scholarly journals 253 MICROPROPAGATION, A MEANS TO ENHANCE SWEETPOTATO YIELD AND QUALITY

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 466a-466
Author(s):  
Jonathan R. Schultheis ◽  
Wanda W. Collins ◽  
Charles W. Averre
Keyword(s):  
North Carolina ◽  
Certified Seed ◽  
Field Studies ◽  
Plant Production ◽  
Marketable Yield ◽  
Production Program ◽  
The North ◽  
Yield And Quality ◽  
Production Scheme ◽  
Micropropagated Plants

Micropropagated sweetpotato is utilized in California as pan of its seed production program. Sweetpotato yields and quality might be improved in North Carolina by incorporating micropropagation as pan of its plant production scheme. Field studies were conducted in 1992 and 1993 to determine the effects of micropropagation, virus, and hill selection on yield and qualify of Jewel and Beauregard varieties. In 1992, yield was increased in Beauregard with micropropagated plants compared with plants that were derived from the North Carolina seed program. However, no yield advantage was measured when Jewel was micropropagated. In 1993, yield from micropropagated Beauregard sweetpotato plants was the same as when plant material was derived from the North Carolina Certified Seed program. Virus-free micropropagated Beauregard plants yielded more number one and canner grade roots than micropropagated plants that harbored the virus at planting. Russet crack symptoms were significantly greater in roots that were not micropropagated compared with micropropagated plants. Total marketable yield of Jewel was increased when obtained from micropropagated versus nonmicropropagated plant stock. Micropropagated Jewel obtained from a California selection yielded nearly 20% less than the North Carolina selection. Yields from micropropagated planting stocks consistently were equal to or better (typically 10 to 20%) than from plant stock not micropropagated.

Critical Period for Palmer Amaranth (Amaranthus palmeri) Control in Pickling Cucumber

2018 ◽  
Vol 32 (5) ◽  
pp. 586-591
Author(s):  
Samuel J. McGowen ◽  
Katherine M. Jennings ◽  
Sushila Chaudhari ◽  
David W. Monks ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Critical Period ◽  
Relative Yield ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Marketable Yield ◽  
Yield Data ◽  
Pickling Cucumber ◽  
Cucumber Yield

AbstractField studies were conducted in North Carolina to determine the critical period for Palmer amaranth control (CPPAC) in pickling cucumber. In removal treatments (REM), emerged Palmer amaranth were allowed to compete with cucumber for 14, 21, 28, or 35 d after sowing (DAS) in 2014 and 14, 21, 35, or 42 DAS in 2015, and cucumber was kept weed-free for the remainder of the season. In the establishment treatments (EST), cucumber was maintained free of Palmer amaranth by hand removal until 14, 21, 28, or 35 DAS in 2014 and until 14, 21, 35, or 42 DAS in 2015; after this, Palmer amaranth was allowed to establish and compete with the cucumber for the remainder of the season. The beginning and end of the CPPAC, based on 5% loss of marketable yield, was determined by fitting log-logistic and Gompertz equations to the relative yield data representing REM and EST, respectively. Season-long competition by Palmer amaranth reduced pickling cucumber yield by 45% to 98% and 88% to 98% during 2014 and 2015, respectively. When cucumber was planted on April 25, 2015, the CPPAC ranged from 570 to 1,002 heat units (HU), which corresponded to 32 to 49 DAS. However, when cucumber planting was delayed 2 to 4 wk (May 7 and May 21, 2014 and May 4, 2015), the CPPAC lasted from 100 to 918 HU (7 to 44 DAS). This research suggested that planting pickling cucumber as early as possible during the season may help to reduce competition by Palmer amaranth and delay the beginning of the CPPAC.

