Effectiveness of mustard short-cycle cover crops for management of Phytophthora capsici and Fusarium spp. in cucurbits

Biofumigation;Brassica juncea L. ‘Florida Broadleaf’;Sinapis alba L. ‘Tilney’;Phytophthora capsici;Glucosinolates

Thru Ppoyil, Shaijal B. ; Babadoost ; Mohammad

关键词: Biofumigation;    Brassica juncea L. ‘Florida Broadleaf’;    Sinapis alba L. ‘Tilney’;    Phytophthora capsici;    Glucosinolates;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/24199/ThruPpoyil_Shaijal.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This research was conducted to determine the effectiveness of mustard Brassica juncea L. ‘Florida Broadleaf’ (FBL) and Sinapis alba L. ‘Tilney’ for management of Phytophthora capsici and Fusarium spp. in cucurbits. To accomplish this goal laboratory, greenhouse, and field studies were conducted during 2008-2010. In the laboratory studies, mustard extracts were tested for inhibition of colony growth, sporangia production, zoospore germination, and oospore germination of four P. capsici isolates (PC-1, PC-2, PC-3, and PC-4). In addition, the mustard extracts were tested for inhibition of colony growth of F. oxysporum (F-2 and F-3) and F. solani (F-1) isolates. The FBL extract significantly reduced the colony growth of all four isolates of P. capsici compared to that of control treatment. In addition, FBL extract significantly reduced the sporangia production of PC-1 isolate of P. capsici compared to that of control treatment. FBL and Tilney extracts significantly reduced sporangia production of PC-3 isolate of P. capsici. The FBL extract significantly reduced germination of P. capsici oospores compared to that of control treatment. None of the mustard extracts significantly affected zoospore germination of any of the isolates of P. capsici. The FBL+Tilney and Tilney extracts significantly reduced colony growth of F-3 isolate of F. oxysporum and F-1 isolate of F. solani, respectively, but colony growth of other Fusarium isolates were not affected.In the greenhouse trial, thirteen glucosinolates were detected and quantified in both FBL and Tilney mustard cultivars. FBL roots had significantly lower total glucosinolate content (µmol/g) than FBL foliage. Conversely, Tilney roots had significantly higher glucosinolate content (µmol/g) than Tilney foliage. Mean total glucosinolate content (µmol/g) was not significantly different for FBL and Tilney cultivars. Sinigrin was the major glucosinolate detected in both FBL and Tilney cultivars. Mustard extracts were tested against P. capsici crown infection of ‘Eureka’ cucumber, ‘Magic Lantern’ pumpkin, and ‘Dickinson’ pumpkin in the greenhouse. None of the ‘Eureka’ cucumber seedlings were infected by P. capsici. However, all of the ‘Magic Lantern’ pumpkin seedlings were infected. The FBL+Tilney and FBL extracts significantly reduced P. capsici crown infection in ‘Dickinson’ pumpkin seedlings compared to the control. Four field trials, including 2008-spring, 2008-fall, 2009-spring, and 2010-spring were conducted in two fields in Tazewell County near Pekin, Illinois. Both fields had naturally infested soils with P. capsici and a history of Phytophthora blight. Similar to the greenhouse trial, 13 glucosinolates were also detected and quantified in the field grown FBL and Tilney cultivars. Foliage of FBL and Tilney did not significantly differ in total glucosinolate content (µmol/g) compared to that of roots. Mean total glucosinolate content (µmol/g) was also not significantly different for FBL and Tilney cultivars in the field trials. Sinigrin and glucoalyssin were the major glucosinolates detected in FBL and Tilney cultivars, respectively. No glucosinolates were detected in soil samples collected after incorporation of mustard plants into the soil. This was likely due to hydrolysis of glucosinolates in the soil samples at higher temperatures during the transit of soil samples from the fields to the laboratory. Biomass (gram fresh weight/m2) of mustard plants collected from 1 m2 area of field plots was determined. Mean biomass was the lowest in 2008-fall and the highest in 2008-spring field trials. Mean biomass of FBL and Tilney mustard cultivars was not significantly different from each other in any of the trials. Mean glucosinolate content in mustard plants incorporated to 1 m2 area of the plots (µmol/ m2) was the lowest in 2008-fall and the highest in 2008-spring trials. In the field trials, following incorporation of mustard plants, ‘Eureka’ cucumber, ‘Magic Lantern’ pumpkin, and ‘Dickinson’ pumpkin were seeded and monitored for P. capsici and Fusarium spp. infection on the plants. No Fusarium infection was detected on any of the cucurbit plants. Also, P. capsici did not infect any of the ‘Eureka’ cucumber seedlings and vines in the field. None of the mustard treatments significantly reduced vine- and fruit-infection byP. capsici in the cucurbit crops tested. Soil samples were collected before and after incorporation of mustards to determine density of P. capsici oospores and Fusarium spp. colony forming units (cfu). The FBL+Tilney treatment significantly reduced oospore density of P. capsici and cfu count of Fusarium spp. in the plots incorporated with mustard plants compared to the same plots before incorporation of mustard plants. Mustard incorporation into the soil did not affect seed germination of the cucurbit crops used in this study.