Differential growth and yield responses of local potato cultivars from basic seed tubers

ABSTRACT Potato quality of seed tubers is a determinant factor that allows obtaining high yields, and its use must be a priority for a country or a producing region. Lack of information about how local cultivars perform differentially according to the environment has been identified in order to support potential seeds production programs. The research was carried out in 2018 at the Obonuco Research Center of Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), with the aim of analyzing the growth and yield of basic tuber seeds of five potato (Solanum tuberosum spp. andigena) cultivars. 1,080 seed tubers from each cultivar (treatments) were planted in a completely randomized block design and three replications. Mean comparison Tukey-Kramer (p≤0.05) test was performed for the yield analysis. From emergency to final harvest, destructive sampling was carried out every fifteen days in order to calculate dry matter and leaf area and establish growth models based on the accumulated degree-days (DD). The yield and proportion of seed tubers per plant were determined according to local resolution for seed certification in Colombia. Growth variables fitted better with the Hoerl, Gaussian, and third-degree polynomial models. The leaf area index of the potato cultivars reached the maximum value at 876 DD, with values ranging from 2.91 to 6.11 DD. The highest yield per plant was obtained by the Ica Única cultivar (2.73 kg plant-1). However, this cultivar showed the lowest percentage of seed tubers, with 50.59% compared to the others, which ranged between 80.82 and 87.40%. Differential potato growth responses through models based on the DD would explain the differences in final yield and seeds tuber production.

The impact of haulm killing on yield and quality of potato (Solanum tuberosum L.)

Disease-free and superior quality seed tubers could be obtained by haulm (vine) killing, which also reduces weight loss during storage. Higher resistance during storage ensures that seed tubers will be at the desired physiological age at the time of planting. The use of healthy seed tubers of appropriate physiological age will have positive impact on yield and quality. This study aimed to investigate the effects of haulm killing on seed potato yield and yield components (total tuber yield, average tuber yield/plant, number of tubers and average tuber weight) under semi-arid climate of Artova district in Tokat province, Turkey. The field studies were carried out during potato growing seasons of 2017 and 2018. The experiment consisted of two factors, i.e., potato cultivars and haulm killing. Five different potato cultivars, i.e., ‘Agria’, ‘Marabel’, ‘Hermes’, ‘Marfona’ and Madeleine were included in the study. The haulm killing treatments were ‘haulm killing’ and ‘no haulm killing’. Haulm killing positively affected the number of tubers per plant and average tuber weight, which are directly related to the tuber yield. Tuber seed yield in the first and second year with haulm killing treatment was 40.78 and 44.05 tons/ha, respectively. The yield without haulm killing in the first and second years was 37.78 and 38.76 tons/ha, respectively. The dry matter ratio of tubers with haulm killing was 21.89% in 2017 and 22.35% during 2018. The dry matter ratio of tubers without haulm killing was 20.57% in 2016 and 21.03% during 2017. The results revealed haulm killing had positive impact on yield, yield-related parameters and dry matter content of seed tubers. Therefore, haulm killing is recommended for higher yield and better quality of seed tubers.

Varietal effects on Productivity of Potato (Solanum tuberosum L.) in Kuru, Northern Guinea Savanna, Nigeria

A study on varietal effects on the productivity of potato (Solanum tuberosum L.) was conducted during the 2017 and 2018 cropping seasons at the Research Farm of the National Root Crops Research Institute (NRCRI) Kuru, Jos in Plateau State, Nigeria. The study was aimed at assessing the effect of variety on productivity of potato. The treatments consisted of two varieties of potato (improved variety: Daimat, local variety). The experiment consisted of 4 that were laid out in a 2×2 split plot arrangement in a randomized complete block design (RCBD) and replicated three times. Crop data collected were percent germination, plant height, leaf area, number of leaves, number of branches, number of stems, stem girth, number of tubers per plant, number of seed tubers per plant, number of ware tubers per plant, weight of seed tubers per plant, weight of ware tubers per plant and total yield of potato (tons/ha). Although there was no significant effect of variety on the growth parameters of potato but the improved variety performed better than the local variety. The improved variety is here by recommended for adoption in the study area.

