Average Tuber Research Articles

On-Farm Evaluation of Orange Fleshed Sweet Potato Varieties Under Acidic Soil of North-East Region in Bangladesh

An on-farm trial with four orange fleshed sweet potato varieties viz. BARI Mishti Alu-4, BARI Mishti Alu-8, BARI Mishti Alu-12, BARI Mishti Alu-13 including local check (Muli Alu) were evaluated at farming system research and development (FSRD) site, Jalalpur, Sylhet, Bangladesh during rabi season for two consecutive years (2016-2017 & 2017-2018) under Surma‐Kushiyara Floodplain of Bangladesh. The experiment was laid out in a randomized complete block design (RCBD) with six dispersed replications. The results revealed that the genotypes varied considerably in tuber root yields and yield attributing characters. Considering the average tuber root yield performance orange fleshed sweet potato varieties performed better than local variety (Muli Alu). However, among the varieties under studied BARI Mishti Alu-12 produced higher roots yield (40.63 t ha-1) than the other tested varieties. Considering economic return, the highest gross margin (Tk. 5,65,110 ha-1) and benefit cost ratio (5.50:1.00) was also obtained from sweet potato var. BARI Mishti Alu-12 and the lowest returnfrom var. BARI Mishti Alu-4 with benefit cost ratio of 3.54. Though the local cultivar (Muli Alu) produced lower root yields but it provided considerable gross margin (Tk.3,76,240 )and BCR (3.99:1.00 ) which closed to BARI Mishti Alu-12. It is due to higher demand of local cultivar with high price in the local market. Therefore, the genotypes BARI Mishti Alu-12 and local cultivar (Muli Alu) were found suitable for their better growth and yield under the acidic soils
 Bangladesh Agron. J. 2018, 21(2): 59-65

Effect of Fertilizer Sources on Potato Yield and Yield Components under Acidic Soil Condition in Central High Lands of Ethiopia

Agronomic practices like fertilizer application and low soil pH which associated with soil infertility problems are considered to be among the major challenges to potato production in the highlands of Ethiopia. In response to this, an experiment was conducted to compare effect of different sources of fertilizes on potato yield and yield components from 2015-2016 main cropping season(June–August) in four districts of west and south west part of Ethiopia comprising two potato varieties Belete and Gudenie as main plot and five fertilizer source treatments as sub plot. These fertilizer source treatments were control, recommended Urea (165 kg/ha) and DAP (195 kg/ha), recommended Urea (165 kg/ha) and DAP (195 kg/ha) plus 225 kg/ha potassium sulfate (K 2 SO 4 ), recommended Urea (165 kg/ha) and DAP (195 kg/ha) plus 225 kg/ha potassium chloride (KCl) and 242 kg/ha blended mineral fertilizer NPSB with N=18.9%, P=37.7%, S=6.95%, B=0.1% content plus 141 kg/ha urea under both limed and unlimmed soil conditions. The design was split plot with three replications. The data were analyzed using SAS soft ware versions 9.2. The experiment results showed that interaction of location and fertilizer types was highly significant in affecting total tuber and marketable tuber weight in t/ha. The Blended NPSB fertilizer was found superior in Welmera and Gumer location producing maximum total tuber yield of 33.21t/ha and 22.93t/ha respectively, under unlimmed soil condition while recommended urea and DAP provided maximum total tuber yield 31.38t/ha and 24.06t/ha under limed soil condition, respectively. In Jeldu growing location, the recommended urea and DAP plus KCl was produced maximum total tuber yield (19.13 t/ha under Unlimmed; and 23.9 t/ha total tuber yield under limed soil condition). In wenchi, the recommended urea and DAP was produced maximum 25.66 and 30.99 t/ha total tuber yield under both un-limed and limed soil condition, respectively. Interaction of growing year and location was highly significant in influencing average tuber number (total tuber number/plant) and average tuber weight (total tuber weight/tuber number). Interaction of location and growing year was highly significant in influencing dry matter under un-limed and limed soil condition. From these results, it can be concluded that the growing location and fertilizer sources had significantly affected the yield and yield component of potato both under limed and unlimmed soil conditions. Keywords: Potato, Potassium Fertilizer, Acid Soils, Lime Application DOI : 10.7176/JNSR/9-23-02 Publication date: December 31 st 2019

