Plant Protection News (Vestnik Zashchity Rasteniy)

Effectiveness of processing spring wheat crops with Novochizol complexes

S. V. Burlakova — 2025-06-24

The effectiveness of twofold treatment of spring wheat with Novochizol complexes supplemented either with copper ions [Novochizol + Cu2+] or with copper ions and Chitosan [Novochizol + Cu2+ + Chitosan] was assessed. Field experiments were carried out on leached chernozem of the forest steppe of the Ob region of the Novosibirsk Province. Under conditions of moisture deficiency in 2022–2023, concurrent with a moderate level of Septoria disease development, the treatment with both complexes was ineffective. In the case of a high level of disease development, the effectiveness of the [Novochizol + Cu2+] complex reached 46 %, which is 1.5 times lower than the effect of crop protection using the standard chemical fungicide Titul Duo. The complexes under investigation showed practically no protective effect against powdery mildew, including the cases of its high prevalence, whereas the Duo Title reduced the development of the disease by 85 %. The crop treatment with Novochizol complexes displayed a growth-stimulating effect on the quality of wheat plants. In particular, the biomass accumulation increased 1.3–1.5 times, plant height increased by 15–16 %, flag leaf area increased by 16–17 %, productive bushiness increased by 3–9 %, and ear structure improved by 17–30 %. The crop treatment with [Novochizol + Cu2] or [Novochizol + Cu2+ + Chitosan] complexes allowed for an additional yield of 0.3 t/ha, while the use of the Title Duo provided 0.4 t/ha yield gain.

Efficacy of pelargonic acid on non-cropped lands

A. S. Tkach — 2025-06-24

This study presents the results of a two-year field experiment (2022 and 2023) conducted on non-cropped lands in Leningrad region near of All-Russian Research Institute of Plant Protection. The aim of the study was to evaluate the biological effectiveness of pelargonic acid on non-cropped lands. The experimental setup included an untreated control and four different application rates (0.3; 0.5; 0.7 and 1.0 l/100 m2) of pelargonic acid. The experiments were carried out in randomized block design with four replications in accordance with the guidelines for testing herbicides. Net plot size was 25 m2. During the experiments, annual and perennial dicotyledonous, as well as annual cereal weed species, were found on the experimental plots. The total number of weeds in the experimental plots exceeded 250 plants/m2. It was revealed that a few hours after treatments, such weeds as Echinochloa crusgalli, Fallopia convolvulus, Polygonum lapathifolium, Chenopodium album, Spergula arvensis and Sonchus arvensis regardless of their stage of development turned brown and withered. Sinapis arvensis and Erodium cicutarium were less sensitive to treatments with 0.3 and 0.5 l/100 m2 of pelargonic acid. The pelargonic acid caused only temporary control against weeds. In the present study, the weeds recovered about 15 days after treatment: new shoots of Echinochloa crusgalli began to appear on all plots treated with pelargonic acid and did not differ compared to the untreated control. By the 30 days after treatment, the shoots of annual dicotyledonous weeds began to appear on plots treated with 0.3 l/100 m2 of pelargonic acid. The data obtained from experiments indicate that the use of pelargonic acid as a herbicide can be considered as a component of an integrated weed management strategy. Its use as a stand-alone tactic seems most appropriate on non-cropped lands, in cases where rapid weed control is required, and the duration of the protective effect is a less important factor.

Impact of weed management strategies on their growth, community composition, and yield of wet direct-seeded rice under alternate wetting and drying irrigation

M.K. A. Bhuiyan — 2025-06-24

Water management systems of wet direct-seeded rice (WDSR) and alternate wetting and drying (AWD) have proven to be effective resource-conserving (RC) technologies for rice production. However, weed management (WM) practice in RC technology has not been adequately addressed in the literature. This study aimed to investigate weed dynamics and integrated weed management strategies in WDSR under the AWD irrigation system. Two field experiments were conducted with seven weed management options over two consecutive growing seasons, 2009–2010 and 2010–2011, at the Bangladesh Rice Research Institute, Gazipur. Results showed that the weed species Scirpus juncoides, Echinochloa crus-galli, and Cynodon dactylon were the most important. By contrast, Fimbristylis miliaceae, Cyperus iria, and Lindernia floribunda seemed to belong to the least important group. Weeds that interfered up to 55 days after seeding had a significant impact on rice growth and yield. Over time, weed dominance ranking changed. The application of herbicides mefenacet+bensulfuron methyl and pyrazosulfuron ethyl along with one-hand weeding effectively reduced weed growth, leading to higher weed control efficiency and grain yield. These two treatments reduced the weed-related indices, and increased the crop resistance.

First report of the fungus Allophoma zantedeschiae on the white goosefoot Chenopodium album in Russia

M. M. Gomzhina — 2025-06-24

The white goosefoot Chenopodium album is a widespread and harmful weed in Russia. A fungal strain MF-32.211, morphologically similar to Phoma, was isolated from C. album leaves exhibiting leaf spot symptoms. Multilocus phylogenetic analysis, based on sequences of the internal transcribed spacer and the large subunit rDNA, as well as partial β-tubulin and the second largest subunit of RNA polymerase II, allowed for identification of the fungus as Allophoma zantedeschiae. Bioassays demonstrated that it is pathogenic to C. album, causing necrosis on intact leaf segments. The pathogenicity was confirmed by re-isolation of A. zantedeschiae from infected leaves. This is the first report of A. zantedeschiae on C. album, which was not previously known as a host for this fungal species. Additionally, this is the first record of A. zantedeschiae in Russia.

Testing of the fungus Akanthomyces muscarius (Ascomycota: Hypocreales) against the spider mite on lotus under high temperature conditions

G. V. Mitina — 2025-06-24

The entomopathogenic fungus Akanthomyces muscarius (Ascomycota: Hypocreales) strain G-033 VIZR was tested against the spider mite Tetranychus urticae on the lotus Nelumbo nucifera in a water greenhouse. At elevated air temperature (33–36 °C) and an outbreak of the pest (up to 800 specimens per leaf), biological efficiency of fungal conidia (5×10⁷ spores/mL) was high, up to 90 % on 7^th day post treatment, which is comparable to the standard treatment with Fitoverm, CE 2 g/L. One month after, no spider mites were found on the treated leaves. In the second year, when the pest density was low (up to 250 specimens per leaf), a reduced concentration of spore suspension (5×10⁶ spores/ml) was used. Its biological effectiveness was also high (up to 95 %). The trials showed the potential of strain G-033 VIZR against the motile stages of spider mites under conditions of elevated air temperature.

First report of the natural infection of Cephaleuros virescens causing algal spot on avocado leaves in the Philippines

M. A. Balendres — 2025-06-24

The avocado Persea americana is an important tropical fruit that is a good source of vitamins and minerals, as well as fatty acids and lipids. It is also an important fruit tree for growers as a source of livelihood. In April 2024, severe infections of algal spot characterized by circular, orange to brown spots were observed on the leaves of avocado plants grown in Guagua, Pampanga, Philippines. Based on morphology, the pathogen associated with the algal spot was identified as Cephaleuros virescens. This is the first confirmed record of C. virescens on avocado leaves in the Philippines.