Potato Protection Research Articles

Improvement of potato cultivation technology elements in production conditions

The results of improving potato cultivation technology by increasing the efficiency of plant protection system in the conditions of production experience are presented. The study was conducted in 2021–2023 on the lands of the OOO "Druzhba-2" (Bryansk region, Zhiryatinsky district). Two potato varieties of the first reproduction, Red Scarlett (Netherlands) and Gala (Germany), were the object of the study. The experiment scheme included two variants: 1) traditional potato protection system adopted in the farm (control); 2) improved protection system. Both protection systems are aimed at the prevention of pests (Colorado potato beetle, snap beetle larvae), weeds (cleavers, black nightshade, purple deadnettle, lamb's quarters, wild camomile, annual bluegrass, wind bent grass) and diseases (early blight, late blight, silver scurf, rhizoctoniose, various types of rots, pythium). Soils of the sites are sod-podzolic. The forecrop is winter rapeseed. The total area of the production experiment was 120 ha (60 ha under each variety). Potatoes were grown under intensive technology with conventional tillage system on a 75 × 28 cm pattern. Planting rate is 50 thousand tubers per 1 ha. The technology is designed to obtain tuber yields of 40–60 t/ha. Experimentally it has been established that the application of the improved technology with the use of a new plant protection system for the farm contributes to an increase in plant stand density and their safety at the time of harvesting by 2.5–3.0%, increase in the number of tubers from one plant by 7.5–10.0%, average weight of one tuber – by 7–11%, weight of tubers from one plant – by 14.5–23.0%, yield – by 17–26%, marketability – by 12.5–14.5%, marketable yield – by 32–45%, conditional net income – by 16.2–24.5%.

Chitosan as an Antimicrobial, Anti-Insect, and Growth-Promoting Agent for Potato (Solanum tuberosum L.) Plants.

A growing trend in plant protection is replacing chemical preparations with environmentally friendly biological compositions. Chitosan, due to its biocompatibility, biodegradability, and bioactivity, is an effective agent against plant diseases. The purpose of the study was to evaluate chitosan as a potential biopesticide for potato plants. Three variants of chitosan were tested: high (310-375 kDa, >75% deacetylated), medium (190-310 kDa, 75-85% deacetylated), and low (50-190 kDa, 75-85% deacetylated) molecular weight. The chitosan variants were dissolved in lactic and succinic acids and tested for antibacterial and antifungal properties against eight strains of mould and two strains of bacteria responsible for potato diseases. The possible cytotoxicity of chitosan was evaluated against different cell lines: insect Sf-9, human keratinocyte HaCaT, and human colon carcinoma Caco-2. The bioprotective activities of the chitosan were also evaluated in situ on potato tubers. Chitosan inhibited the growth of almost all the selected phytopathogens. The most active was medium molecular chitosan in lactic acid. This formula was characterized by low toxicity towards human cells and high toxicity towards Sf-9 cells. It was also found to have positive effects on the growth of stems and roots, gas exchange, and chlorophyll index in potato plants. Selected chitosan formulation was proposed as a functional biopesticide for potato protection against phytopathogens.

Prospects for the use of various species and strains of symbiotic bacteria (<i>Xenorhabdus sp.</i>) in the biological protection of potatoes from diseases in the European North of Russia

Prospects for the use of various species and strains of symbiotic bacteria (<i>Xenorhabdus sp.</i>) in the biological protection of potatoes from diseases in the European North of Russia

Protein complexes from edible mushrooms as a sustainable potato protection against coleopteran pests.

Protein complexes from edible oyster mushrooms (Pleurotus sp.) composed of pleurotolysin A2 (PlyA2) and pleurotolysin B (PlyB) exert toxicity in feeding tests against Colorado potato beetle (CPB) larvae, acting through the interaction with insect-specific membrane sphingolipid. Here we present a new strategy for crop protection, based on in planta production of PlyA2/PlyB protein complexes, and we exemplify this strategy in construction of transgenic potato plants of cv Désirée. The transgenics in which PlyA2 was directed to the vacuole and PlyB to the endoplasmic reticulum are effectively protected from infestation by CPB larvae without impacting plant performance. These transgenic plants showed a pronounced effect on larval feeding rate, the larvae feeding on transgenic plants being on average five to six folds lighter than larvae feeding on controls. Further, only a fraction (11%-37%) of the larvae that fed on transgenic potato plants completed their life cycle and developed into adult beetles. Moreover, gene expression analysis of CPB larvae exposed to PlyA2/PlyB complexes revealed the response indicative of a general stress status of larvae and no evidence of possibility of developing resistance due to the functional inactivation of PlyA2/PlyB sphingolipid receptors.

