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For potato, diploid hybrid breeding is a novel breeding technique that speeds up the development of new varieties. A consequence of hybrid breeding is the introduction of hybrid true potato seeds as starting material. From these seeds, seedling tubers can be produced in one field season, to use as starting material for a seed or a ware crop in the following year. For breeding purposes as well as for seed crop and ware crop production, it is essential to produce seedling tubers of high quality. The production of seedling tubers is a new step in the potato production chain; therefore, we investigated the effect of tuber quality traits on plant development and yield. With similar seedling tuber weight, more eyes per seedling tuber led to more stems per plant. This was compensated by a lower number of tubers per stem resulting in an equal total tuber number and weight per plant at the end of the growing season. A higher seedling tuber weight led to a higher soil cover in the field. Hybrid potato plants grown from larger seedling tubers produced a greater total tuber weight per plant than plants grown from smaller tubers, while number of eyes and stems per tuber had no effect on final yield when using equal seedling tuber weight. [ABSTRACT FROM AUTHOR]

Purpose: Yam cultivation in soils of low fertility has been a major cause of yield decline in Nigeria. The inadequacies associated with either inorganic or organic fertilizer in the aspects of crop growth and productivity necessitated the introduction of organomineral fertilizers. However, information on the appropriate placement method for sustainable cultivation is still limited. Hence, fertilizer type and placement method were evaluated on white yam yield.Method: Dioscorea rotundata (Tdr 219) performance under different fertilizer types [NPK, 15-15-15 and organomineral fertilizer (OMF) at 30 kg N/ha], and different methods of placement (Side/spot and Ring/circular placements) were evaluated.Results: The average tuber length, circumference, number of ware tubers, and yam tuber weights were higher under NPK treatment, while the number of tubers was higher in OMF treatment. All parameters observed were increased by ring fertilizer placement method compared to side placement. The interaction of fertilizer type and method of placement indicated that under OMF, the ring placement produced comparatively higher tuber weight (13390.0 kg/ha) than side placement (13166.6 kg/ha). However under NPK fertilizer, side placements enhanced tuber weight (15173.3 kg/ha) compared with ring placement (15076.6 kg/ha). The residual cropping revealed that the highest and significant tuber weight was observed in OMF fertilizer with ring placement compared to the other treatments.Conclusion: Side placement was appropriate for NPK fertilizer, however, applying organomineral fertilizer at 2000 kg/ha with ring placement was recommended for the cultivation of yam in low fertility soils.

The purpose of this research is to improve the physical properties and fertility of soil to improve production of shallot. The research method used is a randomized block factorial design with 3 replication. The first factor was application of liquid fertilizer (N) consisting of 3 levels (N0: 0 cm3/L water; N1: 1.5 cm3/L water; N2: 3 cm3/L water). Second factor was cattle manure (A) consisting of 4 levels, namely: A0: 0 g; A1: 40 g cattle manure; A2: 80 g cattle manure; and A3: 120 g cattle manure. The results shown treatment with liquid fertilizer has a significant effect on plant height at weeks after planting (WAP). The study showed that treatment with liquid fertilizer has a significant effect on plant height, tuber weight per clump, and tuber weight per plot, but didn’t not have a significant effect on number of leaves and number of samplings of the shallot plants. Treatment with cattle manure has a significant effect on plant height, tuber weight per clump, tuber weight per plot, and tuber diameter, but does not have a significant effect on number of leaves and number of saplings of the shallot plants. It can be concluded that the higher the application of liquid fertilizer, up to 3 cm3/L , the higher the growth and production of shallot plants, and the higher the application of cattle manure, up to 120 g/plot the higher the growth and production of shallot plants.

Introduction In terms of harvested land area, potato ranks fourth in the world after wheat, corn and rice. In addition to providing energy and good quality protein, it is also considered as a source of vitamin C and minerals. Despite the fact that iron is the fourth most abundant element in the earth's crust, only a small amount of iron can be used by plants in well-ventilated soils. Therefore, iron deficiency is one of the factors limiting the growth and development of plants. Materials and Methods This experiment was carried out in a factorial trial in the base of a completely randomized design in three replications in a greenhouse conditions of Agricultural Research Institute of Hamedan (Jorqan) during the crop years of 2017-2018 and 2018-2029. The experimental factors include the weight levels of microtuber at three levels of 3-1, 3-5 and 5-10 grams and different iron fertilizers at seven levels, control, iron chelate in the form of soil consumption at the rate of 20 micromolar, nano iron oxide in the form of soil consumption to The amount of 20 micromolar was 1 and 2% foliar spraying of iron chelate and 1 and 2% nano iron oxide foliar spraying. The internal temperature of the greenhouse was provided by adjusting the air conditioning system and central heating in the range of 18 to 20 °C at night and 26 to 28 degrees during the day. The humidity of the greenhouse was also 60-65%. At the end of the experiment, after processing the crop, the plants were harvested and the yield and yield components were determined. Leaf greenness index in this experiment using SPAD device (Minolta 502 model) using three fully developed terminal leaves from ten plants in the budding stage in the middle part of the leaf on one side of the main vein, at 9:30 to 10:00 in the morning. It was measured in order to minimize daily changes. To measure the percentage of dry matter, 200 grams of tubers were randomly selected from each treatment, then the tubers were chopped and placed in an oven at a temperature of 75 degrees Celsius, and after their weight was fixed, they were weighed again. Then, based on the ratio of fresh and dry weight of the tubers, the percentage of dry matter of the tubers was determined (Hagman and Martenssen, 2009). Results and Discussion The results showed that the height of the plant, the number of stems per plant, the number of tubers per plant, the weight of tubers, the weight of tubers per plant, the percentage of dry matter and the greenness index increased with the increase in the weight of microtubers, and the most improvement in the morphological and qualitative characteristics of potato in microtubers. 5-10 grams were observed. With the application of iron chelate and nano iron oxide fertilizers, potato yield and yield components increased. The maximum tuber weight in the plant was shown in the treatments of 20 micromolar nano iron oxide and 2% nano iron oxide. The highest tuber weight in the plant in the 1-3 gram microtuber is 405.23 grams related to the consumption of 20 micromolar nano iron oxide, in the 3-5 gram microtuber is 444.61 grams related to the application of 2% iron chelate solution and in the microtuber 5-10 grams in the amount of 556.92, 544.52, 482.6 and 465.82 grams corresponding to the treatments of 20 micromolar nano iron oxide, foliar spraying of 2% nano iron oxide, foliar spraying of 1% nano iron oxide and solution The application was 2% iron chelate Conclusion Microtuber 5-10 grams was able to acquire the best size of microtuber due to having suitable nutrients and accelerating the greening of plants and increasing photosynthesis and providing nutrients. The application of nano iron oxide fertilizer was more effective in improving the quantitative and qualitative yield of potatoes compared to iron chelate. [ABSTRACT FROM AUTHOR]

