Minituber Weight Research Articles

Essential Quality Attributes of Culture Media Used as Substrates in the Sustainable Production of Pre-Basic Potato Seeds

The sustainability of the primary sector is closely linked to meeting the demand for seeds using agro-industrial waste and bioresidues. Sustainability is a multidimensional concept focused on achieving environmental health, social justice, and economic viability. To this end, an experiment was designed based on a combination of biotechnological strategies accessible to many individuals. The first strategy involves the use of compost and vermicompost as cultivation substrates; the second is the in vitro acclimatization of potato plants to these substrates; and the third is the incorporation of Trichoderma asperellum into these substrates to determine the synergistic effect of both. The compost used in this work came from sewage sludge from an agri-food company (Cp); a dining room and pruning waste from a university campus (Cu); and vermicomposted coffee pulp waste (Cv). Each sample was mixed with coconut fiber (Fc) in proportions of 100, 75, 50, and 25%. In the resulting mixtures, María Bonita variety vitroplants were planted and placed in a greenhouse. The biometric response in the three cases indicated a dependence on the type of compost and the proportion of the coconut fiber mixture. The inoculation of Trichoderma asperellum with sewage sludge compost increased stem thickness (42.58%) and mini-tuber weight (6.74%). In contrast, uninoculated treatments showed the best performance in terms of the number of mini-tubers. A 50:50 mixture of sewage sludge compost with coconut fiber and without inoculation of Trichoderma asperellum was the best treatment for the production of pre-basic seeds of the María Bonita potato variety. The use of composted agricultural waste and bioresidues is shown as a valid and low-cost alternative for the sector, even independently of the incorporation of additional inoculants.

Mycorrhizae enhance minituber weight and nutrient content in potatoes transferred from in vitro to hydroponic culture under different phosphorus levels

The survival and productivity of potato plantlets transplanted from in vitro to commercial hydroponic minituber culture are crucial. Mycorrhizal fungi are an efficient tool to enhance potato nutrient uptake, survival, and productivity under these conditions. This study aimed to assess the effect of mycorrhizal fungi on improving the yield of minitubers and nutrient uptake in potatoes transferred from the in vitro environment to the greenhouse. This study was conducted in a greenhouse in Hamadan province, I.R. Iran, in 2013. The experimental design was factorial, including treatments with and without inoculation with the mycorrhizal fungus Rhizophagus irregularis and varying phosphorus (P) concentrations in Hoagland’s solution (100%, 75%, 50%, and 25% of its maximum content, i.e. 0.965, 0.482, 0.241, and 0.12 mM H2PO4 -) with three replications on potato plantlets transferred from in vitro to pots. The results indicated that the highest colonization percentage was achieved with 25% P and inoculation. The highest number of minitubers (8.9), total minituber weight per plant (53.2 grams), plant height (54.6 cm), minituber (0.38%) and leaf (0.363%) P content, minituber (33 mg/kg) and leaf (65 mg/kg) manganese (Mn) content, and minituber (38 mg/kg) and leaf (65 mg/kg) zinc (Zn) content were obtained with inoculation and 75% P of Hoagland nutrient solution, which was statistically comparable to the inoculation with 100% P treatment. In summary, inoculating potato plantlets with mycorrhiza can enhance minituber yield and nutrient uptake and potentially replace approximately 50% of the P requirement in hydroponic solutions.

Effect of planting periods on production potential of potato (Solanum tuberosum) varieties under aeroponics

An experiment was conducted during 2017–18 in the aeroponic unit of ICAR-Central Potato Research Institute inShimla, Himachal Pradesh, to evaluate 3 potato (Solanum tuberosum L.) cultivar’s, viz. Kufri Mohan, Kufri Lauvkarand Kufri Himalini growth and production behaviour under 2 different planting periods spaced 10 days apart duringthe autumnal season. The yield per plant and the total number of mini-tubers were shown to be strongly impactedby the planting season as well as the cultivar, according to the findings. The average number of tubers harvested was 32.7/plant in early (10th September) planting as against 21.2 mini-tubers/plant in late (20th September). Similarly, yield per plant was significantly higher (67.67 g/plant) with early planting than with late planting (35.99 g/plant). The production behaviour of the potato varieties under consideration varied significantly. The maximum yield/plant and mini-tuber numbers were recorded in Kufri Lauvkar (34.17 and 73.12 g/plant, respectively), which were significantly higher than the remaining 2 cultivars, which were statistically at par for both the number of yield/plant and minitubers. A delay in the planting of 10 days under aeroponics results in a significant reduction not only in the vigour of plants but subsequently in the number as well as weight of mini-tubers harvested. Thus, for attaining higher rates of multiplication under aeroponics during the autumn season, planting should not be delayed beyond 10th September in a hilly temperate wet zone.

