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John D. Downes

Animal waste disposal from large operations is an increasing problem, and its value as a fertilizer needs to be determined. Strip tests often are unreplicated creating problems in analysis. In an unreplicated Georgia farm test involving a three manure (0, 1, 2 loads/acre) × 3 N (0, 70, 90 lb/acre) factorial on corn yield from the control plot was not included, making n = 8, and precluding the usual ANOVA and means comparisons. Partial budget analysis is compared to regression analysis and economic evaluation at varying input costs and corn prices. Best estimates were obtained by finding the N equivalent of manure [(56.4 lb N)/load] and regressing yield on sum of N (Nf + Nm), which estimated Y = –14.0 + 1.1724N – 0.00324NN, RR = .982, F = 136.38, P > F =.000, sye = 3.0 bushel/acre, from which Nmax = 181, Ymax = 92.1 bushel/acre. Nopt varied from 139 to 172 bushel/acre with cost N varying from $0.14/lb (manure cost) to $0.40/lb, and corn prices from $1.50 to $2.50/bushel. Manure thus valued at 16.92 per load when costing $8.00, assuming 56.4 lbs/load N. Major point was estimation N equivalent of manure from yield effects and then regression yield on N. Equation easily converted to one in M.

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Leigh K. Hawkins, Fenny Dane, Tom Kubisiak, Bill Rhodes, and Bob Jarrett

A linkage map was constructed of the watermelon genome using F2 and F2:3 populations segregating for resistance to race 1 and 2 of Fusarium oxysporum f. sp. niveum (FON 1 and 2). Sixty-four percent of the RAPD primers used in the parents and F1 detected polymorphism. In the F2, 143 polymorphic bands were scored, 60% of which exhibited the expected 3:1 segregation ratio. A 113 cM linkage map was constructed using Mapmaker version 3 and LOD of 4. DNA pools of Fusarium wilt resistant or susceptible F2:3 lines were created and bulked segregant analysis was used to detect molecular markers linked to FON 1 or FON 2 resistance. Four individuals per line were used to confirm linkages and construct an F2:3 linkage map. One large linkage group was detected in both generations. A large proportion of the RAPD and SSR markers were unlinked and many showed segregation distortion. Single-factor ANOVA for each pairwise combination of marker locus and resistance or morphological trait was conducted. RAPD markers with putative linkages to FON 1 and FON 2 and several morphological traits were detected.

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Rodomiro Ortiz and Dirk Vuylsteke

Two multilocational trials, one comprising 18 Musa clones in three locations and another of 20 genotypes across 11 locations, were set up in 1991 and 1992, respectively, to assess the genotype-by-environment interaction (GxE) for important traits and to select stable high-yielding and black sigatoka (BS)-resistant genotypes. Combined ANOVAs showed significant differences among environments and among genotypes for all traits. GxE affected all growth and yield parameters, except fruit girth. Host response to BS disease also showed significant GxE, but there was no cross-order season-by-year interaction. Hence, genotypic response to BS can be assessed in 1 year during the rainy season, when disease pressure is highest. Genotype-by-location effects were more important than the nonsignificant genotype-by-year effects, supporting the need for multilocational trials. Stability analysis showed that full-sib plantain hybrids (TMPx1) exhibited different host responses to BS as well as different interaction patterns, suggesting that selection for stable BS resistance is possible. The BS-resistant TMPx genotypes had higher yields than the plantain landraces, but showed differences in yield stability. TMPx 1658-4, 2796-5, 5511-2, and 6930-1 have been selected as stable high-yielding hybrids, while the initial best selections (TMPx 548-4 and 548-9) were top yielders only in good environments. [Vuylsteke, D., R. Swennen, and R. Ortiz. 1993. Registration of 14 improved tropical Musa plantain hybrids with black sigatoka resistance. HortScience 28:957–959.]

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Stephen L. Love, Asunta Thompson-Johns, and Timothy P. Baker

Eight hundred and fifty-three clones of Russet Burbank and 1012 clones of Lemhi Russet were obtained from Native Plants, Inc. in 1988. The clones were produced via a tissue culture system designed to produce somoclonal variants. Four cycles of selection were completed from 1988-1991. Selection was based on resistance to blackspot bruise, a tuber flesh discoloration caused by condensation of free tyrosine; or the ability to produce light french fry color following cold storage. At the end of the four selection cycles all but six Russet Burbank clones and seven Lemhi Russet clones were eliminated. ANOVA across years was completed for the eleven somaclonal variants and Russet Burbank and Lemhi Russet checks.

