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  • Author or Editor: Daniel C. Milbocker x
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Pyrus calleryana, Decne, `Aristocrat'; Cryptomeria japonica, D. Don; Populus maximowiczii, Henry × `Androscoggin' and Koelreuteria bipinnata, Franch. trees were grown in low-profile containers. The optimum height and width of these containers was 20 to 30 cm and 84 cm, respectively. Pine bark and mixtures containing 50% or more of pine bark were preferable to mixtures containing leaf mold for filling the containers because the former weigh less. Roots penetrated pine bark mixtures better than sphagnum peat mixtures and also retained their shape better during transplanting. When grown in low-profile containers, trees grew fibrous root systems; after transplanting, roots grew downwardly radial and trees were able to withstand extremely difficult landscape conditions.

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Abstract

Corn (Zea mays L.) grown in combination of fertilized sphagnum peat and ground rubber tires (poly rubber) were chlorotic and slow growing. Growth rates were reduced by excessive amounts of Zn leached from the rubber. Reducing the amount of teachable Zn and supplementing the fertilizer with chelated Fe restored the green color and increased the growth rate of corn plants to comparative levels of plants grown in fertilized sphagnum peat.

Open Access

Trees grown entirely in containers have slim trunks. Since large tree sizes are measured interms of their trunk diameter, heavier trunks increase salable tree sizes. River Birch, Betula nigra liners were grown in containers that were increased in size at different rates determined by their trunk diameter. These measurements revealed the minimum container size necessary for unconstricted growth and measured the reduction in trunk diameter induced by smaller container sizes.

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Abstract

The wild Chinese pear, Pyrus calleryana Decaisne was introduced into the U.S. as a possible source of fire blight resistance for pear improvement but was not used as an ornamental plant because of its low branching habit and thorniness. In 1918 Frank Meyer collected seed of P. calleryana in China which were subsequently planted at the USD A Plant Introduction Station at Glenn Dale, Maryland. A thornless individual was discovered among the resulting seedlings which was named ‘Bradford’ in honor of F. C. Bradford, a former director of the Station. ‘Bradford’ is one of the few ornamental trees without serious disease and insect problems. It is valued for its profuse white flowers, glossy, dense summer foliage and burgundy red fall color – a combination of characteristics found in very few trees. It was introduced to nurserymen in 1960 as “the tree for all seasons,” a medium sized shade tree for the southern and eastern United States including zone 5 (1). It has since been found to be adaptable to a larger area and is increasing in popularity with its full potential still being developed.

Open Access

Abstract

Morphological examination of the vegetative bud of American holly, Ilex opaca Ait., shows it to consist of an apical meristem surrounded by leaf primordia and these in turn by fleshy cataphyls (bud scales). With expansion of the bud into a shoot, flower buds are initiated in the axils of cataphyls and a few leaf primordia. When flowers are not initiated in the leaf axils, vegetative buds develop therein and in the terminal of the shoot. The male inflorescence is a cyme with 3 flowers and the female inflorescence a solitary flower. Both staminate and pistillate flowers normally have 4 sepal points, 4 petals, 4 anthers and 4 carpels though 5 and 6 of each are frequently observed in individual flowers. Pistillate flowers bear no pollen and staminate flowers have only a rudimentary pistil. The trimerous primordium, though variously shaped, is the origin of leaves, cataphyls, resting vegetative buds, bracts, the calyx, and the inflorescence. Differentiation into leaves or cataphyls and inflorescences or resting vegetative buds appeared to be controlled by the physiological condition of the plant at the time of differentiation.

Open Access

Abstract

A tractor-drawn transplanting machine was substantially modified for operation in chemically-killed sods. The modifications included using a rolling coulter, double-disc furrow opener, narrow press wheels and considerable ballast weight. The use of this transplanter makes possible plot and field trials with transplanted-type crops under “no-tillage“ culture.

Sod plots were treated with one or more applications of Paraquat herbicide to kill the vegetation. Tobacco, tomato and pepper plants were established in conventional and no-tillage plots. Plant survivability was generally more variable using no-tillage, but the significant differences were attributed to non-machine cultural problems. The no-till transplanter operátion was adequate under all conditions encountered.

Open Access