Marketable Tuber Weight Research Articles

Comprehensive evaluation of fertilizer treatments on biometric traits and marketable tuber weight across diverse potato varieties

IntroductionThe efficiency of potato production depends to a large extent on the production of quality seeds that meet the requirements of the growing region. The main component of this production includes breeding, which creates the genetic basis of seeds. The process of establishing patterns between the amount of fertilizer application (“Aquarin 12,” “Bona Forte,” “Osmocote Exact High K”), their type, and biometric characteristics of potato plants of the studied varieties “Guliver,” “Beauty of Meshchera,” and “Grand” was explored.MethodsDuring the experimental studies, the methods of variation statistics, the technique of field experiment with the corresponding transformations to achieve normal distribution, and subsequent dispersion analysis were used.ResultsThe results of the research on the evaluation of potato structural elements depending on the plant nutrition system of the studied varieties testify to the expediency of using nutrient solutions in potato cultivation irrespective of their type. In addition, it has been established that increasing the concentration of the nutrient base solution from 75 to 125% of the nutrient formula improves the quality indicators of minitubers, namely the content of starch, sugars, dry matter, crude protein, phosphorus, specific gravity, and ash content, which can contribute to obtaining high-quality potatoes.DiscussionThus, the use of morphological and physiological tools in closed ecosystems is informative for predicting key agricultural characteristics of potato plants. Additionally, integrating organic amendments and biofertilizers, as supported by other studies, could further enhance nutrient uptake and plant health, especially under conditions of low irrigation.

Effect of coffee husk biochar and inorganic NP fertilizer on soil properties, growth and yield of potato (Solanum tuberosum L.) on acidic soil of southwest Ethiopia

Soil acidity and low soil fertility due to nutrient leaching coupled with low inorganic fertilizer usage is a major cause of low crop yields across Southwest Ethiopia. Recently, biochar potential to improve soil fertility has gained significant attention but there are limited studies on the use of biochar in combination with inorganic fertilizers. A field experiment was, therefore, conducted to investigate the effect of combined application of biochar and inorganic NP nutrient on soil physicochemical properties, growth and yield of potato in Andiracha district, Southwestern Ethiopia. The experiment was laid out in randomized complete block design (RCBD) and replicated three times. The treatment consisted of four levels of biochar rates (0, 2.5, 5 and 7.5 t ha−1) and four fertilizer rates of (0, 75,100 and 125% of recommended N P rates). Data were analyzed using SAS version 9.3 Software. Analysis of variance showed that combined application of biochar and inorganic NP fertilizer had highly significant (p < 0.01) effect on days to flowering, stem number, plant height, total leaf area, total dry biomass, marketable tuber number per hill and harvest index and significant (p < 0.05) effect on marketable tuber weight and total tuber weight ha−1. Combined application of 7.5 ton ha−1 biochar with 165 kg N and 60 kg P ha−1 resulted highest tuber yield (42.64 t ha−1), that increased yield by 28.99% compared with recommended NP fertilizer alone (165 kg N ha−1 and 60 kg P ha−1), and by 76.6% compared to the control. The increase was mainly attributed to the improvement in soil physico-chemical properties especially soil pH, CEC, organic matter, total N and available P which is a reflection of increase in soil fertility. Consequently, it was determined that the best course of action for potato production in the area was to apply 7.5 tons of biochar ha−1 together with 165 kg N and 60 kg P ha−1. Therefore, the study recommends adoption of low cost biochar production techniques and capacity building to ensure satisfactory knowledge of biochar use and its adoption by potato growers for soil fertility management and enhanced crop productivity.

