Hydrophobic and/or hydrophilic kaolin particle film treatments to peach (Prunus persica (L) Batsch) trees were evaluated for crop and pest management capabilities in six studies from 1997 to 2000. Unsprayed control and standard treatments, the latter consisting of a commercial pesticide program, were included for comparison. Treatments in initial studies were applied via handgun, which resulted in a uniform and heavy deposit of kaolin after the first application. In contrast, treatments in subsequent studies used airblast equipment, which provided a uniform but less dense coverage, even after multiple applications. Results showed that both formulations of kaolin provided control of oriental fruit moth (Grapholita molesta (Busck)), plum curculio (Conotrachelus nenuphar (Herbst)) and Japanese beetle (Popillia japonica Newman) that was comparable with or better than the standard pesticide program. Effective management of late season catfacing insects (tarnished plant bugs Lygus lineolaris (Palisot de Beauvois) and stinkbugs Acrosternum hilare (Say), Euschistus servus (Say), and E tristigmus (Say)) and leafrollers (undetermined species) was also observed, although kaolin applications significantly increased phytophagous mite (Panonychus ulmi (Koch)) levels. In contrast to arthropod management, kaolin failed to control either peach scab (Cladosporium carpophilum (Von Thumen)) or rusty spot (Podosphaera leucotricha (Ell and Ev) ES Salmon) in any of the 4 years of the study. However, hydrophobic kaolin provided effective brown rot (Monilinia fructicola (G Winter) Honey) control when applied via handgun, and partial control when applied via airblast; hydrophilic kaolin failed to provide any control. These results suggest that hydrophobicity and deposit density may be important factors for effective disease management. The application of kaolin significantly delayed fruit maturation, increased fruit size and increased soluble solids relative to the standard. This effect, attributed to a reduction in plant stress, also resulted in increased fruit number and yield on young trees, indicating that an accentuated beneficial response from kaolin applications may be possible.

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We investigated whether preplant root dips or postplant sprays or drenches could be used to control the black peach aphid, Brachycaudus persicae (Passerini), on young peach trees. In greenhouse trials, B. persicae died after being placed on peach trees that had their roots dipped in imidacloprid before planting. All rates (0.8, 1.6, and 3.2 ml/liter of water) tested controlled this aphid. B. persicae died faster on trees dipped in imidacloprid (1.6 ml/liter of water) for 5 min before planting than on trees dipped for 2 s. Aphids eventually died on all treated trees. Approximately 50% of untreated trees died from B. persicae infestations in greenhouse studies. Results from afield experiment show that peach trees root-dipped in imidacloprid before planting or drenched with imidacloprid after planting eliminate B. persicae infestations and prevent root colonization for at least 1 yr.

Various turfgrass species and cultivars are utilized for orchard floor management. Selection and establishment of low-maintenance species compatible with site conditions results in less need for mowing, fertilizing, and pesticide applications. Koelaria macrantha (Ledeb.) J.A. Schultes is a new turfgrass species that has demonstrated outstanding low-maintenance characteristics. This study evaluated the only commercially available cultivar `Barkoel' and three other species, including Festuca arundinacea Schreb (tall fescue), Festuca rubra L. ssp. falax Thuill (chewings fescue), and Festuca longifolia auct. non Thuill (hard fescue). Turf was seeded in a commercial peach orchard in Oct. 1996 and evaluated through Oct. 1999. After 3 years, the hard fescue cultivars had the best quality, with excellent density and low weed populations. Chewings fescue also had good density and few weeds. Tall fescue had good density, but more weeds than the hard and chewings fescues. Koelaria macrantha `Barkoel' had unacceptable quality, with poor density and the highest weed populations. The fine fescues, hard and chewings, suffered damage from orchard maintenance equipment. Damage was most severe during heat and drought stress in Summer 1999. Growers should limit equipment traffic on hard and chewings fescues during heat and drought stress. Tall fescue showed no significant damage from equipment, but it demonstrated a faster vertical growth rate. This increases the need for mowing. Koelaria macrantha `Barkoel' was not damaged by equipment. While Koelaria had the least density and most weeds after 3 years, it has performed well in our other tests. Higher seeding rates or modifications in seedbed preparation may improve density and reduce weed infestations.

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