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  • Author or Editor: Amr A. Ismail x
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Abstract

Preharvest treatments with succinic acid-2,2-dimethylhydrazide (SADH) had no effect on the rate of ripening of fruit of lowbush blueberry (Vaccinium an-gustifolium Alt.). Ripening (color change) was accelerated in berries receiving 2.24 and 4.48 kg/ha (2 chloroethyl)phosphonic acid (ethephon). Ethephon at these rates accelerated fruit abscission 14 days after treatment The weight, size, soluble solids, pH, titratable acidity and keeping quality of berries were not affected by ethephon or SADH treatments.

Open Access
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Abstract

(2-Chloroethyl)phosphonic acid (ethephon) applied at 1.12, 2.24 and 4.48 kg/ha to mixed black barrenberry (Aronia melanocarpa Willd. — syn. chokepear and black chokeberry, Pyrus melanocarpa Willd.) and native lowbush blueberry (Vaccinium angustifolium Ait) stands at early stages of fruit set and development, effectively thinned black barrenberry fruit without adversely affecting the lowbush blueberry fruit yield or quality.

Open Access
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Abstract

Terbacil (3-tert-butyl-5-chloro-6-mefhyluracil) at either 2.24, 3.58 or 7.17 kg/ha applied under high fertility level (168 kg N/ha from 1-2-2 formulation) significantly increased yield of lowbush blueberries (Vaccinium angustifolium Ait and V. Myrtilloides Willd.). No yield differences were observed among terbacil rates. Rate of fertilizer application affected berry yield.

Open Access

Abstract

Hexazinone was applied preemergent, after pruning, at 1.1, 2.2, 4.5, or 9.0 kg/ha to a commercial lowbush blueberry (Vaccinium angustifolium Ait.) field. Visual ratings indicated a quadratic decline in grasses and a linear increase in blueberry injury associated with hexazinone application. Counts of weed populations showed a highly significant linear decline in meadowsweet (Spiraea latifolia Borkh.) and goldenrod (So-lidago sp.) with an increase in hexazinone rate. Hexazinone treatments did not affect the density of blueberry stems, but flower buds and yield followed a quadratic trend. Hexazinone provided excellent control of many common weed species accompanied by a significant increase in blueberry yield. Chemical name used: 3-cyclohexyl-6-(di-methylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione (hexazinone).

Open Access

Abstract

No differences in plant stand, stem length, growth habit, flower bud formation or yield were detected between fall vs. spring or between mechanical vs. thermal pruning (burning with oil) of lowbush blueberries Vaccinium angustifolium Ait. This suggests that close flail mowing may be an acceptable alternative to burning for pruning lowbush blueberries.

Open Access

Abstract

The respiratory rates for eight stages of development of highbush and lowbush blueberry fruits ranging from immature green to senescence are presented. Based on these data, the blueberry exhibits a typical climacteric respiration curve. An increase in temperature from 15.5°C to 25.5°C resulted in an increase in the respiration rate.

Open Access

Abstract

Effects of selective contact application of 2,4-dichlorophenoxyacetic acid (2,4-D) or N-phosphonomethylglycine (glyphosate) on a mixed stand of blueberry (Vaccinium angustifolium Ait.) and barrenberry (Aronia melanocarpa (Michx.) Ell.) were studied using a selective herbicide applicator. The greater height of barrenberry in its second year of growth provided the selectivity. Herbicide application on the burn year reduced both blueberry and barrenberry plant stands. Selective application of glyphosate or 2,4-D reduced the number of barrenberry plants without seriously affecting blueberry plant stem length or fruit bud number when applied to crop year plants after harvest. Higher rates of herbicides resulted in a greater reduction in barrenberry plant stand. Glyphosate or 2,4-D provided adequate control of regrowth of black barrenberry plants in lowbush blueberry fields.

Open Access

Abstract

N-(phosphonomethyl)glycine(glyphosate) or 2,4-D (2, 4 dichlorophenoxy)acetic acid (2, 4-D) was applied on 2 dates (October 28 or November 10) after leaf abscission of blueberry (Vaccinium angustifolium Ait.) in a commercial field containing lambkill (Kalmia angustifolia L.); plots were thermally pruned the following spring. Lambkill plant stand decreased with increasing rates of glyphosate or 2, 4-D. A late application of glyphosate was more effective than 2, 4-D in reducing lambkill plant stand. Increasing the rate of glyphosate resulted in a greater number of blueberry stems, more flower buds per stem, and a higher yield. Glyphosate applications reduced the length of reemerging lambkill stems but 2, 4-D did not. Glyphosate was as effective in reducing lambkill plant stand at 2.2 kg/ha as 2, 4-D was at 4.5 kg/ha.

Open Access

Abstract

A greenhouse study was conducted to investigate the herbicidal effects of N-phosphonomethylglycine (glyphosate) and 2,4-dichlorophenoxyacetic acid (2,4-D) on black barrenberry Aronia melanocarpa (Michx.) Ell. Phytotoxicity symptoms were more evident and regrowth was less in plants receiving 2,4-D than those treated with glyphosate. Placement of herbicides on all foliage caused more visual injury than placement on half the foliage but did not influence survival. Higher rates of both herbicides resulted in more injury and reduction in plant survival than the lower rates.

Open Access

Abstract

The economic feasibility of using hexazinone for weed control in lowbush blueberries (Vaccinium angustifolium Ait.) was determined by using the partial budgeting technique. Four rates of hexazinone were evaluated to determine the effect on net income in a blueberry enterprise. Response function analysis also was utilized to ascertain the hexazinone level that would maximize blueberry yield and profitability. Partial budget analysis indicated that hexazinone use at 1.1, 2.2, and 4.5 kg/ha was expected to increase net income, indicating its use was economically feasible. Hexazinone use at 9 kg/ha was judged to be economically infeasible, since it decreased net income. Response function analysis revealed that 2.3 kg/ha of hexazinone maximized profits. Chemical names used: 3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-tria-zine-2,4(1H,3H)-dione (hexazione).

Open Access