Critical timing of Palmer amaranth (Amaranthus palmeri) removal in sweetpotato

2020 ◽  
Vol 34 (4) ◽  
pp. 547-551 ◽  
Author(s):  
Stephen C. Smith ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Sushila Chaudhari ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Logistic Model ◽  
Yield Loss ◽  
Relative Yield ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Marketable Yield ◽  
Yield Data ◽  
Critical Timing

AbstractPalmer amaranth is the most common and troublesome weed in North Carolina sweetpotato. Field studies were conducted in Clinton, NC, in 2016 and 2017 to determine the critical timing of Palmer amaranth removal in ‘Covington’ sweetpotato. Palmer amaranth was grown with sweetpotato from transplanting to 2, 3, 4, 5, 6, 7, 8, and 9 wk after transplanting (WAP) and maintained weed-free for the remainder of the season. Palmer amaranth height and shoot dry biomass increased as Palmer amaranth removal was delayed. Season-long competition by Palmer amaranth interference reduced marketable yields by 85% and 95% in 2016 and 2017, respectively. Sweetpotato yield loss displayed a strong inverse linear relationship with Palmer amaranth height. A 0.6% and 0.4% decrease in yield was observed for every centimeter of Palmer amaranth growth in 2016 and 2017, respectively. The critical timing for Palmer amaranth removal, based on 5% loss of marketable yield, was determined by fitting a log-logistic model to the relative yield data and was determined to be 2 WAP. These results show that Palmer amaranth is highly competitive with sweetpotato and should be managed as early as possible in the season. The requirement of an early critical timing of weed removal to prevent yield loss emphasizes the importance of early-season scouting and Palmer amaranth removal in sweetpotato fields. Any delay in removal can result in substantial yield reductions and fewer premium quality roots.

scholarly journals The effect of biodegradable direct covers on the root development, yield and quality of cucumber

2014 ◽  
Vol 26 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Izabela Zawiska ◽  
Piotr Siwek
Keyword(s):  
Root Development ◽  
Dry Matter ◽  
Soluble Sugars ◽  
Average Diameter ◽  
Field Studies ◽  
Nitrate Content ◽  
Marketable Yield ◽  
Yield And Quality ◽  
Yield Quality ◽  
Whole Plants

ABSTRACT The results of three years (2009-2011) of field studies using two types of biodegradable nonwoven covers (aromatic polyester IBWCH 75 g m-2 and polylactic acid PLA 54 g m-2) on the yield, quality and root development of cucumber are presented. Seeds of parthenocarpic cucumber (‘Mirabelle’ F1) were sown directly into the field at the beginning of May/June and covered with nonwoven field covers. A plot that remained uncovered served as the control. The covers were kept in place until the first flowers appeared. Cucumbers were harvested every three days for 5-6 weeks. Fruits were evaluated for dry matter, soluble sugars and nitrate content. After the last harvest, whole plants were harvested and evaluated for weight, surface area, total length and average diameter of the roots. The experiment showed that the covers increased the marketable yield of cucumber in 2009 and 2010 (regardless of the type of polymer), but did not influence the yield in 2011. In 2011 the fruits from the covered plots had higher levels of soluble sugars and dry matter in comparison to the control. The covers did not influence root development.

Сортакартофеля,адаптированныекусловиямСевера

2019 ◽  
Author(s):  
A.G. Tulinov ◽  
A.Y. Lobanov ◽  
M.Y. Shlyk ◽  
T.V. Kosolapova
Keyword(s):  
Starch Content ◽  
Field Studies ◽  
Komi Republic ◽  
High Yield ◽  
Early Variety ◽  
Potato Varieties ◽  
The North ◽  
Yield And Quality ◽  
The Russian Federation

