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  • Author or Editor: D.C. Ferree x
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Abstract

Young, actively growing, container-grown Malling Merton (MM) 106 apple trees (Malus domestica Borkh.), trained to a single shoot in a greenhouse, were oriented at vertical, 45° from vertical (45°), 90° from vertical (90°), or 90° from vertical and rotated at 1 rpm (90° rotated), and summer-pruned to remove none or 50% of 70.0-cm shoots. Orientation in a nonvertical position and summer pruning delayed a decline in net photosynthesis (Pn) exhibited by vertical unpruned trees. Pruning but not orientation increased total shoot growth, shoot number, and the number and total area of leaves of subsequent growth, but decreased average leaf size. Within 1 week after orientation, unpruned trees at 45° or 90° showed a decline of terminal shoot growth. However, 60 days after pruning a delayed growth of axillary shoots along the tree axis resulted in no difference in total shoot growth, leaf area, or leaf number on subsequent growth compared to vertical unpruned trees. Orientation at 45° and 90° increased the dry-weight root:shoot ratio and induced rootsuckers. Pruning decreased the root dry weight in all tree orientations. Rotation of unpruned trees increased apical growth, axillary shoot numbers, and dry weight of subsequent growth, and decreased root growth compared to unrotated trees.

Open Access
Authors: and

Abstract

Vigorous, 5-year-old trees of apple [Malus domestica Borkh. cv. Red Prince Delicious/Malling (M) 9] were unpruned or pruned on July 3, August 3, or September 3 in 1979 and 1980. July and August pruning maintained number of fruit/tree and July pruning increased the number of fruit borne in the canopy interior compared to the unpruned control. September pruning decreased fruit numbers compared to July and unpruned trees. July and August but not September pruning reduced cork spot. Pruning reduced fruit size, soluble solids, and watercore but did not affect fruit color or flesh firmness. Limb orientation had no effect on fruit number, soluble solids, or watercore, but fruit on vertical limbs were better-colored and smaller than those on horizontal limbs. Spur-borne fruit in the canopy interior were larger, but less colored, compared to fruit on horizontal and vertical limbs located near the canopy periphery.

Open Access
Authors: and

Abstract

Trees of apple [Malus domestica Borkh. cv. Red Prince Delicious/Malling (M) 9] planted in 1974 on a 1.52 x 3.05 m spacing exceeded the allotted space by 40% at the initiation of the study in 1979. Trees were unpruned (control) and pruned on July 3, August 3, or September 3 in 1979 and 1980. Pruning decreased limb and trunk cross-sectional area. Horizontal limb cross-sectional area increase was less than that of vertical limbs. Pruning increased spur leaf numbers, area, and size on the 1978 limb section but only July and August pruning prevented the decline in spur numbers occurring on control limbs. July pruning increased bloom per cluster but decreased total bloom on the 1978 limb sections. August and September pruning were most efficient in maintaining tree height while all pruning treatments maintained tree spread.

Open Access

`Seyval blanc' and `Vidal blanc' grapevines (Vitis sp.) grown in large containers were root-pruned at different severities and/or stages of development and the effects on growth of both cultivars and fruiting of `Seyval blanc' were determined. As the severity of root pruning increased, stomatal conductance (g s) and transpiration (E) decreased and the number of wilted leaves increased in both cultivars. In both cultivars, root pruning reduced net photosynthesis (Pn) and E for as long as 18 to 20 days, as well as total leaf area and dry weight of leaves and petioles plus tendrils. The reductions were proportional to the degree of root pruning. A similar pattern existed for cane and root tissue of `Vidal blanc'. As the severity of root pruning increased, berry and cluster weight, and titratable acidity (TA) of `Seyval blanc' decreased. There was no effect of root pruning on berries per cluster, soluble solids content (SSC), or pH of the juice. No interaction was significant for any factor between time of root pruning and fruiting measured on `Seyval blanc' vines. Root pruning at bloom reduced leaf area, number of leaves, and dry weight of petioles, trunks, and canes. Root pruning at veraison had no effect on any vegetative or fruit parameters. Fruiting `Seyval blanc' vines had less leaf area and smaller petiole and cane dry weights than did nonfruiting vines.

Free access
Authors: and

Abstract

Spray treatment a single dormant application of high concentrations of anionic (Triton CS7) and nonionic (Triton N57 and Triton X100) surfactants caused up to 5 days delay in bud break in apple (Malus domestica Borkh.), but had less effect on grape (Vitis spp.) and peach (Prunus persica (L.) Batsch) and none on pear (Pyrus spp.). Surfactants tended to extend the bud break period but were frequently lethal to buds, particularly at concentrations of 3% and 5% active ingredient. In field studies, surfactants delayed the early stages of flower bud development but not bloom of apple or peach and did not control apple scab caused by Venturia inaequalis (Cke.) wint. or powdery mildew caused by Podosphaera leucotricha (Ell & Ev.) Salm.

