With the acceleration of the adjustment of planting structure, the demand for foraged sunflower seeds is increasing. Sunflower is an easy-to-manage, labor-saving and economical crop. Due to the excessively extensive field management and the continuation of many years of disease, many diseases have become more prevalent and have been increasing year by year, which has directly caused a decline in sunflower production, threatening its production and development and farmers' income. After several years of field investigations and experimental studies, the occurrence and control techniques of sunflower sclerotinia are summarized as follows. 1. The results of the survey on symptoms and incidence showed that before 1996, Sclerotinia sclerotiorum rarely occurred in our district. The incidence rate was less than 1.5%. It began to rise to about 3% in 1998, reached 5% in 1999, and was 8% in 2002. Around 2003, it reached 20.1%, and the severe block reached 45%. The heavy rain in October 2003 caused a large area of ​​sunflowers to fall, exacerbating the disease epidemic, and yield loss of more than 30%. There are two main manifestations of the disease in our district: stem rot and flower rot. Stem rot can occur in all parts of the stem, initially appearing on the stem surface oval brown lesions, gradually expanding, about 15 to 20 days after a large area of ​​dark brown lesions around the stem forming a buckle after the plant wilting death Or when the wind falls down, this type of symptoms is more common in the lower part of the stem or the head and neck. Flowers (spill) rot sunflowers appear water-stained hazel-like round lesions after flowering on the disk, expanding to a full disk to make the tissue rotten and soft, and there is no obvious foul odor after decomposition. When the weather is wet or in the rain, white mycelium will appear, and eventually black sclerotia will form. The bacteria can also spread to the front of the flower disk. The mycelium spreads among the grains, forming a black sclerotia network covering the flower disk. In the later period, the entire disk was dropped or some or all of the grain landed due to the decay of the disk structure. The symptoms on the grain are generally not very obvious. In severe cases, peels are bleached and white, and kernels are brown, losing their commodity and planting value. 2. Pathogens and epidemic pathogens are Sclerotinia, Sclerotinia, black. The disease occurred in the sclerotia of the stem and there were more sclerotia on the disk. The sclerotia are resistant to adverse environments. They still have viability in 10 minutes at -40°C or 55°C in hot water, and only rot in the flooded state for 30 days. When the conditions are appropriate, the sclerotium begins to germinate, and the mycelium can be directly formed into the host, and the ascitium plate can also form ascospores and ascospores. After the ascospore is transmitted to the host surface by wind and rain, it germinates into hyphae and causes sunflower disease. Pathogens in the form of sclerotia are overwintering in soil seeds, and the rate of seed colonization in severe sclerotiorum is more than 10%. The sclerotia are mixed in the seeds, and the pericarp, seed coat, cotyledons and embryos can carry the bacteria. After sowing can cause seedling death or seedling roots and rhizomes. Most of the sclerotia in the soil are distributed in a soil layer of 0 to 10 cm. The sclerotia germinates the mycelium directly from the wound and invades the root or stem of the sunflower. The sclerotia of the surface layer of the soil can produce apical discs and release ascospores. The spores can spread to the stems and leaves or faceplates with wind and rain, and can be directly or invaded from the wound. Pathogens secrete oxalic acid and some enzymes in the process of infection, if the gum enzyme, multi-fat lactaldehyde enzyme promote decomposition of the host tissue decomposition, disease symptoms. 3. The prevention and control technology due to the severe occurrence and harm of sunflower sclerotinia disease in 2003 brought a great deal of hidden danger to the production of sunflower in 2004. It mainly increased the number and density of seed bacteria and sclerotia in the soil, and should be adopted in control technology. The following measures. 3.1 The rotation sclerotia can survive for several years in the soil, and most of the vitality is lost after three years. Therefore, taking sunflower and grass crops for crop rotation can greatly reduce the incidence. The longer the rotation time, the better the effect, but it cannot be rotated with leguminous and cruciferous crops. 3.2 Doing a good job in rural hygiene The diseased plants, broken leaves, sick discs, and grains should be completely removed from the fields and burned to reduce the pathogens. 3.3 Seed treatment Imported from a disease-free zone or collected from a healthy disk, the sclerotia of the inclusions were selected and removed, and 50% Seroker WP and 50% sclerotium WP were used before seeding. 0.3% ~ 0.5% of seed dressing, control effect can reach more than 80%. 3.4 Flowering Timely Spraying When the sunflower buds and blossoms, in case of overcast or rainy days, or if it is a serious disease and even the land block, it should be treated as soon as possible. The medicine can be used 50% quick WP or 800 to 1000 times, or 50% Carbendazim WP 500 times, can also be used 40% sclerotin net wettable powder 500 times in the flowering period every 7 days after spraying 2 to 3 times, the control effect is significant.
We are specialized manufacturers from China, PCL nose lift suppliers/factory, wholesale high-quality products of Thread PCL R & D and manufacturing, we have the perfect after-sales service and technical support. Look forward to your cooperation!
PCL Thread Lift:reduces wrinkles, lines and creases
PCL PDO face lift: lifts and tightens saggy or flabby skin, improving definition
PCL PDO PLLA :naturally improves skin elasticity and texture
PCL lifting :brightens skin tone and complexion
PCL remove wrinkles: produces more defined facial contours such as cheekbonesPcl Thread Lift pdo threadcan sculpt more pleasing feature e.g. angle of the mouth
Natural, Beautiful, You---Auro thread
PCL Thread
Pcl Thread,Pcl Polycaprolactone,Pcl Eye Thread,Pcl Lifting Thread
Auro Technology Limited , http://www.aurocn.com