The influence of end-of-day (EOD), supplemental, cool-white fluorescent light on pepper (Capsicum annuum L. cv. Keystone Resistant Giant No. 3) seedling growth and fruit production after transplanting to the field was investigated. Seedlings were exposed to this light source, which is high in the red wavebands, from one (1988) or two bulbs (1989) for 1 hour before the end of the natural photoperiod. Each year control plants were exposed to ambient light and received no supplemental fluorescent light. Before transplanting to the field, seedlings exposed to two bulbs were shorter and had smaller leaves than plants in the control treatment. Supplemental fluorescent light treatment, regardless of number of bulbs, reduced plant height, leaf area, fruit weight, and fruit count at the first harvest. Total fruit production was not affected by supplemental light, suggesting no residual effect of the light treatment during transplant production on total subsequent fruit production.
Heather A. Hatt Graham and Dennis R. Decoteau
Temperature management has emerged as an important tool for plant height control in greenhouse production systems. This is particularly important in vegetable transplant production where chemical controls for plant height are limited or not legal. Plant height is a function of the number of nodes and the length of each internode, and both are strongly influenced by greenhouse temperatures. Node number, or formation rate, is primarily a function of the average greenhouse temperature, increasing as the average temperature increases. Internode length is strongly influenced by the relationship between the day and night temperature, commonly referred to as DIF (day temperature - night temperature). As DIF increases, so does internode length in most plant species studied. Although the nature and magnitude of temperature effects vary with species, cultivar, and environmental conditions, these two basic responses can be used to modify transplant growth. Although data are limited, controlling transplant height with temperature does not appear to adversely influence plant establishment or subsequent yield.
J. Pablo Morales-Payan and William M. Stall
Experiments were conducted to assess the effects of rate combinations of nitrogen (N) and a soil-applied biostimulant based on seaweed (Ascophyllum nodosum) extract (SSE) on the growth of papaya seedlings for transplant production. Seedlings were grown in 180-mL Styrofoam containers filled with a sphagnum/vermiculite/perlite growing medium. N (0 to 2 g per plant) and SSE (drench, 0 to 1 mL per plant) were applied at sowing and 15 days after emergence. N and SSE rates affected overall growth as well as time to attain adequate size for transplanting. In general, increasing N rates resulted in increased growth, and adding SSE enhanced N effects. In terms of increasing overall transplant growth and decreasing the time required from emergence to adequate transplanting size, the best results were found at the highest N and SSE rates.
Amnon Koren* and Menahem Edelstein
Achieving a uniform stand of grafted vegetable transplants in the field is critical to the grower because of the high cost of the grafted transplants. Low and erratic stands can lead to monetary losses even in an otherwise successful crop. Establishing a uniform stand of grafted vegetable transplants in the field depends on several additive parameters prevailing in the nursery and in the field. These include seed quality, grafted-transplant quality, and agrotechniques suitable for the special needs of grafted transplants. Seed quality and seed health should be given special emphasis as compared with non-grafted-transplant production. Grafted transplants spend more time in the nursery, are treated manually more, and are more susceptible to seed-borne pathogens. Field preparation, plastic mulch, irrigation and fertilization are important, especially in warm, mediterranean climates.
A.M. Clements and L.A. Weston
Fall cole crops of exceptional quality and high market value are produced in Kentucky. Tobacco is an integral part of agriculture in the southeastern states and production of fall cole crops following tobacco may increase diversification and Potential profits. A float system was utilized for transplant production. Field plots were established with broccoli and cabbage grown conventionally, planted into killed sudex cover, cultivated tobacco stubble and directly into tobacco stubble. Data were collected on soil fertility, insect and weed populations, crop quality and yield. Periodically, foliar samples were analyzed for nitrate, total nitrogen, phosphorus, potassium and calcium content. Fall cole crops grown conventionally or in killed sudex cover produced comparable results and head size. Insect pressures were reduced in killed sudex covers. Total yield and quality were reduced when seedlings where planted directly into tobacco stubble.
Joyce G. Latimer
Mechanical conditioning is an excellent means of regulating the growth of vegetable transplants and some ornamental bedding plants. It improves the stature, appearance, handling characteristics, and overall quality of treated plants. The application procedures reported for transplants have included wind, shaking, brushing, and more recently impedance; all of which result in physical displacement of the growing points. Brushing has been most commonly studied for mechanical conditioning in high density transplant production. Brushing reduces plant height, increases stem and petiole strength, improves insect resistance in the greenhouse, tends to improve stress tolerance and enhance stand establishment in the field, and has no effect on crop yield. Although growers using the technique have been very pleased with the quality of brushed vegetable transplants, widespread commercial application of brushing is limited by a lack of automation.