Of the Russet Burbank clones, three were significantly (p = .05) more resistant to blackspot bruise and one had significantly better fry color after cold storage. All four clones had significantly reduced yield in comparison to the check clones. Of the Lemhi Russet clones, three were significantly more resistant to blackspot bruise, and four had significantly better fry color than the check clone. Only one of the seven clones (one with superior fry color designated L1908) did not show a significantly lower yield potential.

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John A. Barden

In 1990, 15-yr-old `Smoothee Golden Delicious' trees on M.9, M.9/MM.111, and MM.111 were used. On each of 4 trees per rootstock, 3 branches (1.0-1.7 cm dia) were selected. On 7 June (45 DAFB), crop loads were adjusted to 3, 5, or 7 fruit per cm2 branch cross sectional area (BXSA), and each branch was girdled. On 6 Sept all fruit were harvested; fruit weight, ground color, percent blush, soluble solids, starch, and firmness were regressed against crop load. Each was negatively related to crop load, most strongly for soluble solids, ground color and blush. Rootstock influenced several factors and some interaction with crop load occurred.

In 1991, heavily cropping 10-yr-old trees of Empire/M.7A were used. One each of 7 trees, branches (1.2-2.0 cm dia) were thinned to 4, 8, or 12 fruit/cm2 BXSA on 5 June (40 DAFB). One branch per crop load per tree was girdled on 5 June. On 29 Sept fruit were harvested for evaluation. ANOVA indicated significant interactions between crop load and girdling for fruit weight, firmness, soluble solids and starch. Each showed a significant negative linear regression with crop load on girdled branches; on ungirdled branches none of the regressions were significant.

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Xin Zhao, Edward E. Carey, and Fadi M. Aramouni

Consumers of organic food tend to believe that it tastes better than its conventional counterpart. However, there is a lack of scientific studies on sensory analysis of organic food. A consumer taste test was conducted to compare the acceptability of organically and conventionally grown spinach. Spinach samples were collected from organically and conventionally managed plots at the Kansas State University Research and Extension Center, Olathe. One hundred-twenty-two untrained panelists (80 female and 42 male) participated in this consumer study. Fresh and 1-week-old spinach leaves were evaluated by 60 and 62 consumers, respectively, using a 9-point hedonic scale (9 = like extremely, 5 = neither like nor dislike, 1 = dislike extremely). The ANOVA results showed that fresh organic spinach had a higher preference score than corresponding conventional spinach, although not at a significant level (P = 0.1790). For the 1-week-old spinach, the difference diminished, and instead, conventional spinach had a higher preference rating. Among 61 consumers who made comments regarding the sensory evaluation, 29 claimed that organic spinach was more tasty and flavorful; 19 consumers thought conventional spinach was better; 13 consumers could not tell the difference. Even though this consumer study did not reveal significant differences in consumer preference for organic vs. conventional spinach, further well-designed sensory tests are warranted given the trends indicated in our study. Assessment of sensory attributes of organic vegetables after storage also deserves further attention. Ideally, both consumer tests and descriptive analysis using trained panelists will be considered.

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R.B. Batts and A.W. MacRae

Trials were conducted at Plymouth, NC in 2004 and 2005 to determine the effect of halosulfuron on the yield and grade of white-skinned and red-skinned Irish potatoes when used in combination with different infurrow insecticides. Factors for the factorial design used included potato variety, halosulfuron timing, halosulfuron rate, and insecticide. In-furrow insecticides included imidacloprid. aldicarb, and phorate at 30.3, 293, and 233 g ai/1000 m of row, respectively. Halosulfuron was applied at 26.3 or 52.6 g ai/ha preemergence (PRE), postemergence, over the top (POST), or postdirected (P-DIR) to the potatoes. Preemergence applications of halosulfuron were made after last hilling of the bed, POST applications were made at early flowering, and P-DIR sprays were applied at late flowering. Crop injury was evaluated visually at 2 and 4 weeks after treatment (WAT). Potatoes were dug and graded at maturity. Data was subjected to analysis of variance (ANOVA) with means separated using Fisher's protected LSD (p = 0.05). No interaction between insecticides and halosulfuron were observed. However, some yield differences were seen due to halosulfuron alone. Minimal (<10%) injury was seen with PRE and P-DIR applications. Substantial injury was only seen at 2 WAT, and only from POST treatments. At this timing, halosulfuron applied at the low rate injured potato 14-19% across the insecticides, while the high rate caused significantly higher injury (23% to 24%). Injury from the POST timing did affect yield. Higher levels of smaller potatoes (USDA Grade #1) were found in the POST treatments, when pooled over years, varieties and rates. This indicates that tuber development may have been delayed due to foliar injury. This is supported by the lower levels of USDA Grade #3 potatoes from POST applications compared to other timings. When pooled across years, varieties, and rates, the lowest total yields were with the POST timing.

