ISHS Acta Horticulturae 631: XXVI International Horticultural Congress: Issues and Advances in Transplant Production and Stand Establishment Research
TRANSPLANT QUALITY, DISEASE CONTROL AND YIELD IN FRESH MARKET TOMATO AS AFFECTED BY PACLOBUTRAZOL AND COMMERCIAL BIOLOGICAL CONTROL AGENTS |
| Authors: | S. Dikshit, M.A. Bennett, R.J. Precheur, M.D. Kleinhenz, R.M. Riedel |
| Keywords: | plant growth regulator, Bacillus subtilis, Streptomyces grieseoviridis, Lycopersicon esculentum Mill. |
| Abstract:
Excessive stem elongation reduces the quality of vegetable transplants. Stretched and thin stems make transplant handling and establishment difficult, and thus lead to losses, especially if field planting is delayed due to poor weather. Paclobutrazol is a plant growth regulator with anti-gibberellin activity and has strong height control properties. We investigated the use of paclobutrazol as a presoak seed treatment on fresh market tomato (‘Early Cascade’) while also using the transplant production phase to introduce commercial biocontrol agents with antagonistic properties against Phytophthora spp. causing Buckeye Rot, a common disease in unstaked fresh market tomato. When applied outside controlled environments such as greenhouses, biocontrol agents are seldom effective, perhaps due to insufficient microbial colonization in the rhizosphere and a failure to compete with the soil borne pathogens. Enhancing colonization during transplant production in the greenhouse could improve disease protection in the field. Results from two years of study indicated that paclobutrazol application reduced internode length by 30% in 4-week seedlings and 18% in 6-week-old seedlings. At 4 wks after field transplanting, treated transplants contained 40% more first cluster fruits than control plants, with the number of second cluster flowers also higher in treated plants. Paclobutrazol did not affect disease levels, yield, or interaction with biocontrol agents. Biocontrol treatments did not influence marketable yield in either year. The disease pressure in 2001 was low. However, tomato plants treated with MycostopTM had significantly more diseased fruit in 2001. Most of the 2002 growing season weather was hot and dry, so disease pressure developed only later in the season and, consequently, biocontrol treatment differences were not significant. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