Analysis of modern means of mechanization and technologies for potato protection

Analysis of modern means of mechanization and technologies for potato protection

Potato mycocenoses in the fields of the Novozybkovsky district of the Bryansk region with different levels of radioactive contamination and economic use

The peculiarities of the formation of mycocenoses in potato plantings growing in fields with different levels of radioactive contamination and economic use were studied. The experiments were carried out in 1991–1998 in the fields of the Novozybkov agricultural experimental station in the Bryansk region (pollution density l37Cs = 1.2 ± 0.2 MBq/m2) and the lands of the Komsomolets Agricultural Complex withdrawn from economic use (l37Cs 1.8 MBq/m2). Differences were noted in the incidence of potato plants with diseases in the field small–scale experiment (1992), depending on the fertilizers applied (background – peat manure compost (PMC) or additionally NPK + Mg), their balance (different doses of nutrients), as well as agricultural cultivation techniques. In the variants with the introduction of NPK + Mg and the use of the herbicide Promethrin SC or sodium humate, a significant decrease in the incidence of tubers with scab by 25–60% was revealed. Weather conditions influenced the development of pathogens. In 1994 rhizoctoniosis developed most actively in potato plantings and common scab on tubers (hydrothermal coefficient (GTС)may–august = 2.35, which is significantly higher than the average long–term norm for 1991–1998–1.35). In the experiment on potatoes of the Temp variety of Belarusian selection (1994), the possibility of restraining the development of pathogens due to pre-planting treatment of tubers with fungicides was shown: when using contact the decrease in the total level of development of phytopathogens and saprophytes was 1.4 times less than in the control, and when using the systemic fungicide Tect 450 CS – 2.3 times. The use of biologically active substances for the pre-planting treatment of potato tubers (Agate-25K, TPS, Crezacin, KRP and Epin-Extra R) led to a decrease in plant infestation with late blight by 2.2–4.5 times, infestation of tubers with scab by 17–32%, rhizoctoniosis by 10– 36% and later than in the control, the development of diseases, which determined the tactics of fungicidal protection of potatoes during the growing season. There was an increase in potato yield by 11–29% and a significant decrease in the accumulation of137Cs in tubers by 7–15%.

Chemical protection of potatoes from fungal diseases, taking into account the stability of the variety

In the conditions of the Moscow region in 2019-2022 the effectiveness of funicides of new chemical classes in the potato protection system against rhizoctoniosis, late blight and alternariosis was studied, taking into account the different resistance of varieties (Gulliver, Grant, Sante) to diseases. Potato tubers were treated with the preparation Idikum, SC before planting, its biological effectiveness in reducing the incidence of rhizoctoniosis in the full germination phase was 76.7-95.7 %. It was found that the effectiveness of the preparation depended on the degree of disease development, the stability of the variety and the phase of crop development. In addition, when etching the planting material with Idikum, SC, there was no population of rhizoctosis sclerotia and the spread of dry rot on tubers of the new yield significantly reduced (1.6-5.0 times) compared to the control. The proposed scheme of potato protection in conditions of epiphytotic development of late blight and early blight based on combined chemicals Metaxil, SP, Inside, SC with contact fungicides Raek, CE, Talent, SC, Tirada, SC showed high efficiency in reducing harmfulness of the diseases, which allowed to extend the growing season of plants, to ensure a higher yield of potatoes, its marketability and quality. The use of preparations provided an increase in yield by 36.3-47.5 %, depending on the prevailing weather conditions of the growing season and on the variety in relation to the control (without treatment). It has been established that the biological effectiveness of the protection scheme in reducing the degree of late blight and early blight increased from susceptible to relatively stable varieties and, accordingly, this trend continued with an increase in yield. Higher increases were obtained on unstable varieties Gulliver and Sante (10.6-13.5 t /ha, or 45.7-56.0 %), lower – on the relatively stable variety Grand (7.8 t/ha, or 36.0 %). The contribution of the application of the protection scheme to the overall variation of gross and marketable potato yields was 76.5-81.0 %, gene-type - 7.9-12.5 %, the interaction of these factors – 3.7-4.7 %.

