bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibiosis to Beet Armyworm (Spodoptera exigua) in Lycopersicon Accessions
Authors: Eigenbrode Sanford D. , Trumble John T.
Published: February 2019

Four accessions of Lycopersicon hirsutum f. glabratum Mull. and eight accessions of L. hirsutum f. typicum Humb. & Bonpl. were evaluated for their resistance to the beet armyworm [Spodoptera exigua (Hübner)]. Survival of S. exigua neonate larvae for up to 96 hours on foliage of all these accessions differed significantly from their survival on a susceptible tomato cultivar. Spodoptera exigua survival did not differ significantly between the two forms of L. hirsutum. Antibiosis to S. exigua in L. hirsutum f. glabratum appears similar to the levels found to other Lepidoptera. Accessions of L. hirsutum f. typicum included the very susceptible PI 199381 and the two most resistant accessions, LA 2329 and LA 1777. Insect resistance had not been reported previously in four of the L. hirsutum f. typicum accessions. Spodoptera exigua survival was significantly negatively correlated with the density of type IV glandular trichomes on the leaf surfaces, calculated across all 12 accessions. This relationship did not occur within L. hirsutum f. glabratumor L. hirsutum f. typicum accessions, nor was it significant if PI 199381 was excluded from the analysis. Leaf-surface exudates of L. hirsutum f. glabratum accessions were dominated by the methylketones 2-undecanone and 2-tridecanone. Leaf-surface exudates of L. hirsutum f. typicum were dominated by three sesquiterpenes-zingiberene, δ elemene, and γ elemene. Resistance was not correlated with the amounts of these specific compounds within or across botanical form. Spodoptera exigua survival in L. hirsutum f. typicum (excluding PI 199381) correlated negatively with the total estimated amount of leaf-surface volatiles extracted. PI 199381 may be useful as a susceptible parent for intraspecific crosses to examine S. exigua resistance in L. hirsutum.
Rapid Estimation of Fruit Starch and Soluble Sugar Concentrations in Kiwifruit
Authors: Seager Nicky G. , Haslemore Roger M.
Published: February 2019

Experiments investigating kiwifruit [Actinidia deliciosa (A. Chev) C.F. Liang et A.R. Ferguson var. deliciosa] maturation were undertaken requiring the determination of total soluble sugar (TSS) and starch concentrations in numerous fruit samples. The phenol-sulfuric acid assay was judged to he a convenient method for determining TSS from tissue extracts and gave results similar to those obtained by high-pressure liquid chromatography. The starch procedure adopted involved gelatinizing fruit tissue using hot water and a thermostable α -amylase (Termamyl); hydrolizing starch using amyloglucosidase; and determining glucose using glucose oxidase. The methods enabled one person to analyze up to 40 kiwifruit samples for TSS and starch concentrations during 9 hours and likely will be applicable to research concerning fruit development and maturation.
Performance of Micropropagated `Queen Elizabeth' Rose following Mechanically Induced Stress
Authors: Korban Martine , Donnelly Danielle J.
Published: February 2019

Mechanically induced stress (shaking stress) applied during shoot multiplication (Stage II) or rooting (Stage III) of micropropagated `Queen Elizabeth' rose was evaluated to determine its effects on in vitro hardening. Shaking during Stage II did not alter the growth responses of the shoots before transfer to Stage III. Shaking during Stage III, at 150 rpm for 15 min daily for 2 weeks, only caused a reduction in leaf dry weights before transfer to soil. Automated shaking stress during Stages II or III did not apparently promote hardening of cultured plants or improve their ex vitro performance.
Summer Squash Production Using Conservation Tillage
Authors: NeSmith D.S. , Hoogenboom G. , McCracken D.V.
Published: February 2019

Three summer squash (Cucurbita pepo L.) cultivars were grown using conventional tillage and no-till soil management practices during 1991 and 1992 in the mountain regions of Georgia. Soil bulk density and N content as well as crop dry weight, leaf area, and yield were monitored to assess the potential for using conservation tillage in squash production. Soil bulk density of the surface (0 to 10 cm) layer under no-till exceeded. that under conventional tillage at planting by 0.25 Mg·m-3, and 1 month after planting by as much as 0.16 Mg·m-3. However, growth-limiting bulk densities (>1.45 Mg·m-3) did not occur. Total soil N to a 30-cm depth was similar for the two tillage regimes. There were no significant cultivar × tillage interaction effects on plant dry weight, leaf area, or crop yield. Total yields were similar for the two tillage regimes; however, early yield during 1991 was 27% less using no-till. There is potential for the use of conservation tillage in summer squash production in the southeastern United States. However, the current lack of registered herbicides for weed control and possible early market price incentives are likely disadvantages to widespread acceptance of such cultural practices.
Rapid Propagation of Blueberry Plants Using ex Vitro Rooting and Controlled Acclimatization of Micropropagules
Authors: Isutsa Dorcas K. , Pritts Marvin P. , Mudge Kenneth W.
Published: February 2019

A protocol is presented that enables a propagator to produce field-sized blueberry transplants within 6 months of obtaining microshoots from tissue culture. The protocol involves subjecting microshoots to ex vitro rooting in a fog chamber under 100 μmol·m–2·s–1 photosynthetic photon flux for 7 weeks, transferring plants to a fog tunnel for 2 weeks, then to a greenhouse for 7 more weeks. Plant survival and rooting of cultivars Berkeley (Vaccinium corymbosum L.) and Northsky (Vaccinium angustifolium ×corymbosum) were near 100% under these conditions. Plantlets in fog chambers receiving 100 μmol·m–2·s–1 grew rapidly, while those at lower irradiance levels grew more slowly, and supplemental CO2 enhanced growth only at 50 μmol·m–2·s–1. Growth rates slowed when plants were moved into the fog tunnel; but by the end of 16 weeks, plants that were under high irradiance in the fog chamber had root systems that were 15 to 30 times larger than plants under low irradiance. Within 6 months, these plants were 30 to 60 cm tall and suitable for field planting.
Cranberry Tolerance to Clopyralid
Authors: Patten Kim , Wang John , Katz Fred , Riemer Don , Kusek Chuck , Hopen Herb
Published: February 2019

