germination and uniformity in seedling morphology is easy to manage in plant nurseries, allowing seedlings of high quality to be raised. The quality of seedlings affects their growth and yield after transplantation. Good-quality seedlings exhibit morphological
Masahumi Johkan, Kazuhiro Shoji, Fumiyuki Goto, Shin-nosuke Hashida, and Toshihiro Yoshihara
James M. Dangler
Transparent polyethylene is used to enhance sweetpotato [Ipomoea batatas (L.) Lam.] transplant production in hotbeds and unheated field beds. Black plastic is used also in unheated field beds. The use of these bed covers, however, frequently results in transplant damage due to overheating. Despite the positive results obtained by using rowcovers in sweetpotato transplant production, recommendations for their use are not included in extension publications. Successful adoption of rowcovers by sweetpotato transplant producers in Alabama is illustrated.
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.
W. Todd Watson
Studies have demonstrated that the size of transplanted trees has a measurable impact on establishment rates in the landscape. Larger trees require a longer period of time than smaller trees to produce a root system comparable in spatial distribution to similar sized non-transplanted trees. This lag in redevelopment of root system architecture results in reduced growth that increases with transplant size. Research has demonstrated that smaller transplanted trees become established more quickly and ultimately result in larger trees in the landscape in a few years. Additional studies dispute these findings. This paper provides a review of current research on the effect of tree size on transplant establishment.
David S. Koranski and Chad G. Ingels
Petunia seeds of `White Cascade', `Red Flash', and `Red Madness' were sown in 406 plug trays on the same date. The first transplanting occurred when the plants could be removed from the cells without root damage. Subsequent transplanting occurred for four weeks. The first transplanting of `White Cascade' flowered two weeks earlier than the second while the third transplanting was one week behind the second. `Red Flash' flowered two weeks earlier for the first transplanting. There was no effect on time to flower for the `Red Madness'. The highest fresh and dry weights corresponded to the earliest flowering transplants. Optimum growth and development for most petunia cultivars was obtained with the earliest transplanting without root damage.
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.
Daniel I. Leskovar
Pepper cv. `Jupiter' plants were field-grown from containerized transplants produced with either overhead (SPl) or sub-flotation (SP2) irrigation, or from direct seeding, in 3 years. Shoot and root growth were measured at frequent intervals. At planting, SPl transplants had larger basal root length and numbers than SP2 transplants. At the end of the growth period, 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. The coordination of growth (linear logarithm relationship) between root and shoot, changed after fruit set only in transplants. Over all seasons, transplants exhibited significantly higher yields than direct-seeded pepper plants.
Jim E. Wyatt
Comparisons were made between conventional and float system growing methods for tomato (Lycopersicon esculentum Mill.) transplants and subsequent production. Effects of cupric hydroxide application to the interior surface of plant-growing trays were compared to untreated controls. Tomato transplants grown in the float system had higher fresh and dry weights; were larger after establishment in the field; and produced higher early yields of small, medium, and large tomatoes than plants grown by conventional methods. Mean fruit weight was higher from conventionally grown transplants early in the season. Total number of fruit and total yield were not affected by transplant production method. Transplants grown in cupric hydroxide-treated trays were larger and had fewer roots emerging through the bottom of the trays than transplants grown in untreated trays. Cupric hydroxide treatment had no effect on tomato earliness, yield, or mean fruit size.
Charles S. Vavrina
Tomato transplants when planted to the cotyledon leaves, or to the first true leaf, yielded more than transplants set to the top of the root ball. Yield increase appears to be a function of increased extra-large fruit number, which suggests advanced maturity. Results held across four widely separated geographic locations for both spring and fall plantings. These data suggest that planting tomato transplants deeper is commercially beneficial in Florida.
Amnon Koren* and Menahem Edelstein
Grafting technology for vegetable transplants was introduced to Israel eight years ago by Hishtil Nurseries, Inc. The main goal of grafting was to find a substitute for methyl bromide, the elimination of which was pending. The use of grafted watermelon transplants soon followed. Presently, more than 40% of watermelon transplants are grafted. The chief reason for the success of grafted transplants is their tolerance to soil-borne pathogens, including Fusarium, Monosporascus, and Macrophomina. Yields of grafted transplants are often much higher, and it has been shown possible to grow watermelons with saline water (4.5). A limitation of grafted transplants is that presently, we do not have a good solution for nematodes. A drawback is that in order to get good watermelon taste and flavour, the grower needs the experience to adjust agrotechniques, especially determining the best harvest date. Grafted tomato transplants were also introduced early on. Grafted tomato transplants can have excellent resistance to fusarium crown rot, corky root, and other soil-borne pathogens. Some rootstocks have been observed to tolerate water salinity of 8 ec and still produce commercially acceptable yields. Limitations to the use of grafted tomato transplants are the lack of compatibility of some of the cultivars with the rootstocks and the breakdown of nematode resistance at high soil temperatures. Melons, eggplants, and cucumbers are grafted under some conditions.