Induced Expression of CYP51a and HK1 Genes Associated with Penconazole and Fludioxonil Resistance in the Potato Pathogen Fusarium oxysporum.

Preventing antifungal resistance development and identifying pathogens with high, medium, and low risk of resistance development to a particular fungicide or fungicide class is crucial in the fight against phytopathogens. We characterized the sensitivity of potato wilt-associated Fusarium oxysporum isolates to fludioxonil and penconazole and assessed the effect of these fungicides on the expression of fungal sterol-14-α-demethylase (CYP51a) and histidine kinase (HK1) genes. Penconazole stunted the growth of F. oxysporum strains at all concentrations used. While all isolates were susceptible to this fungicide, concentrations of up to 1.0 μg/mL were insufficient to cause a 50% inhibition. At low concentrations (0.63 and 1.25 μg/mL), fludioxonil stimulated growth in F. oxysporum. With an increase in the concentration of fludioxonil, only one strain (F. oxysporum S95) exhibited moderate sensitivity to the fungicide. Interaction of F. oxysporum with penconazole and fludioxonil leads to respective elevated expressions of the CYP51a and HK1 genes, which upsurge with increasing concentration of the fungicides. The data obtained indicate that fludioxonil may no longer be suitable for potato protection and its continuous use could only lead to an increased resistance with time.

Strategies for Engineering Virus Resistance in Potato.

Potato (Solanum tuberosum L.) is an important vegetable crop that plays a pivotal role in the world, especially given its potential to feed the world population and to act as the major staple food in many developing countries. Every year, significant crop loss is caused by viral diseases due to a lack of effective agrochemical treatments, since only transmission by insect vectors can be combated with the use of insecticides, and this has been an important factor hindering potato production. With the rapid development of molecular biology and plant genetic engineering technology, transgenic approaches and non-transgenic techniques (RNA interference and CRISPR-cas9) have been effectively employed to improve potato protection against devastating viruses. Moreover, the availability of viral sequences, potato genome sequences, and host immune mechanisms has remarkably facilitated potato genetic engineering. In this study, we summarize the progress of antiviral strategies applied in potato through engineering either virus-derived or plant-derived genes. These recent molecular insights into engineering approaches provide the necessary framework to develop viral resistance in potato in order to provide durable and broad-spectrum protection against important viral diseases of solanaceous crops.

Efficiency of the application of biological BT preparations in the protection of potatoes from harmful organisms in the western Forest Steppe of Ukraine

Goal. To study the possibility of using biological preparations of ITI Biotechnca sowing of nightshade crops and to determine their effectiveness against harmful organisms.
 Methods. Laboratory (identification of pathogens) and field (analysis of vegetation indicators) research methods. The study of the effectiveness of biological preparations was carried out on the basis of the Ukrainian Research Plant Quarantine Station of the Institute of Plant Protection against a natural infectious background. During the growing season, three foliar treatments with drugs were carried out.
 Results. The research results showed that the use of ITI Biotechnik insecticides provided a better effect on larvae of the Colorado potato beetle of 1—2 ages. The effectiveness of drugs against the Colorado beetle for the drug Bitoxybacillin BT was 71.5%, for Actofit BT — 49.5%, Boverin BT — 80.4%, Metarizin BT — 65.2%. The use of insecticides of biological origin contributed to an increase in vegetation indicators, as well as an increase in the yield of potatoes compared to the control. The use of drugs of a fungicidal and stimulating nature contributed to the growth of yield and higher marketability of potatoes. The highest yield was formed in the Podolyanka variety when treated with BioGibervit BT and was 21.3 t/ha. The best protection against potato diseases was obtained with the use of Bactophyt BT, where the effectiveness against Alternaria was 66.8%, and against late blight — 89.8%. Stimulating drugs provided an immunoprotective effect of 65—70% against phytophthora and 40—47% against Alternaria.
 Conclusions. The use of a number of individual biopreparations produced by ITI Biotechnika during the growing season makes it possible to control pests, reduce the damage to plants by diseases, and increase the yield of potatoes. Biological drugs and growth stimulants that have shown the best effectiveness can be recommended for the formation of a potato protection system based on BT drugs.