Introduction of Nutrient Solution of Silicon Sulfonated With Elemental Sulfur S8 for the Mini-tuber Production of Potato Cultivars from in vitro Micro-tuber

This study with aims to investigate the effect of nutrient solution sulfonated silicon with elemental sulfur S8 in the mini-tuber production of potato cultivars in the greenhouse of Potato Research Station of Ardabil Province, Iran was done during April till August of 2022. This experiment was carried out based on the factorial experimental design in two factors and three repetitions. The first factor with two levels including: 1. foliar spraying with nutrient solution sulfonated silicon with elemental sulfur S8 and 2. Control (without nutrient solution sulfonated silicon with elemental sulfur S8) and the second factor consists of micro-tubers of five cultivars in the name of Agria, Jelli, Anosha, T297 and Sheida. The foliar spraying with S-8 nutrient solution was done in five stages of vegetative growth, plant growth and development, tuberization, flowering and tuber development and tuber bulking. The results of analysis of variance showed that there was a significant difference between the levels of nutrient solution, cultivars and the interaction between nutrient solution and cultivars in terms of mini-tuber number and weight per square meter, mini-tuber number per plant and plant height. Anosha cultivar had the highest values in terms of mini-tuber number and weight per square meter and tuber number per plant traits by using nutrient solution and was placed in the group A. The Agria, Jelli, Sheida and T297 cultivars were placed in the group B and had the highest amount by using nutrient solution in terms of these characteristics. The Agria, Jelli and Anosh cultivars had the highest plant height by using nutrient solution. Based on the results, using sulfonated silicon nutrient solution with elemental sulfur S8 causing an increase mini-tuber number per square meter (515 numbers), mini-tuber number per plant (5 numbers), mini-tuber weight per square meter (47 kg) and plant height (92 cm) became.

Effect of growth regulators on the morphological traits of three potato cultivars in vitro

The experiments were conducted to study the effect of sub cultures (3 sub-cultures) of in vitro propagated plants of three cultivars of potato (Arnova, Riviera and Provento) and their interaction with Indole Acetic acid (IAA) at 0.0 , 1.0 mg L-1 and Benzyl Adenine ( BA) at 0.0, 0.5, 1.0 and 2.0 mg L-1 concentrations on morphological traits of vegetative (plant height, number of shoots, leaves , nodes and length of shoots) and roots (number of roots and their lengths) system. The cultures were incubated under temperature of 25 ± 2°C and illumination for 16 h day-1. The plants were transferred to the greenhouse and data were taken on the number of minitubers, their diameter and weight after 90 days. The results showed the effectiveness of IAA at 1 mg L-1 increasing in plant height (16.06 and 14.83 cm for Rivera and Provento cultivars, respectively), and in number of leaves and nodes (18.08 leaf plant-1 for Rivera and 16.92 nod plant -1 for Provento), and the number of roots and their length. (11.25 root plant-1 and 11.25 cm for Rivera and Arnova cultivar, respectively). The results also showed the effectiveness of the combination of IAA (1 mg L-1 ) + BA (0.5 mg L-1 ) increasing the number and length of shoots (6.50 shoot plant-1 and 4.83 cm for Provento and Rivera cultivar). A decrease in the number of roots was also observed with increasing concentrations of BA which added to the medium with or without of IAA. Results also recorded the highest average of diameter and weight of minitubers was 8.63 cm and 3.64 g for the mother plants of the Riviera and Provento cultivars, respectively, while the mother plants and in vitro propagated plants of three cultivars did not differ in the average number of minitubers.

