Phytosanitary Treatment Research Articles

Physiological and enzymatic monitoring of treated seeds of cultivars soybean during storage

The objective was to analyze the influence of industrial soybean seed treatments on physiological quality throughout the storage and to evaluate the worth of the alcohol dehydrogenase (ADH) enzyme as a marker for quality monitoring. The statistical design used was completely randomized in a 2 × 5 × 5 factorial schemes involving two cultivars, five phytosanitary treatments, and five evaluation periods during storage. Before treatment, the lignin content of the seed coat of the cultivars was analyzed. The physiological quality was evaluated by the first count of germination and the germination, and the ADH enzyme was also quantified. The deterioration of soybean seeds during storage was directly linked to the type of molecule and the viscosity of the spray solution used in the treatment of seeds. The treatment of soybean seeds with predominantly aqueous solution and the use of systemic insecticidal molecules, combined with fungicides and polymers, impaired the germination of the stored seeds, and the deleterious effects became greater over time. ADH has potential as a marker of the physiological quality of treated and stored soybean seeds.

Efficacy of hot water treatment for postharvest control of western flower thrips, Frankliniella occidentalis, in French beans.

The western flower thrips, Frankliniella occidentalis, is a quarantine pest of French beans that requires phytosanitary treatment to meet quarantine requirements for strict lucrative markets. In this study, the efficacy of hot water treatment against F. occidentalis eggs and its effects on the postharvest physicochemical quality parameters of French beans was evaluated. The immersion time of 8.01 min (95% critical limits CL 7.77-8.24) was predicted by the probit model as the minimum time required to achieve a 99.9968% control level. Confirmatory tests with a large number of F. occidentalis eggs were performed to validate the estimated time to achieve probit-9 control level, and there were no survivors from the 50 103 eggs treated. Likewise, none of the 55 364 eggs exposed to 45 ± 0.2°C for 7min (observational time) survived. The effect of the treatment schedule on French beans quality parameters was assessed and there were no differences in weight loss, moisture content, total soluble solids, titratable acidity, pH, and reducing sugars between treated and untreated samples. Our results indicate that hot water treatment (at 45 ± 0.2°C for a duration of 8.01 min is an effective phytosanitary treatment for the control of Frankliniella occidentalis on French beans, with no significant impact on pods quality. © 2022 Society of Chemical Industry.

Immersion in hot water as a phytosanitary treatment for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) in bell pepper (Capsicum annuum L.)

The False codling moth (FCM), Thaumatotibia leucotreta is a major quarantine pest that hampers Capsicum production and trade in sub-Saharan Africa (SSA) and may need a postharvest treatment to meet quarantine standards of lucrative overseas markets. In this study, we evaluated the efficacy of hot water treatment (HWT) as a potential nonchemical quarantine control option against T. leucotreta in bell pepper and its effect on the quality parameters of the peppers. Infested bell pepper harboring different immature stages of T. leucotreta were subjected to a hot water treatment of 50 ± 0.2 °C for eight different time-points to determine heat susceptibility of immature stages of T. leucotreta. The third-instar was the least heat susceptible, followed by second-and first-instar larva and the egg stage, respectively. The immersion time of 44.23 min (95% CL 43.22 – 45.24) was estimated to be the minimum time required to attain 99.9968% control level. In the large scale confirmatory experiment, there were no survivors from the 20,325 third instar individuals treated in bell pepper (180 – 220 g). Additionally, none of the 25,384 third instars exposed to 50 ± 0.2 °C for 32 min survived. The impact of the HWT schedule on bell pepper fruit quality parameters was assessed and there were no significant effects on weight loss, moisture content, total soluble solids, titratable acidity, dry matter and pH post treatment. These results provide strong evidence that the HWT schedule is an effective phytosanitary treatment for control of T. leucotreta, and may be adopted to facilitate access to overcome the phytosanitary barriers imposed by importing countries to capsicum from SSA.