Приведены основные результаты оценки адаптированных к условиям Севера сортов картофеля, сочетающих высокую урожайность и качество клубней, а также устойчивость к болезням. В питомниках конкурсного испытаний (2016 2018 годы) было изучено два сорта Зырянец и Вычегодский в сравнении со стандартным районированным в Республике Коми сортом Невский (среднеранний) и рекомендованным сортом Удача (раннеспелый). Новые сорта картофеля имеют следующие характеристики: урожайность 29,7 29,9 т/га, содержание крахмала 15,2 18,8, высокая устойчивость к грибным болезням (фитофтороз, альтернариоз) и рекомендуются к возделыванию вI Северном иIX Уральском регионах Российской Федерации.The article presents the main results of the assessment of potato varieties adapted to the conditions of the North, combining high yield and quality of tubers, as well as resistance to diseases. In the nurseries of competition tests (20162018), 2 varieties were studied Zyryanets and Vychegodsky in comparison with the standard Nevsky (medium early) variety zoned in the Komi Republic and the recommended variety Udacha (early ripe). As a result of field studies, new potato varieties have the following characteristics: yield 29.729.9 t/ha, starch content 15.218.8, high resistance to fungal diseases (late blight, alternaria) and recommended cultivation in the I North and IX Ural regions of the Russian Federation.

Laser point-quadrat sampling for estimating foliage-height profiles in broad-leaved forests

2001 ◽  
Vol 31 (3) ◽  
pp. 410-418 ◽  
Author(s):  
Philip J Radtke ◽  
Paul V Bolstad
Keyword(s):  
North Carolina ◽  
Leaf Area ◽  
Field Studies ◽  
Area Index ◽  
Quadrat Sampling ◽  
Range Finding ◽  
The North ◽  
Broad Leaved Forest ◽  
Western North Carolina ◽  
Point Quadrat

A technique for estimating the vertical distribution of foliage area in broad-leaved forests was developed. The technique is similar to optical point-quadrat sampling, where estimates are based on heights to the lowest leaves above numerous sample locations beneath a canopy. In optical point-quadrat sampling, heights to lowest leaves are measured with a telephoto lens. Here, heights were measured using a commercially available laser range-finding instrument. The laser point-quadrat technique was tested in field studies conducted under broad-leaved forest canopies in western North Carolina and east-central Minnesota, U.S.A. Foliage-height profiles obtained by laser point-quadrat sampling were consistent with two of four published foliage-height profiles observed in 1995 at the North Carolina field locations. Total leaf area estimates obtained by laser point quadrats were not significantly correlated with values of leaf area index estimated by recent litter fall analyses at the North Carolina and Minnesota field locations. Although further evaluation and refinement of the technique is needed, laser point-quadrat sampling shows promise as a means of obtaining foliage-height profiles at a significantly reduced effort and with greater accuracy than methods commonly in use today.

scholarly journals Sweetpotato Response to Simulated Glyphosate Wick Drip

2017 ◽  
Vol 31 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Stephen L. Meyers ◽  
Katherine M. Jennings ◽  
David W. Monks
Keyword(s):  
Field Studies ◽  
Shoot Tips ◽  
Storage Roots ◽  
Marketable Yield ◽  
Application Timing ◽  
Yield And Quality

Field studies were conducted in 2009 at Clinton, NC and 2014 at Pontotoc, MS to determine the influence of simulated glyphosate drip on sweetpotato yield and quality. Treatments consisted of three glyphosate solution (140 g ae L–1) drip volumes (0.16, 0.32 and 0.48 ml) by four application timings [(4 wk after transplanting (WAP); 6 WAP; 8 WAP; and 4 WAP followed by (fb) 6 WAP fb 8 WAP]. A non-treated check was included for comparison. Visual sweetpotato injury consisted of chlorosis at the shoot tips approximately 1 wk after treatment fb necrosis and stunting. At 6 WAP and 8 WAP, sweetpotato injury following glyphosate applied 4 WAP was 71 and 65%, respectively. Injury from glyphosate applied 4 WAP fb 6 WAP was 78%. Injury from glyphosate applied 6 WAP was 26% at 8 WAP. In 2009, jumbo, no. 1, canner, and marketable yield of the non-treated check were two to three times greater than glyphosate treatments (0.16, 0.32, 0.48 ml). Likewise, yield of the non-treated check was substantially greater than those treated with 0.16 to 0.48 ml glyphosate solution in 2014. In 2009 and 2014, sweetpotato yield of all grades increased as glyphosate application timing was delayed. In 2009, no. 1 yield from glyphosate 8 WAP (8,210 kg ha–1) was similar to the non-treated check. In 2009, there were no cracked storage roots in the non-treated check. However, sweetpotatoes receiving 0.16 to 0.48 ml glyphosate solution displayed 8 to 17%, 11 to 18%, 5 to 13%, and 11 to 16% cracking (by weight) in jumbo, no. 1, canner, and marketable storage roots, respectively. Compared to the non-treated check, glyphosate applied 4 WAP, 6 WAP, or 4 WAP fb 6 WAP fb 8 WAP had a greater percentage of cracked marketable sweetpotato storage roots.

