Search

To achieve an effective reduction of the damage by root feeding grubs of Melolontha spp. in organic strawberry plantations, we have tested an approach targeting different stages of the insect’s biological cycle. Adult beetles were caught by using light traps or by manual shaking off trees associated to the monitoring of cockchafer swarm flights supported by forecasts models. Phytosanitary pre-crops and the application of biological control agents were tested against the larvae. The three predictive models utilized to forecast the period of emergence of the cockchafer were suitable to support the deployment of the light traps before the adults’ swarm flights. Traps positioned at 4-m height were more effective in attracting the beetles than those kept at 2-m height. Buckwheat in mixtures with either a mustard or leguminous species used as pre-crops was able to reduce the population of grubs, and considering also its capacity in solubilizing recalcitrant phosphorous sources should enter in a rotation with strawberry or any other crop susceptible to grubs damage. The distribution of two different strains of entomopathogenic fungi resulted in a reduction of the damage to plants due to the cockchafer grubs’ activity, even though the efficacy resulted to be dependent on environmental and agronomic factors, including the kind of formulation used. It is concluded that to assure a sufficient level of control of Melolontha spp. in organic strawberry plantations, it is necessary to integrate several methods that are targeting the different biological stages of the insect and are based on different kinds of practices.

The blackcurrant gall mite (Cecidophyopsis ribis) is the most important pest of blackcurrant crops. Over recent years withdrawal from plant protection programmes of chemical products (endosulfan and amitraz) used for the control of this pest in Poland, has led to an observed increase in population numbers. In 2013, fenpiroxymate (Ortus 05 SC) became registered for control of this pest. It is deemed best that chemical protection should be used during the migration period; when big gall mites emerge from buds in search of new buds. The studies were carried out in a plantation of blackcurrants during 2011-2013. The assessment of migration of the blackcurrant gall mite was carried out on the cultivars ‘Ben Hope’, ‘Ben Alde’r, ‘Ojeby’n and ‘Ruben’. Every year, from selected cultivars buds were collected. They were then placed on blackcurrant leaves within Petri dishes. After one, three and five days of placing buds on the leaves, the estimated number of eriophyid mites on the leaves was calculated. The data has shown a very useful method for monitoring blackcurrant gall mite, which can be used in calculating the treatment dates for this pest. Also, the data has shown that differences in the periods of migration of the mite are dependent on the cultivar and time of flowering. Among the cultivars observed the least susceptible to colonization by the blackcurrant gall mite was a Polish cultivar ‘Ruben’, while the most susceptible cultivar was ‘Ben Hope’.

Blackcurrant leaf midge (Dasineura tetensi) is one of the most common pests of blackcurrant (Ribes nigrum). The aim of this study was to investigate changes in the content of phenolic compounds in the leaves damaged by the larvae of this pest. Additionally, susceptibility of different blackcurrant cultivars to the midge attack was investigated. Qualitative and quantitative analyses of control and pest-infested blackcurrant leaves were performed using LC-PDA-QTOF/MS and UPLC-PDA-FL systems. A total of 39 types of phenolic compounds were identified in blackcurrant leaf extracts and they included 3 flavan-3-ols, 14 hydroxycinnamic acid derivatives, and 22 flavonols. Feeding of blackcurrant leaf midge on blackcurrant leaves lowered the content of leaf polyphenolic compounds. The greatest differences in polyphenolics between control and infected leaves were observed in 'Ruben', 'Fariegh', 'Foxendown', 'Ores', 'Ben Hope', 'Ben Connan' and 'Tisel' cultivars that were probably highly susceptible to the pest attack. In the other cultivars: 'Ben Finlay', 'Polares', 'Tiben', and 'Gofert' the differences in phenolics content were less pronounced, so they were probably less susceptible to D. tetensi attack. Plant polyphenolic compounds was strongly involved in pathogen-plant interaction, and their accumulation significantly decreased as a result of the pathogen attack.

