Highest Tuber Yield Research Articles

Selection of Canadian potato clones for agronomic and frying quality traits

ABSTRACT The demand for cultivars suitable for processing, especially as frozen French fries, is increasing in Brazil. The Canadian expertise is high regarding the development of cultivars with processing characteristics; however, the growing conditions in Canada are quite different from those observed in Brazil. Thus, the aim of this work was to evaluate the performance of Canadian potato clones for their tuber yield, frying quality, plant vigor, and plant cycle, as potential new cultivars or to be used as a new source of variability for crosses. The experiments were conducted in Pelotas-RS and Canoinhas-SC, Brazil, in spring 2017. A set of 12 advanced Canadian potato clones from the Centre de Recherche Les Buissons, QB, Canada, were compared to three control cultivars used for processing. A randomized complete block design with three replicates, with two rows of 20 plants each per plot was used. Tuber yield, frying quality, plant vigor, and plant cycle traits were evaluated. Data were submitted to analysis of variance, grouping of means, and selection gains. It is possible to select genotypes with higher tuber yield and better frying quality, but it is difficult to add also a short cycle. In an attempt to select productive genotypes, with good frying quality, a not so long cycle, and vigor at least equivalent to the control cultivars, clones 15 and 16 were the best at both sites.

Agronomic Performance of Sweet Potato (Ipomoea batatas (L.) Lam) Fertilized with Poultry Manure Enriched with Oil Palm Refuse Bunch Ash in a Low Fertile Soil

A field experiment was conducted to investigate the efficiency of poultry manure enriched with oil palm refuse bunch ash (OPRBA) on the growth and yield of sweet potato in a low fertile soil. The experiment was laid out in a randomized complete block design with three replications. The treatments involved five rates (0, 2, 4, 6 and 8 t ha-1) of oil palm refuse bunch ash (OPRBA) in the first year of the experiment. In the second year, the treatments were 0, 4, 6, 8 and 10 t ha-1 of OPRBA. All plots were treated with a basal application of 15 t ha-1 of poultry manure. Data were collected on vine length (cm), number of branches, number of nodes, number of leaves, leaf area index (LAI) and total dry weight (g m-2) at 8 weeks after planting. Data on yield components were collected on tuber length (cm), tuber girth (cm), number of tubers, tuber size (kg), tuber weight (kg) and tuber yield (t ha-1). The results showed that vine length, number of branches, number of nodes, number of leaves and leaf area index and total dry weight increased significantly (p < 0.05) while increasing the rate of OPRBA. The highest tuber yield (50.22 t ha-1) was recorded for plants treated with 6 t ha-1 of OPRBA in 2016. In 2017, plants treated with 6, 8 and 10 t ha-1 OPRBA had the highest tuber yield (29.10, 30.00 and 32.00 t ha-1, respectively). Tuber yield correlated significantly (p < 0.05) and positively with total dry weight (r = 0.748), LAI (r = 0.938), number of branches (r = 0.679), number of leaves (r = 0.879), number of nodes (r = 0.440), number of tubers (r = 0.561), tuber girth (r = 0.751), tuber length (r = 0.864), tuber size (r = 0.952) and vine length (r = 0.940). It is therefore suggested that poultry manure at the rate of 15 t ha-1 should be enriched with OPRBA at the rate of 6 t ha-1 for optimum production of sweet potato.

The performance and profitability of sweet potato (Ipomoea batatas L.) as influenced by propagule length and application rates of cattle dung in humid ultisols

