Mahetootmise keskkonnamõjud läbi olelusringi

Euroopas tuleb hinnanguliselt umbes 30% kogu eratarbimise keskkonnamõjudest toidusektorist, kuid näiteks veekogude eutrofeerumisse panustab toidutootmine isegi 60% ulatuses (Tukker jt., 2006). Jätkusuutliku toidutootmise arendamine, mis vähendaks oluliselt keskkonnakoormust, on EL-i strateegiline eesmärk. Keskkonnasõbralike tehnoloogiate valikul tuleb mõõta nende mõjusid läbi olelusringi ehk võtta arvesse ka vajalike sisendite tootmise keskkonnamõjusid. Vastasel korral võib soovitav keskkonnakoormust vähendav muudatus ühes tootmise etapis põhjustada hoopis suuremaid keskkonnamõjusid teises etapis. Artikkel annab lühiülevaate mahepõllumajanduse keskkonnamõjudest läbi olelusringi võrreldes tavapõllumajandusega

Organic farming research in Estonia

The growth of organic farming in Estonia has been rapid in recent decades. To support this development various research projects have been conducted but still a lot of new knowledge is needed to improve the performance of organic sector. Organic agriculture is based on nutrient recycling and it uses a variety of practices that are valuable also for conventional farming in the future because resources of non-renewable synthetic fertilizers are limited and food should be produced more sustainably. Holistic perspective including ecological, economic and social aspects is needed for organic farming studies and future projects should target these issues more thoroughly

Reliability of the entomovector technology using Prestop-Mix and Bombus terrestris L. as a fungal disease biocontrol method in open field

Botrytis cinerea Pers.: Fr. is a major plant pathogen, and a new approach is needed for its control in strawberry to minimise the increasing use of synthetic fungicides. The biofungicide Prestop-Mix, which contains Gliocladium catenulatum, is effective against Botrytis infections; however, the need for frequent applications increases the costs for farmers. Here, we demonstrate that bumble bees, Bombus terrestris L., effectively disseminate the preparation onto flowers in open field conditions. Over the course of three years, we found a highly significant decrease in the rate of Botrytis infection. Pathogen control was achieved with relatively low numbers of G. catenulatum spores per flower, even using flowers that are not highly attractive to bumble bees. An even distribution of spores was detected up to 100 m from the hives, either due to primary inoculation by bumble bees or secondary distribution by other flower visitors such as honey bees and solitary bees. We showed that the application of a biocontrol agent by bumble bees is reliable for the use of environmentally friendly pest control strategies in northern climatic conditions. This low cost technology is especially relevant for organic farming. This study provides valuable information for introducing this method into practice in open strawberry fields

The effect of biofungicide Prestop Mix on respiration, water loss and longevity of bumblebee Bombus terrestris L.

In this study the effect of biofungicide Prestop Mix on respiration, water loss and longevity of bumblebee Bombus terrestris L. was investigated

The effect of biofungicide Prestop Mix on metabolic rate, water loss and longevity of bumblebee Bombus terrestris L.

Prestop Mix is based on a natural soil fungus Gliocladium catenulatum J1446, which is applied to control fungal plant diseases. Bees can be used as vectors in carrying the biofungicide powder onto crop flowers; this has two benefits: pollination and plant protection from fungal pathogens. An important precondition is for the biopreparation to be safe for bees, therefore lethal and sublethal effects have to be tested. One way to assess sublethal effects of pesticides is to measure the metabolic rate (MR) and water loss rate (WLR) of an insect

Acute effect of low-dose thiacloprid exposure synergised by tebuconazole in a parasitoid wasp

Agricultural practices often involve tank-mixing and co-application of insecticides with fungicides to control crop pests. However, natural methods relying on biological control agents such as hymenopteran parasitoids have been shown to be highly effective in suppressing crop pest populations. The current body of insecticide risk assessment data accounting for fungicide co-application is very small, the present study being the first to examine this in a parasitoid wasp. Through low-dose exposure to dry residues of the neonicotinoid insecticide thiacloprid, we examined its mortal and knockdown effect on Aphelinus abdominalis when co-applied with increasing doses of the fungicide tebuconazole. Both of these acute effects of thiacloprid were synergised (toxicity increased to a greater-than-additive effect) by tebuconazole, resulting in significant mortality from low-dose co-applications of tebuconazole, and significant knockdown even without co-applied tebuconazole, the effect increasing as tebuconazole concentration increased. We show the highly toxic effect that a low dose of thiacloprid imposes on A. abdominalis populations, and a synergistic toxicity when co-applied with low doses of tebuconazole. Our work suggests a need for updating pesticide risk assessment methods, accounting for pesticide mixtures, in order to make these risk assessments more field relevant

