scholarly journals Yam Protection: I: Seed-Piece Treatment with Fungicide

1969 ◽  
Vol 68 (2) ◽  
pp. 185-192
Author(s):  
J. S. Mignucci ◽  
P. R. Hepperly ◽  
H. Vélez ◽  
R. Torres
Keyword(s):  
Tuber Yield ◽  
Total Yield ◽  
Parasitic Nematodes ◽  
Tuber Weight ◽  
Good Seed ◽  
Yield Losses ◽  
Dioscorea Rotundata ◽  
Treated Seed ◽  
Highly Correlated ◽  
Field Plots

Preplant fungicide baths were tested on yam (Dioscorea rotundata Poir cv. Habanero) seed pieces (114-g sections) from sound tubers to determine their effect on emergence and yield of yams. Field plots were free of damaging populations of parasitic nematodes and had not been previously planted with yams. Yam seed pieces treated with captan or captan plus thiabendazole or captan plus benomyl increased field emergence (95, 96 and 91%, respectively) over that of nontreated controls (52%). Early emergence (5 weeks after planting) was greater for captan plus thiabendazole (24%) than for captan plus benomyl (1%), captan alone (2%), or the nontreated control (1%). Final stand counts (9 weeks after planting) were not statistically different among the fungicide treatments (91-96%). These counts were highly correlated with total tuber yield (r = 0.84**), total number of harvested tubers (r = 0.77**), and mean tuber weight (r = 0.74**). Plants from nontreated seed pieces produced a higher number of tubers per plant (1.64) compared with those from fungicide treated seed-pieces (1.16-1.20). Yield losses in nontreated seed pieces (48%) were related to losses in mean tuber weight (37%) and in total number of tubers (20%) per area when compared to the treated seed pieces. Greatest per plant and total yield and greatest tuber weight were found for the captan plus thiabendazole treatment, compared with captan alone or captan plus benomyl. Early and greater emergence of yam seed pieces appear to be important determinants of yield and tuber size in Habanero yams. In this experiment, even with good seed pieces and in a well-prepared seedbed, yam emergence and yield were diminished by one-half without fungicide treatment.

scholarly journals Effects of nitrogen on yield and chlorophyll of potato (Solanum tuberosum L.) cultivars

1970 ◽  
Vol 38 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Semiha Güler
Keyword(s):  
Solanum Tuberosum ◽  
Tuber Yield ◽  
Solanum Tuberosum L ◽  
Total Yield ◽  
Correlation Coefficients ◽  
Tuber Number ◽  
Tuber Weight ◽  
Nitrogen Rate ◽  
Leaf Chlorophyll ◽  
Nitrogen Rates

Effects of nitrogen on the leaf chlorophyll (chl), yield and yield attributing characters of potato as tuber number and mean tuber weight were studied. Correlation coefficients between the investigated characters were determined. Five nitrogen rates (0, 150, 200, 250 and 300 kg/ha) and four potato cultivars (Burren, Slaney, Anna and Emma) were used in the study. First, second, third class tuber yields and total tuber yield, tuber number per plant, and leaf chl were significantly influenced by both nitrogen rate and cultivar, whereas mean tuber weight was affected only by cultivar. Maximum total yield was obtained at 200 kg N/ha. There was significant linear relationship between leaf chl and N applied (R2=0.91). There were significant correlations between chl and yield and yield related characters. Total yield significantly correlated with leaf chl. Correlations between first class yield and total yield as well as total yield and tuber number per plant were highly significant.   Key words: Potato; Solanum tuberosum L.; Leaf chlorophyll; Nitrogen; Yield DOI: 10.3329/bjb.v38i2.5141 Bangladesh J. Bot. 38(2): 163-169, 2009 (December)  

scholarly journals Comparative Effect of Poultry and Swine Manures on the Performance of White Guinea Yam (Dioscorea rotundata Poir) in an Ultisols Environment

2018 ◽  
Vol 10 (4) ◽  
pp. 516-521
Author(s):  
Nwabueze C. NWAOGUALA ◽  
Kolawole E. LAW-OGBOMO
Keyword(s):  
Leaf Area Index ◽  
Tuber Yield ◽  
Poultry Manure ◽  
Application Rate ◽  
Tuber Weight ◽  
Dioscorea Rotundata ◽  
Area Index ◽  
Application Rates ◽  
Guinea Yam ◽  
Better Than