Potato protection from fungi spread diseases with biological preparations usage

Goal. To study possibility of biological preparations and their compositions with microelements against fusarium-fomos rot.
 Methods. Laboratory (pathogens identification) and field (analysis, tubers materials treating) techniques of researches. The biological preparations researches efficiency conducted separately and in complex with microelements conducted on the base of Ukrainian science-research plant quarantine station Institute of Plant Protection NAAS on natural infectious background during 2021—2022. The tubers put into the biological preparations suspension: Biospectre BT (1.5 l/t); Glocladyn BT (2 l/t); Trychopsyn (2.5 l/t) and then joined them with microelements complexes — microfertillizer Urozhay TK (2 l/t) before planting. Two rootless feeding conducted by the same preparations during the growing period.
 Results. The researches results showed that the potato treating of variety Sante by biopreparations and in combination with microelements before planting and during growing favored the plant increase on 4.4—13.7%, stems quantity increase in bush on 5.3—13.2, yield increase on 9.5—15.5% and ill tubers quantity decrease in 2.5—3.7 times in comparison with control variant. The biological preparations efficiency in combination with complex of microelements consisted of for variety Sante 72.0—73.2% to the most spread disease fusarium-phomos rot. The analogeous resulys received for variety Virineya. The potatoes biological preparations treating before planting and during growing favored the plants’ growth on 7.8—16.3%. The quantity of ill tubers decreased in 2.0—3.1 times. The composition biological preparations with microelements efficiency against fusarium-phomos rot consisted of 49.5—68.0%.
 Conclusions. The following biological preparations usage Biospectre BT (1.5 l/t); Gliocladyn BT (2 l/t); Trychopsin (2.5 l/t) before tubers planting and during growing separately and in complex with microfertillizer Urozhay TK allowed to decrease tubers defeating in 2.0—3.7 times and to receive additional 9.5—16.3% of potato yield.

Rhizoctonia potato disease in production conditions in the forest-steppe of Western Siberia

The authors carried out a scientific study from 1990 to 2022 on 20 varieties of potatoes to study the pathogenesis of Rhizoctonia in crop production conditions and substantiate the methods of the system of protection against the disease. The fungus R. Solani persists annually in the soil and on seed tubers in the form of mycelium and sclerotia. It was found that more than 60% of the grounds of potato agroecosystems have the content of the causative agent of Rhizoctonia is many times higher than the established ETH (Economic threshold of harmfulness). Furthermore, monitoring of the phytosanitary state of potato seed material showed that, on average, about 60% of the tubers are inhabited by the causative agent of Rhizoctonia, including about 30% of the sclerotial form, which is six times higher than the phytosanitary regulations. Thus, in the region’s conditions, a double mechanism of phytopathogen transmission is provided annually. The causative agent of Rhizoctonia infects potato sprouts, subsequently causing their complete death (on average 12%) and shootouts, reducing the density of productive plants in crop plantings. At subsequent stages of growth and development of potatoes, significant expansion of the disease on the stems was noted (on average 31.4%), and stolons were damaged and died (9.3 and 5.5%, respectively), which disrupted the processes of stolon and tuberization. In the region’s conditions, Rhizoctonia occurs in the form of epiphytotic with a prevalence of 88% or more. Therefore, the potato protection strategy against Rhizoctonia should be based on methods that reduce the initial population density of the R. Solani fungus in the soils of agroecosystems and on seed tubers. Essential elements of potato cultivation technology are cropping rotation with a saturation of no more than 30% (biological efficiency - 43.2–79.5%); phytosanitary precursor, including green manure pairs (biological efficiency - 49.0–75.9%); mandatory etching with chemical preparations (biological efficiency - 54.9–98.8%) or natural origin. Using entomopathogenic fungi Metarhizium robertsii and Baeuveria bassiana can be a promising direction in reducing Rhizoctonia. Dressing seed tubers with conidia of entomopathogenic fungi suppressed the development of the disease in potato plantings by 1.8–3.7%, providing an increase in yield by 12.1–19.2%. The study of the influence of Metarhizium robertsii and Baeuveria bassiana on the pathogenesis of Rhizoctonia will be continued.