Purpose: Yam cultivation in soils of low fertility has been a major cause of yield decline in Nigeria. The inadequacies associated with either inorganic or organic fertilizer in the aspects of crop growth and productivity necessitated the introduction of organomineral fertilizers. However, information on the appropriate placement method for sustainable cultivation is still limited. Hence, fertilizer type and placement method were evaluated on white yam yield. Method: Dioscorea rotundata (Tdr 219) performance under different fertilizer types [NPK, 15-15-15 and organomineral fertilizer (OMF) at 30 kg N/ha], and different methods of placement (Side/spot and Ring/circular placements) were evaluated. Results: The average tuber length, circumference, number of ware tubers, and yam tuber weights were higher under NPK treatment, while the number of tubers was higher in OMF treatment. All parameters observed were increased by ring fertilizer placement method compared to side placement. The interaction of fertilizer type and method of placement indicated that under OMF, the ring placement produced comparatively higher tuber weight (13390.0 kg/ha) than side placement (13166.6 kg/ha). However under NPK fertilizer, side placements enhanced tuber weight (15173.3 kg/ha) compared with ring placement (15076.6 kg/ha). The residual cropping revealed that the highest and significant tuber weight was observed in OMF fertilizer with ring placement compared to the other treatments. Conclusion: Side placement was appropriate for NPK fertilizer, however, applying organomineral fertilizer at 2000 kg/ha with ring placement was recommended for the cultivation of yam in low fertility soils. [ABSTRACT FROM AUTHOR]

Irrigation water scheduling methods influence the growth, yield, and water productivity of crops including potatoes. Therefore, a study was conducted to evaluate the effects of irrigation frequency determination methods on tuber yield, irrigation water productivity and fertilizer use efficiency of potatoes at Koga irrigation scheme, in Northwest Ethiopia. The treatments were consisted of two irrigation frequency determination methods (wetting front detector and crop water requirement) and six NPS fertilizer rates (0, 90.8, 136.2, 181.6, 227.4 and 272.0 kg ha−1, which were factorial combined in a randomized complete block design with three replications. Growth and tuber yield data of potato were collected based on the standard procedure. Irrigation water productivity, partial factor productivity, and agronomic efficiency were calculated using their respective models. The collected data were analyzed using SAS version 9.4. The results revealed that the wetting front detector method recorded the highest tuber weight (79.5 g), tuber yield (41.9 t ha−1), and irrigation water productivity (9.1 kg potato m−3 water) compared to crop water requirement method. NPS fertilizer at the rate of 272 kg ha−1 also produced the highest tuber weight (86.5), tuber yield (58.1 t ha−1) and irrigation water productivity (12.4 kg potato m−3 water). Treatment combination of wetting front detector and 272 kg ha−1 NPS recorded the highest plant height (64.m cm) and stem number (10.4). Wetting front detector method recorded the highest partial factor productivity (275.2 kg potato per kg NPS) compared to crop water requirement. Wetting front detector combined with NPS rates generally recorded higher partial factor productivity compared to the respective NPS rates combined with crop water requirement. NPS fertilizer at 272 kg ha−1 combined with wetting front detector gave the highest net benefit (236,591.7 ETB ha−1) with acceptable marginal rate of return (248.9%), which is recommended for economical production of potato in the area.

IntroductionPotato (Solanum tuberosum L.) is an annual and autotetraploid plant of the Solanaceae family that uses its underground tuber. In 2019, among West Asian countries, Turkey and Azerbaijan had a higher level of potato cultivation than Iran. Nitrogen consumption management in potato cultivation is one of the factors affecting the quantitative and qualitative characteristics of the tuber yield produced. Some researchers consider potato yield it consists of three components the number of stems per square meter, the number of tubers per stem, and the weight of tubers per plant. One of the problems with the overuse of nitrogen fertilizers is the accumulation of nitrate in the tubers. The amount of nitrate allowed depends on the diet of the person. Some studies show that from 93 mg per day of nitrate consumed per day for an adult, 33% to potatoes, 21% to green leafy vegetables, 15% to other vegetables, 8.5% to beverages, 4.2% to Meat products account for 2.1% to various grains, 1.6% to bread and 5.1% to other items.Materials and MethodsThe present study conducted in 2018-2019 in Kabootarabad Agricultural Research Station of Isfahan. The effect of N application and nitrogen splitting on the tuber yield and nitrate accumulation of potato tubers in this study investigated. For this purpose, the split plots tested in a randomized complete block design with three replications in which three nitrogen levels (90, 180 and 270 kg ha-1) of the main plots and two nitrogen splitting methods (three and four stages) formed the sub-plots. At harvest time, two meters of the middle rows of each plot used to estimate the yield. Tubers with less than 35 mm in diameter considered non-marketable yield. To measure tuber nitrate, the prepared samples placed in paper bags and sent to the laboratory of Soil and Water Research Department of Isfahan Agricultural Research Center. After washing, the samples grated and after drying in an oven (temperature 65 °C) and grinding in a shaker (shaker), the amount of nitrate determined by spectrophotometry. All soil and plant tests performed in the laboratory. SAS software used to analyze the data and Duncan's multiple range test (at 5% probability level) used to compare the means.Results and DiscussionThe effect of nitrogen interaction and its splitting on total yield and efficiency of nitrogen utilization at the level of one per cent and on the characteristics of marketable yield, non-marketable yield, tuber nitrate, number and weight of tubers at the level of five per cent was significant. With the consumption of 180 and 270 kg N ha-1 by the four-step splitting method, the non-marketable yield was equal to 11.2 and 14.43% of the total tuber yield, respectively. With the consumption of 270 kg N ha-1 and three stages of nitrogen splitting, the amount of nitrate in the tuber reached 197 mg kg-1 of fresh weight of the tuber. In both three- and four-stage nitrogen splitting methods, nitrogen application efficiency reduced to one third by consuming 270 kg N ha-1 compared to 90 kg N ha-1 treatment. Therefore, the use of nitrogen fertilizers in excess of the recommended amounts can, in addition to economic losses, be associated with a decrease in fertilizer use efficiency and an increase in tuber nitrate beyond the allowable limit.ConclusionThe results showed that nitrogen splitting is a correct management approach when it recommended based on the amount of nitrogen consumption (in this study 180 kg ha-1). The use of excess nitrogen, even in splitting, not only did not increase economic yield but in some treatments (three-stage splitting of 270 kg N ha-1) was associated with an increase in tuber nitrate beyond the allowable limit (170 mg kg-1 tuber fresh weight). In the amount of nitrogen application more than the recommended fertilizer, in both methods of nitrogen splitting, the efficiency of fertilizer application decreased. So that in the treatment of 270 kg N ha-1 compared to the treatment of 90 kg N ha-1, the efficiency of fertilizer application reached one third.