Influence of spraying tips on the efficiency of chemical control of soybean rust

Asian rust is responsible for significant reductions in soybean yield. The application of fungicide is the main method of control of this disease, and to maintain the efficiency of phytosanitary treatment it is necessary to know several features of the application technology. Spray tips are fundamental for the quality of phytosanitary products application and exert a direct influence on spraying efficiency. The objective of this study was to evaluate the efficiency of different spray tips in spray deposition and leaf cover in the lower, middle and upper thirds of soybean plants in three distinct phenological stages. Another objective was to evaluate the efficiency of the commercial mixture trifloxystrobin + prothioconazole (FOX®), applied by different spray tips, in the control of Asian rust and soybean yield. The experiment was conducted for two agricultural years, and six spray tips were evaluated: TT 11001, TTJ60 11002, TXA 8003, 30HCX 12, GRD120 02 and GAT11002 in three fungicide applications with intervals of 15 days, in the phenological stages V6–V7, R1 and R4, using the working pressure of 5 bar and spray volume of 200 L ha−1. The coverage and deposition of spray promoted by all spray tips, in the three phenological stages of soybeans, were sufficient to provide satisfactory control of rust, with means of disease severity ranging from 1.69 to 4.70%, compared to the control (mean severity of 54.34%), without significant loss of yield in the sprayed plots. All evaluated spray tips can be recommended for use in spraying FOX® fungicide (trifloxystrobin + prothioconazole) in soybean crop for Asian rust control, when the spray volume applied is 200 L ha−1.

Production of Irrigated Rice in the Second Stage of the River Formoso Project in the Brazilian Savanna Region

The information survey was carried out in the second stage of the Formoso River Project in Formoso do Araguaia - TO, in the COPERJAVA area - Mixed Cooperative Rural Valley of Javaés Ltda, located in the Brazilian savanna region. During the research period, some practices related to the production of irrigated rice were monitored, such as straw burning, soil preparation, sowing, nitrogen fertilization cover, and phytosanitary treatments to control weeds, insect pests, and diseases. Monitoring was made in the cultivated areas to observe the development of irrigated rice, and to regulate the height of the water depth in the plots and its uniformities of the water depth. Activities were developed to regulate equipment and facilities involved in rice production. These provided an increase in the knowledge acquired about the irrigated rice crop, emphasizing the need and importance of the association between the theoretical basis acquired during the course and the practice in the field.

Structure from Linear Motion (SfLM): An On-the-Go Canopy Profiling System Based on Off-the-Shelf RGB Cameras for Effective Sprayers Control

Phytosanitary treatment is one of the most critical operations in vineyard management. Ideally, the spraying system should treat only the canopy, avoiding drift, leakage and wasting of product where leaves are not present: variable rate distribution can be a successful approach, allowing the minimization of losses and improving economic as well as environmental performances. The target of this paper is to realize a smart control system to spray phytosanitary treatment just on the leaves, optimizing the overall costs/benefits ratio. Four different optical-based systems for leaf recognition are analyzed, and their performances are compared using a synthetic vineyard model. In the paper, we consider the usage of three well-established methods (infrared barriers, LIDAR 2-D and stereoscopic cameras), and we compare them with an innovative low-cost real-time solution based on a suitable computer vision algorithm that uses a simple monocular camera as input. The proposed algorithm, analyzing the sequence of input frames and exploiting the parallax property, estimates the depth map and eventually reconstructs the profile of the vineyard’s row to be treated. Finally, the performances obtained by the new method are evaluated and compared with those of the other methods on a well-controlled artificial environment resembling an actual vineyard setup while traveling at standard tractor forward speed.