This study was conducted in 2013 and 2014 at the Teaching and Research Farm of the Faculty of Agriculture, University of Benin, Benin City, Nigeria. The aim of the study was to evaluate the effect of propagule length and cattle dung application rates on the growth, yield and profitability of sweet potato (Ipomea batatas L.) in a humid Ultisols. Treatments consisted of three different propagule lengths of vine cuttings (30, 40 and 50 cm) and three rates (0, 225 and 450 kg N ha −1 ) of cattle dung in a 3 × 3 factorial arrangement fitted into randomized complete block design and replicated three times. The productivity of sweet potato was enhanced by the application of cattle dung and increasing propagule length positively. Growth and yield variables varied significantly with propagule length and cattle dung application. Number of vines, vine girth and number of leaves increased significantly with increase in propagule length. Cattle dung application rates of 225 and 450 kg N ha −1 had statistically at par number of vines, vine girth, vine length, number of nodes and leaves and leaf area index but significantly higher than unfertilized plants. The highest tuber yield of 26.10 and 22.00 t ha −1 was obtained from vine cutting of 40 cm and 20 t ha −1 cattle manure, respectively. The interaction of propagule length and cattle dung application rate on all growth and yield parameters were not significant. Tuber size significantly (P ≤ 0.05) correlated positively with number of leaves (r = 0.351), number of nodes (r = 0.288), number of tubers (r = 0.377), tuber length (r = 0.475). Tuber yield significantly correlated positively with the number of leaves (r = 0.335), number of tubers (r = 0.281), tuber length (r = 0.365) and tuber size (r = 0.652). The appropriate propagule length and cattle dung application rates were 40 cm and 225 kg N ha −1 , respectively as they had the highest return per naira invested. Key words : economic analysis, growth variables, organic fertilizer, tuber yield

FEATURES OF FORMATION OF PRODUCTIVITY OF DIFFERENT VARIETIES OF TOPINAMBUR

The article presents the results of studies of the characteristics of growth and development, the formation of the productivity of topinambur varieties. The value of the assimilation surface of plants, the productivity of photosynthesis of various genotypes of Jerusalem artichoke was determined. On one plant of Jerusalem artichoke varieties White yield formed the largest number of leaves - 52.4 pcs., Which is 11.8% more than control. Due to the large size and number of leaves, this variety of Jerusalem artichoke provided the maximum leaf area of a single plant - 114 cm2, as well as the leaf area from the reference areas - 63.5 thousand m-2 / ha. Indicators of the net productivity of photosynthesis of Jerusalem artichoke varieties were in the range of 8.3-14.2 g/m2 per day. The varieties of this crop, White Kiev and White, are high yields compared with the control, had higher photosynthesis productivity indices by 4.8-8.3%. The mass of tubers of a single plant of the Jerusalem artichoke varieties was in the range of 304-407 g. It should be noted that White Kiev and White harvest formed large tubers of mass by 8.4-12.7% compared with the control. Research results indicate that, on average, over the years of research (2016-2017), Jerusalem artichoke varieties had a different effect on tuber yield. Thus, the highest yield of tubers (28.5 tones per hectare) was provided by the middle ripening variety White, which is 7.3 tones per hectare more than the early varieties of Vadim (control). In the middle of the day.

Effect of planting pattern and season on some agronomic performances and yield of sweet potato cv. Japanese Orange

Sweet potato (Ipomoea batatas (L.) is one of the most important root crops in the world. It is primarily grown as a second crop during the dry season in Thailand. Several cultivars are produced with some being imported from Japan, especially cv. Japanese Orange, Yellow and Purple which are popular because they have high value and are rich in phytochemicals. Thai farmers use only one planting pattern for production although there are five recommended patterns available. The objectives of this study were to investigate the effect of different planting patterns on yield, agronomic traits, and determine associations among agronomic traits of sweet potato cv. Japanese Orange. The experiments were conducted during the rainy and dry seasons of 2017. An RCBD with 5 planting patterns and 3 replications were used. Tuber yield, no. of tuber/plant, no. of tuber/ha, no. branch/plant, tuber diameter and tuber fresh weight were measured. The results revealed that during the rainy season, pattern 5 (three vines per hole) had highest tuber yield (11.2 ton/ha), no. of tubers/plant (7.7) and number of tubers/ha (408.9×103) whereas pattern 3 (one vine) had highest no of branches/plant (4.7) and tuber diameter (36.9 mm). In the dry season, patterns 1, 5 and 3 had the highest yields (7.13, 6.71 and 6.48 ton/ha, respectively) pattern 1 had significantly higher tuber fresh weight (84.17 g) than the other four patterns. Pattern 5 had the highest number of tubers/plant and number of tubers/ha during the dry season. We found positive correlations between tuber yield and number of tuber per plant, number of tuber per ha, vine length, vine girth, number of nodes per plant at 60 and 75 DAP.