Tolerance of cranberry (Vaccinium macrocarpon Ait.) at different phenological stages to the postemergent broadleaf herbicide clopyralid (0.21 or 0.42 kg a.i./ha) was evaluated in Washington, New Jersey, Massachusetts, and Wisconsin. Tolerance varied among states, rates, and application times. Applications made during early shoot growth, especially at the high rate, usually resulted in the most crop injury (leaf cupping and epinasty and reduced yield); while applications at the low rate made after vegetative development occurred usually resulted in less or no injury. No phytotoxicity occurred when applications were made before shoot growth (Washington and New Jersey). Chemical name used: 3,6-dichloro-2-pyridinecarboxylic acid (clopyralid).
Feasibility of Improving Cucumber Yield without Chemical Control in Soils Susceptible to Nematode Buildup
Authors: Hanna H.Y. , Colyer P.D. , Kirkpatrick T.L. , Romaine D.J. , Vernon P.R.
Published: February 2019

Studies were conducted for 2 years in root-knot-nematode-infested soils to determine growth and yield response of `Dasher II' cucumbers (Cucumis sativus L.) to double-cropping with nematode-resistant tomatoes (Lycopersicon esculentum Mill.), using nematode-free cucumber transplants and preplant treatment with ethoprop nematicide. Cucumbers grown following the nematode-resistant `Celebrity' tomato during the same season produced significantly more plant dry weight, more fruit per plant, and higher premium and total yields than did cucumbers double-cropped with the nematode-susceptible `Heatwave' tomato in both years. The cucumber produced longer stems in 1992 and fewer culls in 1993 following resistant tomatoes. Cucumber plants raised in nematode-free soilless mix for 3 weeks before transplanting produced significantly longer stems and more plant dry weight than did direct-seeded cucumbers in 1992, but not in 1993; however, they produced significantly higher premium yield in both years, and higher total yield, more fruit per plant, and fewer culls in 1993. Preplant treatment with ethoprop significantly increased cucumber stem length, dry weight, premium and total yield, and number of fruit per plant in 1992 but not in 1993. Ethoprop treatment had no effect on the percentage of culls in either year. Chemical name used: O-ethyl S,S-dipropyl phosphorodithioate (ethoprop).
Yield Stability Differences among Tomato Genotypes Grown in Latin America and the Caribbean
Authors: Ortiz Rodomiro , Izquierdo Juan
Published: February 2019

The environment substantially affects the performance of tomato (Lycopersicon esculentum Mill.) genotypes in Latin America and the Caribbean (LAC). Therefore, stability analysis can be used to select stable, high-yielding genotypes. Nine openpollinated and six hybrid tomato genotypes and the most representative local tomato cultivar were evaluated at 20 LAC locations. Each cultivar's yield stability was quantified using the regression of individual genotype's yield on the environmental index, which was measured by the mean of all the genotypes grown in an environment. A high-yielding and stable tomato cultivar had a mean yield higher than the general mean, b1 (coefficient of regression) = 1, s2d (deviation from linearity) = 0, and r2 (coefficient of determination) >0.50. `Narita' (hybrid) and `Dina RPs' (open-pollinated) were the most stable genotypes for marketable-fruit yield in LAC. `Flora Dade', an open-pollinated genotype that is grown widely in LAC had unstable marketable-fruit yield. Neither heterogenous composition of an open-pollinated genotype nor heterozygosity per se of the hybrids could explain the yield stability achievement across environments. Therefore, alleles that confer broader adaptation might be required to achieve tomato yield stability across environments. Hence, it is possible to select for yield stability in tomato.
Seedling Development of Sugar Maple and Black Maple Irrigated at Various Frequencies
Authors: Graves William R.
Published: February 2019

Growth, dry-matter partitioning, and specific mass of lamina of black maple (Acer nigrum Michx.f.) and sugar maple (A. saccharum Marsh.) irrigated at 10-, 26-, and 42-day intervals were compared. Total dry mass, stem length, and surface area of lamina were greater for sugar maple than for black maple for plants irrigated every 10 days. Reducing irrigation frequency curtailed growth of both species, but the reduction was greater for sugar maple than for black maple. The shoot: root ratio was lower for black maple than for sugar maple and was reduced by drought in both species, particularly among plants irrigated every 26 days. Specific mass of lamina increased as plants aged, was greater for black maple than for sugar maple, and decreased in response to irrigation at 42-day intervals. The slower growth, lower shoot: root ratio, and greater specific mass of lamina of black maple indicate this species has a greater capacity to withstand drought than sugar maple.
Micropropagation of Pacific Dogwood
Authors: Edson John L. , Wenny David L. , Leege-Brusven Annette
Published: February 2019

Idaho's population of Pacific dogwood (Cornus nuttallii Audubon) has declined. Propagation of disease-resistant clones would be useful to horticulturists and conservation biologists. In vitro-derived microshoots, incubated for 1 month on woody plant medium supplemented with 6.04 mm calcium gluconate and 4.44 μm benzyladenine, produced an average of 3.1 axillary microshoots per explant. Up to 62% of the elongated microshoots had rooted ex vitro 5 weeks following a 4.5%IBA talc dip. Plantlets resumed shoot growth within 2 months of acclimatization, and 70% survived after 1 year. This protocol is more rapid and efficient than propagation by layering or rooting the difficult-to-root stem cuttings of this species. Chemical names used: 2,3,4,5,6-pentahydroxy-caproic acid (calcium gluconate), benzyladenine (BA), 3-indolebutyric acid (IBA).
A FILM-COATED BROCCOLI SEED PRODUCT
Authors: Watkins James T.
Published: February 2019