Open Access
Authors: and

Abstract

Laboratory and field application methods of (methyl 1-(butylcarbamoyl)-2 benzimidazolecarbamate) (benomyl) and oil were evaluated for their influence on net photosynthesis of leaves of potted apple trees. Superior 70-second viscosity oil applied as a dip caused a significant reduction in net photosynthesis of young leaves at both the 1.26 ml and 2.52 ml/liter levels, with the greater reduction at the higher level. Benomyl alone or in combination with oil had no influence on net photosynthesis. Spray application in the laboratory or by commercial field sprayers had no effect on net photosynthesis of fully expanded leaves.

Open Access
Authors: and

Abstract

Various treatments resulting in physical stress to leaves of apple (Malus domestica Borkh.) were tested for their influence on net photosynthesis (Pn) and transpiration (Tr). Brushing to simulate handling or wind rubbing reduced both Pn and Tr in one study and had little effect in another. Shaking 1 min/day had no influence on Pn or Tr. Six or more 1-cm cuts/leaf reduced Pn and had no effect on Tr. Removal of 20% of the leaf area and twenty-four 1-cm cuts/leaf reduced Pn in young expanding leaves; the amount of cut surface exposed by injury was more important than the amount of leaf area removed. Scoring and feeding of two-spotted spider mites [Tetranychus urticae (Koch)] reduced Pn.

Open Access
Authors: and

Abstract

Young, container-grown ‘Topred Delicious’/Malling (M) 9 apple trees (Malus domestica Borkh.) trained to a single shoot out-of-doors were summer pruned to remove 0, 25, 50 or 75% of 78 cm shoots. Net photosynthesis (Pn) and transpiration (Tr) were as much as 36% greater on older, basal leaves of trees with 50 and 75% shoot removal than on unpruned trees. These differences were present for 39 days after pruning. Basal leaves did not abscise in the 11-week period after pruning on trees with 75% shoot removal and remained longer on trees with 50% shoot removal than on unpruned trees. Leaf area removed by pruning was partially compensated by leaves on subsequent regrowth. All summer pruning treatments suppressed the area of individual leaves on regrowth by about 50% of the size of similar aged leaves on unpruned trees. Summer pruning suppressed the dry weight of basal stem sections and roots roughly in proportion to shoot removal amounts, while dry weight of shoot regrowth was less influenced. Eleven weeks after pruning, dry weight of roots on summer pruned trees with 25, 50 and 75% shoot removal was 20, 39 and 50% less, respectively, than root dry weight of unpruned trees.

Open Access
Authors: and

Abstract

Trees of apple [Malus domestica Borkh. cvs. Jonathan/Malling (M) 26] were summer-pruned each August from 1978-1980 by heading all shoots longer than 10 cm, and their response was compared to trees receiving only a light dormant-pruning by thinning-out cuts. Cropping treatments were a full crop or defruiting in June. Final length of shoot regrowth on summer-pruned trees was 82% and 76% less than terminal growth of control trees in 1979 and 1980, respectively, but terminal shoots produced the year following pruning were 55% and 62% longer on summer-pruned tress than on controls in 1979 and 1980, respectively. Summer-pruned trees with a full crop had 13% shorter terminal shoot length than defruited trees in 1979, but cropping had no effect in 1980. Trees with a full crop had a smaller annual increase in trunk cross-section than defruited trees, but were not affected by summer pruning. Summer pruning restricted tree canopy dimensions, resulting in 43% less canopy volume than control trees in 1979 and 1980, increased canopy openness to light penetration, and hastened flower opening. Pruning treatments did not affect fruit set. Fruit yield per tree was reduced by summer pruning, but yield per canopy volume was not affected. Fruit size was decreased by summer pruning in 1979 but was increased in 1980. Fruit soluble solids were reduced by summer pruning in 1979 and 1980, fruit color was increased in 1978 and 1980, but not in 1979. Flesh firmness was unaffected by summer pruning.

Open Access
Authors: and

Abstract

Succinic acid-2,2-dimethylhydrazide (daminozide) and (2-chloroethyl)phosphonic acid (ethephon) and multiple applications of selected pesticides were tested for their influence on net photosynthesis (Pn) and transpiration (Tr) of leaves of apple (Malus domestica Borkh.). Application by aerosol, spray, soil surface incorporation, and fumigation using commercially available pesticide materials adaptable to each had no influence on Pn. Rates of aldicarb in excess of 5 g/20 cm diameter pot (2.9 liter) caused a reduction in Pn. Rates above 14 g/20 cm pot reduced Tr and induced leaf chlorosis and defoliation. One to 3 applications of diazinon, methomyl, and oxamyl had no affect on Pn or Tr but 5 applications reduced Pn and had no effect on Tr. Plictran decreased Pn of both ‘Delicious’ and ‘Golden Delicious’ leaves after 5 applications. A single application of daminozide or ethephon had no measurable influence on Pn or Tr. The growth regulators did not alter the influence of pesticides on Pn. Plictran and oxamyl increased the severity of leaf spotting on ‘Golden Delicious’.

Open Access