Preliminary Investigation of Whole Versus Sliced (Cut) Potato (Solanum tuberosum L.) Tubers Performance in Pankshin, North Central, Nigeria

Potato is a highly perishable crop and storage facilities for the crop are also limited. Consequently, to keep planting materials (seed) from the end of one cropping season to the beginning of another pose a great challenge to growers. This study was conducted during the 2019 cropping season in Pankshin, Plateau state, Northern Guinea savanna zone, Nigeria to compare the performance of whole seed tubers (T1) and slice seed tubers (T2) of potato. The treatments were laid out in a randomized complete block design (RCBD), each replicated thrice. Individual plots have a dimension of 3 m x 5 m with distance of 1 m between blocks and 0.5m between plots. Parameters evaluated were rate of plant germination from cultivated tubers, plant height and fresh yield. The data were analysed using T – test. Results showed that there was no significant difference between whole seed potato and sliced tuber seed for all the parameters tested. This study suggests that in areas where seed tubers are scarce, growers should cut there potato seed tubers to enable them have more seeds for planting. Storage facilities should be provided to farmers by government and spirited individuals or groups in order to reduce the high costs of seeds for planting.

Agronomic Performance of Temporary Immersion Bioreactor – Derived Potato Microtubers in a Peruvian Low Input Cropping Agriculture System

Potato cultivation is limited by a lack of access to quality propagation material. The application of micropropagation techniques combined with the diagnosis and sanitation of the main pathogens of the crop, has contributed to increased production efficiencies. In this regard, the use of temporary immersion bioreactors (TIBs) has improved the quality of microtubers micropropagated along with savings in costs of production. With the final goal of applying these technologies for commercial production, the current study investigated the agronomic performance of Peruvian Canchan potato microtubers derived from TIBs (basic agamic seed 1 and 2) under low-input agro-technology in the coastal zone of Peru. The results indicated that following 75 d of growth, plants derived from microtubers produced in TIBs displayed slower vegetative growth than those from conventional tubers. However, at harvest, these differences were no longer apparent. Although plants raised from conventional tubers produced the highest fresh mass of tubers, significantly more propagules were produced by plants regenerated from basic agamic seed 1 and 2 derived from micropropagation in liquid media. These results demonstrate that much more planting material (seed tubers) can be obtained from microtubers in the field (basic agamic seed 1) than from the conventional commercial seed tubers.

Selection of potato clones derived from seed tubers for nutritional efficiency to phosphorus

To develop agricultural systems that produce more food with limited availability of phosphorus (P) it is necessary to explore the genetic variability of plants and select potato clones that are more efficient at P use. The objective of this study was to evaluate the performance of four potato clones for P nutritional efficiency in closed off-soil growing system using native soil as substrate. Therefore, seed tubers from the four potato clones (Asterix, Atlantic, SMIC 148-A and SMINIA 793101-3) were planted in plastic pots with native soil as a substrate, where the treatments consisted of two levels of P (0.025 and 0.11g kg-1 KH2PO4). 52 days after planting, the concentration of P in the shoot, the shoot and the total dry mass, the rooting efficiency, P absorption, P translocation and use of P were evaluated. SMIC 148 -A is the clone that most concentrates P in the shoot and that produces more total dry mass under low P, while SMINIA 793101-3 is the most efficient clone in the absorption and translocation of P under low nutrient level, however, the Asterix and Atlantic clones showed greater efficiency in the use of P

PENINGKATAN PERTUMBUHAN DAN HASIL BAWANG MERAH (Allium ascalonicum, L) DENGAN APLIKASI PERBEDAAN KONSENTRASI BIO SLURRY DAN PEMOTONGAN UMBI BIBIT

ABSTRACT This study aims to determine the effect of bio slurry and cutting of seed tubers on the growth and yield of shallot plants in the Dukuh Kepoh Food and Horticultural Garden, Tohudan Village, Colomadu District, Karanganyar Regency with a height of ± 105 m above sea level, from April until June 2020. This study used a factorial method with a complete randomized block design (RAKL), consisting of two treatment factors, while the two treatment factors with 12 treatment combinations, each treatment was repeated (3) times. The first treatment, the concentration of bio slurry (S) which consists of 4 levels, namely (S1: Bio slurry 0 ml / l, S2: Bio slurry 50 ml / l, S3: Bio slurry 100 ml / l, S4: Bio slurry 150 ml / l). The second treatment was cutting the seed tubers (P), which consisted of three levels (P1: Cutting 1/4 part of seed tubers, P2: Cutting 1/3 parts of seed tubers, P3: Cutting 1/2 parts of seed tubers). The results showed that the treatment with bio slurry (S) had no significant effect on all observed parameters. Treatment by cutting seed tubers (P) had a very significant effect on plant height, weight of fresh tubers per plant, weight of fresh tubers per plot and had a significant effect on the number of fresh tubers per plant, but had no significant effect on the number of tubers per plot and weight of fresh stems. The combination between the treatment of bio slurry and cutting of seed tubers (SxP) did not significantly affect all observed parameters, The highest yield of fresh tubers per plot was obtained in treatment (S2P2) with a yield of 800.00 g, while the lowest tuber weight per plot was obtained in treatment ( S1P3) with a yield of 433.33 g. Keywords: shallot, bio-slurry, seed tuber cutting

