The Colletotrichum spp. is a significant strawberry pathogen causing yield losses of up to 50%. The most common method to control plant diseases is through the use of chemical fungicides. The findings of plants antimicrobial activities, low toxicity, and biodegradability of essential oils (EO), make them suitable for biological protection against fungal pathogens. The aim is to evaluate the inhibition of Colletotrichum acutatum by thyme, sage, and peppermint EO in vitro on detached strawberry leaves and determine EO chemical composition. Our results revealed that the dominant compound of thyme was thymol 41.35%, peppermint: menthone 44.56%, sage: α,β-thujone 34.45%, and camphor: 20.46%. Thyme EO inhibited C. acutatum completely above 200 μL L−1 concentration in vitro. Peppermint and sage EO reduced mycelial growth of C. acutatum. In addition, in vitro, results are promising for biological control. The detached strawberry leaves experiments showed that disease reduction 4 days after inoculation was 15.8% at 1000 μL L−1 of peppermint EO and 5.3% at 800 μL L−1 of thyme compared with control. Our findings could potentially help to manage C. acutatum; however, the detached strawberry leaves assay showed that EO efficacy was relatively low on tested concentrations and should be increased.
Previously, Colletotrichum spp. has been considered a warmer climate pathogen as these meteorological conditions are most optimal for its development. However, climate change is fostering the spread of plant disease and complicating the ability to predict meteorological conditions for disease development. This study aims to determine meteorological conditions for anthracnose development, evaluate the susceptibility of different strawberry cultivars and detect the distribution of strawberry pathogens in temperate climate conditions. The experiment was carried out in the Institute of Horticulture Lithuanian Research Centre for Agriculture and Forestry (LAMMC) in Lithuania during the 2018–2019 strawberry growing season. To evaluate the contamination levels (fungal and bacterial pathogens) of strawberry plant parts, soil and susceptibility to Colletotrichumacutatum, samples were collected at four different locations in Lithuania from eleven cultivars. The results revealed that Colletotrichum spp. was not equally prevalent in the soil at all strawberry farms tested. The evaluation indicated that strawberry leaves and stems were similarly contaminated with pathogenic fungi. The most frequently isolated fungi from the leaves and stems were Mycosphaerella spp., Alternaria spp., Fusarium spp., Colletotrichum spp., Phytophthora spp., and Botrytis spp. Our study confirmed that the response of cultivar susceptibility to C. acutatum was unequal. The most suitable temperature for C.acutatum development was 25 °C. Monitoring of meteorological conditions, evaluation of inoculum source and appropriate cultivar selection could reduce or avoid yield losses caused by the C. acutatum.
The Allium genus belongs to the family Amaryllidaceae. These species are native to the Northern Hemisphere and grow in various regions. Among Lithuania’s perennial Allium plant species, the most well known and cultivated are Allium schoenoprasum L., Allium angulosum L., Allium nutans L., Allium fistulosum L., and Allium ursinum L. These Allium species are important for practical insights and are discussed in this review to present their specific features. The changing climate impacts perennial plants’ agrobiological and nutritional properties, but not all kinds can adapt to new conditions, reducing species diversity. Perennial Allium species adapt well in local growing areas, but yields remain constant or may increase when the bulbs are transplanted under conditions similar to the plant’s native growing location. In addition, the susceptibility of garlic to pests and pathogens also poses a serious threat to genetic resources stored in uncontrolled field collections. Since ancient times, Allium species have played a significant role in the human diet, in traditional medicine for many ailments the treatment of, and in official medicine as a supplemental ingredient. This review analyzes the nutritional importance and consumption of the perennial Allium species, their biochemical composition, and their tolerance to environmental conditions.
