Volumen 29 (2021): Edición 1 (June 2021)

The studies were performed for four consecutive years (2016–2019) at the Fruit Growing Research Station (North-East part of Romania), using eleven sweet cherry genotypes as research material. Five of them are new cherry cultivars – ‘Cătălina’, ‘Andreiaş’, ‘Maria’, ‘George’, and ‘Margonia’ – obtained by means of controlled hybridization or open pollination, and six of them are their progenitors (‘Van’, ‘Boambe de Cotnari’, ‘Stella’, ‘Fromm’, ‘Ciliegia di Ottobre’, and the ‘HC 27/4’ hybrid). The experiment compared the traits of new cultivars with those of their progenitors. The following traits were evaluated: tree vigor, frost damage, the phenological stages, and the physical and chemical traits of the fruit. The highest values concerning the fruit's weight have been recorded for ‘Andreiaş’ (10.0 g) and ‘Maria’ (7.6 g), the content of soluble substance was between 16.6 and 19.5°Brix, the titratable acidity was between 0.413 and 0.675 mg malic acid·100 mL⁻¹ juice, and the total content of polyphenols was recorded with values between 268.00 and 488.75 mg GAE·100 mL⁻¹ of fresh juice. The new cultivars have mostly superior traits, especially frost damages, productivity, fruit quality, and fruit's cracking percentage compared with their parental genotypes.

This study aimed to estimate the morphological and physiological effects of chitosan foliar spray and/or three irrigation levels of 100%, 60%, and 40% of field capacity on grapevines grown in plastic containers to simulate water shortage conditions. The results showed that water irrigation deficit significantly reduced leaf area, trunk cross-sectional area, plant dry weight, root dry weight, relative chlorophyll content, leaf total carbohydrates, catalase activity, leaf midday water potential (ψ), relative water content (RWC), and crop evapotranspiration (ET_c), but increased the proline content. Under well-watered condition, foliar-applied chitosan, in particular, 5 and 10 g·dm⁻³ increased plant growth and biomass production compared with untreated plants. Also, chitosan sprays during deficit irrigation conditions significantly improved plant tolerance to water deficit by enhancing the morphological and physiological parameters of grapevines. The results of this work suggest the opportunity to grow grapevines under deficit irrigation conditions using chitosan foliar spray. Increased plant biomass and root weight, and the positive impacts of chitosan as antitranspirant on increased ψ, RWC, and decreased ET_c play the main role in drought stress avoidance mechanisms in grapevines raised under moderate deficit irrigation conditions.

The purpose of this experiment was a selection of scab resistant apple cultivars suitable for juice production. Special attention was paid to cloudy juices. During three successive seasons, apple cultivars were processed into juices using laboratory method of juice extraction. Considering the possibility of both clear and cloudy juice production, apples were pressed with and without mash enzymation. The parameters investigated were: pressing yield, titratable acidity, soluble solids, juice density, and juices’ sensory characteristics. Average values indicate that all the cultivars fulfilled the requirements of the Code of Practice of the European Fruit Juice Association concerning investigated chemical components, however, in single years, there were some deviations that should be taken into consideration offering single cultivar juices. Considering a low yield of juice without mash enzymation (below 70%), cultivars ‘Renora’ and ‘Retina’ are not recommended for cloudy juice production. Sensory quality of juices, irrespectively if cloudy or clear, depended mostly on taste acceptability and in fact on soluble solids to acidity ratio. Juices with the ratio above 17 were usually scored higher concerning the taste than those with lower values. An example of exception was ‘Free Redstar’ which is highly astringent. Considering the efficiency of pressing and soluble solids content several investigated cultivars were highly suitable for concentrated apple juice production. Especially valuable may be considered ‘Regine’, ‘Rebella’, ‘Sawa’, and ‘Topaz’ and can be recommended for planting in industrial orchards, which became of special interest in recent years.