The lesser evil: Consumer acceptance of X-ray irradiation compared with alternative phytosanitary treatments

X-ray irradiation is becoming a mainstream phytosanitary food treatment that is compatible with solving sustainability challenges. However, understanding how consumers respond to X-ray irradiation is still underdeveloped in research. In two studies, the current research sheds light on the acceptance of X-ray irradiation by New Zealand consumers, compared with an existing treatment, methyl bromide. Study 1 used focus groups to provide insights into barriers and opportunities of X-ray irradiation perceived by participants who accept, are passive towards, or reject irradiation. Acceptors of X-ray highlighted familiarity of use, non-residue/lack of chemicals, and environmentally friendly as positive factors, whereas danger of radiation and long-term health concerns were strong themes for rejection. Subsequently, study 2 extended this to provide a snapshot of measures representative of such themes to understand current attitudes towards X-ray irradiation itself, and as a replacement for methyl bromide usage. The results of study 2 indicated that when provided with information on X-ray in isolation, under half the respondents (39%) indicated a willingness to eat foods treated with X-ray. However, when forced to choose between food that had been treated with either X-ray or methyl bromide, the majority of respondents (84%) chose irradiation. Overall, the studies present an overview that whilst consumers may be apprehensive or passive about acceptance of X-ray irradiation (study 1), they overwhelmingly accept X-ray irradiation over the current alternative in New Zealand, methyl bromide (study 2). This was voiced by participants as accepting ‘the lesser of two evils’.

Transgenerational responses to heat and fasting acclimation in the Angoumois grain moth

Transgenerational plasticity (TGP) is a physiological mechanism where environmental experiences of parents affect phenotypes of the offspring, and potentially facilitates organisms' survival in stressful environments. The Angouimois grain moth, Sitotroga cerealella (Olivier), is a dominant primary grain pest in Africa, particularly affecting sorghum and maize staples. Despite its widely known economic significance, little is known on its thermal responses, particularly how acclimation in one generation impacts fitness in successive generations. We tested how heat (acute and dynamic) as well as fasting acclimation in one generation affects physiological tolerance (i.e., critical thermal maxima [CTmax] and heat knock down time [HKDT]) using laboratory-reared S. cerealella populations. Specifically, we assessed whether pre-exposure to heat or fasting stress confers fitness costs or benefits in subsequent generations (i.e., through TGP). Results showed acclimation had significant effects in interaction with temperature ramping rates on CTmax. Moderate acute heat (34 °C) and dynamic temperature (28–38 °C) acclimations reduced F1 CTmax and HKDT, particularly at low ramping rates (for CTmax). We did not find fasting acclimation to significantly affect CTmax, indicating a lack of evidence for cross tolerance and/or susceptibility. For HKDT, all acclimation treatments (including fasting) showed significantly lower HKDT compared to controls, and mostly so, for the 38 °C and dynamic acclimation (28–38 °C) treatments, indicating a transgenerational fitness cost of acclimation. This is the first report of the costs of transgenerational plasticity in a stored product pest of economic significance and has implications in designing heat-based phytosanitary grain treatments.

Vine Protection on Family Farms: Decision Making and Pesticide Use

Family farming is defined as the one which is managed by the family and uses mostly family labor. In the north of Portugal, family farm products are primarily intended for consumption by the household, and secondarily for local sale. Grape production is in many farms the main source of income, and is the one in which the farmer is willing to apply more pesticides to guarantee the quantity and quality required for processing. However, vineyard family farmers do not always register their practices and are rarely subject to any controls. Therefore, the way in which decision-making and compliance with the rules are carried out in these farms are not known. To understand the decision-making processes regarding phytosanitary treatments of these farmers, as well as their perception and caution with the use of pesticides, a checklist-type questionnaire was applied to a sample of 109 family farmers in the NUTIII region in Portugal. Issues related to: i) sociodemographic characteristics, and ii) agricultural practices related to the vineyard protection, were analyzed. The univariate data analysis was associated with the application of a principal component analysis (PCA). The obtained results reveal that the use of pesticides in family farm vineyards is a widespread practice and that the decision making and choice of the pesticide is, in most situations, carried out without the necessary caution, technical monitoring or registration. Respondents with a higher level of education say that they are more careful about the use of pesticides and individual protection. The younger and more educated age groups are more compliant when it comes to regulatory obligations such as the registrations.

