اثر متقابل نوع و تاریخ کاشت با جمعیت‌ متنوع ژنتیکی کدو آجیلی بر شیوع بیماری سفیدک پودری

Butternut pumpkin is one of the important vegetable crops economically. The seeds have high nutritional value due to their edible oil and protein content with a high medicinal value. Butternut pumpkin is attacked by several diseases, of which powdery mildew (PM) is the severe one causing significant damages globally. Thus, in this study, the effect of sowing type and dates on fourteen genetically diverse Iranian local butternut pumpkin cultivars was analyzed for the incidence, and screening for resistance to PM. The two different sowing types and dates were carried out in the two open fields with a two weeks interval i.e. first and 3th weeks in April, and in the green-house. On an average, the results showed that the lowest (42%) powdery mildew severity percentage (PMS) was in the first field sown in the first week of April (field1) with a significant difference with the field2 (48%) (Sown two weeks later), indicating 6% increase in PMS in comparison to the field1 significantly. Whereas, in the green-house the PMS (55%) was higher than that of both the field trials with 10% increase in comparison to the field1 significantly. There were also significant differences between the related pumpkin cultivars in terms of PMS. In this regard, the highest PMS was recorded on”Orumieh1” (85%) followed by “Maragheh3” (82%), and the lowest ones on “Shahreza” (6%) and “Maragheh1” (9%) significantly. The resistant and moderately resistant genotypes remained almost constant in interaction with PM in the two related fields, and green-house. So, in this study, we established that integration of the early sowing and resistant sources, could influence the PM in the butternut pumpkins enabling the growers as a management practice of the PM appearance concurrently.