Due to the withdrawal from the plant protection industry of several main insecticides (e.g. endosulfan, amitraz and propargite) commonly used to control the strawberry mite (Phytonemus pallidus spp. fragariae), there is a constant need to search for new control measures against this pest. The efficacy of spirotetramat (Movento 150 OD at rates of 0.5 and 0.7 and Movento 100 SC at rates of 0.75 and 1.0 l ha−1), abamectin (Vertimec 018 EC, 1.0 l ha−1) and abamectin (1.0 l ha−1) + the adjuvant Slippa (0.2 l ha−1) for control of strawberry mite was evaluated in the current study. Pyridaben (Sanmite 20 WP, 2.25 kg ha−1) was used as a reference product. All of the products were used twice at weekly intervals, after fruit harvest, when the population of P. pallidus exceeded the risk threshold. All products significantly reduced P. pallidus populations in strawberry plantations compared to control plots. The results obtained with spirotetramat were dependent on dose and formulation, and ranged from 60% to over 90% efficacy. The efficacy of abamectin for controlling the mobile forms of strawberry mite was 81–99%. This active ingredient applied in combination with the adjuvant did not display any better level of control than when applied alone (efficacy 77–95%). The results obtained with the reference product (pyridaben) were similar or slightly lower (average > 80%) than those obtained with the test products.

BACKGROUND: The Strawberry is an economically important crop in Poland. However, the production of strawberries is difficult and costly, as pests and pathogens causing diseases often damage plants. The strawberry mite - Phytonemus pallidus (Banks) is the most dangerous among pests and one of the most difficult to control. In the past, active substances such as Endosulfan, Amitraz and Propargite, were used to control the pest but they have been withdrawn from the pest control program a few years ago. OBJECTIVE: The intention of this study was to evaluate the efficacy of Abamectin and fungus Beauveria bassiana to control the strawberry mite on strawberry plants in the open field, as well as the susceptibility of selected strawberry varieties and genotypes to the pest. METHODS CONTROL EXPERIMENTS: Studies were performed on ‘Honeoye’ plants. Naturalis (Beauveria basiana )a t a dose of 1.0–1.5 l/ha+adjuvant Protector (pine resins) at a dose of 0.3 l/ha, Naturalis – 1.0 l/ha+TerraSorb ® Complex SB ( – amino acids, biostimulants) – 1.5 l/ha (2013) and Vertimec 018 EC (abamectin) at a dose of 1.0 l/ha were estimated. The population of strawberry mite was notated both before, and after the application of the tested products. SUSCEPTIBILITY OF CULTIVARS: The observations of the strawberry mite presence on the strawberry cultivars, were carried out in years 2012–2013 on an experimental cultivar trial plantation. The population of the pest was counted on strawberry leaves, taken from plants of different varieties and genotypes. RESULTS: Vertimec 018 EC showed good efficacy in the control of the strawberry mite, but the long-lasting effect was observed only following two applications of the product. Naturalis (Beauveria bassiana)+Protector proved to be more effective than the treatment of Naturalis+TerraSorb ® Complex, however the pest control was poorer and of short duration than after application of Vertimec 018 EC. CONCLUSIONS: In experiments carried out in the open field Abamectin proved to be more effective than Naturalis. Some strawberry varieties such as ‘Dukat’, ‘Flair’, ‘Real’, ‘Salut’, ‘Vima Rina’, ‘Malling Pearl’ were not infested by to strawberry mite - the pest specimens were not observed on experimental plots within two years of this experiment. A high population of the strawberry mite was noted on strawberry cultivars such as ‘Evita’, ‘Hokent’, ‘Albion’, ‘Feriusz’, ‘Honeoye’ and ‘Karel’.