Effect of Earthing-Up Frequency on Growth and Yield of Anchote (Coccinia abyssinica) Varieties at Gimbi District, Western Ethiopia

Anchote (Coccinia abyssinica (Lam.) Cogn) is a tuberous root crop native to Ethiopia. It is a good source of protein, carbohydrates, calcium, and iron. However, little attention has been given to the improvement of genetic and agronomic practices such as selection of variety, staking, weeding, fertilizer application, and earthing-up frequency. Thus, the attainable yield is below the potential. The experiment was arranged in a 3 × 5 factorial arranged in a randomized complete block design (RCBD) with three replications with the objective of determining the effect of earthing-up frequency on the growth and yield of anchote varieties. The interaction effect of earthing-up frequencies and varieties significantly affected anchote leaf number plant−1, shoot dry weight plant−1, unmarketable tuber weight ha−1, vine diameter, shoot fresh weight plant−1, tuber fresh weight plant−1, marketable tuber weight ha−1, and total tuber yield ha−1. Total tuber yield ha−1 was perfectly correlated with tuber fresh weight plant−1 (r = 1), and all parameters were significantly correlated with tuber dry matter plant−1, and tuber dry matter plant−1 was positively and significantly correlated with total tuber yield ha−1 (r = 0.46). Consequently, the highest total tuber yield was observed from earthing-up four times (26.94 t ha−1) and three times (26.88 t ha−1) with Desta 01, while the lowest was observed from the control with Acc405 (15.11). The highest economical tuber yield was obtained from three times earthing-up frequency (26.878 t ha−1, 25.50 t ha−1, and 23.92 t ha−1 for Desta 01, Acc405, and Acc173), and the lowest was observed from the control (22.83 t ha−1, 15.11 t ha−1, and 21.11 t ha−1 for Desta 01, Acc405, and Acc173), respectively. Therefore, for the study area, it is better to apply three times earthing-up frequencies (35 days, 49 days, and 63 days from planting date for once, twice, and three times earthing-up, respectively) with Desta 01 variety followed by Acc405. Since the experiment was conducted using irrigation, it is suggested to be repeated under rainfed conditions to draw a definite conclusion.

EFFECT OF NITROGEN, PHOSPHOROUS AND POTASSIUM LEVELS ON THE PRODUCTIVITY OF INDUSTRIAL POTATOES

The experiment was conducted using Potato( Solanum tuberosum L.) at the eastern Radwaniyah at private field during fall season 2020/2021 and spring 2021 to study the effect of nitrogen levels to 350, 275, 200 kg N h-1 ( N1, N2, N3) and phosphorous to 100, 180, 360 kg P2O5 h-1 ( P1, P2, P3) and potassium to 100, 200, 300 kg K2O h-1 ( K1, K2, K3) to vegetative growth and yield of industrial potato, The seeds of the hybrid potato Sinora, Class A, were planted in the fall season on 15/9/2020 and Elite in the spring season on 31/1/2021. The experimental fertilizers were added in four batches and in proportions according to the stages of plant age, Factorial experiment with RCBD using three replications. The results showed that changing the levels of the elements used to N3, P3, K3 led to a significant increases in most traits of vegetative growth for both seasons, while the change of phosphorous and potassium levels to P2 and K3 had a significant effect on the quantitative and qualitative yield for both seasons. The N1P2K3 interaction gave the highest marketable tuber weight, marketable yield plant-1, total yield for the fall and spring seasons, and the highest percentage of dry matter in tubers in the fall season.

Effect of Biofertilizer and Metribuzin on the Yield Traits of Potato under the Influence of Water Stress