Sakata Seed America investigated the possibility of marketing a film-coated broccoli seed product. Film coating is the process of applying a colored polymer film material onto the seed surface that completely covers the seed and any seed pesticide. Film-coated seed has the benefit of providing uniform and precise pesticide placement, is dust free, safe to handle, can be highly visible in the soil, and has increased flowability in seed planters. The drawbacks arc the cost of the film-coating machinery and the film product as well as the slower application rate. The basic application procedure of film products to broccoli seed and the effects of film products on seed viability and seed storage will be discussed.
CONTROL OF SEPTORIA LEAF SPOT OF PISTACHIO (PISTACIA VERA)
Authors: Call Robert E. , Matheron Michael E.
Published: February 2019

Studies were established in 1992 and 1993 in a mature commercial pistachio orchard to determine the effectiveness of several fungicides for control of septoria leaf spot (Septoria pistaciurum). Fungicide treatments used in 1992 were Bravo 720F at 3.0 lbs./A (ai.) and 4.5 lbs./A a.i.; Kocide 101 50W at 8.0 lbs./A a.i. plus Benlate 50W at 1.0 lb./A a.i. Fungicide treatments in 1993 were Bravo 825 WDG at 3.0 and 4.5 lbs./A a.i. and Benlate 50W at 2.0 lbs./A a.i. Treatment replications consisted of two treated trees separated by nontreated trees within the row and nontreated tree rows dividing treated rows. At crop maturity, disease severity was determined by counting the number of leaf spots caused by septoria on ten leaves collected at random from each of the two trees of each replicated plot. All treatments significantly reduced disease severity compared to trees receiving no fungicide treatments. Experimental plots were too small to detect any apparent effect of fungicide treatments on yield. Leaves around nut clusters not receiving fungicide treatments were senescent at crop maturity, while leaves on treated trees showed no sign of senescence.
EFFECT OF INSECTS AND INSECTICIDES ON ONION SEED AND BROCCOLI SEED PRODUCTION IN SOUTHWEST ARIZONA
Authors: Rethwisch Michael D.
Published: February 2019

In 1991 and 1992, insecticide trials were conducted on onion and broccoli grown for seed, respectively, near Yuma, Ariz., to evaluate the effects of insects and insecticide treatments on seed production. Four insecticides (Agri-Mek, Ammo, Capture, Lorsban) were evaluated on onions where both western flower thrips [Frankliniella occidentalis (Pergande)] and onion thrips (Thrips tabaci Lindeman) were present. Visual differences between treatment resultant from onion thrips damage were evident within 10 days after treatments were applied at flower opening. Lorsban, Ammo, and Capture treatments provided control of onion thrips based on condition of seed heads. Ammo and Capture were the only treatments that increased seed yield, as the Lorsban treatment was thought to repel bees needed for pollination. Pyrethroid treatments yielded 40% more seed than the nontreated check, which yielded more than Lorsban and Agri-Mek treatments. Four insecticide treatments (Thiodan, CGA-215944, and two rates of RH7988) were evaluated on broccoli seed where green peach aphid [Myzus persicae (Sulzer)] was present. All treatments reduced aphid numbers compared to the nontreated check, with RH7988 providing most control. Seed yields (g/plant) were reduced in all insecticide-treated plots compared with the nontreated plots, although percentage of seed sized larger than 4.5/64” was apparently correlated with increased aphid control. Seed yield per plant was higher from the lower rate of RH7988 than the higher rate. Plants treated with RH7988 had almost 0.5 g/plant more seed sized 5.5/64” than other treatments.
PURPLE NUTSEDGE CONTROL IN FALL VEGETABLES WITH EPTC AND SUMMER FALLOW
Authors: Tickes Barry
Published: February 2019

Purple nutsedge (Cyperus rotundus) has become increasingly widespread in vegetable crops planted from August to October in the low deserts. A herbicide that is both effective and safe to crops has not yet been found. Several tests were conducted in southwestern Arizona to evaluate the efficacy of EPTC combined with summer fallow for the control of purple nutsedge. Preirrigation applications of the emulsifiable concentrate and granular formulation of EPTC were ineffective. These same treatments, applied after irrigation, when the top 6 inches of soil were dry, were very effective (75% to 90%) in controlling the emergence of purple nutsedge shoots. These tests demonstrated the importance of proper application and cultural practices when using this treatment before planting fall vegetables.
IMPLEMENTATION OF A SUSTAINABLE SMALL FARM EDUCATIONAL PROGRAM IN THE GILA RIVER INDIAN COMMUNITY, ARIZONA-A BEGINNING
Authors: Gibson Rick , Rhodes Everett , Sunna Marshall
Published: February 2019

An educational attempt to assist Gila River Indian Community members to return to a sustainable small-farm heritage has shown initial success after 1 year. The project uses horticultural technology to help tribal members overcome severe social concerns. The first phase addressed the needs of youth at risk through a 10-acre farm at the Gila River Indian Community Juvenile Rehabilitation and Detention Center in Sacaton, Ariz. During 1993, the farm operation leveled 10 acres of squash, corn, and watermelons; planted and cared for 200 deciduous fruit and citrus trees; and planted and cared for 150 commercial Christmas trees. Produce was either sold to community members or donated to community food centers at the schools or at homes for the elderly. The youth were led by 14 volunteers who completed an intensive training program and were certified as Master Gardeners by the Univ. of Arizona. They have donated -300 hours of time to the project. The project gave youth at risk an opportunity to learn new concepts and skills, gain exercise, and work off detention time. As tribal leadership observed the initial successes, they gave permission to address health and nutrition as well as other youth-at-risk targets within the community beginning in 1994.
EFFECTS OF WILTHIN ON BLOSSOM THINNING OF `LOADEL' PEACHES
Authors: Yoshikawa Frank T. , Martin G.C. , Ramos D. , Yeager J.T.
Published: February 2019