Effect of 6-Benzyl Aminopurine Different Concentration on Potato (Solanum tuberosum L.) Minitubers in Net House and in Field

Background: 6-benzyl aminopurine (BAP) is a dominant regulation in minitubers formation. BAP treatment enhances both Crop quantity and quality parameter like days to emergence, number of shoots, shoot length, root length, number of stolons, number of minitubers, potato shape index and fresh weight of minitubers. The purpose of this study was to optimise the effect of different concentrations of BAP on potato (Solanum tuberosum L.) minitubers in a net house and in field. Methods: The present investigation, effect of BAP different concentration on potato (Solanum tuberosum L.) microtubers and minitubers were done at Central Potato Research Institute Campus, Modipuram, Meerut during 2012-13 and 2013-14. This experiment design was split plot with five replications and three treatments. In vitro BAP treatments for microtuber growth parameters included three doses (0.75 mg/l, 1.5 mg/l and 2.25 mg/l). BAP treated microtubers were planted in net house, again in next season BAP treated minitubers were planted in field. Growth and yield parameters were recorded. Result: The concentration of BAP (1.5 mg/l) led to decrease in all parameters as compared to BAP at (2.25 mg/l) treatments in both the varieties. Same result was also observed in field.

Optimization of industrial (3000 L) production of Bacillus subtilis CW-S and its novel application for minituber and industrial-grade potato cultivation

A commercial plant probiotic product was developed employing Bacillus subtilis CW-S in submerged fermentation. The effects of molasses and urea on cell growth were investigated with the goal of low-cost manufacturing. Plackett–Burman and Central-Composite Design (CCD) were utilized to optimize production parameters to maximize productivity. The stability of the formulated product and its efficacy in cultivating minituber in aeroponics and industrial-grade potatoes in the field were assessed. The results showed that the medium BS10 (molasses and urea) produced satisfactory cell density (7.19 × 108 CFU/mL) as compared to the control (1.51 × 107 CFU/mL) and BS1-BS9 (expensive) media (1.84 × 107–1.37 × 109 CFU/mL). According to validated CCD results, optimized parameters fitted well in pilot (300 L; 2.05 × 109 CFU/mL) and industrial (3000 L; 2.01 × 109 CFU/mL) bioreactors, resulting in a two-fold increase in cell concentration over laboratory (9.84 × 108 CFU/mL) bioreactors. In aeroponics, CW-S produced excellent results, with a significant increase in the quantity and weight of minitubers and the survival rate of transplanted plantlets. In a field test, the yield of industrial-grade (> 55 mm) potatoes was increased with a reduction in fertilizer dose. Overall, the findings suggest that CW-S can be produced commercially utilizing the newly developed media and optimized conditions, making plant probiotics more cost-effective and accessible to farmers for crop cultivation, particularly in aeroponic minituber and industrial-grade potato production.

The response of different potato cultivars to plant growth-promoting rhizobacteria (PGPRs) and chemical fertilizers in aeroponic culture conditions

Optimization of nutrients in an aeroponic culture system is the most important factor for the quantitative and qualitative production of healthy potato seeds. This study was conducted in Ardabil agricultural center and natural resources greenhouse in an aeroponic culture system in 2019–2020. The study was based on a completely factorial randomized design. The reactions of the seedlings of three cultivars of potato (Agria, Banba, Caesar) to the combination of three bacterial inoculants (PGPRs) (Azospirillum lipoform, Pseudomonas putida, Aztobacter crococum), and two stages of chemical fertilizer nutrition were investigated. We found out that the maximum number and weight of mini-tuber per plant was obtained in cv. Banba. The maximum number of stolons, the number of days up to tuberization, and the maximum average weight of minitubers were achieved by applying the chemical fertilizer. PGPRs had a significant impact on the increase in the plant height and on the length of stolon in cv. Banba. The largest plant height and number of days up to tuberization were achieved in the cv. Caesar, and the greatest number of stolons was obtained in cv. Banba. We concluded that the application of the chemical fertilizer in aeroponic culture system promoted the potato yield.