PM 7/20 (3) Erwinia amylovora

PM 7/20 (3) <i>Erwinia amylovora</i>

Low Doses Gamma Irradiation as Quarantine Treatment for Controlling Bactrocera zonata (Saund, 1841) and Its Impact on Guava Fruits Quality

The current laboratory study investigates the effect of low doses of gamma irradiation range of (5-50 Gy) cesium cell- 137 on the different developmental stages eggs, 1st, 2nd , 3rd instars larvae and pupae of peach fruit fly, Bactrocera zonata. In addition to that the evaluation of phytosanitary irradiation dose on 3rd instar larvae and their effects on the biochemical quality of guava fruits were proven. The findings indicate that irradiation of eggs with dose 25Gy prevents adult emergence, while the dose 45Gy prevents pupation and the dose 50Gy prevents the hatchability of eggs. Moreover, exposure of larvae with the dose 50 Gy resulted in 98.5, 91 and 86 % mortality for the 1st, 2nd and 3rd instars larvae, respectively. No adult emergence was reported in 1st, 2nd and 3rd instars at the dose level 30, 35 and 45 Gy, respectively. The 3rd instar larvae appeared to be the most tolerant stage to radiation treatment than the 2nd and 1st larval instars. When adult emergence was used as a criterion for determination of the effective irradiation dose, 50 Gy was adopted for phytosanitary irradiation dose for B. zonata. Large scale confirmatory tests were applied to 25,000 3rd instar larvae of B. zonata in guava fruits resulting in non- F1 adults’ production with a confidence level of 91.8%. In conclusion, the irradiation dose of 50 Gy induces the inhibition of adult emergence of 3rd instar larvae and is suggested as a possible minimum dose for phytosanitary treatment of B. zonata fruit fly without causing significant effect (p ≤ 0.05) on some biochemical characteristics of guava fruits.

Vacuum Steam Treatment of Metrosideros polymorpha Logs for Eradication of Ceratocystis huliohia and C. lukuohia.

A new and devastating disease, rapid ohia death (ROD), in Hawaii led to a state quarantine that regulates interisland transport of ohia wood and plant material to prevent spread of the causal pathogens. Heat treatments of ohia logs in commercial trade were considered for phytosanitary treatment. Vacuum steam (VS) was evaluated for its ability to eradicate the pathogens, Ceratocystis lukuohia and C. huliohia, in main stem logs from ROD-affected forest trees. Replicate loads of three debarked logs (24 to 43 cm in diameter, 1.7 to 2.0 m long) were VS treated at 56°C for 30 min (five loads) or 60°C for 60 min (four loads) at a sapwood depth equal to 70% of log radius. Percentage isolation of Ceratocystis from VS and ambient temperature logs before treatment and summarized by source tree ranged from 12 to 66% and 6 to 31% based on carrot baiting assays of tissue taken from outer and inner sapwood, respectively. No viable Ceratocystis was detected in sapwood locations for the 60°C/60 min schedule or inner locations for the 56°C/30 min schedule after treatment. Only one subsample (0.48%, n = 208) of the latter schedule treatment yielded Ceratocystis. Time needed for treatment ranged from 7.4 to 15 h for the 56°C/30 min schedule and from 8.6 to 19.2 h for the 60°C/60 min schedule. These results demonstrate that VS is an effective and efficient method for treating large-diameter ohia logs that mill owners and regulatory plant pathologists may consider for use in Hawaii.

High energy X-ray fruit irradiation qualification with Monte Carlo code

In nuclear and medical fields, Monte Carlo simulations are commonly used to make validations (radioprotection, radiotherapy, etc.). In this study, we have considered the relevance of using Monte Carlo codes for industrial radiation processing. We carried out a feasibility study for phytosanitary treatment of a pallet of fruits by X-ray irradiation. Monte Carlo simulations were performed, using MCNPX™ code and RayXpert® software. We have determined the dose distribution throughout the irradiated product. Also, we focused on the analysis of the absorbed dose uniformity, by calculating Dose Uniformity Ratios (DUR). We also have studied the impact of the radiation source definition strategy (use of double-sided source or one single-sided source making translation steps and rotation). An experimental dose mapping study of this pallet of fruits was also performed. It determines the dose distribution throughout the product container by placing enough dosimeters in and around the product load. The good agreement between the Monte Carlo simulation results and the dose mappings leads us to consider the use of Monte Carlo codes for the calculation of the dose distribution in an irradiated product in order to qualify the process.

