080A, 100A, or 175; volume 7, 24, or 44 cm3, respectively) or in flats of different root cell configurations [Todd 100A, Grow-Tech (GT) 200, or Growing Systems (GS) 135; shaped as inverted pyramid, cylinder, or cylinder with a bottom lip, respectively]. During 2 consecutive years, plants grown in Todd 080A trays had 60% less leaf area and shoot and root dry weights than plants grown in Todd 175 trays. Plants grown in Todd 100A trays had 30% less leaf area and shoot and root dry weights than plants grown in the larger volume tray. Stem length was less affected by container size. The rate of shoot dry weight gain during the 3 weeks after transplanting in the field was greater in plants from the smaller containers (Todd 080A and Todd 100A) in 1987. Final height (7 weeks after planting) of plants from Todd 080A or Todd 100A flats was 12% and 7% less, respectively, than those of plants grown in Todd 175 flats, while final plant quality was reduced 34% and 21%, respectively, in plants from these flats in 1987. Similar, but smaller, effects were recorded in 1988. Container type had little effect on plant growth in the greenhouse and no effect on growth in the landscape. The maximum quality rating in the landscape, awarded to plants from Todd 100A flats, was 12% greater than that of plants from GT 200 flats in 1987 and 5% and 9% greater than plants from GT 200 and GS 135 flats, respectively, in 1988. Final plant performance of marigold seedlings was reduced more by root restriction or transplant size than previously reported with vegetable species.