Downy mildew of sunflower, caused by Plasmopara halstedii (Farl.) Berl. et de Toni, is a relevant disease of this crop. High virulent pathotypes have been identified in several countries, while there are few data on the spread of P. halstedii pathotypes in some important sunflower-growing areas of Europe. The goal of this study was to give up-to-date information on the pathotype structure of P. halstedii in Hungary and provide some actual data on the virulence phenotype of the pathogen for six European countries. Infected leaves of different sunflower hybrids and volunteers were collected in seven countries (Hungary, Bulgaria, Serbia, Turkey, Greece, Romania, and Italy) between 2012 and 2019. A universally accepted nomenclature was used with a standardized set of sunflower differential lines for pathotype characterization of isolates. The virulence pattern of the isolates was determined by a three-digit code (coded virulence formula, CVF). A total of 109 P. halstedii isolates were characterized. As a result of our survey, 18 new P. halstedii pathotypes were identified in Europe. Two out of the eighteen pathotypes were detected from the Asian part of Turkey. The detailed distribution of pathotypes in Hungary is also discussed.

Two neem-derived pesticides were examined under in vitro and in vivo conditions to test their efficacy in controlling Plasmopara halstedii pathotype 704, a causal agent of downy mildew in sunflower. All the tested concentrations of neem leaf extract and the highest concentration of commercial neem product significantly reduced the sporangial germination under in vitro conditions. In in vivo experiment, 3-days old pre-treated seedlings with both concentrations of neem leaf extract and the highest concentration of commercial product showed a significant reduction in the infection indicating possible systemic effect of neem. When the seedlings were treated following the infection with P. halstedii (i.e., post-treatment), only the highest concentrations of neem leaf extract and the commercial product showed a significant reduction in the infection indicating curative effect of neem. Possibilities for the control of P. halstedii with neem-derived pesticides are discussed.

Downy mildew of sunflower (Helianthus annuus L.) is caused by Plasmopara halstedii (Farl.) Berl. et de Toni, leading to significant losses in crop production worldwide. The number of new and more a...

The damage caused by the southern root-knot nematode (Meloidogyne incognita) in coffee plants has been reported in various countries, including Indonesia. The measures to control the nematodes on coffee seedlings and fields depend on synthetic nematicides. Addressing this issue requires not only a more environmentally friendly and cheaper technology but also equal effectiveness comparable to synthetic nematicides. This study aimed to test the effectiveness of fortified bacterial consortium (FBC) involving a combination of liquid organic fertilizer (LOF), botanical pesticide, and a bacterial consortium to control M. incognita infection in Coffea arabica seedlings. The treatments in this study consisted of control, synthetic nematicide with the active ingredient fluopyram, and various FBC concentrations ranging from 20%, 40%, 60%, 80%, and 100%. The results demonstrated that the application of 60% to 100% FBC increased plant growth. The most effective and efficient treatment for increasing plant growth was the application of 60% FBC. When compared with control plants, 60% FBC treatment resulted in 6.8% longer root, 9.5% higher plant, 5.3% heavier plant fresh weight, and 4.8% heavier root fresh weight. We also found that the application of 60% to 100% FBC increased the amount of chlorophyll in leaves. FBC application also reduced the number of nematodes in the soil up to 60.6%, the number of galls up to 286.4%, and the severity of root damage up to 118.2%. This study indicates that the application of 60% FBC is the most effective and efficient in controlling M. incognita and stimulating the growth of C. arabica seedlings. Key words: Bacillus; pseudomonas; endophyte; rhizobacteria; fluopyram.

Plasmopara halstedii (Farl.) Berl. et de Toni is the oomycete that causes sunflower downy mildew (SDM). Traditional means of controlling this pathogen are using resistant hybrids, crop rotation and seed coating with fungicides. Disease control strategies that use a variety of approaches are becoming an increasingly essential aspect of pest management strategies. We conducted this exploratory investigation to evaluate whether specific plant resistance inducers might work against P. halstedii. In this study we used azadirachtin (AZA) a botanical insecticide; benzothiadiazole (BTH) and Trichoderma asperellum. Three-day-old susceptible sunflower seedlings were pre-treated with different doses of inducers for two hours. The seedlings were immediately inoculated of 7 different pathotype of P. halstedii. As a control, metalaxyl-M a systemic fungicide was used. Nine-day-old sunflower plant leaves were sprayed with bidistilled water to stimulate sporangial growth. In vivo experiments showed that BTH, T. asperellum and the highest doses of AZA significantly reduced downy mildew symptoms. The various pathotypes of the pathogen significantly affected the plant height and disease symptoms under experiments.

Sheath blight poses a major challenge in rice cultivation, with current control methods relying heavily on synthetic fungicides. Environmentally sustainable alternatives, such as bioactive compounds derived from agricultural waste, offer promising potential for integrated disease management. This study investigated the antifungal efficacy of rice husk-derived liquid smoke against Rhizoctonia solani, the causal agent of rice sheath blight, and identified its active compounds using gas chromatography-mass spectrometry (GC-MS) analysis. Liquid smoke was produced through the pyrolysis of rice husks and incorporated into potato dextrose agar at concentrations of 1%, 2%, 3%, 4%, and 5% (v/v). R. solani was isolated from infected rice plants, and its pathogenicity was confirmed on rice seeds and seedlings. The in vitro antifungal activity was assessed by measuring colony diameter and calculating the percentage of mycelial growth inhibition over 7 days. The results demonstrated that liquid smoke significantly inhibited the growth of R. solani in a concentration-dependent manner (p < 0.001; exact p = 4.36 × 10-²⁴), with the 5% concentration achieving 100% inhibition. Qualitative microscopic observations revealed morphological abnormalities in fungal hyphae at higher concentrations. GC-MS analysis identified 40 bioactive compounds in the liquid smoke, including phenolic compounds and organic acids, which are known for their antimicrobial properties. The findings suggest that rice husk-derived liquid smoke possesses potent antifungal activity against R. solani due to the presence of these compounds. This study concludes that rice husk liquid smoke can serve as an effective, eco-friendly alternative to synthetic fungicides for controlling sheath blight disease in rice cultivation.