White Guinea yam (Dioscorea rotundata Poir) is an important staple food in a number of African countries, including Nigeria and Ghana. However, the tuber yield in these areas is below its potential yield. The most probably constraint to low tuber yield is the low soil nutrient status. A field trial was conducted at the Experimental Farm of the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City, Nigeria, between April and November 2016 and 2017, to evaluate the effect of poultry and swine manures on the growth and tuber yield of white Guinea yam (D. rotundata) in an ultisols environment. The trial was laid out in a 2 × 3 split plot arrangement fitted into randomized complete block design with three replicates. The main plots were organic fertilizers (poultry and swine manures) and the sub-plots were represented by three rates (0, 300 and 450 kg N ha-1) of application. Data collection on growth characters were on vine length (cm), vine girth (cm), number of nodes, number of leaves and leaf area index. At harvest, tuber length (cm), tuber girth (cm), number of tubers per plant, tuber weight and tuber yield (t ha-1) were also evaluated. The results showed that growth and yield variables varied significantly (p < 0.05) with organic fertilizer types and application rates. Poultry manure treated plants produced higher (p < 0.05) number of nodes and leaves than swine manure treated plants. Application rates of 300 and 450 kg N ha-1 of poultry manure significantly increased vine length, vine girth, number of nodes and leaves as well as leaf area index. Tuber weight and yield were higher in plants treated with poultry manure with the application rates of 300 and 450 kg N ha-1 performed better than control in 2016, while the application rate of 300 kg N ha-1 had the highest tuber weight and yield in 2017. Application rates of 300 and 450 kg N ha-1 performed better than the control (0 kg N ha-1) in 2016. However, in 2017, application rate of 300 kg Nha-1 had the highest tuber weight and yield. The present study suggests that poultry manure at application rate of 300 kg N ha-1 could be adopted by white Guinea yam farmers for high productivity of the crop under intense and continuous cropping in humid ultisols environment.

scholarly journals Parental Value for Tuber Yield in Potato Under High Temperature Environments in Climate Change Conditions

2019 ◽  
Vol 4 (1) ◽  
pp. 630-640
Author(s):  
Gastelo Manuel ◽  
Luis Diaz ◽  
Katherine Quispe ◽  
Merideth Bonierbale
Keyword(s):  
Climate Change ◽  
Late Blight ◽  
High Temperatures ◽  
Tuber Yield ◽  
Total Yield ◽  
Climate Change Scenarios ◽  
Tuber Weight ◽  
Early Maturity ◽  
Breeding Programs ◽  
Average Tuber Weight

AbstractPotato crop is expanding to areas with temperatures higher than those required. Climate change is increasing temperatures in traditional areas of potato production, thereby affecting tuber yield. The International Potato Center has developed a population adapted to these new conditions, being more tolerant to high temperatures, resistant to late blight, virus PVX and/or PVY and early maturity. In breeding programs it is very important to know the parental value of the progenitors. The parental value of 34 selected potato clones was determined through general combining ability for marketable, total yield and average tuber weight under high temperatures. Using the line by tester mating design, the potato clones were crossed as lines and varieties Katahdin, Huagalina and clones CIP398098.204 and CIP302533.31 as testers. The field experiments were carried out in three locations in Peru: San Ramon, La Molina and Majes, where average temperatures at night were between 15.25 to 21.65°C, and during the day fluctuated between 21.47 to 27.20°C. We used a randomized complete block design, with three replications. At harvest the number and weight of marketable and non-marketable tubers were taken. Then the average tuber weight, marketable and total yield per hectare was calculated. 18 potato clones were identified with high parental value for marketable yield, seventeen for total tuber yield and 11 for average tuber weight; nine of them combine high parental value for the three characteristics studied. These clones with late blight resistance, heat tolerant, adapted to medium altitudes, growing period of 90 days and high parental value can be used as parents in breeding programs, to obtain new varieties under the new climate change scenarios with high temperatures. 12 crosses that presented high SCA are the most promising for the development of superior clones.

Yield and Yield Components of Six Sweet Potato (Ipomoea batatas) Cultivars I. Contribution of Yield Components to Tuber Yield

1975 ◽  
Vol 11 (1) ◽  
pp. 39-48 ◽  
Author(s):  
S. B. Lowe ◽  
L. A. Wilson
Keyword(s):  
Sweet Potato ◽  
Yield Components ◽  
Ipomoea Batatas ◽  
Tuber Yield ◽  
Total Yield ◽  
Tuber Number ◽  
Tuber Weight ◽  
Marketable Yield ◽  
Yield And Yield Components ◽  
Positive Correlations

SUMMARYTotal yield and yield components (tuber numbers and mean tuber weights) of six local sweet potato cultivars were compared in wet and dry season crops. There were significant negative correlations between tuber number and mean tuber weight in five of the six cultivars, and positive correlations between these yield components and total yield, suggesting that cultivars may be grouped into ‘tuber number-tuber weight’ and ‘tuber weight’ types, as well as a ‘random type’ in which yield is related to neither component. Marketable yield tended to be directly related to both components, and cultivars with lower tuber numbers usually produced a higher percentage of marketable yields. The significance of these findings for sweet potato yield improvement is discussed.