Effects of the frequency and amount of drip irrigation on yield, tuber quality and water use efficiency of potato in sandy soil of Yulin, northern Shaanxi, China

Reasonable irrigation is still lacking for potato production in the sandy areas of Yulin, northern Shaanxi Province. To solve this problem, field drip fertigation was conducted to examine the growth, yield and quality of potato during the whole growing season. We further analyzed the responses of these indices to different irrigation frequencies and amounts. There were three irrigation frequencies (d), i.e. 4 (D1), 8 (D2) and 10 (D3), and three irrigation amounts, i.e. 60%ETc (W1), 80%ETc(W2) and 100%ETc(W3), where ETc was the crop water requirement, resulting in a total of nine treatments. Under the same irrigation frequency, plant height, leaf area index, dry matter, tuber yield and economic benefits of W3 were higher than those of W1 and W2. W1 had the highest irrigation water use efficiency (IWUE), while water use efficiency was not significantly affected by irrigation amount. The average tuber yield of W3 was 43442 kg·hm-2, which was 23.3% and 11.6% higher than that of W1 and W2, respectively. The net income of W3 was 23492 yuan·hm-2, which was 40.4% and 18.7% higher than that of W1 and W2, respectively. Tubers from W3 had the highest starch and vitamin C contents but the lowest reducing sugar content, which were 14.4%, 18.54 mg·(100 g)-1 FW and 0.7%, respectively. At the same irrigation amount, tuber yield, IWUE, starch and vitamin C contents of D1 were the highest, but the reducing sugar content was the lowest at the low and medium irrigation amounts. At the high irrigation amount, D2 had the highest tuber yield, IWUE, net income, starch and vitamin C contents but the lowest reducing sugar content, which were 46572 kg·hm-2, 23.04 kg·m-3, 26,622 yuan·hm-2,14.6%, 19.53 mg·(100 g)-1 FW and 0.7%, respectively. Based on the interacting effects of drip irrigation frequency and amount, both yield and quality of D2W3 reached the maximum. Results from the principal component analysis showed that D2W3 had the highest score. D2W3(8 d, 100%ETc) had the greatest yield and quality and relatively higher water use efficiency, which was thus considered as the optimal combination of drip irrigation frequency and amount. The results could provide a scientific basis for the drip irrigation scheduling design for high-yield, high-efficiency and high-quality potato production in the sandy areas of Yulin, northern Shaanxi.

English

Phytophthora infestans is the major bottleneck in potato production in Ethiopia. Selection of appropriate planting time is highly location specific and the most important subject in rain-fed potato production. However, research recommendation on optimum planting time and fungicide application frequency for high lands area of Arsi (Kulumsa) is lacking. Thus, field experiment was carried out to evaluate the effect of planting time and fungicide application frequency on disease severity, yield and yield components of potato at Kulumsa during main cropping season of 2017. The treatments consisted of four planting time in the months of June and July and four fungicide application frequencies at the rate of 2.5 kg ha-1 of Ridomil Gold M.Z 68% W.P. Treatments were combined in 4 × 4 factorial arrangement and laid out in randomized complete block design with three replicates. Data on disease, tuber yield and yield components were analyzed using Statistical Analysis System Version 9.3. The interaction effect between treatments showed a highly significant (p<0.01) effect on disease incidence and area under disease progress curve and a significant (p<0.05) effect on percent severity index. Early planting in June produced significantly higher number of marketable and total tuber numbers per hill which were progressively reduced in subsequent plantings, whereas delay planting in July resulted in higher number of unmarketable tubers per hill. The interaction between early planting and different fungicide application frequencies gave the highest average tuber weight, marketable and total tuber yield per hectare. Therefore, the combination of early planting in June and twice fungicide application gave the optimum results in the study area. Key words: Disease incidence, fungicide, integrated disease management, potato tuber, production season. &nbsp

Genetic Diversity of Potato Cultivars for Nitrogen Use Efficiency Under Contrasting Nitrogen Regimes