Early detection of pathogenic fungi in controlled environment areas can prevent major food production losses. Grey mould caused by Botrytis cinerea is often detected as an infection on lettuce. This paper explores the use of vegetation indices for early detection and monitoring of grey mould on lettuce under different lighting conditions in controlled environment chambers. The aim was focused on the potential of using vegetation indices for the early detection of grey mould and on evaluating their changes during disease development in lettuce grown under different lighting conditions. The experiment took place in controlled environment chambers, where day/night temperatures were 21 ± 2/17 ± 2 °C, a 16 h photoperiod was established, and relative humidity was 70 ± 10% under different lighting conditions: high-pressure sodium (HPS) and light-emitting diode (LED) lamps. Lettuces were inoculated by 7-day-old fungus Botrytis cinerea isolate at the BBCH 21. As a control, non-inoculated lettuces were grown under HPS and LEDs (non-inoculated). Then, the following were evaluated: Anthocyanin Reflectance Index 2 (ARI2); Carotenoid Reflectance Index 2 (CRI2); Structure Intensive Pigment Index (SIPI); Flavanol Reflectance Index (FRI); Greenness (G); Greenness 2 (G2); Redness (R); Blue (B); Blue Green Index 2 (BGI2); Browning Index 2 (BRI2); Lichtenthaler Index 1 (LIC1); Pigment Specific Simple Ratio (PSSRa and PSSRb); Gitelson and Merzlyak (GM1 and GM2); Zarco Tejada–Miller Index (ZMI); Normalized Difference Vegetation Index (NDVI); Simple Ratio (SR); Red-Eye Vegetation Stress Index (RVSI); Photochemical Reflectance Index (PRI); Photochemical Reflectance Index 515 (PRI515); Water Band Index (WBI); specific disease index for individual study (fD); Healthy Index (HI); Plant Senescence Reflectance (PSRI); Vogelmann Red Edge Index (VREI1); Red Edge Normalized Difference Vegetation Index (RENDVI); and Modified Red Edge Simple Ratio (MRESRI). Our results showed that the PSRI and fD vegetation indices significantly detected grey mould on lettuce grown under both lighting systems (HPS and LEDs) the day after inoculation. The results conclusively affirmed that NDVI, PSRI, HI, fD, WBI, RVSI, PRI, PRI515, CRI2, SIPI, chlorophyll index PSSRb, and coloration index B were identified as the best indicators for Botrytis cinerea infection on green-leaf lettuce (Lactuca sativa L. cv Little Gem) at the early stage of inoculated lettuce’s antioxidative response against grey mould with a significant increase in chlorophyll indices.
Strawberry anthracnose is becoming more important from a scientific and economic standpoint. The Colletotrichum spp. pathogen complex includes C. fragariae, C. gloeosporioides and C. acutatum. The aim was to use microsatellite (SSR) markers to assess the genetic diversity of Colletotrichum species. We used seven SSR primer pairs previously developed for the C. acutatum (3) and C. gloeosporioides (4) species. To analyze the genetic diversity of C. fragariae, it was discovered that SSR primer pairs created for C. gloeosporioides were helpful. SSR molecular markers were used in this study for the first time to identify the species of C. fragariae. The average polymorphism information content (PIC) value across all SSR primer pairs was 0.72, making them all informative. The most informative SSR primers were CG22 and CG30, with PIC values of 0.83 and 0.82, respectively. We believe these primers are suitable for the genetic diversity analysis of C. fragariae species. Therefore, the SSR primer pairs CG20 and CG30 are suggested for the genetic investigation of C. acutatum and C. gloeosporioides. A higher incidence of Colletotrichum spp. polymorphism in Lithuania can be linked to adaptation to survival in our environment, according to this study’s findings on the number of alleles and the degree of genetic diversity, which are higher than the results reported in the literature.
Alternative plant protection methods should be promoted to mitigate the dangers and consequences of using chemical pesticides, ensuring a safe environment and protecting human health (Directive 2009/128/EC). One of the objectives of the EU organic production action plan is to provide substitutes for plant protection methods, decrease the adverse effects on the environment, and promote the diversity of living organisms. The use of synthetic and non-organic chemicals has significantly expanded, damaging human health and the environment. This study aimed to evaluate alternative plant protection solutions for the improvement of the strawberry cv. Elsanta plant’s generative development, yield, fruit quality, and biochemical composition. The two-year strawberry experiment conducted in a tunnel greenhouse included chemical and biological means (Bacteria and Thyme preparations). The experiment randomised a block design with four replicates and 32 plants per replicate. The treatments were conducted at the 10% flowering state (BBCH 61–65), every 7–10 days (a total of four times): (1) Control, (2) Chemical, (3) Bacteria, and (4) Thyme. We evaluated the yield, fruit weight, size, number of leaves, crowns, flowers, inflorescences, fruit firmness, soluble solids, and Vitamin C. The highest fruit weight at the first picking was in the Bacteria treatment. The number of rotten fruits was similar after all treatments. Additionally, they were firmer and bigger in size but had a smaller soluble solids content. The strawberry ascorbic acid and soluble solids content (Brix %) showed significant variation. The highest ascorbic acid concentration in the fruit was after the Thyme application (45.06%). Our study showed that alternative plant protection measures can reduce the use of chemical fungicides and maintain proper fruit quality.