ЗАЩИТА КАРТОФЕЛЯ В ПЕРИОД ЕГО ВЕГЕТАЦИИ И ХРАНЕНИЯ

The paper analyzes well-known and new chemical preparations of foreign and domestic production, on the basis of which the justification for the need to develop a new effective domestic preparation for the protec-tion of potatoes during its growing season and storage is given. It is noted that increasing the resistance of potatoes to diseases can be achieved by specialized crop rotations, high-quality varieties, agrotechnical and technological techniques, as well as biological and microbiological preparations, agrochemicals and plant growth regulators. However, the use of only agrotechnical techniques does not provide high protection of potatoes from diseases. Therefore, a new drug "Amophenone" was justified for use, which has a number of advantages over the standard standard tetramethylthiuram disulfide (TMTD). It is shown that "Amophe-non" is highly effective against dry fusarium rot of potatoes, which is confirmed by the experimentally ob-tained results of inhibition of the growth of Fusarium Sambucinum mycelium.

First report of Alternaria alternariacida causing potato leaf blight in the Far East, Russia.

Early blight of potato (Solanum tuberosum) is caused by Alternaria species and occurs annually in major potato producing regions of Russia. Diseased potato leaves displaying early blight symptoms were collected in July 2016 from a commercial field in Primorsky Krai, Russia (43.8242° N, 131.6219° E). The disease incidence was 30 to 40%. The initial symptoms appeared as typical early blight symptoms with a dark brown margin and diffused chlorosis on the leaf blade. Symptomatic leaves from different plants were randomly collected to isolate axenic cultures of the causal agents. Infected leaves were placed in wet chambers (moist filter papers in Petri dishes), and incubated at 25°C, 16 h/8 h dark/light photoperiod for 2-4 d. Single conidia were transferred to potato dextrose agar (PDA, Crous et al. 2009) in Petri dishes and incubated at 25°C for 7 d in the dark. Colonies were white-olivaceous, reverse side - olivaceous. Isolates were transferred onto potato carrot agar (PCA, Crous et al. 2009) and incubated at 22°C under a 16 h/8 h dark/light photoperiod for 7 d to stimulate sporulation. Most isolates (85%) were identified as A. protenta according to the morphological characteristics and molecular data, although one isolate showed sporulation that was somewhat atypical, having a smaller (especially narrower or more slender) conidia. Conidiophores were long, erect, and 65 to 100 µm × 5 to 6 µm in size. Conidia were solitary, long-ovoid in body with six to eight transverse septa, and 85 to 100 µm× 6 to 10 µm in size. Conidial beaks were filamentous, 110 to 200 µm × 2 to 5 µm in size. Genomic DNA was extracted from cultured isolates using the CTAB-chloroform extraction method (Griffith & Shaw 1998), and five gene regions including the internal transcribed spacer (ITS) region, translation elongation factor 1-alpha (tef1), RNA polymerase second largest subunit (rpb2), Alternaria major allergen (Alt a 1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified with the primer pairs ITS1/ITS4, EF1-728F/EF1-986R, RPB2-5F2/FRPB2-7cR, Alt-for/Alt-rev, and gpd1/gpd2 respectively (Woudenberg et al. 2014). PCR products were Sanger sequenced. All sequences for isolate A16PrPL21 were identical to isolate CBS 105.51; (accession nos.: ITS, KJ718105; tef1, KJ718454; rpb2, KJ718279; Alt a 1, KJ718625; gpd KJ717959) of A. alternariacida Woudenb. & Crous. ITS, tef1, rpb2, Alt a 1 and gpd sequences were deposited in GenBank under the accessions OM348531, MN580518, MN580529, MN562258 and MN544404 respectively. Based on morphological and molecular data, the isolate was identified as Alternaria alternariacida Woudenb. & Crous. A. alternariacida is closely related to A. silybi, which is also found in the Far East (Woudenberg et al. 2014). Phylogenetic distances between these strains are based on differences at the ITS, TEF1 and Alt a 1 gene regions. A pathogenicity test was carried out with isolate A16PrPL21 on nine 5-week-old healthy potato plants (cv. Nevsky) grown in a greenhouse at 23 ± 2 °C. Seed tubers were grown in the greenhouse to obtain the seedlings. Inoculation was performed by spraying a conidial suspension (105 spores/ml) prepared from 10-day-old A. alternariacida culture grown on PCA at 23° C with a 12-h photoperiod. Nine negative control plants were treated with sterile distilled water. The inoculated plants were then maintained in a greenhouse at 25 °C with high humidity and 12-h light period. All test plants were covered with plastic bags for 24 h to maintain high relative humidity and incubated at 24 to 28°C. Leaf spot symptoms, brown lesions with chlorotic halos, similar to those previously observed in naturally infected plants, appeared 5 d post inoculation for all inoculated plants. After 7 d, the spots reached 18 to 25 mm in size. The symptoms were similar to the original symptoms that occurred in the field. Negative control leaves were symptomless. Koch's postulates were fulfilled by reisolating the pathogen from inoculated leaves and identified as A. alternaricida by rpb2 gene sequence and morphological characteristics. To our knowledge, this is the first report of disease caused by A. alternaricida on potato plants. Early blight, caused by large-spored Alternaria, is a widespread disease on potato. A. alternaricida is among a group of species that cause early blight, according to current research. Studies of the Alternaria species' biology and analyses of their distribution are important for improving potato protection from early blight.

