Application of harvade (2,3 Dihydro-5, 6-dimethyl-l, 4-dithiin 1,1,4 tetroxide) and ethephon (2-chloroethyl phosphonic acid) in combination with Dupont-WK (D-WK) surfactant (principle functioning agent the dodecyl ether of polyethylene glycol) resulted in significant leaf abscission of Ficus carica. Two applications at weekly intervals of 200 ppm harvade or 400–800 ppm ethephon in combination with 20% D-WK surfactant resulted in acceptable defoliation without plant injury in two tests. In one test, defoliation was achieved with lower rates of harvade or ethephon but significant plant injury occurred. Plant injury was as great with D-WK applied alone as with the addition of harvade or ethephon.

Effects of 8 peach seedling rootstocks on tree growth, survival, and fruit yield of ‘Redhaven’ and ‘Loring’ peach scion cultivars were tested in Alabama, Arkansas, Georgia, North Carolina, and South Carolina. Lovell seedling rootstock was a standard for comparison. Six years of data indicated that Siberian C was not an acceptable rootstock because tree survival and fruit yield were low. Halford was equivalent to Lovell for tree growth, fruit yield, and survival. Fruit size was unaffected by rootstock. Nemaguard and 2 North Carolina selections were resistant to root-knot nematodes (Meloidogyne spp.) but they were not resistant to ring nematodes [Criconemella xenoplax (Raski) Luc and Raski]. Soil fumigation improved tree survival in nematode-infested soil.

Daminozide residue levels in fruit and vegetative parts of apple trees were determined the year following foliar spray treatments with daminozide at recommended rates and times and at excessive rates and times closer to harvest than recommended. Trees were sampled in December, March and August following spraying. Daminozide residues were found in all vegetative plant parts, with the highest residue levels found in the buds, bark and xylem of spurs, and in terminal and lateral buds; the lowest residue levels were found in the bark and xylem of stems. Residue levels were affected by both rate and time of application. Residue levels increased as application rates increased, but the response to rate was less when treatments were applied 21 d after bloom (125 d before harvest) than when treatments were applied closer to harvest. The highest residue levels were from treatments applied the day of harvest. Higher residue levels were found in March samples than December samples. Residues had been dissipated to low levels by the August sampling date. No daminozide residues were found in apple fruit from trees treated the previous year with recommended levels of daminozide applied at the recommended time. However, low residue levels were found in fruit treated with 2 × and 4 × rates of daminozide at times closer to harvest than recommended.

Harvester and Alred Elberta peach trees (Prunus persica (L) Batsch) were sprayed with either daminozide [butanedioic acid mono (2,2-dimethylhydrazide)], ethephon [(2-chloroethyl)phosphonic acid] or G&+7 (gibberellin G&+,). Following harvest, treatments were sorted subjectively on the basis of ground color and surface firmness. Firm ripe fruit were placed in 4°C storage, green fruit were held at 23-

Daminozide is a growth regulating substance widely used on apples and other fruit crops to affect various fruit and tree characteristics. Daminozide residues were determined in ‘Starkrimson’ Red Delicious apples orchard-sprayed at both recommended and excessive rates, at recommended periods before expected harvest, and at several application times closer to harvest than recommended. Analyses were conducted on the whole raw fruit, including the peeling, and on applesauce processed from the peeled and cored fruit, immediately after harvest, and after cold storage periods of 30, 60 and 90 d. Residues in both the fresh and processed fruit were directly proportional to the concentration of daminozide in the foliar sprays, regardless of application date. The highest residues in both fresh and processed apples were in fruit from trees sprayed 14 to 28 d before harvest at all spray concentrations. Residues from all spray concentrations and all application dates were persistent for 90 d at 0°C storage for fresh fruit and at 23°C storage for processed fruit. Only the residues in fruit sprayed with four times the recommended level at 2 or 4 wk before harvest exceeded the U.S. Environmental Protection Agency tolerance level (30 ppm). Residues ranged from <2 to 32 ppm. Unsymmetrical dimethylhydrazine (UDMH) levels were directly proportional to the daminozide residues in the applesauce. Average UDMH residues ranged from 0.03 ppm for fruit sprayed with the recommended rate of daminozide to 0.8 ppm for fruit with the highest daminozide residues.