Effects of Media and Plant Growth Regulators on Mini-Tuber Yield of Granola Cultivar of Potato in Aeroponics System

<p>Potato is a perennial plant (<em>Solanum tuberosum L</em>.) in the nightshade family, which is one of the most developed and competitive vegetable crops compared to other vegetables. Furthermore, its production could not meet the increasing demand, which led to very intensive research and development programs. This research aims to examine the effect of nutrients and growth regulators on the yield of mini-tuber in the aeroponic system and to determine the best type of nutrient, as well as the type and concentration of plant growth regulators to increase mini-tubers yield in an aeroponics system. This experiment has been carried out experimentally using a split-split plot design. The main plots were the types of nutrient media, which consisted of Grow More-modified nutrient and AB-Mix nutrient. The sub-plots were the types of plant growth regulator (PGR), which consisted of BAP and GA<sub>3</sub>, while the sub-sub-plot were the concentrations of PGR, which consisted of 0; 5; 10; 15; 20 and 25 µM. Each combination of treatments was repeated three times. The results showed that the use of media type, PGR and PGR concentration affected the formation and yield of Granola cultivar of potato mini-tubers. Knols grown in AB-Mix nutrient medium supplemented with 20 µM GA<sub>3</sub> resulted in the best mini-tuber formation, as shown by the average number of mini-tubers of 8.33, the total weight of mini-tubers of 21.38 g and the average mini-tuber diameter of 13.05 mm.</p>

PRE-BASIC SEED POTATO PRODUCTION IN AEROPONIC CULTURES

The current study was carried out to investigate Pre-Basic Seed Potato Production in soilless cultures under Egyptian conditions. Furthermore, the study investigated the possibility of plantlets direct acclimatization of three potato varieties in Aeroponic culture system comparing with substrate culture system (peat moss and vermiculite 3:1 v/v). Also, the growth and the yield of three cultivars (Diamant, Lady Rosetta and Spunta) were compared. Aeroponics showed better survival rate and promising method for acclimatization of potato plantlets ex vitro. Moreover, Varietal differences were noticed between the three tested varieties. The best response as survival rate, stem length and leaf area were observed by Spunta followed by Lady Rosette while Diamant came in the last place. However, Diamant produced the highest plant dry matter. Aeroponic system gave higher minituber number per plant while substrates gave higher average minituber weight. The obtained results recommend the use of Aeroponic culture system in acclimatization of in vitro potato plantlets and minitubers to be introduced in pre-basic seed programs in Egypt.

Yield of Potato Minitubers under Aeroponics, Optimized for Nozzle Type and Spray Direction

Potato seed production by conventional methods represents a sizeable investment that, when passed on to farmers, can decrease their profit margins. Potato minitubers produced by aeroponic systems are space- and cost-efficient, and they also provide healthy propagules to be used by farmers. We evaluated the effects of different misting nozzle types, with and without an antidrip feature, and spray direction on potato minituber yield using the Federal University of Viçosa (UFV) Aeroponic System. Potato plants (cv. Agata) propagated from sprouts were grown in a covered, high-density 100-L polyethylene bucket. The experiment was set up in a randomized complete block design with four replicates and eight treatments combining misting nozzle types (Fogger, MA-30, and CoolNet) with and without antidrip and comparing upward with downward spray directions. Plants were evaluated weekly from 33 to 68 days after transplant (DAT). The parameters used to evaluate treatments were number and mass of minitubers as a function of harvest times, dry mass of roots, stems, leaves, and total biomass. The number and fresh weight of minitubers, as well as root dry weight, stems, leaves, and total biomass were affected by misting nozzle types and spray direction. Treatments also affected biomass partitioning of roots, stem biomass, and the shoot:root ratio. There was also an effect of harvest time on the number and fresh weight of minitubers for various combinations of misting nozzle type and spray direction, except for minituber number with the CoolNet misting nozzle without antidrip and downward spray direction. On the basis of the assessed parameters, the best minituber production system was achieved with the Fogger spray combined with no antidrip, a rate of 12 L·h−1, and with the downward spray direction. The UFV Aeroponic System produced an average of 491 minitubers per plant. This system is simple to implement and may lead to a more affordable upscaling of potato seed minituber production.

