Integration of trichoderma pseudokoningii with agrochemicals for disease management and plant development in mulberry

Vegetative propagation of mulberry (Morus spp.) is greatly afflicted by soilborne diseases. Stem canker (Botryodiplodia theobromae) and cutting rot (Fusarium solani) are the major diseases which cause high rate of mortality of stem‐cuttings (vegetative clones), thus affecting the initial establishment of mulberry. Apart from diseases, the poor rooting ability of stem‐cuttings of many promising mulberry varieties also leads to unproductive propagation. An effective biocontrol agent (Trichoderma pseudokoningii), chemical fungicide (Dithane M‐45) and phytohormones (Indole‐3‐acetic acid, IAA and 1‐Naphthalene acetic acid, NAA) were evaluated individually and in combination for their effects on disease control and plant development. In plates, T. pseudokoningii was found to be compatible with Dithane M‐45 at 0.1%, and IAA and NAA at 20 ppm concentrations. Under field conditions, the integration of soil application of T. pseudokoningii (in the form of its formulated product, ‘NURSERY‐GUARD') and dipping of stem‐cuttings in 0.1% solution of Dithane M‐45, or 20 ppm solution of IAA showed better results than their individual application. NURSERY‐GUARD with Dithane M‐45 (0.1%) or IAA (20 ppm) provided 47.6 to 52.4% disease control to stem‐cuttings which resulted in significant increase (over check) in sprouting of stem‐cuttings (53.1–63.3%) and plant survival (52.6–57.8%).     

Integrated management of faba bean chocolate spot caused by Botrytis fabae in Gondar,Ethiopia

Abstract

Integrated management of faba bean chocolate spot (Botrytis fabae Sard.) was studied using moderately tolerant variety, “Hachalu” and the local cultivar at Chilga district during 2016 main cropping season. The objective was to evaluate effect of host resistance, intercropping and fungicide applications on epidemics of faba bean chocolate spot, yield and yield components of faba bean, and sole and intercrop systems productivity. The experiment was randomised complete block design in a factorial combination of two faba bean cultivars, two cropping systems (Hachalu- and local-barley intercropping in 2:1 ratio) and four levels of fungicide (Chlorothalonil) spray and integration in three replications of faba bean and barley, respectively. Cultivars and spray intervals significantly (p?<?.01) affected the seed yield while cultivars alone had significant variation (p?<?.01) on 100-seed weight as a main effect. Therefore, 21-days fungicide spray intervals integrated with Hachalu sole and Hachalu-barley intercropping may be considered for chocolate spot management.     

MAPS Database: Medicinal plant Activities,Phytochemical and Structural Database

Drug development from natural sources is an important and fast developing area. Natural sources (plants) have been used to cure a range of diseases for Thousands of years. Different online medicinal plant databases provide information about classifications, activities, phytochemicals and structure of phytochemicals in different formats. These databases do not cover all aspects of medicinal plants. MAPS (Medicinal plant Activities, Phytochemicals & structural database) has been constructed with uniqueness that it combines all information in one web resource and additionally provides test targets on which particular plant found to be effective with reference to the original paper as well. MAPS database is user friendly information resource, including the data of > 500 medicinal plants. This database includes phytochemical constituents, their structure in mol format, different activities possessed by the medicinal plant with the targets reported in literature.

Availability

http://www.mapsdatabase.com     

Properties of capsaicinoids for the control of fungi and oomycetes pathogenic to pepper

Capsaicinoids are pungent compounds found in pepper (Capsicum spp.) fruits. Capsaicin showed antimicrobial activity in plate assays against seven isolates of five species of fungi and nine isolates of two species of oomycetes. The general trend was that oomycetes were more inhibited than fungi. Assays of capsaicin biosynthetic precursors suggest that the lateral chain of capsaicinoids has more inhibitory activity than the phenolic part. In planta tests of capsaicinoids (capsaicin and N‐vanillylnonanamide) applied to the roots demonstrated that these compounds conferred protection against the pathogenic fungus Verticillium dahliae and induced both chitinase activity and expression of several defence‐related genes, such as CASC1, CACHI2 and CABGLU. N‐Vanillylnonanamide infiltrated into cotyledons confers systemic protection to the upper leaves of pepper against the fungal pathogen Botrytis cinerea. In wild‐type tomato plants such cotyledon infiltration has no protective effect, but is effective in the Never‐ripe tomato mutant impaired in ethylene response. A similar effect was observed in tomato after salicylic acid infiltration.     