scholarly journals Studies on the Occurrence and Population Distribution of Nematodes with yam (Dioscorea rotundata Poir) tubers in Benue State, Nigeria

1970 ◽  
pp. 24-30
Author(s):  
V. Isegbe, M. A. Habib, S. Solomon
Keyword(s):  
Tuber Yield ◽  
Population Distribution ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Tuber Quality ◽  
Plant Parasitic Nematodes ◽  
Dioscorea Rotundata ◽  
Yield And Quality ◽  
Meloidogyne Spp ◽  
Plant Parasitic

Yam (Dioscorea spp) nematodes have been variously reported to reduce tuber yield and quality worldwide. In the present study, a survey was done to estimate types, frequency and population density of nematodes associated with yam tubers at each of the Local Government haedquarters and two villages in Benue state of Nigeria. A total of 250 yam tubers were sampled randomly in the survey markets between April and May, 2017. Each yam sample was processed by peeling the periderm (one inch thick) out of which a 10 g sub-sample tuber was separately put in a blender with some quantity of water and mercerated at low speed for 15 seconds. Plant-parasitic nematodes were recovered from the yam tubers using a modified extraction tray method. Five nematode species were found in association with yam tubers as follows: Scutellonema bradys, Meloidogyne spp, Pratylenchus spp, Rotylenchulus spp and Tylenchus spp. Scutellonema bradys was the most ubiquitous, occuring at a 100% frequency rating in all the samples while Meloidogyne spp, Pratylenchus spp, Rotylenchulus spp and Tylenchus spp. were 29.60%, 16.80%, 8.80% and 4.80% respectively. Though the study revealed that Rotylenchulus spp and Tylenchus spp. were poor parasites of yam tubers, yet there was a widespread distribution of Scutellonema bradys, Meloidogyne spp and Pratylenchus spp on yam tubers in Benue State of Nigeria, thus control of plant-parasitic nematodes is encouraged for improved tuber quality.

scholarly journals Reduced Dosage of Methyl Bromide for Controlling Verticillium Wilt of Potato in Experimental and Commercial Plots

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 469-474 ◽  
Author(s):  
A. Gamliel ◽  
A. Grinstein ◽  
Y. Peretz ◽  
L. Klein ◽  
A. Nachmias ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Methyl Bromide ◽  
Large Scale ◽  
Field Experiments ◽  
Tuber Yield ◽  
Total Yield ◽  
Effective Control ◽  
Large Scale Field ◽  
Commercial Applications

The use of gas-impermeable films to reduce the dosage of methyl bromide (MB) required to control Verticillium wilt in potatoes was examined in field experiments, conducted in soils naturally infested with Verticillium dahliae. The incidence and severity of Verticillium wilt were significantly reduced (by 74 to 94%) by fumigation with MB at 50 g/m2 under standard low density polyethylene (LDPE) or at 25 g/m2 under gas-impermeable films. Fumigation at 25 g/m2 under LDPE was less effective. Disease severity was inversely correlated (r2 = 0.89 to 0.91) with chlorophyll content in the leaves. Fumigation also reduced (by 89 to 100%) stem colonization by the pathogen. Potato yield in the fumigated plots was significantly higher (26 to 69%), than in their nonfumigated counterparts, and was inversely correlated with disease index (r2 = 0.69 to 0.9). The percentage of high-value tubers (above 45 g) was 52 to 56% of total yield in the fumigated plots as compared with 32 to 40% in the nonfumigated controls. Thus, fumigation also improved the commercial quality of tuber yield. Effective control of V. dahliae and yield increases following MB fumigation at the recommended dosage or at a reduced dosage with gas-impermeable films was also observed in a consecutive crop. These results were verified in a large-scale field experiment using commercial applications, further demonstrating the feasibility of reducing MB dosages under farm conditions, without reducing its effectiveness in terms of disease control and yield improvement.

The effects of the growth-regulating compounds methyl decanoate and 2, 3, 5-triiodobenzoic acid on potato tuber size

1976 ◽  
Vol 86 (2) ◽  
pp. 251-255
Author(s):  
D. C. E. Wurr
Keyword(s):  
Potato Tuber ◽  
Size Distribution ◽  
Tuber Yield ◽  
Potato Crop ◽  
Total Yield ◽  
Tuber Size ◽  
Tuber Initiation ◽  
Triiodobenzoic Acid ◽  
Tuber Size Distribution ◽  
Methyl Decanoate

SummaryApplication of methyl decanoate to a potato crop about the time of tuber initiation reduced the total yield and the yield of tubers in the grade 2·5–5·5 cm though neither of these reductions were significant. However, application of 2,3,5-triiodobenzoic acid increased the yield of tubers 2·5–5·5 cm by up to 20% while having no significant effect on total tuber yield. This change in the tuber size distribution was due to a more even partition of photosynthate between tubers and not to an increase in the total number of tubers.

