| Grafting may serve as an alternative to methyl bromide fumigation for soil-borne pest control. Field and laboratory experiments were conducted to examine the use of herbicides in grafted watermelon. The impact of terbacil, halosulfuron, clomazone, and S-metolachlor on field production of triploid watermelon grafted onto bottle gourd and interspecific hybrid squash rootstocks was evaluated in Florida, South Carolina, and North Carolina. Each herbicide was applied pre-transplant (PRE). Halosulfuron was also applied post-transplant (POST). Non-grafted watermelon and untreated control plots were also included. Overall, grafted watermelons responded to herbicides in a similar manner as non-grafted watermelons. No injury was reported from terbacil or halosulfuron PRE at Florida or South Carolina. Injury from clomazone, S-metolachlor, and halosulfuron POST was seen at various levels of severity. Injured plants usually recovered to produce overall yields similar to untreated plants. However, early yield reductions were seen in some trials.;Herbicide uptake and translocation was evaluated in grafted watermelon using soil applied 14C-atrazine and foliar applied 14C-glyphosate. Treatments were made to watermelon grafted onto bottle gourd and interspecific hybrid squash. Non-grafted and self-grafted watermelon were also included. Greater atrazine uptake was seen in watermelon grafted onto interspecific hybrid squash compared to other rootstocks and non-grafted watermelon. When examining the translocation of absorbed atrazine, non-grafted and self-grafted watermelon had a slightly higher percentage of absorbed atrazine reach the shoot compared to watermelon grafted onto bottle gourd and interspecific hybrid squash. No significant differences were observed in glyphosate uptake or translocation when comparing among the grafted and non-grafted plants. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html). |