Response of broccoli (Brassica oleracea var. italica) yield and hollow stem to plant density, trickle irrigation and transplanting date

2010 ◽  
Vol 90 (5) ◽  
pp. 729-735
Author(s):  
K R. Sanderson ◽  
S. A. E. Fillmore
Keyword(s):  
Brassica Oleracea ◽  
Plant Density ◽  
Leaf Tissue ◽  
Field Studies ◽  
Trickle Irrigation ◽  
Marketable Yield ◽  
Yield And Quality ◽  
Plant Densities ◽  
Brassica Oleracea L

Maximizing yield and quality of processing broccoli (Brassica oleracea L. var. italica) is critical to successful production in Atlantic Canada. Field studies were conducted from 2004 to 2006 to evaluate the effect of plant density and trickle irrigation on the yields and incidence of hollow stem for early and late transplanting of broccoli. Treatments consisted of five plant densities ranging from 3.17 to 6.35 plants m–2. Each plant density was either not irrigated or trickle irrigated to maintain at least 25 mm total precipitation per week. The highest marketable yield was achieved at 5.56 plants m–2 when grown in an early transplanting with trickle irrigation in a single row with 90 cm between the row and 20 cm within the row. Overall, earlier transplanting dates were more productive. Trickle irrigation increased marketable yield by an average of 12% over the 3 yr of tests. Average head weight, head diameter, and the incidence of hollow stem decreased as plant density increased. Leaf tissue N was not affected by plant density, trickle irrigation or transplanting date.Key words: Brassica oleracea L. italica, plant density, yield, growth

scholarly journals Testcross Performance of Three Selection Cycles from Four Pickling Cucumber Populations

1999 ◽  
Vol 124 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Christopher S. Cramer ◽  
Todd C. Wehner
Keyword(s):  
North Carolina ◽  
Recurrent Selection ◽  
Female Parent ◽  
Fruit Shape ◽  
Fruit Yield ◽  
Population Cycle ◽  
Marketable Yield ◽  
Testcross Performance ◽  
The North ◽  
Pickling Cucumber

Progress was measured in four populations of cucumber (Cucumis sativus L.) improved by recurrent selection. The populations were the North Carolina wide base pickle (NCWBP), medium base pickle (NCMBP), elite pickle 1 (NCEP1), and hardwickii 1 (NCH1). Families from each of three cycles (early, intermediate, and late) from each population were randomly chosen and crossed with Gy 14 to produce gynoecious hybrids. Gy 14 is a gynoecious inbred used commonly as a female parent in the production of pickling cucumber hybrids. Once the plants had 10% oversized (>51 mm in diameter) fruit, plots were sprayed with paraquat to simulate once-over harvest. Selection cycles were evaluated for total, early, and marketable yield, and fruit shape. Testcross performance for fruit shape rating increased over cycles for the NCWBP and NCMBP populations when tested in either season. Testcross performance for total and early yield of the NCEP1 population tested in the spring decreased with selection, but remained constant over cycles in the summer season. The majority of yield traits in each population remained unchanged across selection cycles. Of the four populations studied, the NCMBP population had the greatest gain (7%) in testcross performance over cycles and averaged over all traits. In addition, testcross performance for fruit shape rating had the greatest gain (11%) with selection and averaged over populations. Years and seasons greatly influenced testcross performance for fruit yield and shape rating. In most instances, the fruit yield and shape of Gy 14 was higher than the testcross performance of population-cycle combinations. The performance of several families exceeded that of Gy 14 when testcross combinations were made. Those families could be selected for use in the development of elite cultivars. Chemical name used: 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat).