Developing cultivars that use nitrogen more efficiently is a sustainable strategy for reducing nitrogen use in crop production. To assess the genetic diversity for nitrogen use efficiency (NUE) and related traits in potato, a total of 97 (88 for the Western-European market and 9 Ethiopian) cultivars were evaluated at two nitrogen levels (40 kg/ha and 120 kg/ha) for 24 quantitative traits in Debre-Tabor and Injibara (Ethiopia) in the 2013 main rainy season (June to September). Highly significant variation was found among genotypes for almost all measured traits. Plant height, NUE, tuber yield, and yield-related traits and model parameters for canopy development (maximum canopy covers area under the canopy curve) were significantly affected by N levels across locations. Dutch cultivars had more rapid initial canopy development and matured earlier than the Ethiopian cultivars at both N levels and locations. A hierarchical cluster analysis grouped the cultivars in 9 and 11 genetically distinct classes at low and high N, respectively. The genetic component accounted for a large portion of the phenotypic variation for plant height, tuber number per plant, average tuber weight, and NUE under both N regimes, as indicated by a high heritability. Strong phenotypic correlations were observed between NUE and tuber number per plant, days to maturity, tuber dry matter %, maximum canopy cover, and area under the canopy curve under both low and high N conditions. The result is indicative to set the best parental line selection criteria for crossing purpose and utilize the cultivars for further potato NUE breeding programmes.

Spring planting favors yield of new Brazilian potato cultivar BRS F63 Camila

ABSTRACT The objective of this work was to evaluate the effect of different planting dates on the morphological variables and yield of new potato cultivars. The treatments were three cultivars (Agata, BRS Clara and BRS F63 Camila) and three planting date (October, December and February), carried out in two crop years (2014/15 and 2015/16). Total and marketable yields, average mass of total and marketable tubers, growth period, leaf area index, number and dry weight of the tubers were evaluated. The first planting date resulted in higher yield than the third date. Cultivar BRS F63 Camila was the one with highest yield in this first planting date (47.4 t ha-1), due to greater number of tubers produced in relation to the other cultivars and to higher average tuber weight (166 g tuber-1) in relation to Agata (113 g tuber-1). In the second planting date, no difference in yield was observed among cultivars. In the third planting date, BRS Clara was the cultivar with highest yield (21.3 t ha-1), due mainly to higher average weight of tubers (105 g tuber-1) in relation to Agata (49 g tuber-1), a fact favored by the higher leaf area index and longer growth period of BRS Clara. Depending on the planting date, one should choose the cultivar that results in maximum yield potential, since it is a plant management with low cost and high yield impact. For the second planting date, any of the studied cultivars can be used.

Field Performance of Xanthosoma sagittifolium L. Schott Minitubers Grown Under the Influence of Poultry Manure and NPK Fertilizers: Changes in Content of Some Secondary Metabolites

