- OOMYCETE DISEASES OF CUCURBITS 295
diseases, thus well-drained fields should be selected and excessive irri-
gation should be avoided. Also, cucurbit crops should not be planted
in areas of the field that have poor drainage.
Non-vining cucurbit crops (e.g., summer squash) should be planted
on dome-shaped raised beds (approximately 25 cm high). The field
should be scouted regularly for Phytophthora symptoms, especially
after major rainfalls, and particularly in low areas of the field. When
symptoms are localized in a small area of the field, the infected plants
should be plowed into the soil. Healthy fruit should be removed from
the infested area and they should be checked for disease development
routinely. Growing cover crops (e.g., mustards) and mulching with plant
materials including straw and rye vetch can also be used to minimize
the dispersal of the pathogen.
Chemical Control.Until 2000, there were no effective fungicides
that could controlP. capsiciin cucurbits. Since then, however, several
fungicides have been developed that can protect cucurbit crops against
P. capsici(Babadoost and Islam 2003; Babadoost 2013). Timely applica-
tions of effective fungicides can now minimize losses of cucurbit crops
toP. capsici.
Fungicide seed treatment and foliar spray application can prevent
seedling death and reduce foliar blight and fruit rot. Seed treatment
with either mefenoxam (Apron XL LS at the rate of 0.42 mL kâ^1 g seed)
or metalaxyl (Allegiance FL at the rate of 0.98 mL kgâ^1 seed) can protect
seedlings of cucurbits againstP. capsicifor up to 5 weeks after planting
(Babadoost and Islam 2003). Spray applications of fungicides can
provide effective protection against foliar blight and fruit rot caused by
P. capsiciin cucurbit fields. Effective fungicides againstP. capsiciare
ametoctradin+dimethomorph (Zampro 525F), cyazofamid (Ranman
400SC), dimethomorph (Forum 4.16SC), famoxadone +cymoxanil
(Tanos 50WDG), fluopicolide (Presidio 4SC), mandipropamid (Revus
2.09SC), mefenoxam (Ridomil Gold EC, Ridomil gold Copper 65WP),
phosphonates (Agri-Fos, Phostrol, ProPhyt), and zoxamide+mancozeb
(Gavel 75DF). Spray application of fungicides should begin at the first
sign of the disease and applied at weekly intervals throughout the
season. Applications of fungicides with different modes of actions
should be alternated. Label guidelines of fungicides should be carefully
followed.
Integrated Management.No cucurbit varieties with measurable resis-
tance to P. capsici are available. Management practices currently
include selecting fields with no history ofP. capsici, crop rotation
with nonhost crops and effective weed control for 4 years, fungicide
seed treatment, minimizing soil moisture, sanitation, avoiding using