Research on the growth and yield of shallots at various concentrations of liquid organic fertilizer fermented cow urine has been carried out in Jorong Kopi, Nagari Bukit Sileh, Lembang Jaya District, Solok Regency, which is located at an altitude of ± 1400 m asl. The aim of the study was to obtain the best concentration of fermented cow urine organic liquid fertilizer for optimal shallot growth and yield. The research design used was a single factor randomized block design (RBD) with the treatment being tested was cow urine liquid organic fertilizer. There are 6 treatment levels applied, namely: 0 ml/1 liter of water, 10 ml/1 liter of water, 20 ml/1 liter of water, 30 ml/1 liter of water, 40 ml/1 liter of water, 50 ml/1 liter of water. Each treatment consisted of 4 replications. Observational data were analyzed for variance and continued with Duncan's Multiple Range Test (DMRT) at 5% significance level. The observed variables were plant height, number of leaves, number of tubers/clump, fresh weight of tubers/clump, dry weight of tubers/clump and yields/ hectare. The results showed that the application of cow urine fermented liquid organic fertilizer gave the highest yield at a dose of 50 ml/1 liter of water. This can be seen in plant height, tuber fresh weight/clump, tuber dry weight per clump and yields per hectare. [ABSTRACT FROM AUTHOR]

This paper analyses the effect of dosage (0.25 dm3 ha–1 or 0.50 dm3 ha–1) and time (the leaf development stage – BBCH 14–16, tuber initiation stage – BBCH 40–41, at both the leaf development stage and tuber initiation stage) of silicon-based stimulant Optysil application (200 g SiO2 and 24 g Fe in 1 dm3) on early potato yield and yield components. Optysil resulted in an increase in tuber number and tuber weight per plant. As a result, under periodic water deficits during tuber bulking, Optysil increased marketable tuber (with a diameter above 30 mm) yield by an average of 6.90 t ha–1 (50%) and under drought conditions during the potato growth period by 0.70 t ha–1 (8.6%). Under periodic water deficits during tuber bulking, the marketable tuber number per plant and marketable yield were greatest after applying 0.50 dm3 ha–1 of Optysil in the tuber initiation stage (BBCH 40–41). Under drought conditions, the most practical were two Optysil applications at 0.25 dm3 ha–1. The Optysil application improved the market value of the early potato yield by increasing the share of medium-sized tubers (with a diameter of 41–50 mm).

This paper analyses the effect of dosage (0.25 dm3 ha-1 or 0.50 dm3 ha-1) and time (the leaf development stage - BBCH 14-16, tuber initiation stage - BBCH 40-41, at both the leaf development stage and tuber initiation stage) of silicon-based stimulant Optysil application (200 g SiO2 and 24 g Fe in 1 dm3) on early potato yield and yield components. Optysil resulted in an increase in tuber number and tuber weight per plant. As a result, under periodic water deficits during tuber bulking, Optysil increased marketable tuber (with a diameter above 30 mm) yield by an average of 6.90 t ha-1 (50%) and under drought conditions during the potato growth period by 0.70 t ha-1 (8.6%). Under periodic water deficits during tuber bulking, the marketable tuber number per plant and marketable yield were greatest after applying 0.50 dm3 ha-1 of Optysil in the tuber initiation stage (BBCH 40-41). Under drought conditions, the most practical were two Optysil applications at 0.25 dm3 ha-1. The Optysil application improved the market value of the early potato yield by increasing the share of medium-sized tubers (with a diameter of 41-50 mm). [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is one of the most important vegetable crops in the world. Weeds are the most global problem in onion production. Purple nutsedge (Cyperus rotundus L.) is one of the most damaging weeds, which propagates rapidly through extensive underground system and tubers. The aims of this study were to evaluate the effect of solarization duration and tuber weight on characters of C. rotundus and assessed different treatments on the weed control and onion yield. For this purpose, two separate experiments were conducted in South of Kerman Agricultural Research and Education Center, Jiroft, Iran. The solarization experiment conducted to investigate the effects of solarization duration [0 (control), 5, 10, 15, and 20 days] and tuber weight (small, medium and large) on tuber viability and the number of produced tubers of C. rotundus. The weed management experiment conducted as a randomized complete block design with eight weed management methods with three replications. The results of the solarization experiment showed that in all solarization duration tuber viability eliminated except for control. The maximum percentage of tuber viability found in the interaction of non-solarization with large and medium tuber weights. Also, the results of the weed management experiment revealed that after hand plucking treatment, deep disking twice with 20 days interval followed by application of Glyphosate twice after each disk treatment (T8) was the best weed management method. The highest onion yield was obtained in hand plucking and T8 treatments by 96.53 and 70.67 ton ha-1, respectively.

Under climate change conditions, biostimulants play an important role in plant adaptation to abiotic stress. This paper analyses the effect of the seaweed extracts Bio-algeen S90 (Ascophyllum nodosum) and Kelpak SL (Ecklonia maxima) and humic and fulvic acids HumiPlant (leonardite extract) on early crop potato yield and yield components. Three very early potato cultivars Denar, Lord and Miłek were tested. Biostimulants did not affect the number of tubers produced by potato plants but increased the tuber weight per plant and average tuber weight and, as a result, the tuber yield. The yield-increasing effect of biostimulants depended on the hydro- thermal conditions during potato growth. Bio-algeen S90 and Kelpak SL produced better results in a warm and very wet growing season, whereas HumiPlant produced better results in a year with lower air temperature and with drought periods during potato growth. The use of biostimulants in early crop potato culture assured higher yield under abiotic stress conditions, and also contributed to improving its marketable value by an increase in the productivity of the marketable-size tubers and, simultaneously, decreasing the share of large tubers with a diameter above 50 mm. The tested potato cultivars showed a similar response to the biostimulants applied.

The sugar content in the potato tuber determines the optimum harvest time, the type of processing and its handling during storage. The aim of this study was to evaluate the growth and yield of four potato varieties under greenhouse conditions and to determine the soluble sugar content of this tuber at different maturity stages. For this, potatoes (5 ± 1 g) of four varieties were sampled at four maturity stages, from the beginning of tuberization to physiological maturity, in which the soluble sugar content was determined by high-performance liquid chromatography (HPLC). The Alpha variety had the longest growth cycle (1,230 degree days, P ≤ 0.05), while Mondial had the highest yield (380 g, P ≤ 0.05), 75, 31 and 31 % more than Vivaldi, Alpha and Atlantic, respectively, attributed to the highest average tuber weight (61 g, P ≤ 0.05). The highest content of sucrose, glucose and fructose (7.65, 2.22 and 0.37 mg·g-1, respectively) was recorded 21 days after the start of tuberization, quantities that decreased (P ≤ 0.05) during tuber development. Atlantic stands out with the lowest levels (P ≤ 0.05) of sucrose, glucose, fructose and total sugars in the different stages of tuber maturity. Average tuber weight was negatively correlated (P ≤ 0.05) with the contents of sucrose, reducing sugars (glucose and fructose) and total sugars.

