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  • Author or Editor: R. E. Byers x
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Abstract

Storage of brodifacoum (Volid) and chlorophacinone (Rozol) anticoagulant rodenticides with organic phosphate spray materials in a sealed container for more than 57 days slightly reduced Pine vole (Microtus pinetorum) mortality and bait acceptance of Volid, but did not affect Rozol efficacy. Storage of both materials with zinc phosphide bait did not affect acceptance or mortality of pine voles. Pine voles surviving a 3-day exposure to zinc phosphide surface-coated corn and oat bait (ZnP-grain) (2%, w/w) were much less susceptible to a subsequent 5-day exposure to ZnP-grain or ZP Rodent Bait-AG, 14 days after the first exposure. ZP Rodent Bait-AG caused greater mortality than ZnP-grain in both pre-exposed or voles not previously exposed to ZnP-grain bait. Chemical names used: 2-(P-chlorophenyl)phenyl-acetyl[-l,3]-indandione [Rozol; 0.005% chlorophacinone (CPN)]; and 3-[3-(4′bromo[1, 1′-biphenyl]-4-yl)-1,2,3,4-tetrahydro-l-napthalenyl]-4-hydroxy-2H-1-benzopyran-2-one [Volid; 0.001% brodifacoum (BFC)].

Open Access
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Abstract

Hand placement of 2-Diphenylacetyl-1,3-indandone (Diphacinone, DPN) and [(chloro-4-phenyl)-1-phenyl-1] acetyl-2-dioxo-1-3-indane (Chlorophacinone, CPN) baits applied in 2 applications at ca 30 day intervals at 11.2 kg/ha (10 lbs/A) each were effective in the control of pine voles (Microtus pinetorum LeConte) in apple orchards. In a cultural experiment designed to control pine voles, one Diphacinone preparation gave near 100% control with one application in plots previously cultivated and treated with residual herbicide in July and November.

Open Access

Abstract

Airblast application of fertilizers, desiccating herbicides, or surfactants reduced fruit set and increased fruit size of ‘Redhaven’ peach [Prunus persica (L.) Batch]. The addition of the surfactant, aikylaryl polyoxyethylene glyco phosphate ester (Spray Aide), to ammonium thiosulfate (ATS) at rates from 0 ml/liter to 5 ml/liter did not increase thinning. When rates of ATS/ha remained constant, water volumes from 2338 Iiter/ha to 420 liter/ha did not affect thinning. Forty-six percent to 62% more flower buds developed on twigs from chemically thinned trees than on hand thinned trees. Most of this flower bud increase was on the 5 basipetal nodes of current season shoots. Treatment of the stigma, petals + anthers, peduncle, or calyx with ATS reduced fruit-set. Necrotic regions in the peduncle of some flowers could be seen under a microscope 48 hr after treatment. Flowers sprayed with DuPont WK or NH4NO3 + X-77, plus methylene blue (added as a tracer) had blue dye in the veins of the calyx, pedicle, and peduncle of some flowers after 24 hr.

Open Access

Abstract

Caged feeding tests of 77 Malus clones, representing 15 species and hybrid species, revealed 9 cultivars apparently less susceptible to feeding by pine voles than ‘Golden Delicious’. Malus X sublobata PI 286613 shoots were attacked least; other cultivars of special promise include ‘Charlotte’, ‘Hucker No. 1’, ‘N.Y. 11928’, ‘Robusta 5’, ‘Sissipuk’, and ‘Ivory’s Double Vigour’.

Open Access
Authors: and

Abstract

Trunk looping of several apple cultivars on seedling roots reduced terminal shoot growth and trunk enlargement below the loop and increased root suckers. Growth was reduced most in the early years of tree growth. In the 5th, 6th, and 7th growing seasons, annual trunk enlargement was not affected, but growth suppression in the 2nd, 3rd, and 4th years reduced final trunk diameter measurements after seven seasons. Similarly, terminal shoot length was suppressed greatest in the early years and to a lesser extent in the 5th through the 7th growing seasons. Fruit number was unaffected by looping in the 5th growing season, but looping increased fruit number and fruit/cm2 trunk cross-sectional area in the 6th and 7th seasons in ‘Golden Delicious’, ‘Starkrimson Delicious’, and ‘Northwest Greening’, but not ‘Stayman’.