Biology and Control of Black Nightshade (Solanum nigrum) in Cotton (Gossypium hirsutum)

1991 ◽  
Vol 5 (4) ◽  
pp. 713-722 ◽  
Author(s):  
Paul E. Keeley ◽  
Robert J. Thullen
Keyword(s):  
Soil Moisture ◽  
Sprinkler Irrigation ◽  
Yield Losses ◽  
Accelerated Degradation ◽  
Black Nightshade ◽  
Excellent Control ◽  
Late Application ◽  
And Control ◽  
Field Plots ◽  
Weed Resistance

A 4-yr study (1985, 1987, 1988, 1989) was conducted on the same field plots at Shafter, CA to evaluate the efficacy of prometryn in controlling black nightshade on planting beds of cotton. Two rates (1.7 and 2.2 kg ai ha–1) were applied at two times (mid March before the preplant irrigation and early April at cotton planting) each year. Incorporation of prometryn into moist planting beds with a powered rotary tiller operated at 10 cm deeper resulted in excellent control of black nightshade under low to moderate weed pressure in 1985 and 1987. Control of nightshade with early and late applications of 1.7 kg ha–1of prometryn under high weed pressure in 1988 was only 70% at harvest, and yield losses of cotton averaged 25%. Yields of cotton treated with 2.2 kg ha–1of prometryn in 1988 were not significantly different from weed-free plots. Only the late application of 2.2 kg ha–1of prometryn prevented significant cotton losses under extreme weed pressure in 1989. Cotton yield losses with the other prometryn treatments ranged from 78 to 100%. Losses of cotton in weedy-check plots that received only cultivation ranged from 22% in the absence of rain or irrigation at cotton planting in 1987 to as much as 100% when rain fell in 1988 or plots were irrigated at planting in 1989. Plots hoed one time 4 wk after cotton planting yielded an average of 84% as much seed cotton as weed-free plots. In an attempt to determine why the efficacy of prometryn declined between 1985 and 1989, several experiments were conducted in 1988 to 1990 to discover reasons for this poor control of nightshade. Because efforts failed to provide evidence for the movement of the herbicide with water, the development of weed resistance to prometryn, or accelerated degradation of this herbicide in soil, increasing weed seed populations in soil were believed to have contributed greatly to the declining nightshade control from prometryn. The fact that prometryn applied and incorporated into flat soil provided excellent control of nightshade in 1990 under sprinkler irrigation indicated that both soil moisture and incorporation techniques limited activity of prometryn in planting beds in 1988 and 1989. Incomplete control of nightshade plus good soil moisture at planting contributed to the high weed populations in 1988 and 1989.

scholarly journals Performance of potato (Solanum tuberosum L.) varieties with and without straw-mulch at Shankharapur, Kathmandu, Nepal

2020 ◽  
Vol 3 (2) ◽  
pp. 193-204
Author(s):  
Kalyani Shrestha ◽  
Shrawan Kumar Sah ◽  
Reeti Singh ◽  
Yam Narayan Devkota
Keyword(s):  
Tuber Yield ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Medium Size ◽  
Tuber Weight ◽  
Potato Varieties ◽  
Straw Mulch ◽  
Crop Varieties ◽  
Randomized Complete Block Design ◽  
Benefit Cost

The suitability of crop varieties in a particular location determines the productivity of crops. A field experiment was conducted from February to May 2020 at Shankharapur, Kathmandu, Nepal to evaluate the growth and productivity of potato varieties with and without mulch. Five potato varieties (Cardinal, Janakdev, Khumal Bikas, MS- 42.3, Panauti Local) were evaluated under straw-mulch and no-mulch conditions. The treatments were arranged in two factorial Randomized Complete Block Design (RCBD) with 3 replications. The results revealed that the highest tuber yield was produced by Janakdev (34.29 t ha-1) followed by Panauti Local (29.52 t ha-1). Similarly, straw-mulch gave higher yield (25.9 t ha-1) as compared with no mulch condition (21.73 t ha-1). The higher tuber yield in the Janakdev and Panauti Local was because of higher tuber weight per hill, higher number and weight of medium size (50 -100 g) and oversize (> 100 g) tuber per hill. Similarly, higher yield in straw mulch was due to higher number and weight of tuber per hill. Higher gross return, net return was observed and the benefit cost ratioin varieties Janakdev (4.08) and Panauti Local (3.53) and rice straw mulch (2.88). Therefore, potato varieties Janakdev and Panauti Local with straw mulch are most suitable for Kathmandu like climate for improving productivity and profitability.

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