In order to achieve optimum quantitative and qualitative yield of potato in each region, new cultivars need to be compared. As such, this study has been carried out to compare 13 new potato cultivars along with two cultivars of Agria and Banba with each other to identify suitable cultivars for leaf area index, agronomic, and qualitative traits under climatic conditions of Razan. The statistical design, used in the present study, has been complete randomized block with three replications. Results show that Manito cultivar has reached the maximum leaf area index later than other cultivars, having 12 tubers per plant, which is 112% and 83% superior to Banba and Agria, respectively. Also, Natascha cultivar with a leaf area index of 3.65 has been 57% and 19% leafier than Agria and Banba, respectively. Tuber weight in Ottawa (157.8 g per tuber) has been 70.5% and 20.4% greater than Agria and Banba, respectively. Manito cultivar yields 71399 kg/ha, which is 123% more than Agria and 70% than Banba. Protein percentage of tubers in this study do not differ among the potato cultivars, while the difference is significant among the potato cultivars in tuber starch percentage and the highest values belong to Manito (18.09%) and Ottawa and Concordia cultivars, in the second and place. Generally, Manitou, Caruso, and Faluca cultivars are recommended for planting in the Razan on the basis of traits of maximum leaf area index, number of tubers per plant, and tuber yield. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is one of the most important vegetable crops in the world. Weeds are the most global problem in onion production. Purple nutsedge (Cyperus rotundus L.) is one of the most damaging weeds, which propagates rapidly through extensive underground system and tubers. The aims of this study were to evaluate the effect of solarization duration and tuber weight on characters of C. rotundus and assessed different treatments on the weed control and onion yield. For this purpose, two separate experiments were conducted in South of Kerman Agricultural Research and Education Center, Jiroft, Iran. The solarization experiment conducted to investigate the effects of solarization duration [0 (control), 5, 10, 15, and 20 days] and tuber weight (small, medium and large) on tuber viability and the number of produced tubers of C. rotundus. The weed management experiment conducted as a randomized complete block design with eight weed management methods with three replications. The results of the solarization experiment showed that in all solarization duration tuber viability eliminated except for control. The maximum percentage of tuber viability found in the interaction of nonsolarization with large and medium tuber weights. Also, the results of the weed management experiment revealed that after hand plucking treatment, deep disking twice with 20 days interval followed by application of Glyphosate twice after each disk treatment (T8) was the best weed management method. The highest onion yield was obtained in hand plucking and T8 treatments by 96.53 and 70.67 ton ha-1, respectively. [ABSTRACT FROM AUTHOR]

Increasingly, phosphorus (P) fertilizer is being applied in Inner Mongolia of China to overcome the problem of insolubility of phosphorus in calcareous soil and meet the growth demand of potato plants. As a result, phosphorus use efficiency (PUE) in potatoes decreases continually. In this four-year study in sandy soils, drip fertigating potatoes with phosphorus during the growth season improved phosphorus uptake, plant growth, tuber yield, and PUE. Results show that relative to a single phosphorus application, using a split phosphorus application regime through drip irrigation significantly increased the leaf area index (LAI) and phosphorus uptake rate in the mid and late growth stages of potatoes, and enhanced potato yield and PUE. We concluded that split phosphorus application has the potential to benefit sustainable potato production in Inner Mongolia of China. [ABSTRACT FROM AUTHOR]

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As silicon induces abiotic stress tolerance in crop plants, it was hypothesized that foliar silicon application could improve potato growth in an early crop culture. The effect of dosage (0.25 dm3·ha−1 or 0.50 dm3·ha−1) and time (the leaf development stage, BBCH 14–16, tuber initiation stage, BBCH 40–41, or both the leaf development stage and tuber initiation stage) of application of the silicon-based biostimulant Optysil (200 g SiO2 and 24 g Fe in 1 dm3) on potato growth was investigated. Optysil caused an increase in plant height and above-ground plant biomass, enlarged leaf area and decreased leaf weight ratio (LWR), and, as a result, increased tuber number and tuber weight per plant. The effect of Optysil depended on a water deficit during potato growth. The average tuber weight per plant in the cultivation treated with Optysil was higher by 23% under periodic water deficits during potato growth, and by 13% under drought conditions, than in the cultivation without the biostimulant. Dosage of Optysil had a significant effect on above-ground plant biomass and leaf area in the warm and arid growing season. Under drought stress, Optysil at 0.50 dm3·ha−1 stimulated potato growth more than at 0.25 dm3·ha−1. Under periodic water deficits during potato growth, the time of Optysil application affected potato growth more than the biostimulant dosage. The plants produced greater above-ground biomass and had a larger leaf area with two Optysil applications; one in the initial plant growth period (BBCH 14–16), and a repeated treatment in the tuber initiation stage (BBCH 40–41). The tuber weight per plant was positively correlated with the plant height, above-ground plant biomass, leaf area, and LWR.

Winged beans (Psophocarpus tetragonolobus (L.) DC.) are grown as a vegetable legume crop in Thailand. All parts of the plant, including pods, seeds, leaves, flowers, and tubers are edible and are rich in protein and nutrients. Although the major consumption of winged bean is based on pod and tuber yields, only the people of Myanmar and Indonesia utilize winged bean tubers as food materials. The usefulness of the winged bean as an alternative crop for staple food and feed can shed some light on the impact of winged bean. Therefore, the evaluation of the dual purpose of the winged bean based on pod tuber yields is the objective of this study. In this study, ten-winged bean accessions—six accessions obtained from introduced sources and four accessions obtained from local Thai varieties—were laid out in randomized complete block design (RCBD) with three replications at the Agronomy Field Crop Station, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand from September 2019 to April 2020 and from October 2020 to April 2021. Data, including total pod weight, number of pods, pod length, 10-pod weight, and tuber weight were recorded, and the proximate nutrient and mineral contents in the tubers were also determined. The results revealed that the principal effects of year (Y) and genotype (G) were significant for total pod weight and the number of pods. Moreover, the Y × G interactions were principal effects upon the total pod weights and tuber weights. The results indicated that superior genotype and appropriate environmental conditions are key elements in successful winged bean production for both pod and tuber yields. The winged bean accessions W099 and W018 were consistent in both experimental years for pod and tuber yields at 23.6 and 18.36 T/ha and 15.20 and 15.5 T/ha, respectively. Each accession also proved high in tuber protein content at 20.92% and 21.04%, respectively, as well as significant in fiber, energy, and minerals. The results suggest that the winged bean accessions W099 and W018 can be used for dual-purpose winged bean production in Thailand.

Arrowroot is a plant that has not been widely cultivated in Indonesia. Arrowroot not considered to be a source of food but is often planted in the yard in the countryside as a food reserve during the dry season.Thisresearch is done to determine the number of seeds and optimum organic fertilizer dosage used for optimize growth and yield of arrowroot. Experiment was performed in dryland of experimental field of Agriculture Faculty of SebelasMaret University in Jumantono, Karanganyar. This research was arranged using Complete Randomized Blocked Design (CRBD) factorial with 2 factors of treatment that is the number of seeds and doses of organic fertilizer.The seed quantity consists of 2 levels, which are J1(1 seed per planting hole) and J2 (2 seeds per planting hole). The dose of organic fertilizer consist of 3 levels of P1 (2.5 ton / ha), P2 (5 ton / ha) and P3 (7.5 ton / ha). Data were analyzed using DMRT (Duncan Multiple Range Test). The results showed that the 2 seed per planting hole treatment resulted in better growth and yield of garut on the variable of leaf number, tuber length and tuber weight per plot each of them 26,11 sheet, 23,09 cm and 7,60 kg. The organic fertilizer did not give significant result to the growth and yield of the arrowroot, but organic fertilizer of 5 ton / ha dose tends to give higher yield on number of tuber, tuber weight per plot and tuber diameter.

