Global: Boscalid Control of Early Blight Fell From 70–75% to 30–40% in Swedish Field Trials
주요 테이크 아웃
- 70–75% boscalid efficacy in Swedish trials in 2014
- 30–40% boscalid efficacy after 2015 in the same trials
- 90% of Swedish isolates carried the F129L QoI mutation
- 300 P-days trigger first early blight spray in Wisconsin
중요한 이유
- 농부들을 위해
- Start early blight sprays at a risk threshold such as 300 P-days and alternate SDHI, triazole and other groups instead of repeating one product
- 프로세서용
- Ask growers how they manage early blight resistance, since defoliation late in the season cuts yield and dry matter
- 공급업체용
- Offer Alternaria resistance testing and position SDHI products only in mixtures with a partner from another FRAC group
60초 요약
SDHI fungicides against early blight can wear out in a handful of seasons, and that changes how growers should plan the spray programme. Swedish trials at Nymö recorded boscalid giving about 70 to 75% control in 2014 but only 30 to 40% after 2015. Laboratory work traced the loss to SDH mutations that rose from rare to dominant within three years, with mutant isolates needing over a hundred times more active ingredient. Roughly nine in ten isolates also carried the F129L change linked to strobilurin failure. Wisconsin specialists see the same QoI problem in their fields and time the first spray by a heat model, at 300 P-days, which early plantings had passed by late June 2026. The message for agronomists is to mix and alternate groups and to test local fungal populations. The mutation figures come from one Swedish study, and the situation in other regions may differ.
Early blight fungicides can lose their effect within a few seasons. A Swedish study showed this clearly for boscalid, an SDHI fungicide. The paper appeared in the European Journal of Plant Pathology on 22 October 2021.
Field trials ran at Nymö from 2014 to 2017. In 2014, boscalid controlled early blight with an efficacy of around 70–75%. After 2015 there was a clear drop, down to 30–40%, the authors wrote.
Laboratory tests explained the drop. In 2014, the SdhC-H134R mutation was found at several sites, but at a low frequency. By 2017, most samples carried either SdhB-H278Y or SdhC-H134R. Wild-type isolates were highly sensitive, with EC50 values below 1 µg/mL. Mutated isolates had EC50 values above 100 µg/mL.
평일. 한 번의 클릭으로 구독을 취소하세요.
Strobilurins were already weak. About 90% of the Swedish population carried the F129L substitution, which reduces sensitivity to QoI fungicides. Reduced field efficacy of boscalid has also been reported in several other countries, the authors noted.
Timing sprays with P-days
In the United States, the University of Wisconsin uses a heat-unit model called potato physiological days, or P-days. A value of 300 or more marks the threshold for early blight risk. It triggers the first preventive fungicide application.
By 20 June 2026, early plantings at two Wisconsin sites had passed that mark. Spring Green reached 386 P-days and Arlington 377, according to the extension vegetable pathologist Amanda Gevens. For late blight, the same service uses a disease severity value of 18 or more as the spray trigger.
The Wisconsin update also warns of substantial resistance to QoI fungicides, including azoxystrobin, in the local Alternaria population. Its product list includes SDHI and triazole options, such as boscalid, fluopyram and difenoconazole.
중요한 이유
Early blight is often treated as a minor, late-season disease. Yet the Swedish data show that a single fungicide group can lose half of its field effect within about three seasons. When both QoI and SDHI groups weaken, few tools remain.
Growers should start sprays by a risk model, not by the calendar. They should also alternate modes of action and use mixtures with a partner from a different group. A resistance test of the local Alternaria population helps to choose that partner.
예방 및 통제 · 편집자 주
조기 마름 (Alternaria solani): 재배자들이 할 수 있는 일
- 예방: Balanced nitrogen, crop rotation, removal of infected haulm volunteers.
- 모니터링 : Start sprays by a risk model, such as 300 P-days, not by the calendar.
- 화학적 보호: Difenoconazole (FRAC 3), boscalid (FRAC 7), azoxystrobin (FRAC 11) and copper (FRAC M1). Check the national register of your country.
- 저항 관리: Use groups 11 and 7 no more than two or three times per season, only in mixtures.
이 안내문은 potatoes.news 편집팀에서 정보 제공 목적으로만 작성되었습니다. 특정 회사의 추천 사항이 아니며, 의무적인 사용 지침도 아닙니다. 해당 국가에서 허가된 식물 보호 제품만 사용하고 제품 라벨의 지침을 따르십시오. 제품명 및 등록 번호는 국가마다 다를 수 있으므로 현지 농업 전문가와 상담하십시오.
Photo: Early blight (Alternaria solani) on a potato leaf (illustrative). Linnea Stridh / 위키 미디어 공용, CC BY-SA 4.0
글로벌 감자 개요
주요 뉴스 5가지, 가격 정보, 질병 경보 및 행사 소식. 평일 아침, 광고 없음.
지우면 좋을거같음 . SM
- European Journal of Plant Pathology — Rapid emergence of boscalid resistance in Swedish populations of Alternaria solani (Mostafanezhad et al., 22 October 2021) — https://link.springer.com/article/10.1007/s10658-021-02403-8
- University of Wisconsin–Madison, A. Gevens — Vegetable Crop Update (28 June 2026) — https://vegpath.plantpath.wisc.edu/2026/06/28/vegetable-crop-update-jun-21-2026/
이 자료에 링크되어 있습니다.
- 국가
- 세계