Various rates of Wilthin were applied at full bloom to limbs carrying 150 to 250 flowers to study their activity on blossom thinning of `Loadel' peaches. Wilthin applied at 0.75% and 1.0% significantly reduced fruit set to 29% and 30%, respectively, while the control produced 94%. The effectiveness of the 0.75% rate was dramatic, but it is interesting to note that the 1.0% rate did not lead to excessive thinning nor phytotoxicity on foliage or fruit. More extensive studies need to be done to fully determine the potential of this material. However, these results suggest that further testing of Wilthin on a larger scale is warranted.
Field Chlorophyll Measurements to Assess the Nitrogen Status of Potato Varieties
Authors: Minotti P.L. , Halseth D.E. , Sieczka J.B.
Published: February 2019

We report three N rate experiments conducted on a gravelly loam soil to assess the N status of potato (Solanum tuberosum L.) using a Minolta SPAD-502 chlorophyll meter. Highly significant linear and quadratic trends were obtained for the regression of N rate on marketable tuber yields and SPAD readings. SPAD readings were taken at four times during the growing season and decreased as plants aged. Based on regression analysis, the early season SPAD readings, associated with N rates giving maximum marketable tuber yields, ranged from 49 to 56 units depending on year, variety, and location. Potato variety significantly affected SPAD values in eight of the 12 situations where readings were obtained. Precision in interpretation was improved when the highest N rates were considered “reference strips” to standardize the SPAD readings across varieties and growing seasons. Our results suggest that field SPAD readings can readily identify severe N deficiency in potatoes, have the potential to identify situations where supplementary sidedressed N would not be necessary, but would be of limited value for identifying situations of marginal N deficiency unless reference strips are used.
Time-domain Reflectometry for Measuring Water Content of Organic Growing Media in Containers
Authors: Anisko Tomasz , NeSmith D. Scott , Lindstrom Orville M.
Published: February 2019

The time-domain reflectometry (TDR) method of measuring water content has been applied to mineral soils but not to organic growing media. We investigated the applicability of TDR for measuring the water content of organic media in containers. TDR calibration was conducted for sand, peat, composted pine bark, sand and peat mix, sand and bark mix, and a commercial growing medium (Metro Mix 300). Regression analysis of volumetric water content was conducted with the ratio of apparent: physical length of the probe (La: L) as an independent variable. The calibration curve for Metro Mix 300 was compared to curves generated for a range of soils by other investigators. Additionally, water-content and La: L changes were monitored in Metro Mix 300 for 10 months and were compared to predicted values from the calibration curve. Organic media had a higher water content than sand for the same La: L value. Equations developed by previous authors generally underestimated water content when compared with the calibration curve for Metro Mix 300. We attribute this difference to a large fraction of highly decomposed organic matter or vermiculite and, thus, to the presence of more bound water. Specific calibration of TDR may be required to determine the absolute water content of organic growing media.
Micropropagation of Cephalotaxus harringtonia
Authors: Janick Jules , Whipkey Anna , Kitto S.L. , Frett J.
Published: February 2019

Shoot proliferation of Japanese plum yew [Cephalotoxus harringtonia (Forbes) K. Koch] derived either from a seedling or from a mature clone was achieved in a medium based on Murashige and Skoog salts supplemented with vitamins and casein hydrolysate in the presence of 10% (v/v) coconut water. Rooting was unsuccessful from microcuttings proliferated on agar-based medium, but, when cultured in liquid medium on membrane rafts, detached shoots rooted under mist in greenhouse conditions with or without auxin treatments. Rooted microcuttings successfully acclimated to greenhouse conditions.
Lima Bean (Phaseolus lunatus L.) Response to Irrigation Regime and Plant Population Density
Authors: Sirait Yacob , Pill Wallace G. , Kee Walter E.
Published: February 2019

`Maffei-15' lima beans were subjected to three irrigation regimes (natural rainfall only, partial = 50 mm each week of rain or irrigation from first-flower bud to harvest, and full = 50 mm each week of rain or irrigation from planting to harvest), two between-row spacings (38 and 76 cm), and two in-row plant spacings (5 and 10 cm). The wider in-row spacing increased individual plant vegetative growth but had no effect on economic yield. The combination of 38-cm rows and partial irrigation provided the highest crop growth rate, plant dry matter, leaf area index, water-use efficiency, and economic yieid (equivalent to 3.3 t·ha-1).
Selective Bee Attractants Did Not Improve Cucumber and Watermelon Yield
Authors: Schultheis Jonathan R. , Ambrose John T. , Bambara Stephen B. , Mangum Wyatt A.
Published: February 2019

The effectiveness of two commercial bee attractants, Bee-Scent and Beeline, for enhancing pollination of cucumber (Cucumis sativus L.) and watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] was evaluated by counting the number of bee visitations to blossoms of cucumber and watermelon and their effect(s) on fruit quality, yield, and crop profitability. In 1989, Bee-Scent was tested in a commercial pickling cucumber field. In 1990, watermelon plots were sprayed with Bee-Scent and Beeline and compared with a nontreated control. The compounds did not improve bee visitations for either pickling cucumbers or watermelons. There was no significant improvement in cucumber or watermelon yield or monetary returns.
Rapid Flowering of Microcultured Cranberry Plants
Authors: Serres Rodney , McCown Brent
Published: February 2019