In Ethiopia, the average yield of potato is far below the potential due to different problems like in low soil fertility. Hence, this research was done to evaluate the effects of blended NPS fertilizer rates on yield and yield components of potato. The study was conducted at Abaso Kotu, Dessie Zuria district, Ethiopia, during dry season of 2015. The experiment was consisted a factorial combination of two late maturing potato varieties (Belete and Local) and six NPS fertilizer rates (0:0 (T1), 111:89.7:0 (T2), 111:89.7:16.52 (T3), 55:89.7:16.52 (T4), 111:44.85:8.26 (T5) and 55:44.85, 8.26 (T6)) kg ha-1 and Randomized Complete Block Design with three replications was used. The highest potato plant height was recorded on 111: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate. Belete variety supplied with 111: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate recorded the maximum days (124.3) to maturity of potato. Similarly, Belete variety recorded the higher biomass than local variety. The 111:89.7:16.52 (T3) kg ha-1 and 55.5:89.7:16.52 (T4) kg ha-1 NPS fertilizer rates showed the highest above ground biomass and underground biomass of potato, respectively. The highest average tuber number per hill, tuber weight per hill, marketable, unmarketable and total tuber yield were recorded on potato which was applied with 55.5: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate. It is concluded that 55.5:89.7:16.52 (T4) kg ha-1 NPS fertilizer rate application is recommended for the production of potato varieties at Abaso Kotu, Dessie Zuria District Ethiopia.

In Ethiopia, the average yield of potato is far below the potential due to different problems like in low soil fertility. Hence, this research was done to evaluate the effects of blended NPS fertilizer rates on yield and yield components of potato. The study was conducted at Abaso Kotu, Dessie Zuria district, Ethiopia, during dry season of 2015. The experiment was consisted a factorial combination of two late maturing potato varieties (Belete and Local) and six NPS fertilizer rates (0:0 (T1), 111:89.7:0 (T2), 111:89.7:16.52 (T3), 55:89.7:16.52 (T4), 111:44.85:8.26 (T5) and 55:44.85, 8.26 (T6)) kg ha-1 and Randomized Complete Block Design with three replications was used. The highest potato plant height was recorded on 111: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate. Belete variety supplied with 111: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate recorded the maximum days (124.3) to maturity of potato. Similarly, Belete variety recorded the higher biomass than local variety. The 111:89.7:16.52 (T3) kg ha-1 and 55.5:89.7:16.52 (T4) kg ha-1 NPS fertilizer rates showed the highest above ground biomass and underground biomass of potato, respectively. The highest average tuber number per hill, tuber weight per hill, marketable, unmarketable and total tuber yield were recorded on potato which was applied with 55.5: 89.7:16.52 (T3) kg ha-1 of NPS fertilizer rate. It is concluded that 55.5:89.7:16.52 (T4) kg ha-1 NPS fertilizer rate application is recommended for the production of potato varieties at Abaso Kotu, Dessie Zuria District Ethiopia. [ABSTRACT FROM AUTHOR]

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به‌منظور بررسی اثر سطوح مختلف تنش کم‌آبی و کود نیتروژن بر عملکرد و سایر صفات زراعی سیب‌زمینی رقم بورن، آزمایشی در سال زراعی 92-1391 با سه سطح تنش کم‌آبی S1، S2 و S3 (به ترتیب تأمین 100، 75 و 50 درصد نیاز آبی سیب‌زمینی پس از سبز شدن تا پایان دوره رشد) به‌عنوان فاکتورهای اصلی و 4 تیمار کود نیتروژن N1، N2، N3 و N4 (به ترتیب تأمین 100، 66، 33 و صفر درصد نیاز کودی) به‌عنوان فاکتورهای فرعی به‌صورت کرت‌های خردشده، در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در مرکز تحقیقات کشاورزی و منابع طبیعی استان چهارمحال و بختیاری به اجرا درآمد. در این آزمایش، تنش کم‌آبی درصد ماده خشک غده‌ها را افزایش داد، اما مقادیر نیتروژن روند مشخصی در تغییرات این صفت ایجاد نکرد. با اعمال تنش خشکی و کاهش مصرف کود نیتروژن تعداد غده در بوته و وزن غده‌ها کاهش یافت. عملکرد غده قابل‌فروش در تیمار‌های S1 و S2 اختلاف معنی‌دار نداشت اما تنش آبی (S3) منجر به افت شدید عملکرد شد. تیمارهای N1، N2 و N3 باعث افزایش عملکرد غده قابل‌فروش به ترتیب به میزان 30، 36 و 11 درصد نسبت به شاهد (N4) شدند. به علت کاهش عملکرد غده در تیمارهای S2 و S3 در بالاترین سطح مصرف نیتروژن (N1)، اثر متقابل تنش خشکی و نیتروژن بر عملکرد غده، معنی‌دار شد. تیمار N2 در شرایط تنش شدید کم‌آبی و تنش متوسط دارای بالاترین و تیمار N4 در شرایط بدون تنش دارای کمترین کارآیی مصرف آب بود. بر اساس تجزیه رگرسیون مرحله‌ای، صفت میانگین وزن غده قابل‌فروش به‌تنهایی بیشتر تغییرات عملکرد غده در واحد سطح را توجیه کرد.

Abstract: Increasing the tuber number per plant and promoting tuber formation are important goals for potato production. Thus, it is of significance to understand how environmental factors affect tuber formation, which relates to the development of agronomical practices. The objective of this research was to test whether changing the CO2 or N supply level could alter the C : N ratio in potatoes, and whether a change of the C : N ratio in potatoes closely correlates with tuber formation in potato plants. Potato plantlets were grown in greenhouse with varied CO2 or N levels. The C and N concentrations of plants were measured, and the tuber number and tuber weight were recorded after different growth times. The results show that the C : N ratios in the potato plants increased with increasing CO2 concentration and that potato plants treated with higher CO2 concentrations form tubers earlier. A decrease in the N supply also resulted in a higher C : N ratio and earlier tuber formation. Therefore the hypothesis proposed previously is supported by the present work. In addition, the results that C concentration in plants remained stable under different CO2 or N levels imply that the variation of C : N ratio in the potato plants is mainly due to a change of N concentrations which decreased as the environmental CO2 concentration increased, while increased as the N supply level increased. [ABSTRACT FROM AUTHOR]

