As strawberry enters the flowering fruiting stage, there are more and more diseases on leaves and fruits, of which strawberry powdery mildew and gray mold are the most serious. Both of these diseases are caused by fungi. In severe cases, they can reduce the yield by more than 50% and seriously affect the yield, quality and economic benefits of strawberries.

Normal strawberry fruit

The fruit of the disease

First, the main symptoms </ strong>

1, strawberry powdery mildew </ strong>

The main hazard to strawberry leaves and fruits, but to harm the fruit-based, will produce a white powder on the surface of the fruit. Early fruit infection can affect the fruit development can cause a stiff fruit, in the late lead to uneven fruit coloring, fruit softening; leaf damage in the back of the leaves produce white filamentous, powdery, new leaves are more susceptible than the old leaves, sicker Leaf edge rolled up, the late yellowish brown; powdery mildew in severe cases can also endanger the petioles, calyx and peduncles, the incidence of white powder-like parts of the disease when the petals turn red, the impact open.

2, strawberry gray mold </ strong>

Strawberry gray mold is one of the most important diseases in flower and fruit stage. The reddish brown calyx is one of the main symptoms of early gray mold disease. Young fruit damage Pedicle was softened by water stains, leading to the development of the cessation; fruit has been turned color victims, the early emergence of brownish brown spot stains, the rapid expansion of humidity, the rigid fruit decay, soft flesh, the surface gray mold layer; Starting from the leaf margin, there are dark stains, ranging in size, the late reddish brown spot, leaf margin atrophy, Jiaojiao, the typical feature is the incidence of gray mildew mouse species.

Second, the incidence of </ strong>

1, strawberry powdery mildew </ strong>

Strawberry powdery mildew caused by fungi, the greenhouse production throughout the reproductive period can occur, the first year in November, the second half of March the next year is the period of high incidence of disease, at a temperature of 15-25 ℃, relative humidity of 40-80% easy Incidence and spread, the temperature above 35 ℃ or below 5 ℃ on the disease inhibition, the production of planting density is too high, poor lighting, poor ventilation, air humidity or nitrogen fertilizer more prone to disease.

2, strawberry gray mold </ strong>

Botrytis cinerea is caused by fungi, and Botrytis cinerea belongs to the "low temperature and high humidity" type disease, which occurs mainly after flowering, prone to disease at temperatures of 18-20 ℃ and relative humidity above 60%, night The temperature is less than 10 ℃ less susceptible to disease, usually from early January to late March for the high incidence of disease, excessive irrigation, plastic film water, nitrogen fertilizer and more density and shed ventilation can be induced when the disease.

Third, the prevention and treatment of technical points </ strong>

1, strawberry powdery mildew </ strong>

(1) Agricultural Prevention and Control: timely remove old leaves and dead leaves </ strong>.

(2) Prevention and treatment of medicaments: 200% of biocontrol agent 2% wuyiencin, 48-72 g / mu of Bacillus subtilis (1000 million spores / g), 8000 times of oligozoan hyphae and 0.5% Ether agent 90-120 ml / acre, 5% amino oligosaccharides 50-100 ml / acre spray control; also can choose 42.4% of the pesticides fluoride pyronaridine 8226; pyrazole azoxystrobin 1000-1500 times, 42.8% trifloxystrobin 8226; Fluopyram (Lorenase) 1500-3000 times, 10% difenoconazole water dispersible granules 900-1500 times or 4 % Tetrafluoroether azole (Taco wheat) 50-83 g / acre spray prevention and treatment, spraying the main leaf spraying the back, each interval of 7 days, continuous spray 3 times. Frequent use of drugs should pay attention to the alternate use, to avoid resistance.

2, strawberry gray mold </ strong>

(1) Agricultural control: </ strong> Remove diseased plants in time and dispose of them in a bucket filled with medicinal solution; pay attention to scientific ventilation and proper ventilation for a short time in cloudy days to reduce humidity; avoid excessive Nitrogen fertilizer should be increased by the application of phosphorus and potassium fertilizer; in the pathogenesis of increased winds will be reduced to 50% humidity, closed shed temperature will be increased to 35 ℃, boring shed 2 hours, then the wind cooling, continuous bored 2-3 times To significantly inhibit the role.

(2) Preventive treatment: Trichoderma (200 million live spores / g) WP 500 times, oligozoannula 8000 times, 5% amino oligosaccharides 50- 100 ml / mu, spray stems and leaves, but also the choice of 50% boscalid 1500 times the water dispersible granules, 50% fludioxonil WP 4000 times or 50% 1000 times powder spray, every 7 days 1, continuous spraying 2 to 3 times, it is recommended alternate spraying, in order to avoid resistance, but also the use of Kling smoking agent for fumigation.

Prevent strawberry growth stage disease, </ strong> prevention is the most important work, </ strong> to monitor greenhouse temperature and humidity changes, timely ventilation, observe the occurrence of strawberry disease, early detection and early treatment </ strong> to really get a good return.