Influence of Plant Density and Genotype on Potato Minituber Production from Microshoots and Microtubers

Seed tubers represent the major cost for potato production in Egypt. With the introduction of tissue culture technology, it becomes possible to obtain virus-free potato plantlets or microtubers in vitro for subsequent use in minituber production. These two stock materials were examined for potato minituber production inside a glasshouse at different planting densities (5, 10, 15 and 20) plantlets or microtubers per 20 cm pots filled with soilless medium during the period 2014-2016. Several potato genotypes were also screened for their minituber and seed tuber yield potentials. Results indicated that with the increase in planting density, minituber yield and number per pot and per m2 were increased, but mean minituber weight decreased, in the two-tested cultivars 'Diamant' and 'Universa'. Significant differences among 19 potato genotypes were detected on their minituber yield characteristics, including minituber number and yield per plant, and average minituber weight, using microtubers as starting plant materials. Among 19 tested genotypes, the newly introduced potato cultivars 'Universa', 'Safrane', and 'Triomphe' outper-formed the rest of cultivars in minituber production. Seed potato production in the field was successfully achieved from the culture of the obtained minitubers, and the cv. 'Safrane' recorded the highest seed tuber yield and mean tuber fresh weight, while the cvs. Agria and Nicola recorded the highest numbers of seed tubers per plant.

English

There is limited information on the performance of Kenyan potato varieties under aeroponic systems. Experiments were therefore carried out at the Kenya Agricultural Research Institute (KARI), Tigoni, under an aeroponic system in 2012 and 2013 to evaluate the growth and mini-tubers production of five varieties commonly grown in Kenya and differ in vegetative and reproductive characteristics. The experiment was set up in a randomized complete block design (RCBD) replicated three times. Plant growth expressed by plant height differed among the varieties and these differences became more pronounced with plant age. The effect of variety on number of mini-tubers per plant and total weight of mini-tubers per plant was significant. The number of mini-tubers per plant ranged from 62.2 to 19.2 in season 1 and 56.8 and 17.1 in season 2. Correlations between the number of mini-tubers per plant and the total weight of mini-tubers per plant with days to tuberization, days to senescing, days to maturity, plant height measured at 80 days after transplanting and plant vigor, were positive and significant. The correlation between the number of mini-tubers per plant and total weight of mini-tubers per plant was also positive and significant. It is concluded that mini-tubers production under aeroponic system was variety dependent with Tigoni, Asante and Kenya Mpya being the most productive varieties irrespective of the season. Evaluation of a variety’s suitability/adaptability to the system is therefore necessary to determine the most adapted varieties before embarking on large scale production as this will ultimately affect production costs, with higher yielding varieties more likely to result in lower mini-tubers production costs. Key words: Aeroponics, mini-tuber production, vegetative growth.

Experimenting Hydroponic Culture Systems on Different Substrates to Obtain Potato Minitubers

The production of minitubers using the hydroponic method has become an important component in the production of seed potatoes in developed countries. The objective of the study is obtaining minitubers (Prebase), free from diseases, from the transplantation of vitroplants on industrial substrate and different hydroponic systems. The hydroponic culture involves growing plants on artificial substrates, or in a sterile, porous substrate with a high-water permeability. The parameters analyzed in this study were: average number of minitubers / plant and average weight of minitubers/plant. By using hydroponic system, a high minitubes production was obtained. The trifactor experience of the type 4 x 2 x 2 with 16 variants used the following graduations of the studied factors: experimental factor a, variety, with four graduations: a1 - Braşovia; a2 - Castrum; a3 - Marvis; a4 - Sarmis; experimental factor b, culture substrate, with two graduations: b1 - expanded clay; b2 - perlite; experimental factor c, the hydroponic system: c1 - Wilma; c2 - Nutrient Film Technique. These variants were experimented in 3 repetitions. Castrum variety was remarked by obtaining a high number of minitubers and also by weight of minitubers. Nutrient Film Technique hydroponic system had a positive influence on minituberization, for minitubers number, but also for weight of minitubers. Perlite substrate has determined obtaining high values for both studied parameters.