In order to evaluate yield and some of physiological indices of potato cultivars in relation to different kinds of manures, strip plot layout within a randomized complete block design with three replications was used. Three levels of fertilizer were included manure (t/ha) (20, 40 and 60 t/ha), biologic fertilizer (ml/ha) (0, 100 and 200 ml/ha), and chemical fertilizer (kg/ha) (175, 350, and 525 kg/ha). Cultivars were Marfona, Maradona and Ramus. Marfona had obtained the maximum plant height, total dry matter, LAI, tuber yield, dry matter of tuber, the number of tuber and tuber weight. Application of 60 t/ha manure fertilizer together with Marfona produced the highest yield. In this experiment, fertilizer showed significant effects on potato cultivars yield and physiological indices. Marfona and Ramus had obtained the highest and the lowest total dry matter, respectively. The maximum LAI was related to application of 60 t/ha manure fertilizer, and the minimum one was obtained for application of 40 t/ha manure fertilizer. In cultivar treatments, the highest LAI was obtained for Marfona, followed by Maradona and Ramus. The maximum and the minimum crop growth rate (CGR) was related to chemical and biological fertilizer, respectively. The maximum CGR was related to Marfona, than those of other cultivars. There were not any significant differences among different fertilizers in net assimilation ratio (NAR), fertilizer levels and various cultivars. Thus, it can ve suggested that in order to increasing yield, total dry matter, crop growth rate and other physiological indices should be applied 60 t/ha manure fertilizer with Marfona cultivar in Fereydan region of Esfahan, Iran. [ABSTRACT FROM AUTHOR]

This study has been conducted into the rangelands of Mediterranean climatic zone aim to control the commonly found Asphodelus aestivus Brot. weed plant having poisonous characteristics due to the presence of glycosides inside it. The research was carried out in Gerlengeç village of Biga District at Çanakkale Province, Turkey. Herbicide application was done in the month of April in 2015 while the tuber samples were collected in the month of April in 2016. The following five different herbicides were used in the control of A. aestivus due to the non-availability of any selective and specific herbicide that has being used in the chemical control of this weed species. In general; chlorosulfuron, dicamba+Triasulfuron and tribenuron methyl+thifensulfuron methyl herbicides affect the broad-leaved, metsulfuron methyl+lodosulfuron methyl is used in the control of narrowleaved, while glyphosate is an all-rounder herbicide that is used in the control of broad as well as narrow-leaved weed plants. In addition, two different doses (applied and double) of the above mentioned herbicides were selected to apply. The research was established according to the randomized complete block design (RCBD) by using three replications. The effects of applied herbicides have been investigated on tuber characteristics of A. aestivus in this research. As a result, the applied herbicides showed significant effects on the weight, length, diameter and the number of tuber while the applied doses were found with significantly important effects only on the weight and number of tuber. It concluded that the most effective herbicides were chlorosulfuron and glyphosate, and the best effective dose was observed as the ‘double dose’ in the chemical control of summer asphodel. [ABSTRACT FROM AUTHOR]

Field experiments have been conducted with the objective of identifying optimum rate of the newly introduced NPS fertilizer for profitable production of potato at Koga Irrigation Scheme, Northwestern Ethiopia. Six NPS fertilizer rates and three potato varieties which were factorial combined and laid down in Randomized Complete Block Design in three replicates were tested on two different farmlands. Most growth, yield, and yield components of potato were increased with increasing rates of NPS fertilizer which differed with varieties and locations. Highest marketable tuber yields of Belete (55.37 t ha−1) and Gudene (46.83 t ha−1) varieties were recorded with the of 283.75 kg ha−1 NPS fertilizer in location I (soil with low phosphorous content). The yields of Gudene variety recorded at the range of 181.6 to 283.75 kg ha−1 NPS fertilizer were however statistically similar. Farmer`s local potato variety on the other hand recorded the highest marketable tuber yield (28.98 t ha−1) in location II (soil with high phosphorous content) supplied with 227.0 kg ha−1 NPS which was similar with yields at the range of 102.12 to 283.75 kg ha−1 NPS fertilizer. On soils with low phosphorous content, production of Belete, and Gudene varieties with application of 283.75 and 181.60 kg ha−1 NPS fertilizer rates, respectively, are recommended while on soils with high phosphorous content production of local, and Gudene varieties supplied with 136.20 and 181.60 kg ha−1 NPS, respectively, are recommended for higher profitability of potato production at Koga Irrigation Scheme.

A condition for achieving a high potato tuber yield on an early harvest is to provide plants with good growth conditions. In modern horticulture, plant growth stimulants have been gaining increasing importance. This study examined the effect of dose (0.2 dm3 ha–1 or 0.4 dm3 ha–1) and date (leaf development stage – BBCH 14-16, tuber formation stage – BBCH 41-43, leaf development stage and tuber formation stage) of Tytanit® application (8.5 g Ti in 1 dm3) on the growth of very early-maturing potato cultivars (‘Lord’, ‘Miłek’). Following the Tytanit® application, the plants were higher and produced a greater aboveground biomass and tuber weight, however, the leaf weight ratio (LWR) and leaf area ratio (LAR) were lower than in the cultivation without the growth stimulant. Tytanit® had a greater effect on the leaf weight ratio (LAR) and tuber weight for the ‘Lord’ cultivar. Tytanit® dose had no effect on the plant growth. A double Tytanit® application resulted in a reduction in the length and weight of stems and tuber weight. The date of Tytanit® application had no effect on the weight of leaves. The leaf area ratio (LAR) was the highest when Tytanit® was only applied in the tuber formation stage, and the leaf weight ratio (LWR) was the highest when Tytanit® was applied twice. A positive correlation was found between the tuber weight and the LWR and LAR.

The impact of using humic substance for growing potato on quality indicators of tubers. Humic preparations are concentrated and economical form of organic matter which can relieve humus depletion caused by conventional fertilization methods. The trials were carried out in 2012 and 2013 at the Estonian University of Life Sciences in Estonia. The yield of tubers and starch, and commercial yield of potato, number of tubers per plant, tuber weight was studied in cultivar 'Ants' and 'Laura'. In the experiments humic preparation (HP) "Ruponics" was used in two different treatment variants. "Ruponics" 50 l ha-1 (HP50), "Ruponics" 25 l ha-1 (HP25) and control (HP0) 0 l ha-1 variant. The experiments showed that potato cultivars 'Ants' and 'Laura', HP did not have any significant positive effect on the tuber yield, commercial tuber yield or starch yield in 2012. Yields were higher in 2013 reaching up to 52.4 t ha-1 and year 2013 'Laura' HP50 had yield 35.9 t ha-1. The main role of the addition of HP is improving nutrient mobility in the soil and higher uptake of nutrients to plants. Positive effect of HP should appear when plant is growing under unfavourable conditions.