The use of entomopathogenic fungi for biocontrol of plant pests is recently receiving an increased interest due to the need of reducing the impact of agricultural practices on the environment. Biocontrol efficacy could be improved by co-inoculation of different microorganisms. However, interactions between the fungal species can trigger or depress the biocontrol activity. Co-inoculation of two entomopathogenic fungi (Beauveria bassiana and B. brongniartii) was performed in vitro to evaluate the effects of their joint behaviour on a range of different carbon sources in comparison to single inoculation. The two species showed a very different metabolic profile by Phenotype MicroArrayTM. B. bassiana showed a broader metabolism than B. brongniartii on a range of substrates. B. brongniartii showed a greater specificity in substrate utilization. Several carbon sources (L-Asparagine, L-Aspartic Acid, L- Glutamic Acid, m- Erythritol, D-Melezitose, D-Sorbitol) triggered the fungal metabolism in the co-inoculum. SSR markers and Real Time qPCR analysis showed that different substrates promoted either the growth of one or the other species, suggesting a form of interaction between the two fungi, related to their different ecological niches. The methodological approach that combines Phenotype MicroArrayTM and SSR genotyping appeared useful to assess the performance and potential competition of co-inoculated entomopathogenic fungi.

Spirotetramat applied as Movento 100 SC at dose rates: 0.7 and 1.0 L·ha-1 in a single treatment just after blossom resulted in a very high reduction of currant-sowthistle aphid - Hyperomyzus lactucae L. (Aphidoidea, Aphididae) on blackcurrants ‘Ojebyn’ and ‘Titania’. The results obtained with this pesticide applied at both tested dose rates: 0.7 and 1.0 L·ha-1 were comparable. The efficacy of spirotetramat at 7th day after treatment was similar or slightly poorer compared to standard insecticides, but at 21st day after treatment a higher reduction of aphids than with reference insecticides such as pirimicarb (Pirimor 500 WG at the rate 0.75 kg·ha-1), thiacloprid (Calypso 480 SC 0.15 L·ha-1) and thiamethoxam (Actara 25 WG at the rate 0.1 kg·ha-1) was recorded. With regard to environment safety and biodiversity it must be underlined that on plants treated with Movento 100 SC, high populations of Coccinellidae (both larvae and beetles), Syrphidae (larvae) and Phytoseiidae were noted.

The application of biological control agents (BCAs) is considered as an effective alternative for pest control. However, factors such as the formulation of the product, whose quality can affect the inoculant viability and persistence in soil, the stabilisation of the biocontrol effect under field conditions and the influence of agronomical practices as well as of the environmental conditions (weather and soil) are hampering a wider use of BCAs. After a brief review of these factors, we present some results concerning agronomical and ecological aspects from a case study carried out using different entomopathogenic fungi on organic strawberry plantations, which underline the possibility of improving BCAs efficacy, particularly when integrated into a more general strategy of pest control.

The effectiveness of spirotetramat in the control of pear psylla (Cacopsylla pyri) on pear trees was investigated in five field experiments, carried out in years 2009- 2011. One or two treatments were applied in June; the first treatment in the early stage of larvae hatching from eggs deposited by females from the summer generation, whilst the second application was carried out about two weeks later. In all the experiments, spirotetramat as Movento 100 SC applied at a dose of 2.25 l/ha effectively reduced the pest population after only a single application (total reduction of larvae after one week post-treatment 75.3-91.4%, and 83.7-97.6% at two weeks posttreatment). Movento 100 SC applied after a single application at a lower dose of 1.8 l/ha had a slightly worse effect (the total reduction of larvae at one week posttreatment was at the level of 58.4-91.3%, and two weeks after application at the level of 56-92.6%) - but in this case only a few larvae at stages L4 and L5 were found on pear shoots. The effectiveness of spirotetramat at both doses after two applications was very high. In comparison with standard insecticides the efficacy of spirotetramat was higher or not significantly different. In two experiments the application of standard compounds such as diflubenzuron and novaluron was not effective in controlling pear psylla and therefore did not prevent damage to pear trees. This may suggest that local populations of the pest are resistant to these measures, especially since they have been used for many years to control other pests of pear trees

