‘Redhaven’ peaches (Prunus persica L. Batsch) were sprinkled from the end of rest, January 22, 1975, until the time check trees reached full bloom, April 18, 1975. Sprinkling delayed bloom by 15 days. Energy models predicted bloom one day before it occurred in the check trees. Wood temperatures were lowered as much as 6.5°C in sprinkled trees, but no significant difference in wood cold hardiness was observed. Sprinkled fruit buds were more cold hardy than non-sprinkled fruit buds until early March. Non-sprinkled buds were more cold hardy than sprinkled fruit buds in late March. Sprinkling reduced the number of viable buds/m by late March. Analyses of total and reducing sugars and protein showed no significant difference.
Twenty-four half-sib sweetpotato families were field tested for freedom from injury by sweetpotato weevil and other soil inhabiting, injurious insects (WDS). Three pairs of adult male and female weevils were applied to the crown of each plant at the beginning of storage root enlargement. Naturally occurring numbers of WDS were high enough for considerable injury from those insects. WDS injury free roots ranged from 19% in Centennial, the suceptible control, to 57% in Regal, the resistant control. The highest family mean for percent non-injured by WDS was 55%. Weevil injury free roots ranged from 67% in Centennial to 90% in Regal with 3 families producing mean weevil non-injured roots of 89%. The genetic correlation between weevil injury free and WDS injury free roots was 0.69 ± 0.28. That estimate is preliminary and based on data from one environment. Evaluations will be repeated in 1994 for estimates of GXE to derive genetic correlation estimates with less environmental interactions.