The trials were carried out in 2012 and 2013 at the Estonian University of Life Sciences. Total yield, marketable yield, number of tubers per plant, average weight of tubers, tuber starch content was studied in cultivar 'Ants' (medium late) and 'Laura' (medium early). Following treatments were used: untreated control (T0) Seed tubers were planted directly from storage house (storage temperature 4°C); Thermal shock (TS). Seed tubers were kept before planting 5 days in a room with a temperature of 30°C and 2 days in a room with a temperature of 12°C; Pre-sprouting (PS). Seed tubers were kept before planting 26 days in a room with a temperature of 15°C and 10 days in a room with a temperature of 12°C. From the results in 2012 it was observed that pre-planting thermal treatments increased the number of tubers per plant compared to pre-sprouting. Pre-sprouted tubers gave higher average weight of tubers than in thermal shock variants. Hence, there were lower number tubers with higher weight of tubers in pre-sprouted variants in 2012. The results of experiments (2012–2013) indicated that pre-planting treatments did not have any significant effect on the yield of cultivar 'Ants'. In 2013 the yield of cultivar 'Laura' was significantly increased by pre-sprouting, showing higher number of tubers and higher weight of tubers. Therefore also the share of marketable tubers in the yield of both varieties was higher in pre-sprouted variants in 2012. Therefore, in case of cultivar 'Ants' it could be concluded that the thermal shock increases the number of tubers and decreases the weight of the tubers. The starch yield of cultivar 'Laura' was significantly higher in pre-sprouted variant in 2012. That was due to the significantly higher tuber yield in the same variant.

Copyright of Revista Chapingo Serie Horticultura is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Irrigation water scheduling methods influence the growth, yield, and water productivity of crops including potatoes. Therefore, a study was conducted to evaluate the effects of irrigation frequency determination methods on tuber yield, irrigation water productivity and fertilizer use efficiency of potatoes at Koga irrigation scheme, in Northwest Ethiopia. The treatments were consisted of two irrigation frequency determination methods (wetting front detector and crop water requirement) and six NPS fertilizer rates (0, 90.8, 136.2, 181.6, 227.4 and 272.0 kg ha -1 , which were factorial combined in a randomized complete block design with three replications. Growth and tuber yield data of potato were collected based on the standard procedure. Irrigation water productivity, partial factor productivity, and agronomic efficiency were calculated using their respective models. The collected data were analyzed using SAS version 9.4. The results revealed that the wetting front detector method recorded the highest tuber weight (79.5 g), tuber yield (41.9 t ha -1 ), and irrigation water productivity (9.1 kg potato m -3 water) compared to crop water requirement method. NPS fertilizer at the rate of 272 kg ha -1 also produced the highest tuber weight (86.5), tuber yield (58.1 t ha -1 ) and irrigation water productivity (12.4 kg potato m -3 water). Treatment combination of wetting front detector and 272 kg ha -1 NPS recorded the highest plant height (64.m cm) and stem number (10.4). Wetting front detector method recorded the highest partial factor productivity (275.2 kg potato per kg NPS) compared to crop water requirement. Wetting front detector combined with NPS rates generally recorded higher partial factor productivity compared to the respective NPS rates combined with crop water requirement. NPS fertilizer at 272 kg ha -1 combined with wetting front detector gave the highest net benefit (236,591.7 ETB ha -1 ) with acceptable marginal rate of return (248.9%), which is recommended for economical production of potato in the area., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

The aim of this study was to determine the effect of the size and weight of tubers originating from different altitudes on the yield of most commonly grown potato cultivar Desiree in western Serbia (Macva). Potato seed producing crop, from which the planting material came from, was grown during 2006 and 2007 at two sites with different altitudes: a plain region at 72 m a.s.l. and a mountainous region at 1100 m a.s.l. The investigation was carried out by planting the following mass of planted material: 50 ± 5g, 70 ± 5g, 90 ± 5g and 110 ± 5g in 2007 and 2008 year to produce planting material. Planted tubers originating from 72 m a.s.l. produced a total yield (a two year average) of 26.25 t ha-1. The difference was significantly higher than the variant with planted tubers originating from 1100 m a.s.l. by 2.02 t ha-1 (7.7%). The two year mean highest total yield of 27.87 t ha-1 was achieved by planting the largest mass (110 g) and the lowest 21.07 t ha-1 by planting the smallest mass (50 g) of the tuber. Higher yields of potato tubers in moist conditions in western Serbia (Macva) were achieved by planting larger mass of tubers originating from lower altitude.

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Field trials with the potato cultivars 'Ants' (medium late) and 'Laura' (medium early) were carried out on the experimental fields of the Department of Field Crops and Grassland Husbandry located at Eerika (58°22' N, 26°40' E), Estonian University of Life Sciences in 2010 and 2011. The yield of tubers and starch, marketable yield of potato, number of tubers per plant and tuber weight were studied. We used the following treatments: untreated control (To): seed tubers were planted directly from storage house (storage temperature 4°C); thermal shock (TS): seed tubers were kept before planting 5 days in a room with temperature of 30°C and 2 days with temperature of 12°C; pre-sprouting (PS): before planting the seed tubers were kept 26 days in a room with temperature of 15°C and 10 days with temperature of 12°C. The results are presented as the averages of studied years. According to the average results of two experimental years, the pre-planting treatment with thermal shock increased the number of tubers per plant of cultivar 'Ants' by 30.6%, compared to control treatment. None of the treatments had any effect on the number of tubers of cultivar 'Laura'. The thermal treatment increased the average weight of tubers of cultivar 'Laura' compared to the control treatment (thermal shock by 14.7%, pre-sprouting by 20.7%), but for cultivar 'Ants' the weight of tubers was decreased by 16.7% (thermal shock treatment). The thermal shock treatment increased the tuber yield of cultivar 'Ants' by 10.7% and the presprouting increased the total tuber yield of cultivar 'Laura' by 9.9%. The thermal shock increased significantly the starch content of cultivar 'Ants' and decreased that of cultivar 'Laura'. [ABSTRACT FROM AUTHOR]

We have evaluated and compared different methods and cultivars for the production of quality prebasic seed in potato. Two cultivation systems, aeroponics and greenhouse beds with a peat moss substrate, and three potato cultivars with different vegetative cycle, Agria, Monalisa and Zorba, were assayed. Plants in the aeroponic system showed increased growth and their vegetative cycle extended between 12 and 36 % compared to the plants cultivated in greenhouse beds. Flowering and tuberization dates, Absolute Growth Rates (AGR) during the period of 60 days after planting (DAP) and height presented a wide variation between cultivars. Zorba showed earlier flowering and tuberization, lower AGR and reached a minor height at 60 DAP. Instead the late season cultivar Agria showed later flowering and tuberization, presented higher AGR and reached an increased height at 60 DAP. The total tuber yield per plant was between 34 and 87 % higher in the aeroponic system, with a marked difference for the earlier cultivars Zorba and Monalisa. Tuber numbers increased between 60 and 80 %. Minituber production in aeroponics showed a better size distribution, with a reduction in the percentage of tubers smaller than 12 mm of between 33 and 86 %. In this soil-less culture system average tuber weight increased in Zorba and Monalisa over 60 % but was lower for Agria. Further studies are needed to optimize aeroponics system, which can be considered a high yield potato multiplication system, particularly for early or mid season potato cultivars that may produce best quality minitubers. [ABSTRACT FROM AUTHOR]