Multi-objective optimization of water and fertilizer management for potato production in sandy areas of northern China based on TOPSIS

Sandy areas in the northern China are the primary regions for potato production, but limited water resources and low water/fertilizer use efficiency limit the sustainable development of agriculture. Field experiments were conducted during 2016–2017 to investigate the effects of different drip irrigation frequencies, water amounts and fertilizer rates on the yield, quality, water and fertilizer productivity of potato in the sandy areas of northern China. The water and fertilizer treatments were evaluated using the TOPSIS method to obtain the optimal combination of irrigation frequency, water amount and fertilizer rate for multi-objective optimization. The irrigation frequency included once every 4 days (D4), once every 8 days (D8) and once every 10 days (D10). The irrigation levels consisted of full irrigation (1.0 ETc, ETc is the crop evapotranspiration), medium irrigation (0.8 ETc) and low irrigation (0.6 ETc). The fertilizer (N-P2O5-K2O) levels included low fertilization (F1, 100-40-150 kg ha−1), medium fertilization (F2, 150-60-225 kg ha−1) and high fertilization (F3, 200-80-300 kg ha−1). The results showed that there were significant effects of the irrigation frequency (IF), irrigation level (IL) and fertilization level (FL) on potato growth, yield, quality, water and fertilizer productivity. Using the same irrigation frequency and fertilization level, the highest tuber yield, starch content, vitamin C and partial factor productivity (PFP) were obtained under the full irrigation (1.0 ETc). However, the irrigation water use efficiency (IWUE) decreased as the water supply increased. In addition, these indicators under deficit irrigation increased with the increase in irrigation frequency at the same fertilization level, but the indicators of D8 were the highest under the full irrigation. Under the same irrigation frequency and irrigation level, the tuber yield and IWUE increased as the fertilization rate increased. However, the PFP decreased as the fertilizer rate increased. The trends in plant height, LAI, dry matter accumulation, plant yield and commodity tubers were similar to that in tuber yield. The starch content and vitamin C under deficit irrigation increased with the amount of fertilizer applied, but they increased first and then decreased with the increase in fertilizer rate under the full irrigation. The change in the content of reducing sugars was opposite to that of the starch. Based on the TOPSIS method, the multi-target optimum scheduling of potato was attained with the irrigation frequency of once every 8 days (D8), full irrigation(1.0 ETc and high fertilizer (N-P2O5-K2O) rate (F3, 200-80-300 kg ha−1). The obtained optimum combination of water and fertilizers can provide a scientific basis for irrigation and fertilization optimization and management in the sandy areas of northern China and in other regions with similar environments.

Improvement of Water Productivity, Economics and Energetics of Potato through Straw Mulching and Irrigation Scheduling in Indian Punjab

A field experiment was conducted to assess the effect of straw mulching and irrigation scheduling on water balance, economics and energetics of potato during 2013–2014 and 2014–2015. The experiment was laid out in a split plot design with mulch levels (no mulch and mulch 6.25 t ha−1) in the main plots and four irrigation schedules {ridge planting furrow irrigation (RPFI), bed planting furrow irrigation (BPFI), ridge planting drip irrigation (RPDI) and bed planting drip irrigation (BPDI)} in the subplots. Straw mulching resulted in 19.0% higher potato tuber yield than no mulch as a result of 36.2 mm higher transpiration and 44.2 mm lower soil evaporation. Energy productivity (EP) and energy use efficiency (EUE) were also significantly higher with straw mulch than no mulch with US$498 ha−1 higher net returns in pooled data of both years. Drip irrigation of beds and ridges resulted in 34.9% and 26.4% higher tuber yields, respectively, than furrow irrigation along with savings of 23.3 and 53.3 mm irrigation water, respectively. Seasonal transpiration was 31.0 and 31.7% higher in ridge- and bed-planted drip-irrigated crops, respectively, than furrow-irrigated crops in pooled data. Apparent and real water productivities were significantly higher in drip irrigated crops compared to furrow irrigated crops. RPDI and BPDI crops gave US$612 and US$876 ha−1 higher net returns with 35.7 and 28.8% higher EUE than RPFI and BPFI, respectively.

