Related Papers
HortScience
Potential Uses and Water Demand of Pigeonpeas in Mixed Intensive Horticultural Systems in Dry-subtropical Northwest Mexico
1995 •
Federico Salinas
A water demand model based on the plant–water–climate interactions is proposed to establish the effects of the photosynthetically active radiation (PAR) on the water demand processes of a crop. It is shown that a relationship exists between PAR, leaf temperature, and the transpiration of regional ecotypes of Northwest Mexico from Asia in the middle of the century. These ecotypes were found in the influence area of the Sierra de La Laguna, B.C.S., Biosphere Reserve. Estimated relationship was backed by measurements of leaf and ambient temperatures, and PAR, of which the transpiration is dependent. It is concluded that this procedure is useful to establish the expected level of transpiration of pigeonpeas and thus, their water requirements. The observed phenotype characteristics suggest the usefulness of pigeonpeas in intensive ecosystems; grain yield was near 6 Mg·ha–1. The results enable us to design appropriate horticultural systems in the villages of Sierra de La Laguna, which cou...
HortScience
Thinning and Enhanced Fruit Quality of Stone Fruits with Gibberellins
1995 •
Daniel Ward
Release LC (Abbott Laboratories), a commercial formulation of gibberellins, was applied to apricot, cling peach, freestone peach, nectarine, and plum varieties. Application was by commercial airblast sprayer. Fruit firmness was increased in the season of application in all crops. Meta analysis of the data indicated a maximum response for each crop differed over the rate range of 16 to 48 g a.i./acre. Changes in fruit soluble solids were slight. No differences in fruit color were observed. Reduction in flower bud density (thinning) was observed the following season. The reduction in bud density reduced the time required to hand-thin to a commercially acceptable level. A difference in thinning sensitivity to gibberellin was evident between crops.
HortScience
Coating Waxes on Pepper Fruits cv. Caribbean and Quality on Different Storage Conditions
Judith Zambrano
Pepper fruits (Capsicum annum L. c.v. Caribbean) were treated with two commercial was coatings, Primafresh and Prolong. Fruits were sprayed with Primafresh (original concentration) and Prolong at 0.5% and 1.5% (w/v) concentration. Fruit samples were taken for analysis each of 5 days during 20 days from storage rooms at 1, 5, 10, and 15C. Parameters TSS, titratable acidity, pH, fresh fruit weight loss, texture, and dry matter content were analyzed. TSS and dry matter decreased with the storage time. Titratable acidity increased until 10 days after storage and decreased when fruit were stored for a longer time. The lowest texture deformation was observed at 1 and 5C. Coating treatments reduced the rate of fresh fruit weight loss of peppers compared to uncoated ones.
HortScience
Copper Sprays—Effects on Apple Fruit Typiness and Market Color Grades
1995 •
Rhoda Burrows
Late dormant copper (Cu) sprays and mid-summer foliar Cu sprays are being promoted within the Washington apple industry as a means to enhance fruit typiness and red skin color, respectively. While there appears to be theoretical bases for these practices, they have not been tested for horticultural significance. Differential late dormant spray treatments of Cu hydroxide (the Cu source most commonly recommended by agricultural consultants) were imposed in two `Delicious' orchards. Flower cluster Cu was positively related to Cu rate, but the sprays had no effect on leaf Cu or on six fruit typiness variables. Differential mid-summer spray treatments of water, Cu sulfate, and Cu oxysulfate solutions were imposed in three `Delicious' orchards and one `Fuji' orchard. The Cu sprays increased leaf Cu, but had no effect on market color grade measured using a commercial color sorter. The results appear to reflect Cu physicochemistry and timing of application. These preliminary res...