The trials were carried out in 2012 and 2013 at the Estonian University of Life Sciences. Total yield, marketable yield, number of tubers per plant, average weight of tubers, tuber starch content was studied in cultivar 'Ants' (medium late) and 'Laura' (medium early). Following treatments were used: untreated control (T0) Seed tubers were planted directly from storage house (storage temperature 4°C); Thermal shock (TS). Seed tubers were kept before planting 5 days in a room with a temperature of 30°C and 2 days in a room with a temperature of 12°C; Pre-sprouting (PS). Seed tubers were kept before planting 26 days in a room with a temperature of 15°C and 10 days in a room with a temperature of 12°C. From the results in 2012 it was observed that pre-planting thermal treatments increased the number of tubers per plant compared to presprouting. Pre-sprouted tubers gave higher average weight of tubers than in thermal shock variants. Hence, there were lower number tubers with higher weight of tubers in pre-sprouted variants in 2012. The results of experiments (2012-2013) indicated that pre-planting treatments did not have any significant effect on the yield of cultivar 'Ants'. In 2013 the yield of cultivar 'Laura' was significantly increased by pre-sprouting, showing higher number of tubers and higher weight of tubers. Therefore also the share of marketable tubers in the yield of both varieties was higher in pre-sprouted variants in 2012. Therefore, in case of cultivar 'Ants' it could be concluded that the thermal shock increases the number of tubers and decreases the weight of the tubers. The starch yield of cultivar 'Laura' was significantly higher in pre-sprouted variant in 2012. That was due to the significantly higher tuber yield in the same variant. [ABSTRACT FROM AUTHOR]

The impact of using humic substance for growing potato on quality indicators of tubers. Humic preparations are concentrated and economical form of organic matter which can relieve humus depletion caused by conventional fertilization methods. The trials were carried out in 2012 and 2013 at the Estonian University of Life Sciences in Estonia. The yield of tubers and starch, and commercial yield of potato, number of tubers per plant, tuber weight was studied in cultivar 'Ants' and 'Laura'. In the experiments humic preparation (HP) "Ruponics" was used in two different treatment variants. "Ruponics" 50 1 ha-1 (HP50), "Ruponics" 25 1 ha-1 (HP25) and control (HP0) 0 1 ha-1 variant. The experiments showed that potato cultivars 'Ants' and 'Laura', HP did not have any significant positive effect on the tuber yield, commercial tuber yield or starch yield in 2012. Yields were higher in 2013 reaching up to 52.4 t ha-1 and year 2013 'Laura' HP50 had yield 35.9 t ha-1. The main role of the addition of HP is improving nutrient mobility in the soil and higher uptake of nutrients to plants. Positive effect of HP should appear when plant is growing under unfavourable conditions. [ABSTRACT FROM AUTHOR]

Vitamin C is the main vitamin source in potato tubers, and its antioxidant activity is known to benefit human health. To improve the vitamin C content and understand its accumulation patterns, we selected 10 advanced clones with high vitamin C content from 268 clones. The levels of the selected clones ranged from 32.3 to 38.9 mg⋅100 g-1 fresh weight. Among them, four double-cropping clones with short dormancy were selected for further analysis. The vitamin C content of the potato tubers from six potato clones, including two control cultivars, 'Dejima' and 'Chubaek', was determined on specific days after planting (DAP) and during development. Developmental stages were categorized by weight: I (5-10 g), II (30-40 g), III (70-80 g), and IV (> 120 g). Vitamin C content was highest 90 DAP and dropped slowly by 100 and 110 DAP. Until 90 DAP, we found that developmental stages I and II showed higher contents of vitamin C; however, there were small differences by developmental stage (I to IV) by 100 and 110 DAP. In conclusion, vitamin C content was higher in younger tubers than in mature tubers, and its content was highest 90 DAP in the selected clones. During storage, vitamin C content significantly declined in all clones. The decrease was highest in H06035-4 and H06085-2 compared to 'Chubaek' and 'Dejima', and the differences between selected clones and control varieties narrowed after 4 months of storage. When we consider the agronomic characteristics and consistency of high vitamin C content, H06035-4 was selected as a high vitamin C content promising line. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of the size and weight of tubers originating from different altitudes on the yield of most commonly grown potato cultivar Desiree in western Serbia (Macva). Potato seed producing crop, from which the planting material came from, was grown during 2006 and 2007 at two sites with different altitudes: a plain region at 72 m a.s.l. and a mountainous region at 1100 m a.s.l. The investigation was carried out by planting the following mass of planted material: 50 ± 5g, 70 ± 5g, 90 ± 5g and 110 ± 5g in 2007 and 2008 year to produce planting material. Planted tubers originating from 72 m a.s.l. produced a total yield (a two year average) of 26.25 t ha-1. The difference was significantly higher than the variant with planted tubers originating from 1100 m a.s.l. by 2.02 t ha-1 (7.7%). The two year mean highest total yield of 27.87 t ha-1 was achieved by planting the largest mass (110 g) and the lowest 21.07 t ha-1 by planting the smallest mass (50 g) of the tuber. Higher yields of potato tubers in moist conditions in western Serbia (Macva) were achieved by planting larger mass of tubers originating from lower altitude. [ABSTRACT FROM AUTHOR]

The effects of nitrogen supply of in vitro plantlets on subsequent in vitro tuberization were examined in three potato varieties. In vitro plantlets were raised on MS media with varying amounts of ammonium nitrate, resulting in 70, 80, 100, 120 and 160% of the standard N content in MS medium and various nitrate : ammonium ratios. Tuberization was induced by adding an 8% sucrose solution to 4-week old plantlets and keeping them 2 weeks under short or long days (8 and 16 h illumination per day, respectively), followed by darkness for 9 weeks. Under long days, a lower nitrogen content in the medium and higher nitrate : ammonium ratio were favourable for the development of large tubers (>6 mm). Under short days, the total number of tubers increased with an increase in nitrogen content of the medium in cultivars Gülbaba and Désirée but not in cultivar Boró, while the number of large tubers was not significantly influenced by nitrogen supply. The tuber weight per plantlet was strongly influenced by genotype. Nitrogen supply of the in vitro plantlets had a prolonged effect on in vitro tuberization. Because the optimum nitrogen treatment is genotype specific, the quantity of large in vitro tubers could be increased by adjusting the nitrogen content of the medium. [ABSTRACT FROM AUTHOR]

Using healthy and good quality seed is essential for developing viable and productive plants for quality seed potato production. Four cultivars (Cardinal, Desiree, Ultamiscue and Therawal) were selected for seed potato production during the autumn season. Analysis of variance indicated that a high germination percentage (62.8%) was observed in Cardinal followed by Ultamiscue. Larger canopy was found in Cardinal and Ultamiscue (10.66) as compared to other cultivars. Significantly high number of leaves (29.00) and high number of internodes/plant (12.11) was recorded in Desiree maximum leaf area (185.25cm²) was recorded in Therawal. Desiree was found to produce greater number of bigger (54.36cm²) tubers than other cultivars. Desiree had maximum weight of tubers (848.61 gm). On the basis of total yield the Desiree had highest yield (3.74 tons/hec.). The cultivar Desiree is recommended as better seed potato than the other three cultivars. [ABSTRACT FROM AUTHOR]