Open Access
Authors: and

Abstract

Efficacy of several rodenticides was evaluated in laboratory and field tests. ZP Rodent Bait AG pellets gave greater mortality of pine (Microtus pinetorum) and meadow (Microtus pennsylvanicus) voles in field and laboratory trials than a similar-looking commercially available zinc phosphide (ZnP) pelleted formulation and a whole wheat and cracked corn formulation. Laboratory comparison of six new pelleted formulations (zinc phosphide, ZnP) revealed one that gave similar mortality as ZP Rodent Bait AG. Quintox (vitamin D3) gave average to excellent mortality of voles in laboratory trials, but very poor to fair control of voles in field trials.

Open Access

Abstract

Fruit of apple (Malus domestica Borkh. cv. Golden Delicious) sprayed with triethanolamine salt of silvex [2-(2,4,5-trichlorophenoxy) propionic acid] (2,4,5-TP), a finely dispersed aluminum oxide (Sun Clear), and potassium salt of a fluorochemical carboxylic acid (L-4749) had better finish than controls. Fruit size and seed numbers were significantly reduced by higher rates of 2,4,5-TP. Sprays of a mixture of anion acrylic polymer binding agents (Acrylocoat), poly-l-p-methen-8-9 diyl (Vapor Guard), and a nonionic dimethyl polysiloxane (Dow Corning Silicone 24) increased russeting on ‘Golden Delicious’ apple fruit. Fruit enclosed in a paper bag 16 days after bloom gave a greater reduction in russet than any spray treatment.

Open Access

Abstract

Vydate (oxamyl; methyl N’, N’ dimethyl-N[methylcarbamoyl) oxy]-l-thioox-amimidate) and Sevin (carbaryl; 1 napthyl-N-methyl carbamate) did not give significant thinning of ‘Starkrimson Delicious’ apples (Malus domestica Borkh.) when applied as airblast treatments in 3 years of tests. Neither multiple applications nor the addition of a 70-sec superior spray oil gave significant thinning compared to untreated controls. Airblast treatments of these materials on ‘Golden Delicious’ were effective but were inadequate to reduce crop load to the desired level. The data suggest that Vydate and Sevin are inadequate as thinners if applied with airblast machines. Ethephon treatments caused erratic responses at the rates and timings used. Sevin applied for thinning caused an increase of European red mites and their eggs.

Open Access

Combinations of aminoethoxyvinylglycine (AVG, ReTain) and NAA gave better control of fruit drop of `Golden Delicious' than either alone. When the full rate of ReTain (50 g/A) was compared to a reduced rate of ReTain (86 g/ha) plus NAA, equivalent control of fruit drop of `Golden Delicious' resulted. ReTain delayed softening and starch depletion of `Golden Delicious' fruit. NAA in some cases promoted earlier fruit maturity; but when used in combination with ReTain, maturity was similar to ReTain-treated fruit. Fruit with the highest firmness and starch came out of cold storage in the best condition. Neither 1-methylcyclopropene (MCP, EthylBloc) or NAA inhibited fruit drop of `Golden Delicious' fruit when applied at harvest; but previous ReTain and NAA data indicate that late applications are frequently much less effective than if applied 4 weeks before harvest. Ethephon spray treatments caused more rapid and extensive fruit drop than the control. Trees gassed or sprayed with EthylBloc before ethephon sprays also dropped rapidly. `Golden Delicious' fruit on the tree were dramatically maintained firmer by the EthylBloc gas, and to a lesser extent by EthylBloc sprays by 19.1 N and 10.2 N firmness, respectively, tested on 28 Oct. Starch was maintained by the EthylBloc gas, but not by the sprays. These data indicated that EthylBloc applied as a gas or spray did have a physiological affect but did not control fruit drop. Fruit diameter, soluble solids and color did not appear to be affected. Further study of earlier applications of EthylBloc or combinations with fruit drop control agents may be needed to get fruit drop control. NAA plus Silwet L-77 inhibited fruit drop of `Law Rome', but none of the EthylBloc sprays inhibited fruit drop when applied at harvest. Previous data with ReTain and NAA indicated that late applications are frequently much less effective than if applied 4 weeks before harvest. EthylBloc sprays applied 21 Oct. dramatically maintained fruit firmness tested on 3 Nov. Starch was not maintained by the EthylBloc gas, but starch had almost disappeared by the application time on 21 Oct. Fruit diameter, soluble solids, and color did not appear to be affected. Further study of earlier applications of EthylBloc may be needed to demonstrate fruit drop control. Shading trees with 92% polypropylene shade material for 3 or 7 days caused more rapid fruit abscission at 7 days than 3 days and both were greater than the control.

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