A field experiment was conducted in Al-Mashroo area / Al-Hamzawi, affiliated to Al-Musayyib district, 35 km north of Babylon, to determine how bio-fertilizer and herbicide spraying affected potato yield and quality under different irrigation periods. The RCBD (Randomized Complete Block Design) split-split plot design was used to conduct the experiment with three replications. The experiment had three factors: irrigation periods (5, 7, and 9) days for the main plots. The second element, biofertilizer, has three levels (control treatment without CO, rhizobia R, mycorrhizal M) and sub-plots. The third component, metribuzin, has four stages (no CO, preemergence, postemergence, late postemergence) and sub-sub plots. The statistical investigation indicated that it excelled the following traits: number of marketable tubers plant-1, weight of marketable tubers (g), total yield of one plant (g. plant-1), marketing yield (ton.ha-1). The number of tubers, marketing yield, and plant yield substantially impacted pre-emergence and post-emergence treatments. The (Myco) fertilizer treatment performed better in tuber quantity, weight, and marketing yield (3.26 and 3.77 tuber plant-1, 106.5 and 107.67 g, 23.17 and 24.78 tons ha-1) for both seasons. Irrigation every 7 days increased tuber quantity, weight, yield per plant, and marketing yield (3.37 and 3.89 tubers). 384.3 and 462.3 gm, Plant-1, 112.2 and 115.53 g Plant-1 (20.85 and 22.08 tons ha-1) both seasons. The bilateral interaction between irrigation periods and herbicide was significant in tuber number and marketing yield (3.66 and 3.94 tubers.plant-1, 4.28 and 4.52 tubers.plant-1, 25.57 and 22.83 tons ha-1 and 27.11 and 24.34 tons ha-1) for both seasons. The interaction between irrigation times and biofertilizer was more significant than the 7-day interaction. For both seasons, Mycox produced 4.01 and 4.64 tubers plant-1, 113.6 and 119.70 gram, 25.52 and 27.18 tons ha-1, and marketing yield. The herbicide-bio-fertilizer interaction significantly impacted tuber production, with post-Myco interaction leading to 3.89 and 4.41 tubers per plant-1 in both seasons. The triple interaction was substantial, with 7 days post-Myco resulting in a higher number of tubers (5.32 tubers plant-1) in both seasons.

Evaluation of Purple Sweetpotato Promising Clones Resistance to Scab (Sphaceloma batatas) Disease

Scab disease is the main disease on sweetpotato, planting the resistance varieties to scab disease is an effective, easy, and inexpensive way. The research was carried out in Jambegede Experimental Station in January – April 2021. The material tested were 13 purple promising clones from the breeding section, four check varieties that are Antin 2, Antin 3, Papua Solossa and Ir, Melati. Inoculation of Sphaceloma batatas fungus (spore density 104 spores/ml solution) were done when the plantation 14 days old, in the afternoon, by evenly applying spore suspension to the entire plant. The severity of scab disease is observed when the plants at 60 days old. The sample used were 10 tendrils per clone, the scab intensity was percentage of tendril area infected by scab. Besides, tuber characters such sweetpotatoes as marketable tuber weight, tuber shape, dry matter content, also morphological characters such as plant type, leaf shape, anatomy of leaves such as number of bone leaves, number of stomata and stomata density and the The degree of infection of scab disease were observed. The experiment’s result showed that eight sweetpotato promising clones was resistant, one clones were moderately resistant, four clones were moderately susceptible. Four clone recommended as new variety based on high productivity, good quality of tuber performance namely MSU 10001-15, MSU 10003-07, MSU 10010-43 and MSU 10018-40.

Effect of Biofertilizers and Farmyard Manure on Growth and Tuber Yield of Potatoes (Solanum tuberosum L.) in Highlands of Kenya

Poor soil fertility is among the significant constraints to potato production in Kenya. Increased potato production currently depends on the use of chemical fertilizers for nutrients. The prices of chemical fertilizers continuously increase, becoming unaffordable for small-scale farmers who mostly grow potatoes. Therefore, the continuous use of chemical fertilizers such as NPK may cause complete depletion of other macro and micronutrients in potato production areas of Kenya. In addition, it increases the cost of inputs and triggers environmental pollution. The objective of this study was to evaluate alternative soil amendments using different biofertilizers in potato production. Two field experiments were conducted during the 2019 and 2020 seasons using two potato varieties (Shangi and Kenya mpya). The treatments were 30 t ha-1 of farmyard manure (FYM), two different biofertilizers (Trichoderma asperellum, T.R., and Bacillus subtilis, B.A.) applied at a rate of (150 mL/10 kg) and NPK (0 and 100 kg ha-1) as negative and positive controls respectively. Field experiments were carried out in randomized complete block design in a split-plot arrangement. The results indicated that FYM+TR increased potato yield and plant height by 19.81% and 18.99%, respectively, compared to the control. FYM+TR also increased tuber dry matter, marketable tuber weight, and potato grade by 25.15% 18.99%, respectively, compared to the positive control. The study recommends using FYM+TR and FYM+ BA for potato production in Kenya as they were found to increase crop performance and subsequent yield, which is beneficial to the environment and safe for farmers.

