Fusarium wilt of Tulip

The disease is also known as tulip base rot. It is a fungal disease, which is specialized by Fusarium moniliforme and Fusarium oxysporum. It is host-specific and only harms tulips. All of them are caused by semi-known fungi. The pathogen overwintered with mycelia and chlamydospores in infected bulbs and soil. Under the condition of suitable temperature (20 ℃ ~ 34 ℃) and high humidity, a large number of spores were produced and spread by Rain Water sputtering. Excessive application of nitrogen fertilizer can aggravate the damage, and the application of compost with diseased remains not fully mature can also increase the chance of disease. The transportation of seed bulbs is helpful to the long-distance spread of the disease. Planting diseased bulbs often causes the disease. Tulips often occur during the growing and storage periods. June is the peak of the disease, the ball-carrying bacteria is the main way of transmission of the disease, and the wound on the seed ball and poor ventilation during storage are the main conditions for the epidemic of the disease. Among them, the serious damage of underground pests, the wet viscous weight of soil and the application of immature organic fertilizer are the main conditions for the disease in the field. Infected bulbs often produce ethylene, which affects neighboring bulbs or plants, making them vulnerable to diseases. Excessive application of nitrogen fertilizer in cultivation can aggravate the harm of the disease.

Mainly harmful to bulbs and roots. Most of the diseases occurred at the base of the corm. After the bulb was damaged, small light brown to gray spots appeared on the outer scales, and then the lesions gradually expanded to dark brown, and pink conidia piles could be seen on the diseased tissues in moist environment. The disease site finally shrinks and hardens. If the disease occurs at the base of the bulb, the spot will quickly spread to the outer scale of the entire bulb, and the base of the bulb will rot. The leaves from the susceptible bulbs are easy to yellowing and wilting, the flowers are easy to deform or wilt, the roots are sparse, and the whole plant dies prematurely. When the tulip flower withered, sporadic diseased plants appeared in the field, the leaves were yellow and wilted, the stems and leaves turned red and yellow ahead of time, the base of the branches rotted, showed loose fiber, and the roots were few, which were easy to pull out. Planting ball flow glue, starch tissue decomposes and decays. The outer scale of the disease ball in the harvest period produced bean grain colorless blister-like protuberance, glue or wet rot after blister was broken, the bulb rotted from outside to inside, some showed bluish gray wet rot, and some took the bulb disc as the initial infection point, the wet rot spread around, emitting the pungent smell of lees, and the disease spot was gray-white calcareous after drying. During the storage period, the bulb mainly showed glue flow, and then showed yellowish brown dry rot. If in the greenhouse, the infected plants will wither and die early.

Epidemic characteristics: the disease is easy to occur shortly after planting or when it is about to be harvested. When the soil temperature is higher than 15 ℃, it is beneficial to the spread of the disease.

Prevention and cure method

(1) when the weather is fine, the bulbs can be harvested in advance to prevent sunburn and abrasions. Within 48 hours, the dug bulbs can be soaked in 1000 times of 50% carbendazim wettable powder, soaked in 25 ℃ for half an hour and then dried, which can be disinfected. It can also be soaked in benzoate 1000: 2000 times solution for 15 minutes for 30 minutes within 48 hours, dry, low humidity (