Postharvest Disinfestation Treatments for False Codling Moth and Fruit Flies in Citrus from South Africa

South Africa is the 13th largest producer and second largest exporter of citrus fruit globally. The false codling moth, Thaumatotibia leucotreta, and the fruit flies, Ceratitis capitata, C. rosa and Bactrocera dorsalis, can potentially infest citrus fruit and therefore pose a phytosanitary risk for export markets. Consequently, a wide range of postharvest phytosanitary treatments for disinfestation of citrus fruit from these pests have been investigated. These include cold treatments, irradiation, fumigation, heat treatments, and combinations of some of these. Due to the potential phytotoxic effects of all these treatments, the use of a systems approach that depends on two or more independent measures for acceptable phytosanitary risk mitigation is a preferable option. To date, the only postharvest disinfestation treatments used commercially for T. leucotreta and fruit flies for South African citrus, are stand-alone cold treatments and partial cold treatments, as a component in a multi-tiered systems approach. Research on development of novel and improvement of existing postharvest measures continues as a high priority. This includes postharvest detection technologies, in addition to treatment technologies.

Almeria’s Green Pest Management Revolution: An Opportunity That Arose from a Food Safety Alert

Almería, a province of Spain, is the leader in horticultural production on a Spanish and European scale. The specific conditions of greenhouse cultivation favor plant development, but also the proliferation of pests. This high incidence of pests was controlled in the past mainly by means of chemical phytosanitary treatments. The aim of the present work has been to analyze the tools facilitated by the Andalusian Government (Junta de Andalucía) to replace the usual pest management process, taking advantage of the context of the food safety alert arising from the detection of isophenphos-methyl in peppers from the province of Almeria in December 2007. The results illustrate that, unlike many programs of public subsidies which involve long-term expenditure, the aid in question took advantage of the socioeconomic situation following the food safety alert. The program led to substantial economic savings and met its objectives swiftly, achieving excellent results in terms of removing most of the pesticides used in the “conventional production system”. In the 2006–2007 season, only 515 hectares in Almería used biological control organisms, four years later, it reached 20,081 hectares, and the average area during the last ten years was 24,953 hectares. This shows that Almeria’s green pest management revolution had been consolidated.

Combination treatment including irradiation improved the keeping quality of bitter melon (Momordica charantia L) with retention of functional bioactives while fulfilling phytosanitary requirement for export

Present work dealt with development of a combination process for prolonged extension of shelf life of whole as well as minimally processed bitter gourd samples. In this treatment, GRAS chemicals were used for extension of shelf life while radiation processing was optimized to use as a phytosanitary treatment. The whole process involved dipping the bitter gourd samples in sodium hypochlorite (200 ppm) at 52 °C for 10 min (as disinfectant treatment) followed by potassium metabisulphite at optimal concentration (0.5%) for 10 min at 26 ± 2 °C (as an antifungal treatment). Finally, the samples were exposed to low dose (1 kGy) gamma irradiation treatment as a phytosanitary measure. An extended shelf life of 30 days was obtained, while improving the microbiological quality and retaining the colour, textural and sensory qualities. Combination process significantly enhanced the total phenolic content in processed samples during the storage period as compared to unprocessed control. Antioxidant activities of processed samples in terms of FRAP and DPPH radical scavenging activity as well as the antimutagenic activity were also conserved in treated samples. Thus, the treatment developed enhanced the storage life of processed bitter gourd stored at 4 ± 2 °C while satisfying the phytosanitary requirement for export especially to the countries requiring longer voyage time.