A culture independent method based on qPCR was developed for the detection and quantification of two fungal inoculants in soil. The aim was to adapt a genotyping approach based on SSR (Simple Sequence Repeat) marker to a discriminating tracing of two different species of bioinoculants in soil, after their in-field release. Two entomopathogenic fungi, Beauveria bassiana and B. brongniartii, were traced and quantified in soil samples obtained from field trials. These two fungal species were used as biological agents in Poland to control Melolontha melolontha (European cockchafer), whose larvae live in soil menacing horticultural crops. Specificity of SSR markers was verified using controls consisting of: i) soil samples containing fungal spores of B. bassiana and B. brongniartii in known dilutions; ii) the DNA of the fungal microorganisms; iii) soil samples singly inoculated with each fungus species. An initial evaluation of the protocol was performed with analyses of soil DNA and mycelial DNA. Further, the simultaneous detection and quantification of B. bassiana and B. brongniartii in soil was achieved in field samples after application of the bio-inoculants. The protocol can be considered as a relatively low cost solution for the detection, identification and traceability of fungal bio-inoculants in soil.

The vapourer moth (Orgyia antiqua L.) is a polyphagous pest occuring on many trees and bushes, including apple, currants and raspberry. In 2013 and 2014 monitoring of this pest using pheromone traps to attracting males was carried out in apple orchards at the Research Institute of Horticulture. Butterflies of the vapourer moth were caught on pheromone traps placed in all monitored orchards however: there was no damage to the leaves caused by caterpillars. Adult flight of O. antiqua usually began in the second half of June and ended in late of October or even early November. The second generation of butterflies was more numerous in monitored orchards than the first one. The main flight of males of the first generation took place in July and another in September. The vapourer moth population was not abundant in the monitored orchards and there was no need to control it.

Summary The blackcurrant gall mite (big bud mite) – Cecidophyopsis ribis (Westw.) is the most dangerous pest of blackcurrant in many countries. C. ribis is a key pest in Poland and causes severe damage on some plantations, destroying even more than 50% of the buds. The big bud mite infests most of the commonly grown cultivars and only a few are resistant. Looking for new possibilities to control the pest is still necessary. The experiments were carried out at the Research Institute of Horticulture in 2008–2011. Fenpyroximate active substance in Ortus 05 SC showed high effectiveness in reducing the number of the blackcurrant gall mites emerging from treated buds. Ortus 05 SC (1.25; 1.5 l/ha) and Ortus 05 SC (1.5 l/ha) + Slippa (0.1 l/ha) applied 3 times during migration of the big bud mite, reduced the number of damaged buds by 76–90% compared to the control bush. Also Ortus 05 SC (1.5 l/ha), applied twice: at the beginning and during the full blossom of black currant significantly reduced the number of buds infested by the big bud mite. On the bushes where Ortus 05 SC (1.5 l/ha) + Slippa (0.1 l/ha) were used twice, slightly less damaged buds compared with the treatments without wetting were reported, but the differences were not statistically significant.

Summary The strawberry mite (Phytonemus pallidus) is a very important pest of strawberry in Poland. The pest feeds on the smallest, young folded leaves, flower buds and flowers. Plants heavily infested with mites become severely stunted and crinkled, resulting in changes in fruit size and quality. The pest easily spreads on plantation with strawberry seedlings. P. pallidus has to be control on many strawberry plantations however, its controls is very difficult due to the lack of registered products. Recently there was only one acaricide permitted on strawberry. The aim of these trials was to evaluate the effectiveness of fenpyroximate (Ortus 05 SC) against the strawberry mite. Ortus 05 SC at the rate of 1.25 and 1.5 l/ha as well as Ortus 05 SC (1.125 l/ha) + Slippa (0.2 l/ha) was applied twice with one week interval after strawberry harvest and it gave average level of the control (about 80%). Ortus 05 SC used at the rate 1.0 l/ha gave lower efficacy (30%), especially on heavily infested plantation. In 2013 Ortus 05 SC was registered for control of the strawberry mite in Poland and may be use once during a vegetation season.