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In the Fall 2004 semester, an on-line Introductory Horticulture course was offered to both Baccalaureate (BS) and dual enrolled high school (HS) students through Texas Tech University. In this preliminary study, comparisons were made between the progress of BS and HS students. Mean exam scores, lab report grades, worksheet scores, number of hits, and final scores for all populations were normally distributed. A one-way analysis of variance indicated a significant difference between mean exam scores (F = 6.950, p < 0.01) with HS scoring higher than BS students. Lab report and worksheet scores were significantly higher for BS students (p < 0.001). BS students accessed the website more often than HS students (p <.001). Final grades for the course were not significantly different (F = 6.950, p = 0.391) indicating that HS students performed as well as BS students in this online Introductory Horticulture course.

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Abstract

Highly significant differences in the leaf content of 10 mineral elements occurred between seedling progenies of 7 apple cultivars. Correlations involving all 10 elements occurred between leaf contents of element pairs. A very high correlation between the accumulation of Ca and Mg suggests a common mechanism for the uptake and translocation of these elements. The wide variations between and within progenies indicate the feasibility of selecting rootstocks highly efficient in the uptake of specific nutrients. The proper use as graft components of stocks so selected offers extensive possibilities for the manipulation of the mineral composition of the scion and, thus, the control of nutrient related disorders. Tree-to-tree differences in such disorders in orchards on seedling rootstocks may be accounted for on the basis of differential nutrient uptake.

Open Access

The cutleaf hazelnut [Corylus avellana L. f. heterophylla (Loud.) Rehder] is an ornamental form with strongly dissected leaf morphology. Its stigmas express incompatibility allele S20 but none of the other 25 S-alleles was detected with fluorescence microscopy. Three seedlings from a cross of the cutleaf hazelnut and VR6-28 lacked S20 and were investigated further. Each expressed an allele from the parent VR6-28 (S2 S26), S26 in OSU 562.031 and OSU 562.048 and S2 in OSU 562.049. S2 and S26 are low in the dominance hierarchy, so we expected the new allele from the cutleaf hazelnut to be expressed in their pollen. Unexpectedly, fluorescence microscopy showed that pollen of all three selections was compatible on their cutleaf parent and on each other, and furthermore, self-pollinations showed the excellent germination and long parallel tubes in the styles that are typical of a compatible pollination. Controlled self- and cross-pollinations in the field verified the self-compatibility of two selections. Cluster set for self-pollinations was very high (75-90%) and within the range observed for compatible cross-pollinations. Furthermore, the frequency of blank nuts was low (<10%). The second allele in the cutleaf hazelnut is designated S28, and its presence in seedlings of `Cutleaf' is indicated by the absence of S20. Controlled pollinations in the field also showed that selection OSU 562.069 (S2 S28) from the cross `Cutleaf' × `Redleaf #3' was self-compatible. Fluorescence microscopy showed that two additional seedlings were self-incompatible [OSU 367.052 (S1 S28) and OSU 367.076 (S6 S28)] while a third [OSU 706.071 (S9 S28)] was self-compatible. Self-compatibility may be limited to genotypes that combine S28 with a second allele that is low in the dominance hierarchy.

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`Barcelona' hazelnut (C. avellana L.) shoots were girdled and stool layered in a factorial design with three tissue removal (leaf, bud and meristem removal) and two hormone (with or without 750 ppm IBA) treatments. Percent rooting, rooting grade (0 to 5), shoot length, shoot diameter, and total number of buds were determined. Average percent rooting was >90% for all treatments. Girdling alone gave as high percent rooting as hormone application. The main effect of IBA was on root quality rather than percent rooting. About 75% of the hormone-treated rooted layers could be directly planted (grades 3 to 5), compared to 44% for the control, but shoot length, shoot diameter and total number of buds decreased with IBA application. Bud removal did not affect average percent rooting while meristem removal reduced it slightly. The percentage of layers having grades 3 to 5 was lower for the meristem and bud removal treatments than for leaf removal. Our results support the adoption of stool layerage with girdling and IBA application for the production of strong, well-rooted trees suitable for planting directly in the orchard.

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Abstract

Hazelnut kernels from which the pellicle can be removed easily by dry heat are highly desirable for the international kernel market. Cultivars vary from no to complete pellicle removal after heating. Nut samples of 951 seedlings representing 62 parental combinations were roasted at 130°C for 13.5 min, rubbed, and scored for degree of pellicle removal. Narrow sense heritability, estimated by regression of progeny means on midparent values, was 48% (±10%). This moderately high heritability estimate indicates that selection of easy-to-blanch seedlings should result in rapid progress.

Open Access

The cutleaf hazelnut [Corylus avellana L. f. heterophylla (Loud.) Rehder] is grown as an ornamental for its distinct leaf shape. Its leaves are slightly smaller, more deeply lobed, and more sharply toothed than those of standard hazelnut cultivars. When the cutleaf hazelnut was crossed with cultivars with normal leaves, all seedlings had normal leaves. When seedlings were backcrossed to their cutleaf parent, half of the seedlings expressed the cutleaf trait, and when crossed with each other in pairs, 25% of the seedlings were cutleaf. These segregation ratios indicate that the cutleaf trait is conferred by a single recessive gene for which the symbol cf is proposed. Progenies segregating simultaneously for leaf shape and color indicate that the cutleaf locus is independent of the locus controlling red leaf color and of the locus controlling a chlorophyll deficiency, which appears to be identical to that previously observed in seedlings of `Barcelona'.

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Abstract

Landscape design, landscape construction, landscape maintenance, and landscape irrigation projects require an accurate bidding/estimating procedure for effective cost controls and profit generation. Everything entering into the bid price must end up on a spreadsheet to determine the final figures, including an estimate of profit. As one of the last phases of the bidding process, the spreadsheet calculations are a constant source of potential error in figure transposition, miscalculation, or omission, which could lead to profit loss or to the nonawarding of a project in a competitive bidding situation. Powerful electronic spreadsheets are available for use on microcomputers, but few are used in the industry due to their high cost, the generic nature of the spreadsheet programs, and the unavailability of spreadsheets specifically constructed for bidding. Additionally, electronic spreadsheets generally require formatting with appropriate equations before they can be used (1).

Open Access

Abstract

During the winter of 1983-84, 2 periods of below normal temperatures caused severe damage to ‘Western’ pecan trees [Carya illinoensis (Wangenh.) C. Koch]. Leaf elemental concentrations of N, P, K, Ca, Mg, Mn, Fe, and Zn, and yield/tree, measured during 1983, were evaluated to determine their relationship to damage. The only factors significantly related to the amount of cold damage were N, P, and yield/tree. Leaf N2 and leaf P2 were inversely related, whereas yield was positively related to cold damage.

Open Access

Fruit of `Mohawk' in 1986 and 1988 and `Shoshoni' pecan [Carya illinoensis (Wangenh.) C. Koch] in 1986 were thinned during early August using a pecan shaker with modified shaker pads. Fruit removed ranged from 44% to 57% of the crop load. Fruit thinning increased nut size of `Mohawk' in both years, but did not affect nut size of `Shoshoni'. Kernel percentage of thinned `Mohawk' and `Shoshoni' trees increased, and kernel grade of `Mohawk' improved relative to unthinned trees. Return bloom of `Mohawk' was not affected either year by thinning, but return bloom on `Shoshoni' was increased by thinning. Mechanical fruit thinning appears to be a useful commercial tool until better thinning methods are available.

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