HortScience
Grower Contributions to the Early Stages of Crop Nutrient Trials with Vegetables
1995 •
George Hochmuth
Trials to determine crop nutrients for four vegetable crops grown on the limestone soils of Dade County, Fla., have been conducted in growers' fields to duplicate commercial growing conditions. This has increased grower participation in the experimental process. The four vegetable crops are snap beans, Irish potatoes, sweet corn, and malanga (a.k.a. yautia or tannia, Xanthosoma sagittifolium Schott). The discussion will focus on grower participation in various critical decision-making activities: a) location of plots in a commercial field, b) placement of fertilizers, c) possible problems with Restricted Entry Intervals, d) harvest determinations, and e) grading criteria and quality assessment.
HortScience
Gas Exchange Responses of Papaya Leaves to Light Variation as Influenced by Drought
1995 •
Thomas Marler
Container-grown papaya plants were subjected to a slow drying cycle by replenishing a portion of the mean daily water loss. When light-saturated net CO2 assimilation (A) of stressed plants was ≈70% of well-watered plants, sun–cloud transitions were simulated by placing shadecloth between a lamp and the leaf cuvette. The cuvette was initially positioned to receive photosynthetic photon flux (PPF) of ≈1600 μmol–m–2–s–1. The shadecloth was placed over the cuvette for a 3-min period (250 μmol–m–2–s–1), then removed. Gas-exchange responses were recorded for another 3 min of high light. Within 20 sec of initiating low light on well-watered plants, A was <50% of the high-light value. Stomatal conductance (gs) of these plants began to decline by 60 sec and slowly declined to <90% of the high-light value. Both A and gs recovered to the original values by ≈2 min following return to the high-light conditions. For stressed plants, the decline of gs under low light began earlier and was of...
Hortscience
Does Quality Pay?
1995 •
Laura Kippen
HortScience
Use of Core Subsets in Developing Germplasm Collections of Clonally Propagated Crops
LJ Grauke
Core subsets have been formed in several clonally propagated crops; for pear (Pyrus), strawberry (Fragaria), mint (Mentha), currant (Ribes), blackberry (Rubus), blueberry (Vaccinium), apple (Malus), and pecan [Carya illinoinensis (Wangenh.) K. Koch]. Criteria for selecting entries into each core varies, as does the use each core receives. Core subsets have been selected for each of the major collections maintained at NCGR-Corvallis (pear, strawberry, mint, currant, blackberry, and blueberry). In general, core subsets include 10% of the full collection. Entries were selected on the basis of horticultural characteristics and species representation. Management of the collection is facilitated by recognition of core entries, which are frequently distributed. The 2500 accessions of the Malus collection are represented in a core subset of 200 accessions. Of those, 100 represent the 35 known species, while 100 accessions were selected from elite clones on the basis of horticultural charact...
Hortscience
Early Growth Model of Muskmelon (Cucumis melo L. cv. Hiline) Using Accumulative Windspeed Frequency
1995 •
Entin Daningsih
HortScience
The Effect of Salinity on Growth and Physiology of `Hass' Avocado on Three Rootstocks
1995 •
Mary Arpaia
Salinity effects on `Hass' avocado was studied on three rootstocks, `Thomas' (TH), `Toro Canyon' (TC), and `Duke 7' (D7). Four levels of salinity (1.4, 3.0, 4.5, and 6.0 dS·m–1) were applied to 1-year-old trees grown in sand culture for 10 weeks. Increased salinity resulted in decreased trunk cross-sectional area and reduced shoot growth. Specific leaf area and dry weight decreased linearly with increased salinity. TH was significantly more affected than TC of D7. Leaf necrosis was also greatest in TH. Older leaves had the highest percentage of leaf necrosis, while younger leaves of TH exhibited symptoms only in the 6.0 dS·m–1 treatment. TH had the highest Cl leaf levels. TC maintained the lowest Na levels in the scion plant organs, indicating an ability to sequester Na in the rootstock. TC also had the lowest Na:K ratio in leaf tissue, indicating that TC can utilize K as an osmoticum. Predawn xylem potential decreased linearly with increased salinity in all rootstoc...