New Combined Preparations to Protect Potatoes from the Colorado Potato Beetle

The results of the evaluation of the biological efficacy of the combined insecticide Eforium, CS (thiamethoxam 141 g/l + lambda-cyhalothrin 106 g/l) and the insectofungicide Vibrans Top, CS (thiamethoxam 262.5 g/l + fludioxanil 25 g/l + sedaxan 25 g/l) and ecotoxicological indicators of these drugs are presented. Based on the data obtained, it is concluded that it is advisable to use these drugs in potato protection systems against the Colorado potato beetle in accordance with the established regulations for use, provided that these drugs are available in the State Catalog of Pesticides and Agrochemicals approved for use on the territory of the Russian Federation.

English

As compared to other African countries, Kenya continues to depend on agriculture as source of food and for economic development. Horticulture forms the bulk of agriculture with potato being ranked first in the vegetable category in terms of production and value. It is a lucrative cash and food crop grown in many parts of Kenya. Molo Sub County being one of the regions where the crop is grown enjoys economic value in terms of income generation and food provision. Given the importance of the crop agricultural extension such as plant health clinic training services has a key role in enhancing production through training farmers in innovations on potato protection measures and production improvement. This study thus established the influence of plant health clinic training services on potato production among smallholder farmers in Molo Sub-County, Kenya. Through simple random sampling techniques and purposive sampling, 152 smallholder potato farmers and 10 key informants respectively were selected for the study. Data were collected using structured questionnaires and interviews. The data was analyzed using descriptive statistics and inferential statistics. The type of training access, the relevance of training services, frequency of receiving training, modes of training, and use of training services were found as significant predictors variable influencing potato production at 0.05 significant level (p = 0.000, p = 0.000, p = 0.009, p = 0.000 and p = 0.000, respectively). The study recommends that adequate plant health clinic training services should be provided in potato production. Key Words: Potato production, plant health clinic training services, multiple regression.

Influence of multistrain biological preparations with protective functions on the productivity and quality of potatoes

The article deals with potato protection systems, the use of multi-strain biopreparations with protective functions and chemical pesticides. Preparations were analyzed and selected, as well as a mycological analysis of the soil was carried out to determine the ecological and trophic groups of microscopic fungi, which in turn made it possible to select biological preparations and develop regulations for their use. Techniques aimed at reducing the use of chemical protection agents when growing potatoes in conditions on irrigated light chestnut soils have also been studied, and schemes for applying biological preparations that reduce the pesticide load on agricultural landscapes have been presented. Long-term studies on the use of biological products make it possible, in unstable natural and climatic conditions, not only to reduce the infectious background of pathogenic microflora, but also to increase the productivity of the culture.