Association analysis for yield and yield contributing traits of potato (Solanum tuberosum L.)

To understand interrelationships among different yield and yield attributing traits in potato (Solanum tuberosum L.) an experiment was conducted using twenty potato genotypes including 2 checks namely Khufri Pukhraj and Kufri Chipsona 1. The observations were recorded on eighteen traits. Correlation coefficient analysis revealed that total tuber yield plot-1 was showed highly and significantly positive correlated with specific gravity, number of shoots plant-1, dry matter content of shoots, unmarketable tuber weight plant-1 and starch content at genotypic level. However, it had exhibited highly significant positive association with number of branches plant-1 at genotypic and phenotypic level respectively. Thus direct selection for above traits will be effective and helpful in improving total tuber yield. Path coefficient analysis unveil that total tuber yield plot-1 was found high positive and direct effect for the traits plant emergence %, number of branches plant-1, number of shoots plant-1, dry matter content of shoots, tuber weight plant-1, marketable tuber weight plant-1, unmarketable tuber weight plant-1, harvest index and specific gravity. So these traits would be most suitable for direct selection and improvement of potato genotypes for tuber yield.

Different Combinations Of Biochar And Urea As A Nitrogen Source: Effect On Growth, Tuber Quality, And Yield Of Potato

Field research was carried out to examine the biochar effect on growth, tuber quality, and yield of the potato crop. Treatments were laid out in a randomized complete block design with 7 treatments of different combinations of biochar and urea (BC100%, BC80%+Urea20%, BC60%+Urea40%, BC40%+Urea60%, BC20%+Urea80%, Urea100%, BCC) as nitrogen source with 4 replications, where all treatments supply recommended dose of fertilizer except control treatment (BCC). The tested variety of potato was Janakdev. The recorded observations showed that biochar mixed with chemical fertilizer had a significantly superior effect on growth (height, branches number, canopy), marketable tuber weight and number, tuber size, yield, and dry matter % as compared to sole biochar (BC100%), sole chemical fertilizer (Urea100%), and control (BCC) treatments. Among the treatments, BC40%+Urea60% (Biochar applied @ 10 t/ha) had resulted significantly higher marketable tuber weight and number, tuber size, yield, and dry matter %. Our results thus demonstrate that the application of chemical fertilizer in combination with biochar could effectively enhance the plant growth, tuber quality, and yield of the potato crop.

Evaluating cassava best management practices towards low fertility soil in West Java, Indonesia

Marginal land with low fertility is a major problem in cassava cultivation. The purpose of this study was to determine the best combination of fertilization to increase the growth and yield of cassava on an Inceptisols soil. Urea (46% N), SP-36 (36% P2O5), KCl (60% K2O), NPK Phonska (15% N:15% P2O5:15% K2O), Poly4 Sirius (14% K2O:17% CaO:6% MgO: 19% S), and chicken manure were used as a nutrient source into six treatment combinations. The results showed that fertilizer application significantly affected the plant height, stem diameter, leaf number, diameter of tubers, the total number of tubers, number and weight of marketable tubers, and the total weight of tubers per plant. The highest fresh and dry weight of storage roots was achieved in the best management practice involving application of 138 kg N + 36 kg P2O5 + 60 kg K2O + 37 kg Ca + 13 kg Mg + 41 kg S per hectare compared to other treatments where the weight of marketable tubers was also higher. The right combination of fertilizer rates was needed to achieve high yield targets of cassava and depends on the site- specific conditions of soil fertility and nutrient status.