Regulation of antioxidant production, ion uptake and productivity in potato (Solanum tuberosum L.) plant inoculated with growth promoting salt tolerant Bacillus strains

The exchangeable sodium (Na+) in salt affected soils is a major constraint in potassium (K+) availability to plants that disturb ion transport and inhibit plant growth, adversely. Salt tolerant plant growth promoting rhizobacteria (PGPR) may regulate the Na+/K+ efflux and increase K+ uptake by the plant from the soil. Therefore, a pot study was performed to examine the effect of salt tolerant PGPR Bacillus sp. alone and in consortium, on antioxidant enzyme activity, ion uptake and potato (Solanum tuberosum L.) tuber yield in normal and salt affected soils. We observed that Bacillus sp. (strains SR-2-1 and SR-2-1/1) solubilized insoluble phosphorous and produced indole-3-acetic acid while only SR-2-1/1 produced ACC deaminase in culture medium supplemented with various concentrations of NaCl (0–6%). In the pot experiment, the consortium treatment of strains was found to increase relative leaf water contents whereas decreased the electrolyte leakage and antioxidant enzyme activity both in normal and salt affected soils. Similarly, consortium treatment decreased Na+ whereas increased K+, Ca+2, K+/Na+ and Ca+2/Na+ in plant dry matter in both soils. It has been investigated that inoculation of PGPR significantly (p < 0.05) increased plant biomass, number of tubers per plant and tuber weight as compared to un-inoculated plants in both soils. In addition, PGPR inoculation enhanced auxin production in root exudates of young potato plants and bacterial population dynamics in both soils. Na+ ion regulation (R2 = 0.95) and tuber weight (R2 = 0.90) in salt affected soil were significantly correlated with auxin production in the rhizosphere. Results of this study conferred that consortium of Bacillus strains (SR-2-1, SR-2-1/1) enhanced auxin production in the rhizosphere of potato plants and that ultimately regulated antioxidant enzyme production and uptake of Na+, K+ and Ca+2 in potato plants resulted into a higher tuber yield in both normal and salt affected soils.

Effect of harvesting dates on the yield and tuber quality of processing potatoes

An experiment was conducted to study the effect of harvesting dates and variety on the yield and processing quality of potato tuber. Three processing potato varieties (BARI Alu-25, Asterix; BARI Alu-28, Lady Rosetta and BARI Alu-29, Courage) were used as test crops and they were harvested at different days after planting [80, 90, and 100 days after planting (DAP)]. The three processing potato varieties showed higher tuber yield of Grade A (9.12 t ha-1) and B (13.64 t ha-1). The highest tuber yield (Grade A+B) [29.62 t ha-1] and total tuber yield (35.97 t ha-1) was found in Courage at 90 and 100 DAP harvest, respectively. The variety Lady Rosetta attained the highest percent of processable tuber yield (86.8% of the total tuber yield), the maximum dry matter content (26.37%), specific gravity (1.102) at 90 DAP harvest and this variety also contained the highest mean starch content (111.75 mg g-1 FW) followed by Courage (111.17 mg g-1 FW) and Asterix (103.95 mg g-1 FW). Optimum dry matter content (24.07%), specific gravity (1.091), starch content (110.15 mg g-1 FW), processable tuber yield (26.62 t ha-1) and total tuber yield (32.76 t ha-1) was found at 90 DAP harvest and therefore, it could be mentioned as suitable harvesting date for processing purposes. Among the varieties, Lady Rosetta and Courage were found preferable potato varieties that could be used for processing of potato products.&#x0D; Bangladesh J. Agril. Res. 44(1): 179-193, March 2019