John A. Biernbaum and Natasha Bos Versluys
Important components of water management for transplant production include water quality, the frequency and volume of water application, and the method of application. Water quality factors of concern are alkalinity, soluble salts including sodium absorption ratio (SAR), and ions at potentially toxic concentrations including boron and fluoride. The available water in individual transplant cells is influence by container size and geometry, medium particle size, medium moisture release characteristics, and wetting agents but is primarily determined by irrigation frequency and the amount of water applied at each irrigation. Irrigation scheduling can be done using several methods but is influenced by the crop stage, the water volume applied, and the frequency of drying desired. Transplants can be watered by hose and breaker, stationary sprinklers, traveling boom sprinklers, fog nozzles, or subirrigation. The outcome of experiments testing effects of transplant size, transplant age and fertilizer rates are all influenced by water management.
George E. Boyhan, Raymond Hicks, and C. Randell Hill
There has been interest in producing Vidalia onions organically among both conventional and organic growers. In the 2000–01 season we began to look at producing onions organically. Starting with conventionally produced transplants that were transplanted at standard commercial spacings on beds prepared with 10.2–15.2 cm of incorporated compost and 2,802 kg·ha–1 rate of fresh poultry litter. This was sidedressed with an additional 2,500 less/acre (2,802 kg·ha–1) poultry litter. Yields were about half of conventional onion production. In 2002–03, production of organic transplants with 10.2 cm of incorporated compost with 2.24 t·ha–1 rate of poultry litter, which was followed by an additional sidedressing of 2.24 t·ha–1 rate of poultry litter resulted in similar findings. The weight of harvested transplants was about half that of conventionally produced transplants. In the 2002–03 and 2003–04 seasons various natural mulches were evaluated for weed control. They included wheat straw, oat straw, Bermuda hay, pine straw, and compost. None of these performed better than hand weeding and the wheat straw, oat straw, and Bermuda hay actually reduced yields apparently due to allelopathic effects. Finally in the 2003–04 season rates of poultry litter from 0–22.4 t·ha–1 were evaluated for transplant production with rates of 13.4, 17.9, and 22.4 t·ha–1
yielding plants comparable to conventional transplants. Work continues in the area of organic Vidalia onion production. One of the greatest challenge for future work will be finding a cost-effective and practical method of controlling weeds in transplant production.
Elizabeth T. Maynard
In a wet spring, transplants must often be held beyond the planned transplant date. The plants become overgrown, making mechanical transplanting difficult. We compared several ways of holding `Mountain Spring' tomato (Lycopersicon esculentum L.) transplants. Transplants were 1) planted outside on planned transplant date in late May (NH), 2) held outside for 2 weeks (HOF), 3) held outside for 2 weeks and not fertilized during that period (HONF), and 4) held in the greenhouse for 2 weeks (HGF). Throughout transplant production, half of the transplants in each holding treatment were fertilized with 100 ppm N and half with 25 ppm N from 20N-4.4P-17K or 15N-2.2P-12.3K. HONF reduced plant height 1.7 to 1.5 cm compared to HOF or HGF. Plants grown with 25 ppm N were 5 to 6.4 cm shorter than plants grown with 100 ppm N and showed symptoms of nutrient deficiency. On average, holding treatments reduced marketable yield 20% to 23% and early yield 31% to 37%, compared to NH. HOF and HGF produced similar marketable yield, early yield, and fruit size. HONF decreased early yield in 1997 and decreased marketable yield in 1998, compared to HOF. The differences between holding treatments were usually greater with 100 ppm N. Plants grown at 25 ppm N produced lower marketable and early yields and larger fruit than 100 ppm N. The best method for holding transplants among those tried here is to put them outdoors and continue fertilizing as during transplant production.
William B. Evans and Margaret McMahon
There is significant interest in using non-chemical methods to control seedling height in vegetable transplant production. One method being evaluated is the use of greenhouse films that filter signifcant amounts of far-red light from ambient light, resulting in shorter tranplants. This study was undertaken to evaluate fruit yield and quality of field-grown tomatoes produced from seedlings grown under light-filtering plastics. Tomato seedlings were grown under clear polyethylene tents or light-filtering laminate tents in a polyethylene-covered Quonset greenhouse in northern Ohio. Standard 288 deep plug trays, filled with MetroMix 360, were used. Seedlings were placed under the tents at the cotyledon stage and transplanted 28 days later. Once in the field, they were grown as staked plants under open conditions using locally accepted horticultural practices. Differences in seedling height were detected within a few days after being placed under the tents. Compared to those grown under clear polyethylene tents, seedlings grown under the light-filtering plastic increased in height more slowly and were shorter at transplanting. At harvest, within each of the three cultivars tested, no significant differences in fruit number, yield, or mean fruit size were found between treatments. It is inferred that this non-chemical method for reducing vegetable transplant height may be a viable production option in the future.