The response of white and red cultivar (cv) cocoyam (Xanthosoma sagittifolium (L.) Schott) minituber seeds to different rates of poultry manure (PM) and NPK (20:10:10) fertilizer was studied under field conditions in the 2017 cropping season on an experimental farm at Ngog Bibega, Mbankomo Sub-division, (outskirsts of Yaounde) Centre region, Cameroon. Treatment combinations comprising of three rates each of poultry manure (0, 20 and 30t ha -1 ) and NPK fertilizer (0, 120 and 150 kg ha -1 ) were factorized and fitted into a randomized complete block design with three replicates. Physico-chemical analysis of all treatment plots revealed clay loam textures and poultry manure treatment plots significantly (P<0.05) increased soil pH, organic content, total carbon and cation exchange capacity while NPK treatments significantly (p<0.05) increased available phosphorus compared to the control treatments. Poultry manure(30t ha -1 ) treatments significantly (P<0.05) enhanced plant height, leaf number and leaf area in both cultivars after 6 months of growth as compared to all other treatments. Under the same treatments of poultry manure (30t ha -1 ) the white cultivar plants recorded the most significant mean yield parameters after 9 months of growth. The average tuber number per plant (8), tuber weight (250g), tuber length (14cm) and tuber girth (18.5cm) compared to the red cultivar average yield parameters: tuber number per plant (5.7), tuber weight (124.7g), tuber length (8cm) and tuber girth (14.5cm). Biochemically the application of various treatments of poultry manure and NPK fertilizers significantly (P<0.05) influenced the changes observed in the secondary metabolites studied. Two months after planting, NPK (150kg ha -1 ) treatments showed the most significant phenolic content (1.22±0.13mg eq catechin.g -1 FW) and flavonoid content (1.08±0.16mg g -1 FW) in white cv cocoyam plants. After 6 months of growth, the poultry manure (30t ha -1 ) treatments recorded the most significant protein content (5.04±0.38mg eq BSA.g -1 FW) and peroxidase activity (4.89±1.36 UE min -1 ) in white cv cocoyam plants while red cv cocoyam plants had the most significant glucanase activity (9.33±1.17 mg eq glucose g -1 FW). NPK (150kg ha -1 ) treatments in white cv cocoyam plants recorded the most significant polyphenol oxidase activity (4.99±0.10 in D330 nm -1 min -1 UE -1 g -1 FW) 6 months after planting. Keywords: Xanthosoma sagittifolium L. Schott; Minitubers; cation exchange capacity; Poultry manure; NPK fertilizers; yield parameters and secondary metabolites. DOI : 10.7176/JBAH/9-20-05 Publication date :October 31 st 2019

Evaluation of Some Clones Derived from Two Sweet Potato Cultivars Under Water Deficit Conditions

Sweet potato (Ipomoea batatas, L.) is one of the root crops worldwide especially developing countries as a popular staph food, but due to its highly heterozygosity as cross-pollinated crop wherein many of its traits exhibit constant variation. Also, sweet potato is sensitive to water deficits especially during its formation stage including vine development and storage root induction. Therefore, this study was undertaken in corporation between El-Sabaheya Horticultural Research Station and the Experimental and Research Farm of The Faculty of Agriculture (Saba-Basha), Alexandria University, Alexandria governorate, Egypt, to develop distinct sweet clones. Stem cuttings of both Abees and Mabrouka cultivars were exposed to gamma ray radiation or immersed in colchicine or sodium azide solutions. 8 promising clones were selected to be evaluated under water deficit conditions in two field trials in comparison with their mother plants during the summer seasons of 2017 and 2018. Four irrigation levels (100, 75, 50 and 25% of ET0) were applied. The gained results revealed that the best results for the vegetative growth characters were achieved with the treatment of 100 % of evapotranspiration, except for number of main branches / plant which possessed the highest mean values with the treatment 25 % of evapotranspiration. Tuber root yield character and its component traits were significantly affected by both studied variables (sweet potato genotypes and irrigation levels). As for the main effect of irrigation levels on tuber root yield/feddan and its component characters, there are significant and direct proportional relationship between the independent variable (irrigation levels) and dependent one (studied traits).The highest average values for tuber root yield/feddan were scored at 100 % of irrigation level during the two seasons, followed with the treatment 75 % of irrigation level; while 25 % of irrigation treatment possessed the lowest mean values. The highest average values were recorded for marketable tuber root yield (%) were recorded at 100 % of irrigation level; while the lowest mean values were scored at 25 % of irrigation treatment. Carotene content and percentages of total sugar and starch were not significantly affected by different levels of irrigation from 100% down to 50% except for starch percentage during the second season. The obtained results, clearly demonstrated that there are large and mainly positive direct effects of both average tuber root weight (g) and number of tuber roots/plant on sweet potato yield (ton/fed.). In briefly, It is recommended to select clone A1 (It was developed as a mutation resulting from the exposure of Abees cv. to gamma ray) because it is characterized by a high productivity (ton / fed.) at 100% irrigation level or when there is a shortage of water supply (75% of evapotranspiration) compared with other tested sweet potato genotypes. Also, clone M1 (It was developed as a mutation resulting from immerging of Mabrouka cv. in colchicine solution) could be selected because of its high productivity, suitable for starch extraction, both when irrigation water is available or even when there is a shortage of irrigation water up to 75% of evapotranspiration. Clone M2 (It was developed as a mutation resulting from immerging of Mabrouka cv. in colchicine solution) could be the best choice where severe water shortage conditions (50% and 25% of evapotranspiration) are found.