In recent years, the use of bio-fertilizers enriched with specially selected microorganisms has been used more and more often. The beneficial effects of bio-fertilizers enriched with consortia of microorganisms on strawberry plants have been reported previously. The purpose of the research was to determine the effect of bio-fertilizers containing selected fungal and bacterial strains on the microorganisms living in the rhizosphere of strawberry plants. In the experiments described in this paper, synthetic mineral fertilizers were enriched with selected microorganisms. The fertilizer urea was enriched with the fungi Aspergillus niger and Purpureocillium lilacinum, while the fertilizers Polifoska 6 and Super Fos Dar 40 with strains of the bacteria Bacillus sp., Bacillus amyloliquefaciens, and Paenibacillus polymyxa. Bacteria and fungi belonging to these species can exert a positive effect on the growth of many plants. The results obtained in this study showed that the application of fertilizers enriched with microorganisms had different effects on the analyzed populations of soil microorganisms in the rhizosphere of strawberry plants. There were evidences of both, an adverse effect of the applied fertilizer and/or microorganisms, but more often, the beneficial effect was found on the abundance of the microorganisms in the rhizosphere of the strawberry. The most effective for the population of Pseudomonas bacteria was application of urea and fungi and Polifoska and bacteria. The highest number of phosphorus utilizing bacteria B was scored in the treatments containing NPK, NPK + fungi and urea 60% + fungi. The application of NPK + fungi and urea 100% + fungi as well as Super Fos Dar with bacteria was most beneficial for population of actinomycetes.

Six genotypes of head cabbage (‘Flexima’, ‘Mutsuma’, ‘Septima’, ‘Zeus’, DC6, ‘Ancoma’) have been studied to find an effective method of obtaining polyploids using trifluralin. The effect of various trifluralin concentrations (0.5, 1.0, 1.5, and 2.0 mg·L⁻¹) and treatment conditions (24 °C/24 h, 24 °C/48 h, 30 °C/24 h, and 30 °C/48 h) on organogenesis of organogenic callus, hypocotyl, and seeds was tested. Ploidy level was detected using a flow cytometer. As a result, low survival of hypocotyls and calli was obtained. The shoots induced from calli and hypocotyls failed to develop quality plantlets and most calli and hypocotyls remained recalcitrant for further differentiation. Treated seeds seemed to be promising objects basing on a considerable percentage of plant regeneration. With the increased concentration of trifluralin and increasing press of treatment conditions, the seed germination rate was significantly reduced. Shoot induction from germinated seeds varied among genotypes and treatments. The root induction was independent of treatments but also reduced considerably compared to the control. Under tested conditions, none of the polyploids resulted. Further studies are required to be successful in protocol development.

Ginger (Zingiber officinale) is one of the major high-value cash crops in Nepal. Low yield, conventional farming, and limited access to production resources such as improved cultivars, production technologies, and extension services are the existing problems of Nepali ginger farmers. In this study, we conducted community based-participatory research in Ilam district, Nepal, in 2015–2017. This research aimed to explore the appropriate ginger farming technology considering yield, income, and environment. We compared the effect of four different ginger production technologies on ginger yield and net farm income that include: i) traditional practice with mother rhizome harvest, ii) traditional practice without mother rhizome harvest, iii) good agricultural practice (GAP) with mother rhizome harvest, and iv) GAP without mother rhizome harvest. The experiment was conducted in a randomized complete block design with five replications. The yield of ginger under GAP and without mother rhizome harvest was observed 17.9 t·ha⁻¹, which was 39.8% higher than the farmers’ existing practices and 45.5% higher than the national average. The cost of production was almost the same in all treatments; however, the GAP with mother rhizome-harvested treatment gave the highest benefit–cost ratio (1.5) along with the maximum net farm income ($2072.6·ha⁻¹·year⁻¹). Thus, we suggest ginger producers adopting GAP rules to obtain a higher yield and harvesting mother rhizomes earlier for obtaining maximum profit. The GAP rules will additionally protect the environment. This study also suggests policymakers and related stakeholders promoting GAP as a sustainable production technology in agriculture-based countries like Nepal.

Nematodes are widespread organisms and pose a serious problem in vegetable production. The use of synthetic nematicides is a common method of bringing down the nematode population to increase crop yield. This has, however, brought about serious pollution to the environment. Leaves and twigs of Terminalia glaucescens were extracted in organic solvents and then chromatographed on a silica gel column. Chromatographic fractions obtained from the methanol and acetone crude extracts were characterized with UV-visible, FTIR, and GCMS and tested for their potential nematode suppressing activity in field micro plots. Spectroscopic analysis of the fractions revealed the presence of compounds such as aldehydes, acids, ketones, phenols, terpenes, hydrocarbons, and fatty acid esters. The extract fractions of T. glaucescens were applied at 100, 75, and 50 mg·ml⁻¹ at 100 ml each and carbofuran at 0.5, 1.0, and 1.5 kg a.i.·ha⁻¹. The vegetative growth of pepper plants as well as the number and weight of fruits increased significantly in plants treated with the above-mentioned extract fractions. The protective role of fractions compared favorably with the synthetic nematicide (carbofuran). The most effective in reduction of the nematode population, and plant growth and yield was the highest concentration of 100 mg·ml⁻¹. Thus, organic solvent extract fractions from T. glaucescens can serve as a biopesticide and an alternative to the environmentally hazardous synthetic nematicide.