IMPROVING PRODUCTION AND CHARACTERS OF POTATO MICROTUBERS AND MINITUBERS

This investigation was carried out during the seasons 2012 and 2013 on potato cv. Diamant at the Tissue Culture Laboratory and the greenhouse of Potato and Vegetatively Propagated Vegetables Department, Horticulture Research Institute, Dokki, Giza, Egypt. The present study aimed to study the effect of the in vitro application of chitosan, calcium chloride and the concentration of ammonium nitrate and potassium nitrate on potato tuberization. In addition, to study the effect of foliar application of chitosan, chelated calcium and potassium silicate on growth and yield of the minituber ex vitro. Results revolved that 500 mg/l chitosan gave the highest values of number of shoots and node/plantlets, number of microtuber, fresh and dry weight of shoots and microtubers fresh weight after 8 weeks from culture in vitro. Furthermore, ex vitro spraying with 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium + 400 mg/l potassium silicate produced the highest values of plant length, leaves number/plant, fresh and dry weight of leaves on 75 days after planting. As well as, minituber characteristics (number of minituber /plant, minituber fresh and dry weight/plant, average minituber weight and weight of minituber /plant according to its size) after 100 days from planting recorded the highest significant values with foliar application of 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium + 400 mg/l potassium silicate. It could be recommended that adding chitosan at 500 mg/l to in vitro microtuber production medium (MS + 8 mg/l BA + 80 g/l sucrose) was preferable to produce microtubers. Also, the ex vitro spraying of 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium plus 400 mg/l potassium silicate could be useful for minituber production and enhancing its yield characteristics.

Growing Seed Yams in the Air: the Agronomic Performance of Two Aeroponics Systems Developed in Ghana

Aeroponics has been perceived as a technology crammed innovation, far out of reach of the ordinary farmer. Apart from its continuous dependency on electrical power, the technology comes with very sophisticated inputs such as solenoid valves, timers, misters, CO2 tanks, and air and water pumps. The main objective of this study was to evaluate the option of using gravity-fed and pressurised aeroponics system for propagating seed yams from vine cuttings. The study was setup at the CSIR–Crops Research Institute in collaboration with the Agricultural Engineering Department of the Kwame Nkrumah University of Science and Technology. The basic advantage of the gravity-fed system is its non-dependency on electrical power, pumps or timers and its ability for continuous production. The two systems were set-up using conventional materials and equipment available on the local market. The treatments were arranged in a split-split-plot design with the two aeroponic units as the main plot, four nutrient concentration levels (C1 - , C2 - , C3 - and C4 -) as the sub plots and vine cuttings from three Dioscorea rotundata varieties (Dente, Pona and Mankrong Pona) as sub-sub plots respectively. Results showed there were significant differences (P<0.05) in minituber weight and days to emergence of planted miniubers. The agronomic response of the two systems in producing mini-tubers was suggestive of the fact that both systems could be used to effectively produce mini-tubers.

Effect of season of production on storage and production behaviour of potato (Solanum tuberosum) mini-tubers

Storage, sprouting and production behaviour of different grades of potato mini-tubers of cv. Kufri Girdhari produced during summer (Kharif) and autumn seasons in high hills of north-western Himalaya (9 000 feet amsl) was studied. The study revealed that mini-tubers produced during both the seasons in the high hills store well under ambient conditions till the next potato planting season, i.e. April. Number of sprouts and length of longest sprout per minituber as well as average weight per tuber at the end of storage period was affected significantly by the season of production as well as grade of mini-tubers. However, total physiological loss in weight of mini-tubers from two seasons was almost same but was affected significantly by the grade of mini-tuber. Mini-tubers from both the seasons resulted in same yield and number of tubers per hectare. A gradual and consistent increase in the number of tubers as well as in potato yield with the increasing size of mini-tuber was noticed. Similar field productivity of mini-tubers from two seasons is in total support of the practice of taking two crops of mini-tubers (from in vitro plantlets) under protected conditions. The information generated will be helpful in boosting the fast multiplication of elite planting material of potato in the high hills of north western Himalaya.