Influence of Irrigation Treatments and Humic Acid (HA) Application on Vegetative Growth, Yield, Tuber Quality Water Requirements and Water Utilization Efficiency (WUE) of Potato Plants.

The present investigation were carried out in the two successive summer growing seasons 2018 and 2019 on potato plant, CV. Sponta, at South El- Tahrir district, newly reclaimed sandy soils at the experimental station farm, Horticulture Research station Beheira Governorate to study the influence of irrigation treatments and humic acid (HA) application at different growth stages on vegetative growth, yield potential, tuber quality, water requirements and water utilization efficiency (WUtE) of potato plants. Nine irrigation treatments were applied at three periods, (S1) vegetative growth, (S2) tuber formation and (S3) tuber bulking. Results revealed that there were significant effects due to the irrigation and humic acid treatments and their interactions on potato production in both growing seasons. T1 irrigation treatment gave the mean highest values of vegetative growth traits (plant height, number of branches, fresh and dry weight of plant, yield/plant, and number of tubers plant-1, average tuber weight, yield/feddan, and tuber diameter). Application of humic acid (HA) resulted in improving vegetative growth characters, in both seasons. Water stress treatments at S1 generated the lowest mean values of all vegetative growth characters, which illustrated that this stage is sensitive to water stress treatments. The interaction between irrigation treatments and HA reflected significant differences on the studied vegetative growth parameters. The interaction of T1 treatment and HA application showed superior influence on vegetative growth traits, in both growing seasons. On the other hand, the highest mean values for tuber content of starch were obtained by Ta and HA application.

The Amount of Cassava Tuber Remained on Underground Stem after Chopped with Various Cross-Section and Diameter of Cylinder Blades

This study aims to test and compare the amount of cassava tubers which remained with underground stem after chopped with cylinder blades which had different cross-section and sizes (3x3 Treatments) by using “Kasetsart 50 cassava variety” with the age of 8 months old that planted in sandy loam in Kalasin Province. There are 30 cassava stalks per treatment were used as the sample. The implement of the test was Factorial in Completely Randomized Design. The results found that increasing of diameter of the cylinder blade from 6 – 8 cm caused the increasing amount of cassava tuber remained with underground stem, however, average tuber loss was just in range of 2.56-3.36% wt. (p-value = 0.003), but the increasing did not affect the amount of force used in cassava chopper. As for changing the cross section of cylinder blade (Square, Round and Hexagon), it caused changes in the amount of cassava tuber remained with underground stem after chopping, but there was no exact direction (p-value = 0.036). However, changing of cross section would cause changes of cassava chopper force (p-value = 0.001) that its directions were related to the length of perimeter of each cross-section.

RANCANGAN SISTEM HIDROPONIK BUDIDAYA BAWANG MERAH (Allium Ascalonicum L.) DAN SIMULASI ANALISIS BIAYA

Traditional cultivation of shallot is subject to uncertainty both in productivity and price. This seasonal situation was primarily due to climatic factors. Hydroponics cultivation offers a potential solution to that problem because hydroponics was not dependant to climate. Therefore, production can be maintained throughout a year around. This research aims to design hydroponics system for shallot cultivation, to simulate cost analysis, and to estimate profit. The research was conducted by constructing a hydroponics module with dimension as the following: 100 cm high, 3 m long and 60 cm wide. Growth medium made from rice hush char as deep as 15 cm was used in the module. 114 cloves of shallot were nursed, and transplanted to the bed after shoots developed about 5 cm, with 10x15 cm spacing. Parameters observed in this study included pH, EC, moisture content, and plant growth. In addition, three scenarios of the hydroponics systems were simulated to elaborate cost and profit estimation. The three scenarios included scaling up the cultivation beds, ten year cultivation, and productivity from three types of hydroponics modules. The results showed that during hydroponics cultivation of shallot, EC of nutrient solution was elevated to the last level of 3106 μS/cm, while pH was found to be 7.58. The yield of the shallot was 0.0154 kg/m2 with average tuber diameter of 10-15 mm. This production was suboptimal, yet profit and cost comparisons could be clearly described through the simulations of three types of hydroponics modules. Keywords: cost and profit analysis, hydroponics cultivation, nutrition solution, shallot

Residual Heterozygosity and Epistatic Interactions Underlie the Complex Genetic Architecture of Yield in Diploid Potato.