Mapping Potato Plant Density Variation Using Aerial Imagery and Deep Learning Techniques for Precision Agriculture

In potato (Solanum tuberosum) production, the number of tubers harvested and their sizes are related to the plant population. Field maps of the spatial variation in plant density can therefore provide a decision support tool for spatially variable harvest timing to optimize tuber sizes by allowing densely populated management zones more tuber-bulking time. Computer vision has been proposed to enumerate plant numbers using images from unmanned aerial vehicles (UAV) but inaccurate predictions in images of merged canopies remains a challenge. Some research has been done on individual potato plant bounding box prediction but there is currently no information on the spatial structure of plant density that these models may reveal and its relationship with potato yield quality attributes. In this study, the Faster Region-based Convolutional Neural Network (FRCNN) framework was used to produce a plant detection model and estimate plant densities across a UAV orthomosaic. Using aerial images of 2 mm ground sampling distance (GSD) collected from potatoes at 40 days after planting, the FRCNN model was trained to an average precision (aP) of 0.78 on unseen testing data. The model was then used to generate predictions on quadrants imposed on orthorectified rasters captured at 14 and 18 days after emergence. After spatially interpolating the plant densities, the resultant surfaces were highly correlated to manually-determined plant density (R2 = 0.80). Further correlations were observed with tuber number (r = 0.54 at Butter Hill; r = 0.53 at Horse Foxhole), marketable tuber weight per plant (r = −0.57 at Buttery Hill; r = −0.56 at Horse Foxhole) and the normalized difference vegetation index (r = 0.61). These results show that accurate two-dimensional maps of plant density can be constructed from UAV imagery with high correlation to important yield components, despite the loss of accuracy of FRCNN models in partially merged canopies.

‘Vychegodsky’: a new potato cultivar for the Republic of Komi

Background. The presented information refers to the completed stage of the breeding process carried out at the Institute of Agrobiotechnologies (Syktyvkar) that led to the development of a new mid-early table potato variety – ‘Vychegodsky’. This cultivar was obtained from controlled crossing of cvs. Svitanok Kievsky × Amadeus. The new variety underwent a comprehensive assessment for the main agronomic traits and genetic screening for resistance to wart disease, nematode, and viruses X and Y.Materials and methods. In 2020, according to the results of production tests performed in 2017–2019, the description of the new cv. ‘Vychegodsky’ was finalized. The registered cv. ‘Nevsky’ was chosen as the reference. The study was conducted in the Institute’s experiment fields with a six-field crop rotation, which ensured high soil fertility without the use of mineral or organic fertilizers. The soil was soddy-podzolic. The planting scheme was 70 × 30 cm, at a depth of 8–10 cm, over the experimental plot area of 52.5 m2 (250 tubers), with four replications.Results. The mid-early cultivar ‘Vychegodsky’ is described as follows: the plant is erect, 50–65 cm in height; tubers are roundish-oval, with yellow skin color and light yellow flesh. The studies have shown that in its agronomic traits in the Republic of Komi cv. ‘Vychegodsky’ exceeds the reference cv. ‘Nevsky’. Its yield is 34.3 t/ha, and its marketable tuber weight 55.1 g; it contains 15.7% of starch, 24.1% of dry matter, and 11.2 mg% of vitamin C. The cultivar demonstrates high field resistance to major potato diseases, and genetically determined resistance to wart disease and golden potato nematode.Conclusion. Thus, a new potato cultivar has been released and included into the State Register of Selection Achievements (National List of the Russian Federation).