The capability to uniformlyinduce flowering in cranberry (Vaccinium macrocarpon Ait. `Stevens') in < 1 year from microculture was investigated to accelerate cranberry breeding and to study woody plant reproductive biotechnology. Flower buds were induced on newly micropropagated cranberry plants during the first growing season. A treatment of 2.5 mg of paclobutrazol applied as a soil drench per 2- to 3-month-old potted plant in midsummer, when the plants were grown in coldframes under natural daylength and air temperatures, resulted in 70% of the plants flowering. Plants not treated with paclobutrazol did not flower. Reduced but significant flower bud set was observed on plants treated with paclobutrazol but grown in the greenhouse under natural daylength. Flowering was stimulated by cold treatment coupled with gibberellin sprays and/or repotting to nonpaclobutrazol-treated medium. Chemical name used: β -[(4-chlorophenyl)methyl]-ct-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Removing New Growth Reduces Fruiting in Cranberry
Authors: Roper Teryl R. , Klueh John S.
Published: February 2019

The sources of photosynthate for fruit growth in cranberry (Vaccinium macrocarpon Ait.) can be spatially partitioned as new growth, old leaves and woody stems, or adjoining uprights. New growth, l-year-old leaves, or both were removed at the time of fruit set and following fruit set. Removing new growth at the time of fruit set reduced fruit set, fruit count, and yield. Removing old leaves at fruit set generally did not reduce fruit set, fruit count, or yield. Removing both often had an additional effect. Removing new leaves after fruit set did not affect fruit set or count, but did reduce fruit size. Removing old leaves after fruit set did not reduce fruit set, fruit count, or size. These data suggest that new growth is an important source of photosynthate for fruit set.
Introgressing Cold-tolerant Ogura Cytoplasm from Rapeseed into Pak Choi and Chinese Cabbage
Authors: Heath Douglas W. , Earle Elizabeth D. , Dickson Michael H.
Published: February 2019

Cold-tolerant, Ogura male-sterile, somatic hybrid rapeseed (Brassica napus L.) lines were used as maternal parents in two independent introgression experiments. In one experiment, an atrazine-sensitive B. napus (aacc) somatic hybrid was crossed directly with a male-fertile pak choi (B. campestris Chinensis Group, aa) accession. Allotriploid (sac) progeny were then backcrossed to the recurrent pak choi parent. Forty-five percent of the progeny from the first backcross were determined to be diploids (aa). In the other experiment, an atrazine-resistant B. napus somatic hybrid was crossed first to a bridge line. Three additional backcross generations to Chinese cabbage (B. campestris Pekinensis Group) resulted in Chinese cabbage resistant to black rot (Xanthomonas campestris pv. campestris). These materials may be useful for production of B. campestris hybrid vegetable seed.
MULTIPLICATION OF POTATO TUBERS AND MINI-TUBERS BY SPROUT CUTTING AT 7-DAY INTERVALS
Authors: Frève Andrew , Auger M.
Published: February 2019

A multiplication technique by sprout cutting (spc) was developed at La Pocatière from 1988 to 1992. Tubers (t) or mini-tubers (mt) were warmed and, if necessary, treated to break dormancy. After 2 to 4 weeks of presprouting, they were planted 50 to 100 t per flat (28 × 53 cm) half filled with a soil mixture. The t or mt were planted partially in soil, leaving the bud end out. They produced roots in 3 to 8 days under 16 hours of light at 22 to 24C. When 50% of the sprouts have 3 to 4 cm, they were placed in the dark for 3 days and under the initial lighting condition on day 4. The sprouts were cut on day 5. The mother plants were maintained in the same conditions for another 72 hours before repeating the cycle 6 to 10 times (with the same t or mt). The multiplication rate depended on tuber size, storage period, and cultivar. The t (30 mm) and mt (15 mm) of `Novachip' with 14 and 7 months of storage, respectively, produced 55 and 4.3 spc/t or mt in four multiplications over 28 days. The mt (12 mm) of `Tolaas' with 6 months of storage and without breaking dormancy produced 10.3 spc/mt in eight multiplications over 87 days (it took 4 weeks to grow). An equation considering weeks of storage and t size has been developed with six cultivars and four seedlings to calculate the number of plants multiplied in 1 to 7 weeks.
SPECTRAL CHARACTERISTICS OF CELERY CULTIVARS' LEAF TISSUES
Authors: Tremblay Nicolas , Perron Yvon
Published: February 2019

As plant color is often modified by nutrient status, the use of spectoradiometric properties of leaf tissues appears to be a promising tool for quick and inexpensive diagnosis of crop fertility problems. This study was conducted to examine spectral variability associated with celery cultivars. Seedlings of Florida 683, Matador, Utah 5270, and Ventura were grown in a growth chamber for 10 weeks (transplant stage; TS). Reflectance and transmittance measurements were taken on the tallest leaf with a LI-COR LI-1800 spectroradiometer. Remaining seedlings were potted and transferred to a greenhouse for another 8 weeks (mid-growth stage; MS). Transmittance was established as the parameter most suitable to distinguish cultivars. Maximum F ratio was obtained at λ = 630 mn at TS, while there were two peeks (λ = 470 and 60 mn) at MS. A discriminant function was based on λ = 470; 630 and 670 mn correctly classified cultivars more than 8 times out of 10 at TS, and more than 7 times out of 10 at MS. Further studies should focus on the induction of nutrient deficiencies and the potential interferences of cultivars with their diagnosis.
EFFECTS OF SUCROSE ON METABOLIZE POOL SIZES AND RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE/OXYGENASE ACTIVITY IN STRAWBERRY PLANTLETS CULTIVATED IN VITRO
Authors: Hdider Chafik , Desjardins Yves
Published: February 2019

