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Kentucky is one of seven states in the southeast evaluating 13 Asian pear cultivars for suitability to the region. The cultivars were planted on a (20′ × 10′) spacing in 1989 at three separate locations. Data on time of bloom, tree growth, fire blight susceptibility and fruit quality and yield were collected. This study demonstrates the variability seen in Asian pear cultivars in response to site. There was a significant site by cultivar interaction for fire blight. The Princeton site had significantly more fire blight than either Lexington or Quicksand. Four cultivars, Niitaka, Shin Li, Shinko and Shinseiki had low fire blight ratings which were not significantly different between the three sites. Asian pear growth rates were significantly different between the three sites, but cultivar growth rates were not. Tree growth rate showed a significant negative correlation to fire blight rating. That is infected trees did not grow much. Initial findings show Shinko, Shinseiki and Niitaka to have some tolerance to fire blight spread and to produce good yields of attractive fruit. However, Niitaka had a very tough skin with a tendency towards fruit cracking. The cultivar Shin Li which also had fire blight tolerance did not produce fruit or flowers.
Apple growers would like to use pesticides efficiently and diminish concerns about food safety and pesticide usage. The 1992 Apple IPM Program objectives were: 1) to demonstrate the application of Integrated Pest Management practices in commercial orchards and, 2) to provide the training and support needed to help these growers become self sufficient in IPM practices. Grower training meetings and regular scouting of the orchards were the primary educational methods. End-of-the-season evaluations of past and disease incidence were made. Except for Frogeye Leaf Spot, there were no significant differences in insect pest, disease levels or in fruit quality attributes in IPM versus standard blocks. The IPM blocks had significantly more mite incidence. Growers did produce commercially acceptable crops using IPM based decisions while reducing the average past control cost by $56 par acre. Educational programs did help growers to be more proficient in making IPM based decisions.
Four different netting types were evaluated in the field for excluding Japanese beetles and green June beetles from `Dirksen' thornless blackberry plants. These nets were bird net, crop net, rack mesh, and Agryl P17. Observations were made in an unreplicated trial on `Reliance' grapes using OV3018 and OV7100 nets in addition to those listed. Plants were not sprayed with insecticides or fungicides after net application. Rack mesh appears to be the best net of those evaluated during a dry season for excluding Japanese beetles and green June beetles on thornless blackberries and grapes. Plants covered with rack mesh had minimal fruit and foliage damage due to insects and fruit rot. The use of rack mesh eliminated the need for insecticide sprays for 53 days on thornless blackberries and 41 days on grapes. Light intensity was reduced by the netting, but did not reduce (hornless blackberry yield or soluble solids; however it did unacceptably reduce `Reliance' grape fruit coloration.
Abstract
Freezing studies on ‘Bartlett’ pear (Pyrus communis L.) bouquets of buds, flowers, and small fruit showed injury increased with decreasing temperature, increasing developmental stage, and increasing duration of frost. At the minimum temperature, 30 and 60 minutes of frost exposure in all stages increased injury, however, in the small fruit stage injury at −2°C increased for up to 2 hours exposure. The effect of freezing rate was dependent on minimum temperature and dry florets were injured slightly more than florets misted just prior to freezing.
Abstract
Three consecutive annual nitrogen applications on trees of ‘Bartlett’ pear (Pyrus communis L.) at 120 kg/ha increased leaf N, shoot growth, number of expanded shoot leaves, crop density, fruit size, and yield compared to no N. N application without butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) increased late bloom and fruit russet associated with pear psylla honeydew. Daminozide at 2 g/liter sprayed twice annually for 3 years, 30 and 50 days after bloom with or without N application, reduced minal growth, number of expanded shoot leaves, late bloom, fruit size, density of psylla nymphs, (Psylla pyricola Foerster) and fruit russet from psylla honey dew. The effects of N and daminozide on tree growth, fruit size, and yield, as well as on psylla density, varied from year to year. Daminozide can reduce shoot growth of pear and subsequently reduce psylla densities and resultant damage but with some reduction in fruit size.