Responses of Canopy Growth and Yield of Potato Cultivars to Weather Dynamics in a Complex Topography: Belg Farming Seasons in the Gamo Highlands, Ethiopia

Potato is an increasingly important crop in Ethiopia. The Gamo Highlands are one of the large potential potato producing regions in Ethiopia. The growing conditions are different from those in the temperate regions, where most of the agronomical expertise on potato has been developed. The influence of environmental conditions on the crop in the Gamo Highlands is poorly understood. We conducted field trials with eight potato cultivars in six locations and during two seasons. The canopy cover (CC) and plant height (PH) were measured with high temporal resolution and tuber yields were assessed as well. The experiments were conducted near our newly installed weather stations at different elevations. CC and PH were strongly correlated with temperature sum (Tsum). Tuber yields differed among elevations and cultivars. Nevertheless, these differences were poorly explained by environmental variables. We also found that no single cultivar performed best at all elevations. The number of branches was a predictor of yield, suggesting that radiation interception was limiting tuber growth. Tuber yield was optimal when the number of days to crop maturity was around 100–110 days. We conclude that Tsum is a predictor of crop growth, but environmental variables poorly explain yield variations, which calls for further investigation.

Effectiveness of Alternative Control Methods for Tithonia diversifolia on Water Yam (Dioscorea alata) Plot

Tithonia diversifolia has become a significant agronomic problem to optimum arable crop production in Nigeria which has necessitated effective and timely control if the good yield is expected on infested soil. This study compared the performance of water yam under different weed control methods on Tithonia infested plot at Ogunba village near Baaya-Oje in Surulere Local Government area of Ogbomoso, Oyo State during the 2015 growing season. Eight (8) control treatments were evaluated namely: Weed control with Atrazine, Diuron, 2 hoe weeding, 3 hoe weeding, Black plastic mulch, grass mulch, Diuron + Atrazine + Plastic mulch (IWM) and unweeded plot. The three (3) hoe weeding and the unweeded plot served as the control treatments. The experiment was laid out in a Randomized complete block design with three replicates. Yam setts were planted at a spacing of 1 m x 1 m to give a population of 10000 plants/ha. Atrazine and Diuron were applied at the rate of 2.5 kg a.i/ha, 2 hoe weeding was done at 3 and 6 weeks after planting (WAP), 3 hoe weeding was done at 3,6 and 9 WAP, while grass mulch was applied at the rate of 5 tons/ha. In IWM, Atrazine and Diuron were applied each at the half recommended rate (1.25 kg/ha) before applying plastic mulch. The treatments were applied pre-emergently on a rain wetted soil after planting. Data were collected on growth and yield parameters of yam as well as on Tithonia weed population and dry matter yield. Results showed that weed control methods significantly (P &lt; 0.05) influenced water yam yield. The highest tuber yield (21 tons/ha) in plastic mulch was comparable to IWM (20 tons/ha), 3 hoe weeding (19 tons/ha) and 2 hoe weeding (18 tons/ha). Grass mulch (16 tons/ha), Diuron (15 tons/ha), Atrazine (14 tons/ha) were also not significantly (P &gt; 0.05) different. Thus, it may be concluded that plastic much is the most efficient of the methods for weed control in yam. The implication of this finding is discussed.

Improving potato production through non monetary agronomic manoeuvring

A field experiment was conducted with an objective to improve potato production through non monetary agronomic manoeuvring during the Zaid season of 2015-2016 and 2016-2017 at three village’s viz. Audung, Seru and Namtsering in Tawang district of Arunachal Pradesh. Experiment consist of four inter row spacing and five earthing up treatments. Results revealed that growth, development, yield attributes and tuber yield was greatly influenced by the treatment under investigation. Majority of growth and yield parameters was recorded maximum with the row spacing of 40 and 30 cm inter row spacing. Significantly the highest marketable tuber yield (15.3 t/ha) was produce at 30 cm inter row spacing. Earthing up at 15 days after plant emergence resulted superior performance in most growth and yield parameters. For better potato production 30 cm intr row spacing and earthing up at 15 days after emergence can be used advocated for Tawang district (Arunachal Pradesh).