To identify the physiological and biochemical events leading to the negative effects of sucrose in culture medium on the photosynthetic capacity of plantlets cultivated in vitro, time-course changes in photosynthesis, metabolize pool sizes, and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity were investigated in strawberry (Fragaria × ananassa Duch. cv. Kent) plantlets following their transfer to medium with or without sucrose. When the plantlets grown in medium without sucrose were transferred to a similar medium with 30 g sucrose/liter, their net photosynthesis decreased and their level of phosphorylated compounds increased with time. In addition, initial Kcat, total Kcat, and the activation state of Rubisco decreased in these plantlets. Conversely, when the plantlets grown in medium with 30 g sucrose/liter were transferred to a similar medium without sucrose, their net photosynthesis slowly increased with time and their level of phosphorylated compounds slowly decreased. A slow increase with time of initial Kcat, total Kcat, and the activation state of Rubisco was also observed in these plantlets. The results of the present research suggest that the reduced photosynthetic capacity of strawberry plantlets cultivated in vitro in the presence of sucrose was the consequence of reduced Rubisco efficiency due to its deactivation and the possible presence of a putative tight binding inhibitor.
COMPARISON OF SENSORY, CHEMICAL, AND COLOR ATTRIBUTES OF DISEASE-RESISTANT APPLE CULTIVARS
Authors: Schupp J.R. , Work T.M. , Bushway R.J. , Perkins L.B. , Bushway A.A.
Published: February 2019

In 1989 and 1990, the sensory preference, chemical, and color attributes of three disease-resistant apple cultivars, `Liberty', `Nova Easygro', and `Jonafree', were compared to `McIntosh' at harvest and following 3 months of storage at 2C. Throughout the testing period, panelists equally preferred the flavor of `Liberty' and `McIntosh'. `Liberty' was significantly preferred for texture during the four sampling periods. `Jonafree' was significantly less preferred when compared to `McIntosh'. The color of `McIntosh' was preferred overall, followed by `Liberty'. `Jonafree' was least preferred for color. The percent soluble solids, titratable acidity, fructose, and sucrose concentrations decreased over time. Glucose and the sugar: acid ratio increased with time. Significant differences in chemical and color evaluations were found from year to year.
HYSTERESIS OF SOIL–ROOT INTERFACE WATER POTENTIAL AND TRANSPIRATION IN RESPONSE TO SOIL DEHYDRATION FOR PRUNUS × CISTENA GROWN IN DIFFERENT SOIL MIXES
Authors: Xu Hui-lian , Caron Jean , Gosselin André
Published: February 2019

Water potential at soil–root interface (ψ s-r) indicates soil water availability to the plants. It is related to plant water potential and transpiration. To know the characteristics of ψ s-r, in the plants under a subirrigation system, hysteresis of ψ s-r, as well as xylem water potential (ψ x) and transpiration were examined in response to soil dehydration for Prunus × cistena grown in three soil mixes: mix 1-composted bark, peat, and sand; mix 2—peat, bark, sand, and compost; and mix 3—peat, sawdust, and sand. When the soil mixes were dried from high to low water potential (ψ s), plants grown in mix 2 maintained higher ψ s-r, as well as higher ψ x and higher transpiration. However, when the soil mixes were dehydrated from the bottom, the relationships of ψ s-r, ψ x, and transpiration to ψ s showed strong hysteresis effect. ψ s-r was always lower at a given ψ s when soil was rewetted from dry to wet conditions than when soil was dried from wet conditions. ψ x and transpiration also showed hysteresis in response to soil dehydration. The extent of hysteresis was the largest in mix 2 and the smallest in mix 3. Hysteresis of ψ X or transpiration showed a similar trend to that of ψ s-r. This suggests that ψ s-r is a good indicator of soil water availability to the plants and more directly related to ψ X and transpiration than is ψ s. The difference in hysteresis of ψ s-r among soil mixes might be related to the properties of hydraulic conductance, which are determined by the soil texture. Hence, further study is needed to elucidate the mechanism of the hysteresis phenomenon.
FIELD PERFORMANCE AND SENSORY ANALYSIS OF EARLY TO MIDSEASON TOMATO CULTIVARS
Authors: Handley D. , Schupp M. , Work T. , Work R. , Bushway A.
Published: February 2019

Twelve early to midseason ripening tomato cultivars were evaluated for early and total marketable yield, fruit size, and external characteristics under the cool, short growing season of northern New England. The acceptability of external and internal color, texture, and flavor of four cultivars was evaluated by a sensory panel of 50 members. There was little difference between cultivars in total yield. This was probably due to an early frost that destroyed much of the later ripening fruit. `Summerset' had the highest early and overall yields but the smallest fruit size. `Johnny's 361` had high overall yield and large fruit with good early yields. `Pilgrim' had high early yield, good overall yield, and fair fruit size. `Jetstar' and `Daybreak' fell into the middle of the range for total yield and fruit size, but `Jetstar' had very low early yield. `Pik Red' and `Pik Rite' had low early and total yields but good fruit size. `Moreton Hybrid' had fair early and total yields and small fruit size. In the sensory analysis, `Sunrise' had the highest rated external color, while `Moreton Hybrid' had the lowest rating. Internal color ratings did not vary greatly, although `Sunrise' was least acceptable in this characteristic. `Jetstar' was rated highest for flavor and texture, followed by `Moreton Hybrid', `Sunrise', and `Valley Girl'.
EFFECT OF VAPOR PRESSURE DEFICITS ON TRANSPIRATION OF GREENHOUSE TOMATO PLANTS
Authors: Gauthier Laurent , Trigui Maher , Boisvert André , Benmoussa Mohamed
Published: February 2019