Key pests and their parasitoids on spring and winter oilseed rape in Estonia

The pests and their hymenopterous parasitoids present in a spring and a winter oilseed rape crop in Estoniawere studied. Meligethes aeneus was themost abundant pest in both crops. Other crucifer-specialist pests included: Ceutorhynchus assimilis, C. pallidactylus, C. rapae, C. floralis, C. pleurostigma and Phyllotreta spp., but their abundance was low. Four species of parasitoids of M. aeneus larvae (Diospilus capito, Phradis morionellus, P. interstitialis and Tersilochus heterocerus) and threeof C. assimilis larvae (Mesopolobus morys, Stenomalina gracilis and Trichomalus perfectus) were also found

Keskkonnasäästlikud kasvatustehnoloogiad aianduses

Tutvustatakse keskkonnasõbralike tehnoloogiate uurimistulemusi aianduses

Towards dsRNA ‐integrated protection of medical Cannabis crops: considering human safety, recent‐ and developing RNAi methods, and research inroads

Owing to the expanding industry of medical Cannabis, we discuss recent milestones in RNA interference (RNAi)‐based crop protection research and development that are transferable to medical Cannabis cultivation. Recent and prospective increases in pest pressure in both indoor and outdoor Cannabis production systems, and the need for effective nonchemical pest control technologies (particularly crucial in the context of cultivating plants for medical purposes), are discussed. We support the idea that developing RNAi tactics towards protection of medical Cannabis could play a major role in maximizing success in this continuously expanding industry. However, there remain critical knowledge gaps, especially with regard to RNA pesticide biosafety from a human toxicological viewpoint, as a result of the medical context of Cannabis product use. Furthermore, efforts are needed to optimize transformation and micropropagation of Cannabis plants, examine cutting edge RNAi techniques for various Cannabis–pest scenarios, and investigate the combined application of RNAi‐ and biological control tactics in medical Cannabis cultivation. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry

First evidence of bud feeding-induced RNAi in a crop pest via exogenous application of dsRNA

An ecologically sustainable strategy for managing the pollen beetle Brassicogethes aeneus, a key pest of oilseed rape (Brassica napus) in Europe, is greatly needed. Gene silencing via RNA interference, through sprayed applications of target-specific double-stranded RNA, represents a potential alternative to conventional insecticides. We used dsRNA designed to target a vital gene in this pollen beetle species and allowed the beetles to feed on dsRNA-coated oilseed rape buds. We observed a significant silencing of the target gene; and this was followed by a significant, albeit delayed, reduction in pollen beetle survival rate. Further experiments are necessary in order to better understand the potential for developing a dsRNA-spray approach to pollen beetle management. Spray-induced gene silencing (SIGS) is a potential strategy for agricultural pest management, whereby nucleotide sequence-specific double-stranded RNA (dsRNA) can be sprayed onto a crop; the desired effect being a consumption of dsRNA by the target pest, and subsequent gene silencing-induced mortality. Nucleotide sequence-specificity is the basis for dsRNA's perceived biosafety. A biosafe approach to pollen beetle (Brassicogethes aeneus) management in oilseed rape (Brassica napus) agroecosystems is needed. We examined the potential for SIGS in B. aeneus, via bud feeding, a field-relevant dsRNA exposure route. Oilseed rape buds were uniformly treated with dsRNA designed to target alpha COP in B. aeneus. Our model control dsRNA (dsGFP) remained detectable on buds throughout the entire 3 d exposure period. When applied at 5 mu g/mu L, ds alpha COP induced significant alpha COP silencing 3 d after dietary exposure to buds treated with this ds alpha COP concentration. We also observed a trend of increased alpha COP silencing with increasing concentrations of ds alpha COP at both 3 and 6 d. Furthermore, we observed a marginally significant and significant reduction in B. aeneus survival at 10 and 15 d, respectively. Our results suggest potential for developing a SIGS approach to B. aeneus management-though further experiments are needed to more fully understand this potential