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 &lt;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.

Effects of micronutrient application on different attributes of potato in floodplain soils of Bangladesh

Different crops have variations in their responses to applied micronutrients in soil. A study was conducted on floodplain soil of Bangladesh to explore the response of potato to application of micronutrients in soil. The experimental site was located at farmers’ field in Chandina upazila under Cumilla district of Bangladesh covering the soils of Old Meghna Estuarine Floodplain (AEZ 19) during 2011-12. Randomized complete block design with 3 replications of each treatment was used in the experiment, where seven treatments including a control were tested. Additive element trial technique was followed while designing the treatments taking six micronutrients i. e. Zn, B, Cu, Mn, Fe and Mo at the rate of 3, 2, 2, 3, 5 and 1 kg ha-1, respectively. Macronutrients, such as N, P, K and S were applied at recommended rates to all plots. The highest tuber yield (28.7 t ha-1) was produced by the combined application of Zn and B. Only Zn application was sufficient to obtain the highest content of protein as well as content of almost all the nutrients in potato tuber. Antagonistic relation between Zn and P in soil-plant system was recorded in the study. Zinc and boron application influenced different growth and yield parameters of potato while the other four added micronutrients did not have any significant effect but combined application of Zn, B, Cu, Mn, Fe and Mo had beneficial role for better plant growth and production. Proper management of zinc and boron fertilizers including optimization of application rates of those nutrients can help to uphold the yield and quality of potato in floodplain soil.&#x0D; SAARC J. Agri., 16(2): 97-108 (2018)

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.

Development of anthracnose resistant hybrids of the Greater Yam (Dioscorea alata L.) and interspecific hybrids with D. nummularia Lam.

Controlled pollinations were conducted to develop Dioscorea alata L. hybrids resistant to anthracnose (Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Overall, 10,410 hand pollinations were carried out with Indian (IN) and Vanuatu (VU) clones in 53 different parental combinations, including diploids (2x) and tetraploids (4x) female and male plants. Pollination efficiency and seed set were comparable for IN2x × VU2x (54.6% and 23.0%) and IN2x × IN2x (57.4% and 28.9%). However, seedling survival with better resistance to anthracnose in nursery under natural disease pressure was higher for IN2x × IN2x (67.3%) compared to IN2x × VU2x (47.8%). IN2x female clones were crossed with VU2x and VU4x male clones in 12 parental combinations each. Pollination efficiency was higher for 2x parents (54.6%) compared to 4x parents (47.0%) but seed set (32.8%) and seedling survival (71.7%) were significantly higher for crosses between IN2x × VU4x. Overall, remarkable variation in pollination efficiency, seed set and seedling survival was observed between different parental combinations even when the same pollen parent was used. Interspecific hybridization between D. alata IN2x females and D. nummularia Lam. Vanuatu polyploid male was found to be successful with considerable variation in pollination efficiency, seed set and seedling survival (49.0, 20.8 and 35.3%). The hybrids exhibited intermediate characters between the two species with high tuber yield, anthracnose resistance but with fast tuber flesh oxidation. These results demonstrate the scope of polyploid and interspecific hybridization and the need for the international exchange of germplasm for D. alata genetic improvement.