Transpiration is essential to the performance of tomato plants. In greenhouses, transpiration can be impeded by low vapor-pressure deficits (VPD). An experiment was conducted to measure the effect of VPD on transpiration rates for greenhouse tomatoes grown on a nutrient film. Four treatments were applied: high (0.8 kpa) day and night VPDs; high day and low night (0.4 kPa) VPDs; low day and low night VPDs; and variable VPDs. The VPD was controlled using fogging and ventilation. Hourly transpiration values were recorded. Results show a significant difference between treatments. The measured transpiration rates were compared to the values calculated with a transpiration model. A good fit between measured and calculated values was observed. The model is being used within a dynamic VPD control strategy.
DETECTION OF BACTERIAL RING ROT OF POTATO USING DNA PROBE AND PCR
Authors: Hogue R. , Roy S. , Bernard C. , Laverdière L.
Published: February 2019

One hundred twenty-eight field samples of 25 potato stem sections were analyzed for detecting bacterial ring rot (BRR). Samples containing more than 105, between 105 and 104, and <104 immunofluorescing BRR cells per milliliter of sample, detected using immunofluorescence-antibody staining with MAb9A1, were used to compare the efficiency of two other detection methods. Samples were screened with a digoxigenin-labeled DNA probe (Bh1 2, 0.6 kbp) detected by chemioluminescence on nylon membrane. Samples also were screened with a PCR test using primers derived from the sequence of the Bh12 probe. DNA probe tests on these three bacterial concentrations showed a detection efficiency of 100%, 76.8%, and 8.0%, respectively, whereas detection efficiencies of 100%, 100%, and 84.5% were obtained with PCR tests. Almost all positive samples gave the expected 403 bases ethidium-bromide-stained band when the amplified products were analyzed on 1.4% agarose gel. Thus, the PCR test was a sensitive detection method for screening bacterial ring rot of potato.
COMPARISON OF SIX LOCAL STRAWBERRY CULTIVARS TO MEXICAN BERRIES FOR INDUSTRIAL JAM PRODUCTION
Authors: Khanizadeh Shahrokh , Fortin Jacinthe , Lareau Michel J. , Buszard Deborah J.
Published: February 2019

Frozen fruit of five locally grown strawberry cultivars and a recent introduction were compared to imported berries for making jam. Line scales were used to evaluate sensory attributes. Cultivars differed only in acidity, fruity flavor, and berry integrity. Jam produced with Quebec-grown berries was less acidic and more fruity tasting than that made from imported Mexican berries. `Kent' had better fruit integrity than Mexican berries, followed by `Chambly', `Midway', `Bounty', and `Glooscap'. Frozen local strawberries were preferred to Mexican berries for making jam. Overall impression was better for Quebec-grown strawberries with the exception of `Midway', which had lower overall impression than Mexican berries.
COMPARISON OF TWO METHODS OF DETERMINING ACHENE NUMBERS ON STRAWBERRIES
Authors: Khanizadeh Shahrokh , Vigneault Clément , Buszard Deborah
Published: February 2019

Development of strawberry fruit depends on the number of fertilized achenes on the surface. The achenes are distributed on the receptacle surface in a pattern of more or less regular rows, spirally arranged. The number of achenes is determined by 1) counting the number of achenes per square centimeter of surface on ripe berries; 2) weighing the achenes after separation from the receptacle; or 3) counting the number of achenes after pressing the fruit between two layers of glass. The above methods are laborious and time-consuming. We, therefore, described anew semi-automated method (Image Analysis System, IAS) as an alternative to the above procedures. The IAS is capable of grouping the achenes into two or more categories based on their size (sound or aborted), surface area, color, volume, etc. This will facilitate the study of the relationship between achene number and fruit weight in strawberry.
ALTERNATIVE MANAGEMENT TECHNIQUES FOR ORCHARDS
Authors: Stiles Warren C.
Published: February 2019

Concerns about the impacts of agricultural practices on the environment dictate that all management techniques must be examined from the perspective of minimizing such impacts. Integrated pest management practices such as scouting, use of biological controls, improvement of pesticide application techniques, tree-row-volume spraying, and consideration of the environmental impact of alternative chemical controls offer opportunity for minimizing the adverse impact of pesticides. Improved spray equipment with canopy sensors and spray recovery systems improve deposition and reduce pesticide waste. Applying nutrients on the basis of need as indicated by leaf and soil analyses offers the best means of assuring optimal crop performance and minimizing the potential for contamination of surface and ground water supplies. Soil management practices must be evaluated for their potential to minimize soil erosion and competition, and for their potential contribution to pest management. Ground covers that are nonsupportive of nematodes, disease, or insect pest populations merit additional research. Methods for managing ground covers with low rates of growth regulators or herbicides to minimize invasion by problem weeds, reduce the need for mowing, and regulate competition, while retaining their beneficial attributes in minimizing soil erosion and maintaining soil structure, would be advantageous to orchardists and the environment.
Presowing Seed Treatments to Enhance Supersweet Sweet Corn Seed and Seedling Quality
Authors: Parera Carlos A. , Cantliffe Daniel J.
Published: February 2019