Deconvolution of the genetic architecture underlying yield is critical for understanding bases of genetic gain in species of agronomic importance. To dissect the genetic components of yield in potato, we adopted a reference-based recombination map composed of four segregating alleles from an interspecific pseudotestcross F1 potato population (n = 90). Approximately 1.5 million short nucleotide variants were utilized during map construction, resulting in unprecedented resolution for an F1 population, estimated by a median bin length of 146 kb and 11 genes per bin. Regression models uncovered 14 quantitative trait loci (QTL) underpinning yield, average tuber weight, and tubers produced per plant in a population exhibiting a striking 332% average midparent-value heterosis. Nearly 80% of yield-associated QTL were epistatic, and contained between 0 and 44 annotated genes. We found that approximately one-half of epistatic QTL overlap regions of residual heterozygosity identified in the inbred parental parent (M6). Genomic regions recalcitrant to inbreeding were associated with an increased density of genes, many of which demonstrated signatures of selection and floral tissue specificity. Dissection of the genome-wide additive and dominance values for yield and yield components indicated a widespread prevalence of dominance contributions in this population, enriched at QTL and regions of residual heterozygosity. Finally, the effects of short nucleotide variants and patterns of gene expression were determined for all genes underlying yield-associated QTL, exposing several promising candidate genes for future investigation.

Yield, frying quality, plant vigor, and maturity of potato clones

ABSTRACT The objective of this research was to evaluate advanced potato clones for tuber yield, frying quality, plant vigor, and maturity, grown from minituber seeds, and to assess correlations between these traits. Eight advanced potato clones of Embrapa Potato Breeding Program (F11-09-03, F05-11-03, F54-11-06, F141-11-01, C2718-12-09, C2718-24-09, C2743-09-09, and CL308) and three commercial cultivars (Agata, Asterix and BRSIPR Bel) were evaluated. Experiments were carried out in autumn 2017, in Canoinhas-SC and Pelotas-RS. A randomized complete block design with four replicates was used. We used tuber seeds type IV (minibubers). We evaluated plant vigor, maturity, yield and number of marketable tubers, yield and number of total tubers, average tuber weight, specific gravity, and frying color. Individual and joint variance analyses revealed significant differences (p <0.05) among genotypes for all traits at both locations. The GxE (genotype x environment) interaction was significant for all traits. For the two locations together, clones F05-11-03, C2718-12-09, C2718-24-09 and the control cultivar BRSIPR Bel showed higher marketable tuber yields. The first two clones also showed tubers with high average tuber weight. Clone F54-11-06 showed the later maturity at both locations. Regarding the frying quality characteristics, only clone F141-11-01 showed a pattern comparable to that of the control cultivar Asterix. Also, clones with higher plant vigor had higher tuber yield, but late maturity. Frying quality traits were not correlated between them and among other traits.

Growth and Productivity of Different Potato Cultivars

During the experimental years of 2017 and 2018 eight potato cultivars were evaluated for their growth traits and productivity in tuber yield. The potato cultivars used in these experimental seasons were; Bubu (as a standard check), Chiro, Gebisa, Belete, Gudene, Badasa Jarso and Dedafa. The first six consecutive potatoes are improved cultivars which were released by Ethiopian research institute and University while the last two potatoes were collected from farmers and cultivated as local (native) cultivars. The objective of this study was to compare the growth and productivity potato cultivars grown at eastern regions of Ethiopia. The results revealed that performance of improved potato cultivars were high in both evaluated yield related traits and average tuber yield. The performances of evaluated potatoes were not similar among cultivars and within cultivar throughout experimental seasons. The experimental design was a randomized block design in three replications. The field management; seed tuber selection, land preparation, planting, fertilizer application method and amount, ridging, weeding, cultivation, harvesting, data collection method and collected data analysis has been carried out for all potato cultivars in similar manner. Potato tubers from four middle rows were analyzed for parameters such as tuber yield, tuber number, marketable and total tuber yield. The highest tuber yield was revealed with cultivar Bubu (39.4 t ha-1) while the lowest with Jarso (20.89 t ha-1). The highest tuber number was showed with cultivar Badasa (12.73 plant-1) and the lowest with Belete (7 plant-1). Hence, there were no correlation between average tuber yield and number.