A Study on the Efficiency of Sustainable Wine Grape Vineyard Management Strategies

Crop protection strategies based on cupric products and mainly adopted in organic viticulture produce a consistent environmental impact due to the persistence of copper in soils and its negative effects on edaphic biodiversity. In this work, trials were carried out during the crop years 2018–2020 in a vineyard with an organic management by a low-copper strategy and in a conventional IPM management with an IPM strategy with reduced use of fungicides. Phytosanitary treatments have been strictly planned according to forecasting models, and fungicides have been partially substituted with substances improving the resistance mechanisms of plants. Different strategies of green manure management, in order to improve the health of vines, were also adopted. Results suggest the efficacy of the “GreenGrapes” plant protection strategy in conditions of low downy mildew pressure. Furthermore, no declines in the production quality have been recorded; conversely, the synergic effect of the green manure and the tested biostimulant substances (“GreenGrapes” protocols) and the green manure management improved yield and grape quality, compared with conventional conduction (IPM and Organic) with a grass covering.

Identification of Biochemical Composition and Pesticides Residue in Ten Rose Cultivars Leaves Using FT-IR Spectroscopy

In order to optimize the application of nutritive solutions and the phytosanitary treatments with direct influence on the quality of cut roses from hydroponic culture (soilless culture), it is necessary to study the biochemical composition of the different organs of the plant (leaves). By FT-IR spectroscopy using the standard KBr pellet technique; it was possible to differentiate between 10 Rosa cultivars based on the chemical composition of the leaves and also to identify the pesticide residue within the leaf tissues and some of its effects. Thus, it was observed that the intensity of the bands corresponding to amide I (proteins) and aromatic compounds were weaker in leaf sheath and petiole compared with the leaf lamina. Aldehydes were present only in leaf sheath and petiole and not in the leaf lamina. As for the six pesticides tested, simple bond vibration C–H corresponding to aromatic compounds has been detected at 817 cm-1 and 805 cm-1 in the samples treated with penconazole based pesticide (Topas) and a triadimenol with folpet pesticide (Shavit). Also, application of penconazole increases the concentration of polisaccharides in the treated leaves, while a strong intensity band that could be attributed to the presence of halogenated compounds (chlorinated) C-Cl can be observed at 715 cm-1 for the samples treated with the triadimenol and folpet pesticide. The overall results of the present study could provide helpful information for the development of pesticides that have a shorter persistence and a lower biochemical influence on the plant tissues.

SALARIED AGRICULTURAL LABOUR IN NORTH OF FONGO TONGO: ORGANIZATION OF STAKEHOLDERS IN THE FIELD

In the poorly mechanized countries, the development of agriculture is dependent on labour. The degradation of soils in the southern part of the Fongo-Tongo and the coffee crises have favored the mobility of its population to the north where, they serve as employees or employers in agriculture. This work examines the organization of agricultural actors in the north of FongoTongo from the recruitment of labour to the payment of salaries. In the recruitment points and in farms, during the months of april and may 2015, surveys were carried out by interviews (22) and questionnaires (75). As results, in north of Fongo-Tongo, labour was recruited by direct contact or by telephone from 7:30 a.m. to 10 a.m. The activities of the employees were plowing (65.33% of respondents), sowing, phytosanitary treatments, harvesting and related tasks. The main products grown are: potatoes, cabbage, carrots and leeks. Labour was more used from june to september (77.33%) while from april to may, work was scarce. Strategies adopted by employers for better employee performances included positioning them at intervals set by employers, given them a midday meal and transporting them. Employees are paid at the end of the day or on appointment, individually or in groups.

Phenology of the Mencía Variety Cultivated in a Territory Included in the UNESCO World Network of Biosphere Reserves

The study of grapevine phenology is very useful for vineyard management and control, as it allows the application of phytosanitary treatments at the phenological stages where the crop is most susceptible to different diseases, mainly cryptogamic. This work describes the phenological behaviour of the red Mencía variety, the most common in the Ribeira Sacra Designation of Origin (Northwest Spain), as well as its thermal requirements throughout its vegetative cycle. It has been carried out in a vineyard located in the highest areas of the Sil River canyon, during the year 2021. The observations were made on 10 vines and the phenological scale used was the one standardized by the BBCH. The vegetative cycle, from the beginning of sprouting to the harvest, took 163 days, during which 5097 GDD (Growing Degrees-Days) were accumulated.