Poor emergence and low seedling vigor are characteristics of many supersweet sweet corn (Zea mays L.) cultivars carrying the shrunken-2 (sh2) gene. Four sh2 sweet corn cultivar seeds [`How Sweet It Is' (HSII), `Crisp N' Sweet 711' (CNS-711), `Sweet Belle' (SB), and `Dazzle' (DZ)] were solid-matrix-primed (SMP), SMP with sodium hypochlorite (SMPcl), treated with a fungicide combination (F) (Imazalil + Captan + Apron + Thiram), or primed with the aforementioned fungicides (SMPf). The seed treatments were tested in the laboratory and the field. Seed imbibition and leachate electrical conductivity were lower in SMP seeds than in nonprimed seeds. In the field, emergence percentage and rate of CNS-711 and SB (high-vigor seeds) were not improved by the seed treatments compared to the nontreated seeds. Emergence percentage and rate of HSII and DZ (considered low-vigor seeds) were improved as a result of SMPcl, SMPf, or F treatments compared to nonprimed seeds. Compared to the F treatment, the SMPcl presowing treatment increased DZ seedling emergence rate and percentage. The combined SMP and seed disinfection via NaOCl seems to be a promising fungicide seed-treatment substitute that improves the stand establishment and seedling vigor of sh2 sweet corn cultivars. Chemical names used: 1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1 H imidazole (Imazalil); N-[(trichloromethyl)thio]-4-cyclohexene-1,2-dicarboximide(Captan); N- (2,6-dimethylphenyl)- N -(methoxyacetyl)alanine methyl ester (Apron); tetramethylthiuram disulfide (Thiram).
Nitrogen Form and Solution pH Effect on Organic Acid Content of Cranberry Roots and Shoots
Authors: Allan Deborah L. , Cook Bruce D. , Rosen Carl J.
Published: February 2019

The effect of N form and solution pH on the carboxylic and phenolic acid content of cranberry (Vaccinium macrocarpon Ait. cv. Searles) shoots and roots was determined in a greenhouse experiment. The predominant carboxylic acids measured were malate and citrate. Protocatechuic acid was the dominant phenolic acid detected. Total organic acid concentrations were unaffected by N form supplied. In shoots, higher total concentrations of organic acids were found at pH 4.5 than at 6.5 in the shoot, but there was little pH effect in the roots.
002 HAIRY VETCH COVER CROP PROVIDES ALL THE NITROGEN REQUIRED BY THE TOMATO CROP
Authors: Abdul-Baki Aref A. , Teasdale John R.
Published: February 2019

Nitrogen requirements by fresh-market field tomatoes (Lycopersicon esculentum Mill.) were determined on plants grown in a hairy vetch mulch (HVM) or in black polyethylene mulch (BPM). Nitrogen treatments were 0, 56, 112, and 168 kg/ha delivered weekly through the trickle system. Yields in BPM increased significantly with higher applications of nitrogen from 54 to 91 tons/ha and chlorophyll content of fully expanded leaves increased from 7.8 to 11.3 OD664 per 100 mg fresh weight. In contrast, neither yield nor chlorophyll content of leaves increased significantly by adding nitrogen. The 0 nitrogen treatment in HVM yielded 89 ton/ha and chlorophyll content was 13.5 OD664 making it equivalent to those in BPM that had received 168 kg nitrogen/ha. The results suggest that hairy vetch can provide all the nitrogen required by the subsequent tomato crop and produces high yields and vigorous plants.
019 USE OF PACLOBUTRAZOL TO INCREASE LEAF SIZE AND SALABILITY OF Epipremnum aureum `Golden Pothos' ON TOTEMS
Authors: Conover C. A.
Published: February 2019

Results of a preliminary experiment using paclobutrazol at 0, 12 or 24 mg a.i./3.6-liter pot indicated that its use could enhance the appearance of pothos, but that some refinement of paclobutrazol rates should be made. Two experiments were conducted to determine the rate of paclobutrazol necessary to increase leaf size and optimize plant quality of pothos on totems in 3.6-liter pots grown under shadecloth providing 50% light penetration. In Experiment 1, rooted pothos cuttings were transplanted around a totem pole in a 3.6-liter pot and each pot was treated with a 250-ml drench of water containing Bonzi™ at 0, 4, 8, 12 or 16 mg a.i. Four mg a.i. of paclobutrazol yielded the most desirable plants, based on average leaf size, vine length and plant grade. Experiment 2 was designed to further refine the paclobutrazol application rate. Rooted cuttings of pothos were transplanted around a totem pole in a 3.6-liter pot and each pot was treated with a 100-ml drench of water containing paclobutrazol at 0, 1.32, 2.64, 3.96, 5.28, 6.60 or 7.92 mg a.i. Paclobutrazol applied at a rate of 5.28 mg a.i./3.6-liter pot optimized plant appearance by increasing leaf size and plant grade.
022 GROWTH REGULATOR AND APPLICATION TIME INFLUENCE POINSETTIA BRACT SIZE
Authors: Barrett James E. , Nell Terril A.
Published: February 2019

`V-14 Glory' poinsettias in 15-cm pots were pinched on 24 Sept. and given long days until 8 Oct. Chemical treatments were paclobutrazol drench, paclobutrazol spray, or daminozide/chlormequat (D/C) spray. Time of application was between 8 Oct. and 12 Nov. Heights ranged between 27 and 31 cm. D/C reduced bract size more than paclobutrazol spray, and for both, later treatments had greater affect. Paclobutrazol drench did not have a significant affect.

A second experiment had two cultivars, `Freedom' and `V-14'; three paclobutrazol concentrations, 0.2, 0.3 or 0.4 mg per pot; and three application times, 30 Sept., 14 Oct. or 28 Oct. Treatment on 30 Sept. produced the smallest bracts. The cultivar × concentration interaction was significant with 0.4 mg reducing bract size for `Freedom' but not `V-14'. Treatments on 28 Oct. had less effect on height than the other two dates. `Freedom' were shorter than `V-14'. and higher concentrations had more effect on `Freedom' than `V-14'.