Vplyv odrody na vybrané kvantitatívne a kvalitatívne parameter batátov (Ipomoea batatas L.) pestovaných v Slovenskej republike

The sweet potato (Ipomoea batatas L.) is less-known vegetable species in Slovak Republic. It is known for sweet taste and various possibilities of use in gastronomy. In this study, the effect of cultivar on the important quantitative (yield of marketable tubers per plant, average weight of marketable tubers, yield of marketable tubers per hectare, share of marketable tubers) and qualitative (antioxidant activity, polyphenol content) parameters of sweet potatoes grown in Slovak Republic was tested. The highest yield (1964.16 g/plant; 54.56 t/ha) and average weight (446.18 g) of marketable tubers (> 150 g) were found in white sweet potato cultivar 'Visnjica white'. The highest ratio of marketable tubers was found in orange cultivar 'Beauregard' (87.17%). The purple cultivar 'Visnjica purple' was characterized by significantly lower values of all quantitative parameters of sweet potatoes. On the contrary, the highest antioxidant activity (61.07% DPPH; DPPH: 2,2-Diphenyl-1-picrylhydrazyl) and polyphenol content (4506.90 mg/kg dry weight) were found just in purple cultivar 'Visnjica purple'. The significantly higher values of both parameters, compared to other cultivars, are caused by abundance of anthocyanins. Results of this study revealed that sweet potato is expressed by good yield potential, together with its quality, in conditions of Slovak republic, or Middle Europe in generally.

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 planting configuration and row spacing on growth and production of potato under mulched condition in Dadeldhura, Nepal

An experiment was conducted at the research site of Dadeldhura, Nepal in 2019 to identify optimum plant spacing for potato under mulched condition. Three levels of inter row spacing; 60 cm with single row per bed (1RB), 45 cm with double row per bed (2RB) and 30 cm with triple row per bed (3RB) and intra row spacing (20, 30 and 40 cm) were laid out in factorial randomized complete block design with three replications. Results showed that there was significant difference (p&lt;0.05) for all parameters except on days to 50% germination, 90% flowering, 50% maturity and on main stem number and graded large sized tuber number and it's weight. Growth parameters namely canopy, leaf number and leaf area were significantly higher (p&lt;0.05) in 60 cm (1RB) ×30 cm spacing. Plant height and leaf area index was significantly higher (p&lt;0.05) in 60 cm (1RB) × 20 cm and 30(3RB) ×20 cm spacing respectively. Total number of tubers m-2 , weight of tubers m-2, weight of marketable tubers m-2, harvest index, number of small sized tuber m-2 ,weight of small sized tubers m-2 and weight of medium sized tubers m-2 were found to be 56.24%,39.79%, 47.98%,4.41%,90.56%, 113.23% and 70.15% significantly higher (p&lt;0.05) in 30 cm (3RB) compared to 60 cm on (1RB) inter row spacing respectively and 59.72%, 61.15%, 58.30%, 4.41%, 114.90%, 137.31%, 55.39% higher in 20cm compared to 40 cm intra row spacing. Interaction effect was significant (p&lt;0.05) in marketable tuber number and medium sized tuber number in which the average highest number of marketable tubers (134.44) and medium sized tubers (121.08) was found in 30(3RB) ×20 cm spacing which was 165.95% and 235.03% significantly higher compared to 60×40 cm spacing respectively. So, this study showed that 30(3RB) ×20 cm spacing would be best spacing combination under mulched condition.

Potato cultivar BRS F63 Camila has higher yield at lower plant spacing

ABSTRACT The plant management used in potato crop is usually similar across the main producing regions in Brazil. Same plant spacing are commonly used, despite the differences in climate and soil of the various potato planting areas. The objective of this work was to evaluate the yield of potato cultivars in response to different plant spacing. Experiments were conducted in the field, and the treatments consisted of three cultivars (Agata, BRS Clara and BRS F63 Camila) and three plant spacing (20, 25 and 30 cm) in randomized blocks with three repetitions in two years. The total, marketable and non-marketable tuber yield, total and marketable number of tubers per area and size class, mean total and marketable tuber weight and percentage of tuber dry weight of the tubers were evaluated. Camila was the cultivar with highest yield when spaced 20 cm due to the greater number of tubers in the marketable class 100-200 g. In the 25 and 30 cm plant spacing, there was no difference in yield among cultivars. Depending on the cultivar and the destination of the harvested tubers, producers can choose the most appropriated plant spacing.