Propagation by Stem Cuttings of Tropaeolum pentaphyllum Lam. (Crem): An Alternative for Production of Seed Tubers

The herbaceous vine Tropaeolum pentaphyllum Lam. (Tropaeolaceae), popularly known as crem, has great potential for use, especially its tubers. However, there is still a lack of studies regarding this species. The objective of this study was to test the viability of propagation by stem cuttings for the production of T. pentaphyllum seed tubers. Two experiments were carried out in a greenhouse under controlled conditions. In both experiments, experimental design was completely randomized. In the first one, five treatments were evaluated (stem cuttings with 10, 15, 20, 25, and 30 cm) with three replicates, each one with 10 stem cuttings. In the second experiment, three treatments were evaluated (stem cuttings positions: apical, middle and basal), with four replications, each one with 10 stem cuttings. Data were submitted to analysis of variance (ANOVA) and the means were compared by Tukey’s test (p < 0.05). Stem cuttings with 15 cm length had the highest rate of tuber formation (20.0%) and produced tubers with highest mass (3.2 g). Cuttings from the middle portion of the stem had the highest rooting (52.5%) and tuber formation (45.0%) rates. Thus, cuttings with 15 cm length from the middle portion of the stem are indicated for propagation by cuttings of T. pentaphyllum. Considering the potential for the use of this species in the future, the results found in this study are very important, since the propagation by cuttings would enable the production of a large amount of seed tubers in a short period of time.

Biocontrollers in the management of yam dry rot nematodes

ABSTRACT: One of the main diseases affecting yam crops (Dioscorea spp.) in Brazil is the dry rot caused by Scutellonema bradys, Pratylenchus brachyurus and P. coffeae nematodes. The use of biological control agents is an auspicious procedure which has been tested in order to reduce losses by pathogens. The objective of this work was to evaluate the nematicidal activity in vitro and in vivo of commercial biological products on yam dry rot nematodes. Products based on Trichoderma harzianum (2.0 x 109 conidia mL-1) at dosages of 1.5 and 2.0 L 200 L-1 of water; Bacillus subtilis 20% - 1.0 x 1011 cfu g-1 + B. licheniformis 20% - 1.0 x 1011 cfu g-1 at 100 and 150 g 100 L-1; B. subtilis 200 g kg-1 + B. licheniformis 200 g kg-1 at 130 and 200 g 100 L-1; combination of rhizobacteria including Bacillus spp. and organic carbon at 5L and 7L 100 L-1; and the control (distilled water), were tested in in vitro assays on S. bradys or Pratylenchus sp. In experiments performed under greenhouse conditions, healthy seed tubers were planted in sterilized soil and thirty days later the soil was infested with a suspension of 1,000 specimens of a mixed population of S. bradys and P. coffeae. Then, after 30 days products based on B. subtilis 20% + B. licheniformis 20% - 150 g 100 L-1; T. harzianum 2 L 200 L-1 and rhizobacteria + organic carbon 7 L 100 L-1, at 100 mL per pot, were applied to the soil. Three months after planting, the percentage of sprouting of the seed tubers was evaluated and in the fifth month, the nematode population densities were determined. The sprouting of seed tubers was of 100% in all treatments. Bacillus subtilis 20% + B. licheniformis 20% and T. harzianum caused 89% and 61% mortality in S. bradys respectively, at the highest concentrations. In specimens of Pratylenchus sp., rhizobacteria + organic carbon exhibited 51% and 45% mortality at higher and lower concentrations, respectively. Under greenhouse conditions, B. subtilis 20% + B. licheniformis 20% and rhizobacteria + organic carbon were more effective in reducing nematode population densities, compared to the control. KEYWORDS: Dioscorea spp.; Scutellonema bradys; Pratylenchus sp.