Potato (Solanum tuberosum) aeroponics for quality seed production in north eastern Himalayan region of India

The study was conducted at Central Potato Research Station, Shillong during 2013 and 2014 to evaluate the performance of three potato (Solanum tuberosum L.) varieties, viz. Kufri Megha, Kufri Himalini and Kufri Himsona in an aeroponics system installed under net cum polyhouse. All the varieties exhibited more than 90% survival with root initiation within 4-5 days of transplanting. Kufri Megha started tuber initiation within a month in both the years. Tuber initiation was late in Kufri Himalini in 2014 (60 days) as compared to 2013 (39 days). Kufri Himsona exhibited delayed tuber initiation at 69 to 75 days after transplanting in both the years. The first picking was done within 40 and 80 days after transplanting in Kufri Megha and Kufri Himsona, respectively, in both the years. First picking in Kufri Himalini was delayed by 15days in 2014 as compared to 50 days after transplanting in 2013 due to delayed tuber initiation. The crop duration of Kufri Megha was 110 and 134 days in 2013 and 2014, respectively, allowing for 8 to 9 pickings that yielded 108 to 118 g ubers/plant (38 to 42 tubers/plant) with mean mini-tuber weight of 2.91 to 2.96 g. The number of pickings reduced significantly from 11 to 5 in Kufri Himalini and 7 to 4 in Kufri Himsona from 2013 to 2014. In Kufri Himalini, delay in tuber initiation and reduction in crop duration was observed in 2014. There was a significant reduction in per plant yield in both Kufri Himalini (162 g to 102 g) and Kufri Himsona (138 g to 39.25 g) accompanied by reduction in number of tubers/plant (38 to 27 tubers in Kufri Himalini and 29 to 11 tubers in Kufri Himsona). The mean mini-tuber weight also reduced from 4.32g to 3.87g in Kufri Himalini and 5.03g to 4.13g in Kufri Himsona.

English

A pot experiment was set to examine the impact of the foliar litter ( Hardwickia binata and Azadirachta indica ) and an arbuscular mycorrhizal (AM) fungus on the development of two varieties of potato plants (Aida, Atlas). Three litter doses (0, 25 and 50 g) were applied to the pots after bedding plantlets. The plants were inoculated with AM, Glomus aggregatum . Mycorrhizal colonization, shoot dry weight, size and number of minitubers were evaluated after 12 weeks on the potato growth. Results show that shoot dry weight of plants was improved by litter of the H. binata at 25 and 50 g. Thus, A. indica litter increased size of plants Aida at 50 g and the minitubers numbers Atlas at 25 g. On the other hand, root colonization decreased with increase in the dose of litter with both varieties of potato. Key words: Arbuscular mycorrhizal fungi, potato, litter, micropropagation.

Are Tacca leontopetaloides (Linn.) O. Kuntze Mini-tuber Growth Affected by Media Composition and Tuber Size?

Tacca (Tacca leontopetaloides (Linn.) O. Kuntze) is a tropical plant that is widely used for its starch in some countries as well as a medicinal plant. Tacca has advantages as it can grow on sand in tropical seashore areas and rain forests. Farmers in Madura Island Indonesia cultivated tacca by using mother tubers as propagules and harvest the daughter tubers, but no studies have been conducted on the growth of mini tubers and their cultivation. The purpose of this study was to find the best combination of planting media and the size of mini tuber for growing tacca. The experiment was set in a completely randomized block design with two factors and three replications. The planting media are sand : rice-hull charcoal : cow manure (1:1:1 v/v), soil : sand : cow manure (1:1:1 v/v), soil : rice-hull charcoal : cow manure (1:1:1 v/v), and soil : cow manure (1:1 v/v);mini-tuber weight are1-5 and 5.1-20 g. The result showed that Polynesian arrowroot grow best on sand : rice-hull charcoal : cow manure (1:1:1 v/v) and rice-hull charcoal : cow manure (1:1 v/v) media. Both propagules sizes can be used, but plants from large mini-tuber had better growth and produced larger mother and daughter tubers. Key words: mini tuber, parent tuber, Polynesian arrowroot, organic media planting, secondary tuber