Interference of Yellow Nutsedge (Cyperus esculentus) in ‘Beauregard' Sweet Potato (Ipomoea batatas)

2015 ◽  
Vol 29 (4) ◽  
pp. 854-860 ◽  
Author(s):  
Stephen L. Meyers ◽  
Mark W. Shankle
Keyword(s):  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Yield Loss ◽  
Field Studies ◽  
Shoot Density ◽  
Potato Yield ◽  
Cyperus Esculentus ◽  
Marketable Yield ◽  
Yellow Nutsedge ◽  
Yield And Quality

Field studies were conducted in 2013 at Houlka, MS and 2014 at Houston and Pontotoc, MS to determine the influence of yellow nutsedge density on 'Beauregard' sweet potato yield and quality. Treatments established 2 wk after transplanting (WAP) were yellow nutsedge densities of 0, 5, 10, 15, 30, 40, 50, and 90 shoots m−2within the planted row. No. 1 and marketable yield loss were fit to a rectangular hyperbola model. In 2013 predicted yield loss of no. 1 and marketable grades ranged from 23 to 96% and 18 to 80%, respectively for yellow nutsedge densities of 5 to 90 shoots m−2. In 2014 predicted yield loss of no. 1 and marketable grades ranged from 7 to 74% and 6 to 67%, respectively for yellow nutsedge densities of 5 to 90 shoots m−2. Yellow nutsedge shoot density increased linearly from 2 WAP to harvest. At Houston and Pontotoc, yellow nutsedge shoot density increased 2.3 and 7.6 times, respectively, for every one shoot present at 2 WAP.

scholarly journals INFLUENCE OF NITROGEN APPLICATION ON YIELD AND QUALITY OF `BEAUREGARD' IN NORTH CAROLINA

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 444a-444
Author(s):  
Wilfred R. “Bill” Jester ◽  
Jonathan R. Schultheis ◽  
Charles W. Averre
Keyword(s):  
North Carolina ◽  
Root Length ◽  
Calcium Nitrate ◽  
Root Yield ◽  
Marketable Yield ◽  
N Application ◽  
Yield And Quality ◽  
Grading Standards ◽  
Level Of Significance

Sweetpotato varieties differ in their ability to efficiently use N. This study was conducted to determine if time of N application affected root yield and quality in the variety Beauregard. Nitrogen sidedress single-application treatments were applied at 10, 21, 28, and 35 days after transplanting. Two split application treatments were evaluated: l) 44.8 kg N/ha were applied 10 days after transplanting and 22.4 kg N/ha applied 21 days after transplanting and 2) 33.6 kg N/ha were applied 21 and 35 days after transplanting. The N source was calcium nitrate (15.5–0–0) and totaled 67.3 kg N/ha for all treatments. Plots were four rows and 6 m long, and treatments were randomized in five blocks. Harvested roots were sorted according to U.S. Dept. of Agriculture grading standards and weighed. Highest yields of U.S. no. 1 grade roots were obtained by applying N 21 to 35 days after transplanting. Total marketable yield was highest when application was made at 28 or 35 days after transplanting. Root length, at the 10% level of significance, was shorter when one vs. two N applications were applied. Using one N application compared with two N applications seems to be beneficial as shown by increased total marketable yields and yield of U.S. no. 1 roots and reduced root length.

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