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&lt; 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

The influence of leaf removal on tuber yield and fuel characteristics of Helianthus tuberosus L. in a semi-arid area

Jerusalem artichoke (Helianthus tuberosus L.) is an important source of biomass for bioethanol production. To evaluate the potential, feedstock and tuber yield, calorific value, and ash content were investigated using different leaf removal treatments in 2013 and 2014 in Inner Mongolia, China. Tuber yield was significantly higher in plants from which the lower 1/3 and 1/4 of the leaves were removed than that in control plants. Tuber yield decreased significantly when an even number or the flank 1/2 of the leaves were removed. Highest tuber yields were obtained under the lower 1/3 leaf removal treatment: 163.98 g/plant in 2013 — 97.40% greater than that of the control treatment, and 149.68 g/plant in 2014. Calorific value and ash content of each plant organ did not vary among leaf removal treatments. Further, calorific values of the stems and tubers were higher than those of other organs, including roots, leaves, and flowers (P <0.05). Leaves showed the lowest calorific values but the highest ash content. Stem and tuber ash was lower than in other organs, while calorific value and ash content were inversely correlated. Our results suggest that removing the lower 1/4 to 1/3 of the leaves is a feasible method for improving Jerusalem artichoke tuber yield and quality.

Soil salinity management for increasing potato yield in the coastal area of southern Bangladesh

The study was conducted at farmers’ field of Charfashion upazila in Bhola district under AEZ-18 during the Rabi season of 2015-2016 and 2016-2017 to find out suitable soil salinity management practice(s) for maximizing potato yield as well as farmers’ income. Two planting systems viz. raised bed and flat land, and four management systems with fertilizers and mulching were considered in a factorial experiment. The rate of increase in soil salinity in raised beds was significantly lower than that of flat land. On an average, raised bed planting produced 13.04% higher tuber yield than flat land planting. The combination of raised bed + recommended fertilizer (RF) with cowdung @ 5 t ha-1 as IPNS+ straw mulch (@ 3.5 t ha-1) produced the highest tuber yield in both the years (average 21.66 t ha-1) and it was 75.10% higher than flat planting system with no mulch. This treatment combination also provided the highest average gross margin (Tk. 115945 ha-1) and BCR (2.26). Besides, combination of raised bed + RF+25% K+ straw mulch provided average tuber yield (20.91 t ha-1), gross margin (Tk. 110969 ha-1) and BCR (2.25), which were very close to above treatment combination. The lowest average potato yield (12.51 t ha-1), gross margin (Tk. 39835 ha-1) and BCR (1.50) were obtained from combination of flat land planting + RF +no mulching. So, combination of raised bed + mulching+ RF along with IPNS basis cowdung @ 5 tha-1 or 25% extra K can help minimize soil salinity and produce significantly higher potato yield in the coastal areas.Bangladesh J. Agril. Res. 43(4): 655-668, December 2018

Caladium cv. Florida sweetheart production at different planting depths and sowing dates

Ornamental bulbous crops emergence and yield can be improved by its emergence from soil. The response of Caladium to different planting depths and dates was investigated at Ornamental Horticulture Nursery, Department of Horticulture, The University of Agriculture, Peshawar during the year 2008. Randomized Complete Block Design in a split plot arrangement was used repeated three times. Sowing dates (30th March, 15th April and 30th April) were allotted to main plots whereas planting depths (2.5 cm, 5 cm, 7.5 cm and 10 cm) were kept in sub plots. Findings revealed that Caladium tubers sown on 30th March took maximum days to sprouting (33), produced maximum number of sprouts plant-1 (2.21), gained maximum tuber size (40.88 cm3) with high tuber yield (5397 kg ha-1). On the other hand, tubers sown on 30th April took less days to sprouting (20.21), produced less number of sprouts plant-1(1.53), produced small tuber (33.28 cm3) and total tuber yields was also less (4374 kg ha-1). In case of planting depth, Caladium tubers sown at a depth of 7.5cm resulted in maximum plant height (52 cm), tuber size (41.76 cm3), and tuber yield (5288 kg ha-1) while maximum number of tubers plant-1 (1.92) was observed at a depth of 10 cm. Tubers sown in 2.5 cm depth resulted in minimum tuber yield (4538 kg ha-1) and plant height (46.56 cm). To maximize vegetative as well as tubers production of Caladium cv. Florida sweet heart, it shall be sown on 30th March with 7.5cm depth.