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- Author or Editor: J.G. Latimer x
Cucumber (Cucumis sativus L.) seedlings were brushed with a suspended bar for 1.5 min twice daily for 12 days (ST) prior to planting. One group of plants was brushed for an additional 10 days (LT) after planting. ST reduced stem length 12 to 28% and shoot dry weight 6 to 24% with `Kurume-ochiai-H' least responsive. ST reduced the numbers of female flowers on lateral shoots of `Ritsurin' and `Chikanari-suhyoh' while LT affected `Nanshin' and `Chikanari-suhyoh'. Brushing did not affect the total number of fruits or mean fruit size or weight of any cultivar, but both ST and LT decreased the total yield of `Ritsurin' grown in a plastic house. Brushing provides good growth control of containerized cucumber transplants with some responses differing among the cultivars. [Project funded by JSPS and Monbusho.]
Questionnaires on pesticide use and other aspects of integrated pest management (IPM) were mailed to 1678 lawn care and landscape maintenance firms in the 20 county metropolitan Atlanta area. The survey return rate adjusted for nonapplicable addresses and undeliverable mailings was 25.4%, yielding a total of 350 usable surveys. Responding lawn care and landscape maintenance professionals purchased a total active ingredient of 250,527 lb (93,447 kg) of herbicide, 35,416 lb (13,210 kg) of insecticide and 10,367 lb (3,867 kg) of fungicide during 1993. Most insecticides and fungicides were applied during June, July, and August. About one-third of herbicides were applied during March to May, one-third during June to August, and one-third during September to February. Key pests and plants were identified by survey respondents. Opportunities and impediments to implementation of IPM in the landscape as reported by respondents are discussed.
Nondestructive studies of plant root systems are limited to hydroponic and glass-wall-type growing systems, which are expensive and limit the ways to observe and measure root structures. The following system was adapted from agronomic studies as a convenient, cost-efficient, and sensitive method of monitoring root growth of horticultural crops.
A survey indicated that the landscape maintenance and lawn care industry of the Atlanta metro area was localized in densely populated counties with a high concentration of commercial activity and residential housing. A relatively young age and limited size of most of the firms suggested a lack of barriers to entering the industry, which was supported by gross sales and equipment owned by surveyed companies. Most firms generated no more than $100,000 in sales in 1993 and owned equipment valued at less than $25,000. Most residential accounts were under 10 acres.
Pre- and posttransplant growth of plug seedlings is affected by the nutrition of the plants. The effects of weekly applications of nutrient solution with different N (8—32 mM) or P and K (0.25—1.0 mM) levels on the growth and nutrient composition of impatiens (Impatiens wallerana Hook. f.) and petunia (Petunia ×hybrida hort. Vilm.-Andr.) plug seedlings were quantified. Impatiens and petunia pretransplant seedling growth was most rapid with a NO3 - concentration of 24 or 32 mM (N at 336 and 448 mg·L-1), while P and K had little effect. Increasing the N concentration in the fertilizer also increased shoot tissue N levels of both impatiens and petunia and decreased shoot P level of impatiens and K level of petunia. Posttransplant growth was most rapid in plants that received N at 16 to 32 mM. Decreasing P and K from 1 to 0.25 mM in the pretransplant fertilizer reduced posttransplant growth. Shoot P level of impatiens 15 d after transplanting decreased from 6.9 to 4.8 mg·g-1 as the pretransplant fertilizer N concentration increased from 8 to 32 mM, while N level increased from 18 to 28 mg·g-1 as P and K fertilizer concentrations increased from 0.25 to 1 mM. Using posttransplant growth as a quantitative norm for plug quality, the sufficiency ranges for tissue N level are 28 to 40 mg·g-1 for impatiens and 30 to 43 mg·g-1 for petunia plugs. These results indicate that fertilization programs for high-quality plug production should focus on N nutrition, and that plugs can be grown with greatly reduced levels of P and K.
Good fertilizer management is important in plug seedling production of bedding plants to prevent nutrient deficiencies and toxicities. We determined the effect of N, P, and K nutrition on the growth of plugs of impatiens (Impatiens wallerana Hook. f.), petunia (Petunia ×hybrida Hort. Vilm.-Andr.), salvia (Salvia splendens F. Sellow ex Roem.& Schult.), and vinca (Catharanthus roseus L.). For all four species, shoot N concentration was correlated linearly with shoot dry mass of the seedlings at transplant. Phosphorus or K concentration in the nutrient solution or shoot tissue had little or no effect on the shoot growth of seedlings, but shoot P levels increased with P concentrations in the fertilizer solution (luxury consumption). Salvia was the only species that also exhibited luxury consumption of K. Results of this study indicate that seedling growth of these species is mainly determined by N and this should probably be the main focus of fertility programs in the plug industry, while P and K applications can be reduced.
Pre- and posttransplant growth of plug seedlings is affected by the nutrition of the plants. The effects of weekly applications of nutrient solution with different N (8-32 mm) or P and K (0.25-1.0 mm) levels on the growth and nutrient composition of impatiens (Impatiens wallerana Hook. f.) and petunia (Petunia ×hybrida hort. Vilm.-Andr.) plug seedlings were quantified. Impatiens and petunia pretransplant seedling growth was most rapid with a