Efficient separation of Cinnamomum camphora leaf essential oil and in vitro evaluation of its antifungal activity

Cinnamomum camphora leaf essential oil (CEO) was extracted using enzymatic-ultrasound pretreatment followed by microwave assisted extraction (EUP-MAE) method and simultaneously studied as a mycelial growth inhibitor against five important pathogens which cause potato dry rot. The optimum EUP-MAE conditions with a real CEO yield of 19.23 ± 0.12 mg/g were obtained through Plackett–Burman design and Box–Behnken design as follows: 3 % of enzyme dosage, 2 h of pretreatment time, 5 of pH, 210 W of ultrasound power, 50 °C pretreatment temperature, 16 mL/g of water to solid ratio, 30 min of microwave time and 500 W of microwave power. Compared to the reference methods, EUP-MAE possessed a highest CEO yield than these of ultrasound-microwave assisted extraction (U-MAE) and traditional hydrodistillation (HD). Gas chromatography-mass spectrometry (GC–MS) analysis demonstrated that eucalyptol, camphor, and α -terpineol were the three main constituents of CEO. Results from in vitro antifungal activity assay revealed that the mycelial growths of all the five tested Fusarium solani , Fusarium culmorum , Fusarium trichothecioides , Fusarium sporotrioides , and Fusarium avenaceum were apparently affected by CEO. These findings not only provide a potential paradigm for the separation of plant essential oil, but also guarantee a promising utilization of the CEO for potato protection to control the Fusarium spp.

Metschnikowia pulcherrima as a Biocontrol Agent against Potato (Solanum tuberosum) Pathogens

An increasing trend in protecting plants against phytopathogens is the replacement of chemical pesticides with environmentally acceptable biopreparations. This article focuses on the possible use of yeast Metschnikowia pulcherrima as a biocontrol agent against potato pathogens. The scope included an assessment of the antimicrobial activity of 10 M. pulcherrima isolates against 10 phytopathogens: Fusarium oxysporum, Fusarium sambucinum, Rhizoctonia solani, Alternaria solani, Alternaria, tenuissima, Alternaria alternata, Colletotrichum coccodes, Phoma exigua, Pectobacterium carotovorum, and Streptomyces scabiei, by the agar-well diffusion method. Pulcherrimin formation, enzymatic profiles detected by the API ZYM system, and metabolite formation evaluated by HPLC analysis were conducted for the most active M. pulcherrima isolates. Leucine arylamidase, valine arylamidase, α- and β-glucosidase, and esterases were the most noteworthy in the pattern of activity. In turn, ethanol, glycerol, and organic acids (acetic, succinic, lactic acids) were determined in the largest quantities. The isolate M. pulcherrima TK1 was selected and cultured on supplemented acid whey. An in situ experiment was carried out on the seed potatoes, which showed a 30%–100% reduction in nine phytopathogens; only P. carotovorum was insensitive to yeast treatment. Therefore, M. pulcherrima TK1 was proposed as the potential biological solution for seed potato protection against phytopathogens.

Protection of Potatoes and Mortality of Wireworms (Agriotes obscurus) With Various Application Methods of Broflanilide, a Novel Meta-Diamide Insecticide.

Wireworms are primary pests of potatoes in Canada. Presently, the highly toxic organophosphate phorate (i.e., Thimet 20G) is the only effective insecticide in use in Canada. As such, there is an urgent need for novel alternative treatments that provide competitive tuber blemish protection and wireworm reduction with a safer human and environmental portfolio. Herein we evaluated broflanilide, a novel meta-diamide insecticide for both tuber protection and wireworm mortality. When evaluated in field trials in Agassiz, British Columbia over 6 yr, broflanilide applied as a seed piece treatment (SPT) to mother tubers at 1.5-2.0 g AI/100 kg seed (approx. 50 g AI/ha), or as an in-furrow spray (IFS) at 0.23-0.25 g AI/100 m row (approx. 25 g AI/ha) was as effective at reducing blemishes to daughter tubers by wireworms (Agriotes obscurus) as phorate (Thimet 20G at 3230 g AI/ha), bifenthrin (Capture 2EC IFS at 300 g AI/ha) and clothianidin (Titan ST at 312.5 g AI/ha). In addition, broflanilide SPT and IFS applied at the above rates reduced resident wireworms (in the field at the time of planting) by 95.4-99.0% and neonate wireworms (produced from eggs laid during the growing season) by 98.1-100%. Similar results were obtained when broflanilide IFS (nonsystemic) was paired with clothianidin SPT (systemic) for broad-spectrum potato insect pest control. Strategies for the use of broflanilide on wheat (e.g., Teraxxa F4) in rotation with potatoes (Cimegra), both registered in Canada in 2020 are discussed.