ISHS Acta Horticulturae 631: XXVI International Horticultural Congress: Issues and Advances in Transplant Production and Stand Establishment Research
STAND ESTABLISHMENT TECHNOLOGIES FOR PROCESSING CARROTS |
| Authors: | R. Lada, A. Stiles, M.A. Surette, C. Caldwell, J. Nowak, J. Nowak, A.V. Sturz, T.J. Blake |
| Keywords: | ambiol, anticrustants, antioxidants, antistress compounds, bioconditioning, carrots, emergence, endophytes, germination, glycinebetaine, thermogenic compounds, vigor, water deficit |
| DOI: | 10.17660/ActaHortic.2004.631.12 |
| Abstract:
Achieving an optimal crop stand, especially in mineral soils, has been a great challenge in carrot production. Cool soil temperatures, crusting and low moisture availability are some of the factors that contribute to poor germination, slow seedling emergence and reduced vigor. Several anticrustants such as humic acid, orthophosphoric acid and F-68 were applied to soil immediately after sowing. Although soil application of humic acid promoted early seedling emergence there was no significant difference in crop stand among any of the treatments after 41d after sowing. There was no significant yield difference among any of the anticrustant treatments. Primed seeds promoted early emergence with the cv. Indiana but not with cv. Newport. Priming did not alter root length, yield or grades. GA3 promoted germination at 5°C but there was no synergistic effect with any of the salicylates. Optimal soil moisture for early and uniform seedling emergence was 35-40% Field Capacity (FC). Soil moisture above 40% and below 35% FC reduced seedling emergence significantly. Seed preconditioning using natural and synthetic antistress and antioxidant compounds, glycinebetaine (100 mg L-1) and AMBIOL, a derivative of 5-hydroxybenzimidazole (0.1 mg L-1) both promoted emergence at 40% FC but at a limiting low moisture content of 25% FC, Ambiol was the most effective. Seed bioconditioning using endophytic beneficial bacteria (EPBBs) obtained from carrot crowns, Pseudomonas fluorescens #37 and P. putida #144 both enhanced seedling growth in vivo. Bacillus magnetarium promoted root length but did not increase biomass of the seedlings. Optimal carrot emergence under low soil temperature and moisture conditions can be achieved through seed preconditioning using GA3 and Ambiol and through bioconditioning using selective EPBBs. | |
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