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Shadd Taylor, Derald A. Harp, Kristen McDowell, and Roque Lemus

It is generally accepted that plants closer to structures benefit from the warmth emitted via imperfect insulation and solar energy reemitted as long-wave, thermal radiation. However, while claims of protection are given, little quantifiable information exists on the extent or pattern of this protection. We studied existing plantings of Trachelospermum asiaticum, an evergreen groundcover that is frequently damaged in northeast Texas. The plantings studied were part of a landscape with at least five different identifiable microclimates: 1) near building (NB); 2) mid-bed (MB); 3) bed edge (BE); 4) beneath Quercus virginiana (LO); and 5) beneath Pyrus calleryana`Bradford' (BP). We placed HOBO temperature data loggers recording one temperature per minute in each location. Following our first damaging freeze, we waited 7 days before collecting leaf samples. Leaf samples were collected by using a 25-cm square, 2 cm deep on two sides. The square was placed on the groundcover so that the top of the groundcover was level with the top of the square. All leaves and stems that extruded through the top 2 cm of the square were excised. Four samples were taken from each location, and the number of damaged and nondamaged leaves were counted for each sample. Leaves that were at least 50% discolored were considered damaged. Leaf damage data were analyzed using SAS Proc ANOVA. Leaves in the BE and BP locations showed significantly fewer live leaves than any other locations. NB leaves were virtually undamaged. Average temperatures in the BE and BP locations were 4.5 to 5 °F colder than the “near building” locations, comparable to an a or b zone in the current USDA Plant Hardiness Zone map.

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Mondher Bouden and Jacques-Andre Rioux

The richness of the organic residues in certain fertilizing elements justifies their valorization in horticulture. However, their contents in pathogenic and toxic elements can restrict their use. In this context, this study was conducted in order to evaluate the effect of three organic residues on the environmental medium and the risks of water contamination by the release of heavy metals. Physocarpus opulifolius `Nanus' was transplanted into four substrates. The control substrate contained 4 peatmoss: 5 composted conifer bark: 1 fine crushed gravel (by volume). The three other substrates (25% of peatmoss was substituted by organic residue) contained 10% of fresh bio-filters (FBF), 10% of composted sewage sludges (CSS), or 10% of de-inking sludges (CDS). The pots (5l) were placed in plastic vats and the drainage water was recovered in vessels (17l). The experimental design was in complete blocks with six replications. Samples of the drainage water were collected every 2 weeks for analysis. The pots were fertilized every week (400 mg/Ll of N) and growth parameters were statistically analyzed by ANOVA. The chemical analysis of the residues proves that they contain weak concentrations in organic contaminants. There is an accumulation of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document} in drainage water following the fertilization; the same applies to sulfates and potassium. On the other hand, heavy metals are not released in important concentrations and so the lead, zinc, manganese, and copper contents do not exceed the desirable limits. Moreover, the Physocarpus plants produced in CSS substrates had a growth significantly larger than those plants produced in FBF or CDS substrates. The three organic residues do not constitute a risk of pollution for the environment.

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Rachel B. Elkins, Janet D. Turner, Steve Castagnoli, Clark F. Seavert, Elizabeth J. Mitcham, William V. Biasi, and Ann Colonna

Assessing consumer acceptance is an important aspect of cultivar evaluation. Since 2002, about 2700 consumers have participated in pear preference surveys. Surveys were conducted on multiple dates and at multiple venues from 2002 to 2005 in Oregon and northern California. Survey participants were asked to indicate their preference for pears based on size, appearance, taste, and overall preference. They were also asked to indicate what attributes they liked or disliked about their favorite and least favorite varieties and to indicate their level of purchase intent. Each survey consisted of four to six cultivars, including at least one standard commercial comparison; i.e., Bartlett, Bosc, or Anjou. Data was analyzed (RCBD; Friedman Analysis of Rank or ANOVA/Tukey's HSD) at the OSU Food Innovation Center Experiment Station using Compusense® five v.4.6 software (Guelph, Ont., Canada). Results indicated several alternative possibilities for both summer and winter sales. Among the most preferred cultivars (variable between states) were Anjou (commercial standard winter pear), Bartlett (commercial standard summer pear and most-consumed cultivar), Blake's Pride, Cinnamon, Concorde, and 71655-014. Other major findings were preference for large pears for adults and small for children, overall liking based on sweetness and flavor rather than skin color, and general lack of knowledge of many commercial pear cultivars. Sensory evaluation surveys will be continued in 2006 in California, with focus on differential harvest times for selected preferred cultivars. Consumer preference data is being combined with production and postharvest quality data in order to provide the pear industry a comprehensive data set on potential alternative cultivars.