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  • Author or Editor: L. F. Thompson x
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Interveinal chlorosis has been observed on the oldest leaves of several varieties of flowering crabapple (Malus sargentii Rehl). Our objective was to identify the cause of this disorder. Foliage and soil from 20 Sargent crabapple trees growing on 12 different sites were analyzed for possible nutrient deficiencies or excesses. Analyses showed N to be slightly low, Ca high, and Mg low in all leaf samples. Soil analysis showed Ca to be abnormally high at all sites. We concluded that the leaf discoloration was caused by a Mg deficiency due to Ca suppression of the Mg and that the low foliar N might be a contributing factor in the interveinal chlorosis.

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Experiments at two commercial farms in Bermuda tested the effectiveness of solarization of narrow beds alone and together with metam sodium (MS) to enhance in-field production of broccoli (Brassica oleracea L. var. botrytis L.) and kale (B. oleracea L. var. acephala DC.) transplants. Soil treatments of clear, low-density polyethylene (LDPE) mulch (25 μm), white LDPE mulch (25 μm) plus MS (702 L·ha-1), and clear mulch plus MS were compared to bare soil. Mulches were applied and MS incorporated through rototiller cultivation 20 cm deep into 1.2-m-wide, flat seed-beds in the last week of June 1995. Mulches were maintained for 8 weeks. Either Broccoli `Pirate' or kale `Blue Curled Scotch' were seeded into transplant beds in Warwick and Devonshire parishes, respectively. Stand data was obtained for broccoli and kale 25 and 35 days, respectively, after seeding. Transplants were rated for root infection and biomass at 11 days (broccoli) or 31 days (kale) after seeding. In general, solarization was as effective as MS in suppression of soilborne pathogens of broccoli and kale plants. An additive effect on plant biomass was observed when solarization and MS were combined. All treatments significantly increased the establishment of broccoli plants and decreased root infection by Rhizoctonia solani in both crops. The incidence of Fusarium sp. was significantly decreased by all treatments in kale roots, and in broccoli by MS alone and in combination with solarization. Shoot fresh weight was significantly increased in kale by all treatments and in broccoli by solarization plus MS.

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The Munsell Color System was used to study pecan [Carya illinoinensis (Wangenh.) K. Koch] kernel colors and color changes for 21 clones, 11 locations, and five storage methods for nuts collected over 4 years. Hue readings ranged from 10.0 (10 red) to 22.5 (2.5 yellow). Value readings ranged from 2.0 to 8.0, and chroma readings ranged from 1.0 to 8.0. A total of 91 classes (individual combinations of hue, value, and chroma) were needed to describe all kernel colors. Overall, one class 115.0/5/4 (hue/value/chroma)] accounted for 3979 of the 32,078 readings taken, and the 15 most common classes accounted for 80.7% of all the readings. This system of color determination was well-suited for pecan color determinations and continues to be used routinely as a part of our breeding and genetics program to define this important quality trait in pecan.

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The Munsell system of color notation was used to study differences in kernel color arising between four pecan cultivars (`Cheyenne', `Choctaw', `Western', and `Wichita') grown at four locations (Tulare, Calif., and Brownwood, Crystal City and El Paso, Texas) during two seasons (1987 and 1988) and were stored under different temperatures (ambient and frozen). The hue, value, and chroma of pecan kernels varied significantly in the 2 years of the test. Kernels collected in 1987 were more yellow and lighter and had greater color saturation than kernels collected in 1988. Cultivars differed in hue, value, and chroma at the initial color determination. `Cheyenne' kernels were the most yellow (hue of 18.8) and were the lightest (value of 6.4) of any cultivars tested. `Wichita' kernels were more intensely colored (chroma of 4.7) than `Cheyenne' or `Choctaw' kernels. Kernels from pecan trees in El Paso were more yellow than those from other locations and were lighter than kernels from either Brownwood or Tulare, Calif. Kernels evaluated after being frozen 6 or 12 months could be distinguished from fresh kernels on the basis of hue. Frozen samples were more red than fresh kernels. Kernels frozen 12 months were less intensely colored than fresh kernels or those frozen only 6 months. There was a significant linear relationship between time in the freezer and each color attribute. Hue and chroma were negatively correlated with storage time, while value was positively correlated.