Sensitivity of Venturia inaequalis to Trifloxystrobin and Difenoconazole in Uruguay

The sensitivity of Venturia inaequalis to trifloxystrobin and difenoconazole was studied in Uruguay. Populations of V. inaequalis were collected from apple orchards with different histories of trifloxystrobin use. Sensitivity of populations to trifloxystrobin was analysed using a method for testing spore germination published by FRAC, using a discriminatory concentration of 2.0 mg a.i./l. Resistance to trifloxystrobin was widespread in the region of commercial apple production with resistance detected in all orchards examined, the incidences ranging from 3% to 95%. The highest frequencies were found in orchards with the most intensive use of Quinone outside inhibitors (Q_oI) fungicides. Sensitivities of isolates of V. inaequalis to difenoconazole were assessed at five concentrations using a mycelial growth assay on isolates (33 isolates per orchard) from one non‐commercial (baseline orchard) and two commercial orchards having differing histories of difenoconazole use. Populations in both commercial orchards exhibited reduced sensitivities to difenoconazole compared to the baseline orchard. Resistance factor (RF) values of 6.6 and 11.74 were measured in the orchards with moderate (up to 4 sprays per season) and intensive use (more than 5 sprays per season) of difenoconazole, respectively. A single‐assessment concentration (SAC) was identified for assessing difenoconazole sensitivity of V. inaequalis isolates by fitting linear regressions between log₁₀ EC₅₀ and relative growth (RG) of the isolates at each fungicide concentration testing, and comparing the goodness‐of‐fit of the regression lines. Comparable results were obtained based on EC₅₀ values and RG values at a SAC of 0.05 mg of active ingredient per litre (a.i. per l). Populations from both commercial orchards differed from the baseline population, in that isolates with RG ≥70 were present at substantial levels in the former but absent from the latter.     

Baseline Sensitivity of Australian Phoma ligulicola Isolates from Pyrethrum to Azoxystrobin and Difenoconazole

Ray blight caused by Phoma ligulicola is an important disease of pyrethrum in Australia, and successful management relies upon the fungicides, azoxystrobin and difenoconazole. Azoxystrobin and difenoconazole were introduced into pyrethrum production in 2001. The sensitivity of P. ligulicola isolates collected in 2003 to azoxystrobin (n = 56) and difenoconazole (n = 61) was tested. Testing for sensitivity to azoxystrobin and difenoconazole used a conidial germination and mycelial growth assay respectively. For each fungicide, the effective dose required to reduce mycelial growth or conidial germination by 50% (EC₅₀) was determined by probit analysis. The EC₅₀ values ranged from 0.007 to 0.193 μg/ml for azoxystrobin and 0.04 to 13.8 μg/ml for difenoconazole. No evidence was found for cross‐resistance between azoxystrobin and difenoconazole in this baseline population. This information serves as important baseline data for tracking future changes in sensitivities of P. ligulicola to these fungicides.     

Induction of SCEs and DNA fragmentation in bovine peripheral lymphocytes by in vitro exposure to tolylfluanid-based fungicide

The potential for genotoxic and cytotoxic effects of tolylfluanid-based fungicide (50% active agent) was evaluated using sister chromatid exchange (SCE) and proliferation indices (PI) in cultured bovine peripheral lymphocytes. For the detection of possible genetic damage, DNA fragmentation assay was also applied. Bovine lymphocytes cultured for 72 h were treated with the fungicide at the final concentrations of 1.75, 3.5, 8.75, and 17.5 μg/mL for the last 24 and 48 h of culture without S9 metabolic activation, and during the last 2 h of culture with S9 metabolic activation. In the SCE assays no evidence for genotoxic activity of the fungicide was found in treatments of 24 h without and 2 h with S9. After the 24 h exposure to tolylfluanid, a weak decrease in the PI was observed. With the prolonged exposure time (48 h), dose dependence in the increase of SCE frequencies was observed. Moreover, after 48 h exposure slight fragmentation of DNA at the concentrations of 3.5 and 8.75 μg/mL was demonstrated. SCE quantification is the most widely used approach for the assessment of genotoxic/cytogenetic effects of chemical compounds. Positive results in the assay at 48 h exposure indicated a potential of the fungicide to increase frequency of chromosomal damage (replication injuries) that is the confirmation of early effect of exposure.     

Autumn sowing increases severity of pasmo (Mycosphaerella linicola) on linseed in the UK

Surveys and field experiments showed pasmo to be the most serious disease affecting UK winter linseed in the 1997–98, 1998–99 and 1999–2000 growing seasons. Survey data indicated that pasmo was widespread in England and Scotland, causing extensive loss of leaves and stem and capsule symptoms, on both winter and spring linseed crops. In winter linseed experiments at ADAS Boxworth and Rothamsted, when severe epidemics occurred (1997–98 and 1999–2000), control of pasmo with one or two MBC fungicide sprays increased yield. In experiments when severe pasmo epidemics did not occur (1998–99), fungicide applications did not increase yield. In all three growing seasons, large numbers of air-borne Mycosphaerella linicola ascospores were collected in the summer months. At the time when the winter linseed crop was emerging and becoming established in October/November, there were more air-borne M. linicola ascospores in 1999 than in 1998. April/May rainfall was much greater in 1998 (135 mm) and 2000 (223 mm), when severe pasmo epidemics developed by July, than in 1999 (68 mm) when disease severity in July was less. Regression analyses suggested that yield decreased as percentage area affected by pasmo on leaves or stems in July increased. The formulae relating yield loss to pasmo severity, derived from these experiments, were combined with disease survey data to estimate, retrospectively, the UK national losses from pasmo. Estimated national losses from pasmo on winter linseed, although >50% of crops were sprayed with fungicide, were approximately £2.9M in 1998, £1.6M in 1999 and £0.37M in 2000 (when the area of winter linseed had decreased greatly). Estimated combined losses on winter and spring linseed were approximately £14.8M in 1998, £34.9M in 1999 and £11.0M in 2000.