Bulb onion is an ancient vegetable crop that has been cultivated for at least 5,000 years. In Japan, this cultivation has only 150 years of history, but nowadays, it ranks fourth in total production, fourth in cropping acreage, and second in consumption among vegetables grown domestically. Until the 1970s, open-pollinated onion cultivars were predominantly cultivated throughout the country; they were selected mainly from old US cultivars. Over the past three decades, these open-pollinated cultivars have been replaced with F1 hybrid cultivars that offer higher yield, better disease resistance, uniformity at maturity, and high bulb quality. In this review, an attempt is made to characterize the commercial production and consumption of Japanese bulb onion as well as agronomic characteristics of representative cultivars.

Consumption of ware potatoes in the tropics may be enhanced by storage under conditions that inhibit sprouting, most important of which is the temperature. The effects of storage temperatures (10 °C and 23 °C) and two alternatives to the chlorpropham (CIPC): 1,4-dimethylnaphthalene (DMN) and peppermint oil (PMO), a biorational inhibitor, were evaluated for tuber sprout suppression at postharvest. Tubers of three cultivars – ‘Asante’, ‘Kenya Mpya’, and ‘Shangi’ – with different dormancy lengths were assessed. Storage temperatures and suppressant effects on tuber sprouting, sprout length and sprout numbers per tuber were investigated in replicated storage experiments. Significant differences in sprout inhibition were observed between the two temperatures with suppressive effects higher at 10 °C than in 23 °C. CIPC had the greatest suppressive effect on tuber sprout inhibition at both temperatures. After 24 weeks of storage, the suppressive effects of CIPC at 10 °C was 100% on the three cultivars, whereas all the nontreated tubers sprouted after six (‘Shangi’), twelve (‘Asante’), fourteen (‘Kenya Mpya’) weeks of storage. At 23 °C, the effectiveness of CIPC followed the dormancy period of the cultivars, with ‘Shangi’ recording significantly more sprouted tubers followed by ‘Asante’ and ‘Kenya Mpya’. The inhibition of sprouting by DMN and PMO varied with storage temperatures and cultivars, but were significantly greater than the nontreated tubers. At 10 °C, the effectiveness of DMN treatment was equal to that of CIPC for ‘Kenya Mpya’ resulting in 100% inhibition. In the PMO treatments, complete inhibition of sprouting was observed for 18 weeks on cultivars ‘Asante’, ‘Kenya Mpya’ and 14 weeks on ‘Shangi’. At 23 °C, PMO suppressed sprouts for 14 weeks on ‘Asante’ and ‘Kenya Mpya’ and on ‘Shangi’ for 8 weeks. Storage temperature effects on sprout length and numbers varied with inhibitor type and cultivar. These findings showed that in potato tuber storage, inhibitors can replace low temperature but to an extent depending on the cultivar dormancy character and storage length, thus enabling greater consumption of potatoes in tropical regions.

The tuberization phenomenon in potatoes (Solanum tuberosum L.) is a highly synchronized morphophysiological process occurring on the underground stolons under the influence of various intrinsic and extrinsic factors. This involves the participation of the phytochrome sensory system, transport of sucrose from source to stolon, and several regulatory pathways including tuber-inducing hormone biosynthetic lipoxygenase (StLOX1) gene and major calcium-mediated signaling pathway genes (StCDPK and StCaM1). This study was aimed to explore the impacts of distinctive qualities of the light-emitting diode (LED) light with a specific wavelength on in vitro tuberization of potato. Single nodal segments of potato ‘Kufri Jyoti’ were incubated in vitro on the growth medium at a temperature of 22 ± 2 °C and exposed to various combinations of red (R) and blue (B) LED light. The results showed that the combination of 30% red + 70% blue LED light (R₃₀B₇₀) significantly shortened the tuber induction period, increased the number of tubers, and their yield compared with these parameters in the tissues exposed to the white light (W₁₀₀). The induction of the in vitro tuberization correlated with the enhanced expression of the major tuberizing pathway genes, including the lipoxygenase (StLOX1), calmodulin (CaM1), and calcium-dependent protein kinase (StCDPK). The current study indicated that the combination of red and blue LED lights at R₃₀B₇₀ is the best spectrum for effective in vitro tuberization of potatoes.