New national potato genotypes: yield response to different doses of 4-14-8 NPK fertilizer

ABSTRACT The fertilization of potato crops generally does not take into account the genotype, although genotypes may respond differently to fertilization. This study aimed to determine the yield of new potato genotypes (cultivar BRS Camila and clone CL 02-05), as well as the cultivar Ágata, submitted to four NPK 4-14-8 fertilizer doses (0, 2, 4 and 6 t ha-1) in the crop seasons of 2013/14 and 2014/15. We evaluated the total and marketable tuber yield, total and marketable tuber number, percentage of marketable tuber dry weight, average marketable tuber weight and plant growth period. The experimental design was randomized blocks in split plot scheme, with fertilizer doses allocated as main plots and genotypes as subplots, with three replications. We did not observe significant interaction for any analyzed variable. The clone CL 02-05 showed higher total and marketable tuber yield compared to the other cultivars, mainly due to its higher production of tuber number. However, we observed a high amount of tubers not suited for commercialization from the clone CL 02-05. Cultivar BRS Camila produced fewer marketable tubers than cultivar Ágata in crop season 2014/15, but without difference in marketable yield. On the other hand, plants of cultivar BRS Camila had a longer growth period of 7 days and the tubers of this cultivar accumulated higher percentage of dry weight compared to cultivar Ágata. The new tested genotypes had yield response similar to cultivar Ágata when submitted to doses of 4-14-8 NPK fertilizer. Therefore, the fertilization management of these new genotypes may be similar to that used with cultivar Ágata.

Yield Response of Potato (Solanum tuberosum L.) Genotypes to Late Blight Caused by Phytophthora infestans in Uganda

Potato (Solanum tuberosum L.) is a major food and cash crop, mainly grown by small-scale farmers in the highland regions of Uganda. Potato late blight is one of the major diseases limiting production with potential yield losses over 70%, making host resistance a strong element in integrated disease management. This study was carried out to screen and select high yielding potato genotypes with resistance to late blight in Uganda. Forty-eight genotypes, including advanced clones from the population B3C2 of the International Potato Centre, commercial and farmers’ varieties, were evaluated under two environments for two seasons. Trials were laid out in an 8 × 6 alpha lattice design with three replications. Genotypes showed significant differences in yield and resistance to blight. A higher disease severity was observed in Karengyere (56%). The average RAUDPC (= 100 max) across locations indicated that genotypes 395,077.12 and 392,657.8, with disease severity of 12% and 14%, respectively, were the most resistant. Genotypes Victoria (53%) and NKRN59.124 (48%) were the most susceptible. Mean tuber yield under late blight infection was19.8 t ha−1. The best yielding genotype across sites was 395,112.32 (35.6 t ha−1) while 394,905.8 (10.3 t ha−1), yielded the lowest. The mean marketable tuber weight was 8.9 kg with genotypes 395,112.32 and 395,109.34 having the highest marketable weight of 16.5 kg and 15.6 kg respectively. Correlations between yield and yield related parameters were positive (p ≤ 0.001), while those between RAUDPC were negative. The following genotypes, 395,112.32, 391,919.3, 393,220.54. 393,077.54, 396,038.107. 392,657.8, Kinigi, 395,014.17, NKRN59.58, NKRK19.17 and 395,011.2, were identified as promising parents for a late blight resistance breeding program. These exhibited high to medium resistance to late blight disease and high yields.