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Abstract

Sleeved poinsettia plants (Euphorbia pulcherrima, Willd. cvs. Annette Hegg Supreme and Annette Hegg Dark Red) stored best at 10°C. Lower temperatures (2-7°C) induced chilling damages as manifested mainly by bract blueing. Higher temperatures (up to 16°) resulted in increased leaf petiole epinasty and bract drooping. The bract blueing and leaf petiole epinasty disorders became worse as storage duration increased from 2 to 10 days, while bract drooping decreased during this same period. Plants sleeved and stored in paper were generally of higher quality upon removal than those sleeved and stored in plastic. Under relatively static conditions (15m/minute air speed), poinsettias froze at about −4°. Sleeving poinsettias delayed low-temperature damage. The injury of sleeved poinsettias was related to temperature, air speed, and exposure time which can be estimated by: time to injury (minutes) = 3.94 × chill factor (°C) + 61.9.

Open Access

The Munsell Color System was used to define pecan [Carya illinoinensis (Wangenh.) K. Koch] kernel colors and color changes for 21 clones, 11 locations, and 4 storage methods for nuts collected over a 4-year period. Hue readings ranged from 10.0 (10 red) to 22.5 (2.5 yellow). Value readings ranged from 2.5 to 8.0, and chroma readings ranged from 1.0 to 8.0. A total of 91 color chips (individual combinations of hue, value, and chroma) were needed to describe kernel color variability. In 1987 and 1988, one color [15.0/5/4 (hue/value/chroma)] accounted for 3,979 of the 32,078 readings taken, and the 15 most common colors accounted for 80.7% of all the readings. The Munsell system of color determination was well suited for pecan color determinations. A simplified color rating system with only six color classes was developed for general use by the pecan industry. This system is also routinely used in our breeding and genetics program to define this very important quality trait in pecan.

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Abstract

Hydrocooling, forced air cooling, and hydrocooling plus forced air cooling techniques reduced the 7/8 mass mean cooling time of packaged potted chrysanthemums (Chrysanthemum morifolium Ramat.) by 57, 43, and 70%, respectively, compared to cooling under normal refrigeration. Mass mean 7/8 cooling time for plants in boxes with 0, 1 or 5 sides exposed to normal air movement in refrigerated storage was 49, 21 and 10 hours, respectively. Plants hydrocooled and stored at 2°C for 0, 5, or 10 days had equal postharvest longevity upon removal compared to plants cooled to 2°C in 60 hours and subsequently stored for the same periods. Plants stored at 22°C displayed equal postharvest longevity after 5 days of storage but were inferior after 10 days storage compared to rapidly cooled plants. Reasons for determining plants inferior varied according to cultivar.

Open Access

The Munsell color system was used to study kernel color differences between four pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars (`Cheyenne', `Choctaw', `Western', and `Wichita') grown at four locations (Tulare, Calif., and Brownwood, Crystal City, and El Paso, Texas) during two seasons (1987 and 1988) and stored under different temperatures (20 to 24 °C and -5 °C). Kernel color changed over time from yellow to red hues and from lighter to darker values, but changed very little in chroma. Initial ratings of each color attribute by cultivar were positively correlated with patterns of change in that attribute over time. Kernels collected in 1987 were more yellow and had greater color saturation than kernels collected in 1988. `Cheyenne' kernels were the most yellow of the cultivars tested and `Wichita' kernels were the most red. `Cheyenne' kernels were lighter than those of any other cultivar. Kernels frozen 6 or 12 months were more red in hue than unfrozen kernels, but could not be distinguished on the basis of value (lightness). Kernels frozen 12 months had reduced chroma compared to those frozen 6 months or unfrozen. Shelled kernels of `Wichita' changed hue more in storage than kernels of other cultivars. Shelled kernels held at 20 to 24 °C became darker and developed red coloration quicker than unshelled pecans. Variation in hue and value accounted for the majority of color difference between cultivars. Changes in hue accounted for the majority of color change over time. Differences among cultivars in value (lightness) were consistent over time.

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Abstract

‘McShay’ is an attractive, excellent quality apple (Malus × domestica Borkh.) with field immunity to apple scab. The fruit is similar in color, flavor, and texture to ‘McIntosh’. ‘McShay’ is named in honor of the late J. Ralph Shay and is a late fall dessert apple well-adapted to Oregon's Willamette Valley. ‘McShay’ is the ninth cultivar to be released by the cooperative apple breeding program of Indiana, Illinois, and New Jersey Agricultural Experiment Stations.

Open Access