`Jupiter' and `Verdel' bell pepper (Capsicum annuum L.) transplants set to the depth of cotyledon leaves or to the first true leaf yielded more fruit than transplants set to the top of the rootball. Increased yields and early stand establishment criteria (number of leaves, leaf area, plant weight, and plant height) suggest that planting pepper transplants deeper than is now common is commercially beneficial in Florida. Deeper plantings may place pepper roots in a cooler environment and reduce fluctuations in soil temperature. Moderated soil temperature, in conjunction with earlier fertilizer and water acquisition, may give deeper-planted pepper plants a competitive edge in growth.
Charles S. Vavrina, Kenneth D. Shuler, and Phyllis R. Gilreath
Daniel I. Leskovar
Irrigation methods, rates, timing, and frequency may influence the physical and chemical properties of the growing media thereby affecting root initiation, elongation, branching, development and dry matter partitioning between roots and shoots.
Martin Makgose Maboko and Christian Phillipus Du Plooy
producing tomatoes earlier for the market while eliminating or reducing transplant shock. Direct seeding or transplanting seedlings at the two-leaf stage would reduce production costs in hydroponic production systems. Literature Cited Hall, M.R. 1989 Cell
Rui Zhang, Fang-Ren Peng, Pan Yan, Fan Cao, Zhuang-Zhuang Liu, Dong-Liang Le, and Peng-Peng Tan
may affect subsequent overall growth and may increase survival and reduce transplant shock. Severe root pruning with 2/3 of the total length of the radicle removed generated more taproot branches and achieved a higher surface area value for both fine
Marc van Iersel
Auxins are commonly used to induce root formation during in-vitro culture of higher plants. Because transplanting is often accompanied by root damage and loss of small roots, auxins also could be beneficial in minimizing transplant shock. Vinca (Cataranthus rosea) seeds were germinated in a peat-lite growing mix and transplanted into pots (55 mL) filled with a diatomaceous earth (Isolite) 10 days after planting. Pots were then placed in a tray containing 62.5 mL of auxin solution per pot. Two different auxins [indole-acetic acid (IAA) and naphtylacetic acid (NAA)] were applied at rates ranging from 0.01 to 100 mg/L. Post-transplant growth was slow, possibly because of Fe+2-deficiencies. Both IAA (1–10 mg/L) and NAA (0.01–10 mg/L) significantly increased post-transplant root and shoot growth. As expected, NAA was effective at much lower concentrations than IAA. At 63 days after transplant, shoot dry mass of plants treated with 0.1 mg NAA/L was four times that of control plants, while 10 mg IAA/L increased shoot dry mass three-fold. High rates of both IAA (100 mg/L) and NAA (10–100 mg/L) were less effective. The highest NAA rate (100 mg/L) was phytotoxic, resulting in very poor growth and death of many plants. These results suggest that auxins may be a valuable tool in reducing transplant shock and improving plant establishment.
R.C. Beeson Jr.
Large (≈5 m high) Quercus virginiana Mill. (live oak) trees produced in 0.64-m-diameter in-ground fabric containers were root pruned or not root pruned inside containers before harvest. Harvested trees were grown in two sizes of polyethylene containers for 10 months, then transplanted into a landscape. Water potential (ψT) of small branches (<4 mm in diameter) was measured diurnally during containerization and for 1 year in the landscape. Root pruning had no influence on postharvest survival. Neither root pruning nor container size affected tree water status during containerization or in the landscape. All surviving trees recovered from transplant shock following harvest after 16 weeks in a container, independent of treatment. In the landscape, 35 weeks of daily irrigation were required before dusk ψT declined to within 0.1 MPa of predawn values, a result indicating alleviation of transplant shock. Trunk growth rate during containerization was highest in larger containers. However, in the landscape, root pruning and small containers were associated with higher trunk growth rate. Tree water status during containerization and in the landscape is discussed.
Robert J. Dufault and Jonathan R. Schultheis
To reduce transplant shock of bell peppers (Capsicum annuum L.), we tested the effectiveness of pretransplant nutritional conditioning (PNC) as a promoter of earliness and yield. In Expt. 1, `Gatorbelle' bell pepper seedlings were fertilized with N from Ca(NO3)2 at 25, 75, or 225 mg·liter-1 and P from Ca(H2PO4)2 at 5, 15, or 45 mg·liter-1. Nitrogen interacted with P, affecting shoot fresh and dry weight, leaf area, root dry weight, seedling height, and leaf count. In Expt. 2, transplants conditioned with N from 50, 100, and 200 mg·liter-1 and P at 15, 30, and 60 mg·liter-1 were field-planted in Charleston, S.C., and Clinton, N.C. Nitrogen- and P-PNC did not greatly affect recovery from transplant shock. Although N- and P-PNC affected seedling growth in the greenhouse, earliness, total yield, and quality were similar in field studies among all PNC treatments at both locations. PNC with 50 mg N and 15 mg P/liter can be used with this variety and not have any long-term detrimental effects on yield and quality.
Jerriann Ernstsen, Larry Rupp, and Ray Brown
Typically, dormant seedlings are transplanted when revegetating disturbed lands to prevent transplant shock triggered by water stress. It may be possible to transplant nondormant seedlings by inducing drought-tolerant acclimation responses such as solute accumulation. Artemisia cana and Agropyron intermedium seedlings were subjected to three different water stress preconditioning treatments. After conditioning, seedlings were dried down in their containers until leaf senescence, or were transplanted to disturbed land sites. Leaf water potential components and relative water content were measured. Following treatments, water relations parameters of preconditioned seedlings were not markedly different from controls in either species. At the end of the final dry-down, water stress preconditioning had not induced active or passive solute accumulation, prolonged leaf survival during lethal drought conditions, or differences in transplant survival under the experimental conditions of this study.
John McGrady and Phil Tilt
Transplant nutrient conditioning for desert cauliflower (Brassica oleracea var. botrytis) production has enhanced transplant shock recovery, earliness and increased yield; partial defoliation and traditional hardening may also be effective. `Snowcrown' seedlings fertilized with 50, 150 or 450 mg N 1-1 were clipped to remove 0, 45, 60 or 98% of their leaf area. High root-shoot ratios in the 98% defoliated plants may have resulted in elevated transpiration in new leaves but neither high N conditioning nor defoliation enhanced survival or increased yield. Seedlings raised with 100, 200 or 400 mg N 1-1 were hardened with 4 water/fertilizer withholding regimes prior to transplanting. Non-hardened transplants within each fertilizer regime outyielded hardened transplants. Use of sprinkler or furrow irrigation for day/night establishment of hardened or conditioned transplants will be evaluated.