Influence of vines production methods and their combination with time of harvest on tuber quality and yield of sweet potato

Availability of sufficient sweet potato vines is usually a problem during the planting season because most of the sweet potato vines from the previous harvest dry up before the next planting season. Also, in the process whereby the farmers are resulted to the prolonged multiplication of old vines for the planting of the new fields, the yield and quality of harvested tubers are reduced due to vines degeneration, diseases and pests infestation. Therefore, trials were conducted at Ajase-Ipo community of Irepodun local government area in Kwara state and Ifon community of Ose local government area in Ondo state of Nigeria in 2008 and 2009 to investigate vines producing methods and and their combination with different time of harvest. Three vines production methods investigated are nurseries, vines from sprouts roots and vines from successive planting (Farmers’ practice) and the harvesting time of sweet potato are 120, 140, 160 and 180 days after planting (DAP). The results indicated that, the effects of the vines production methods on the weight of fresh marketable tubers, weight of fresh unmarketable tubers, weight of total fresh tubers, tuber dry matter content and harvest index were significant. At both locations, nursery method gave the significantly highest values (15.2 and 13.8 t/ha) for marketable tubers in 2008 and 2009 at Ajase Ipo and (17.4 and 15.2 t/ha) at Ifon compared to sprouted roots and successive planting methods (Farmers’ practice). The combination of the methods of vines production and time of harvest effects significantly affected the average weight of marketable tubers at Ajase Ipo and Ifon. Nursery method gave the significantly highest values [(13.5 and 15.8 t/ha), (11.8 and 12.9 t/ha), (9.4 and 9.8 t/ha) and (8.4 and 7.9 t/ha)] at Ajase Ipo and Ifon at 120, 140, 160, and 180 days after planting (DAP) respectively compared to sprouted roots and successive planting methods. The combination of the methods of vines production and the time of harvest effects significantly affected the average weight of weevil free marketable tubers and badly infected marketable tubers at Ajase Ipo and Ifon. Consistently, nursery method gave the significantly highest values [(13.5 and 15.8 t/ha), (12.9 and 14.8 t/ha), (10.3 and 13.1 t/ha) and (8.6 and 11.8 t/ha)] weevil free marketable tubers at Ajase Ipo and Ifon at 120, 140, 160, and 180 DAP respectively compared to sprouted roots and successive planting methods that were not significantly different from each other. But, the least values [(6.9 and 7.3 t/ha), (5.8 and 4.1 t/ha), (4.8 and 3.1 t/ha) and (1.6 and 2.3 t/ha)] at Ajase Ipo and Ifon at 120, 140, 160, and 180 DAP respectively were recorded for successive planting method.

Продуктивність картоплі за краплинного зрошення в умовах півдня України

The paper analyzes the impact of the basic elements of the technological process of potato cultivation under drip irrigation in the South of Ukraine. The scheme of the experiment implied the study of different calculated soil layers 0–20; 0–40; 0–60 cm and the methods of fertilizer application: locally at planting time and application with irrigation water N60P60K60 and calculated fertilizer dose to obtain 35 t/ha of potato tubers. During the growing season the pre-irrigation soil moisture was maintained at the level of 80–80–70 %, the least soil moisture was differentiated by the stages of the plant growth and development: planting–producing buds, producing buds–flowering, flowering–plant dying back. The maximum productivity was obtained due to the local application of mineral fertilizers in the dose N 60 P 60 K 60 before planting under moistening the calculated soil layer of 0–60 cm with the product cost price of 1345 thousand UAH/t and the production profitability of 160.3 %. Under these conditions the coefficient of water consumption was minimal – 97.8 m3/t. The reduction of the calculated layer to 0-20 cm caused the decrease in the yield by 2.9 t/ha or 9.9 %, as compared with 0–60 cm. It became possible due to the reduction of the marketable tuber weight by 11.2 and 6.3%, as compared with the soil layer of 0–60 and 0–40 cm. The application of fertilizers contributes to, on the average by the factor, a substantial increase in the yield – 8.5 t/ha or 25.9 %, as compared with the non-fertilized background, where the yield formation takes place at the expense of obtaining tubers of less weight (110.6 against 138.9 g). According to the methods of fertilizer application the tuber yield was on the average 31.6–33.9 t/ha, the efficiency of fertilizer application was 30.0–39.6%.