Effects of Seed Tuber Size and Plant Population on Seed Tuber Yield of Potato (Solanum Tuberosum L.) in Central Ethiopia

Optimizing plant density and seed tuber sizes are the most important agronomic management practices in seed production of potato due to their effects on seed cost and seed tuber yields. A field experiment was conducted under irrigation during in 2014 at Holetta, Ethiopia with the objective of elucidating the effect of varied plant spacing and seed tuber sizes on seed tuber yield production. The results of analysis of variance (ANOVA) indicated that seed tuber size and plant spacing significantly (P< 0.05) influenced on average tuber weight, number of tubers and tuber yield in each seed size categories, seed tuber costs. Highest tuber yield were obtained at closer plant spacing and from medium and large seed tuber sizes whereas the lowest tuber yield were obtained at wider plant spacing and from small seed tuber sizes. The highest numbers of tubers were obtained from large seed tuber sizes and plants grown at closer plant spacing of 50 x 20, 50 x 30 and 60 x 20cm produced highest tuber number. Plant spacing 60 x 20 cm and medium-sized tubers (35-45mm) led to the production of the highest seed tuber yield and appropriate for seed tuber yield production by considering better income, seed saving and intercultural operations. Keywords: Seed tuber size, Plant population, Seed tuber yield, Seed cost DOI : 10.7176/JNSR/9-3-08

Early potato cultivation using synthetic and biodegradable covers

The cultivation of plants under the covers made of synthetic polymers brings many benefits, however, it is associated with the need to utilize or recycle these materials after the period of their use. Such problems are not caused by the covers made of natural polymers. The aim of the study carried out in the years 2013–2014 was to determine an effect of covers made of biopolymers and synthetic polymers on thermal conditions and potato yield. Field study was carried out under sandy loam and silty clay loam soils conditions. The temperature of silty clay loam soil under the covers was on average by 2.9°C higher than in the unprotected area, whereas sandy loam soil had the temperature higher by 2.5°C under biodegradable foil and by 2.7°C under standard foil. Temperature increase under non-woven fabrics was lower than under foils. The highest increase in marketable tuber yield after 40 days from emergence and in full maturity of potato plants was found after at application of standard non-woven fabric P17 (7.2 and 7.4 t/ha, respectively) and the lowest, i.e., 3.0 and 3.4 t/ha, respectively, under biodegradable foil. Cover type had no effect on the number of tubers formed on the first harvest date, whereas a significantly higher number of tubers was recorded in the full maturity of plants in the year characterized by a longer growing period of potato under non-woven P17 on sandy loam soil, and under biodegradable foil on silty clay loam soil conditions. A significant influence of cover on the average tuber weight on the first harvest date was found only on sandy loam soil under non-woven fabrics in 2013, as compared to full maturity of plants under biodegradable covers on sandy loam soil in 2013 and on silty clay loam soil under all covers in 2014.

Potato cultivars differ in response to date of planting in intercrop with poplar (Populus deltoides Bartr. ex Marsh.) in irrigated agro-ecosystem of north-west India

Potato (Solanum tubersum L.) is the world’s third most important food crop after wheat and rice. The current study was conducted to enhance potato yield under agroforestry system through adjustment of planting date and choice of appropriate cultivar. A two-season study (2015–2016 and 2016–2017) was carried out to find cumulative and interactive effect of planting time with potato cultivars on growth and yield performance of potato crop inter-cultivated with 5 and 6-year-old poplar (Populus deltoides) block plantation (spaced at 8 m × 2.5 m). Six potato cultivars [Kufri (K.) Pukhraj, K. Badshah, K. Jyoti, K. Pushkar, K. Chipsona-1 and K. Chipsona-3] were grown at two planting dates (15 November and 30 November) under two growing environments (open-field vs. intercrop in poplar plantation). The trees attained mean diameter, height and crown spread of 18.75 cm, 15.2 m and 28.1 m2, respectively at the age of 6 years. The highest average tuber weight (44.2 g), marketable yield (15.7 t ha−1) and total yield (30.9 t ha−1) were obtained in cultivar K. Pukhraj when it was planted on 15 November in open conditions as well as intercrop in poplar plantation. Thus, under intercropping system when a suitable cultivar combined with appropriate planting date, improves marketable and total yields of potato crop which is essential for sustainability of agroforestry-based cropping systems.

Use of Support Vector Machines and Artificial Neural Network Methods in Variety Improvement Studies: Potato Example

In order to make a contribution to the early generation selections in potato varieties through a classification, the MLPNN and SVM data mining methods were applied to the data set created by considering the selection criteria based on the macroscopic observations and measurements, performed to identify clones that are ineligible and to be eliminated through negative selection from the clones developed in line with the potato variety breeding program, initiated by hybrid combinations in this study. Data set used in the study consists of clones in a study conducted in 2016 as part of the project no. TUBITAK-TOVAG 113O928. A total of 703 potato clones from 12 hybrid combinations were used in the study. In order to identify the clones to be selected, two different models were created by using three attributes (tuber yield, number of tubers and average tuber weight) for each clone, and two different models were created by using two attributes (eyes depth and eyes pit depth) of each clone in order to identify the clones to be eliminated.

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

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.

EFFECT OF PLANTING DATE, IRRIGATION LEVEL AND FOLIAR SPRAY WITH CALCIUM AND/OR BORON ON POTATO CROP PERFORMANCE 2. YIELD AND ITS COMPONENTS, CRACKING PHENOMENON AND TUBER QUALITY

A filed experiment was carried out during the two successive seasons of 2016/2017 and 2017/2018 at the experimental farm of El- Gemmeiza, Agric Res. Station, ARC, Gharbiya Governorate (Middle Nile Delta, Egypt) to study the effect of planting date (20th September (Sep) and 10th October (Oct), irrigation water level at 50, 75 and 100 % of filed capacity (FC) and two foliar spray with Ca (1%) as calcium chloride and/or boron (60 ppm) as boric acid besides unsprayed treatment (control), and their interactions on yield and its components, tuber cracking and tuber quality under clayey soil conditions using flood irrigation system. The adopted treatments were arranged in a split - split plot design with three replicates. The planting dates were arranged in the main plots, irrigation water quantities were arranged in the sub plots, while Ca and/or B foliar sprays were randomly distributed in sub - sub plots. The obtained results indicate that, the tertiary interaction of planting on 10th Oct. , irrigation at 100% FC and sprayed plants with Ca + B resulted in higher values of total tuber yield, average tuber weight , number of tuber № plant-1 , tuber yieldplant-1 ,N, K, Ca and B contents and DM percentages in 1st and 2nd seasons. Total carbohydrates were the highest with the interaction of planting on 10th Oct. and irrigating at 100 %FC and sprayed plants with B. The increases in total tuber yield were about 253.75 and 177.82 % for tertiary interaction of planting on 10th Oct , irrigation at 100% FC and sprayed with Ca + B over the interaction of planting on 20th Sep , irrigation with 50%FC and unsprayed plants, in the 1st and 2nd seasons, respectively. As for tuber cracking %, the lowest values were obtained with the tertiary interaction of planting on 10th Oct, irrigation with 75 %FC and sprayed with Ca + B (11.37 and 10.41 %) in the 1st and 2nd seasons, respectively, while the highest values were obtained with the tertiary interaction of planting on 20th Sep, irrigation at 100 %FC and without Ca and B (25.38 and 26.57 % in the 1st and 2nd seasons, respectively). Conclusively, under similar conditions it could be concluded that , the tertiary interaction of planting on 10th Oct , irrigation at 100 % FC and sprayed plants with Ca + B was superior for enhancing both total tuber yield and quality. Furthermore, on reducing tuber cracking, combination of planting on 10th Oct, irrigation at 75% FC and spraying the plants with Ca + B is recommended.