How to scientifically prevent and control Fusarium wilt and stem spot blight in sesame
I think many people are very familiar with sesame. Sesame has many benefits: it can be made into all kinds of small pastries, and it can also be pressed into sesame oil. So sesame has a great many uses and benefits, and for this reason sesame cultivation is gradually becoming more common now.
What is sesame
Sesame, also known as zhi ma or hu ma (scientific name: Sesamum indicum), is the seed of the hu ma plant, an annual erect herbaceous plant 60-150 cm tall. It is found throughout the world's tropical regions and parts of the temperate regions. Sesame is one of China's main oil crops and has high application value. Its seeds have an oil content of up to 55%. Since ancient times China has had many kinds of foods and delicious dishes made with sesame and sesame oil, and these have long been renowned throughout the world. Sesame is called the crown of the eight shares. Sesame is an oil crop, and the oil pressed from it is called ma oil, hu ma oil, or xiang oil; it is characterized by a mellow aroma and can be used both raw and heated.
Sesame Fusarium wilt, also called half-side yellowing or yellowing, is a typical vascular bundle disease. The pathogen mostly invades from the root tip and wounds of the seedling; after invading from the roots, the pathogen enters the vessels and spreads along the vessels to the stems, leaves, capsules and seeds, causing the whole plant to develop disease and die. The stem base of diseased plants turns reddish brown, the stem vascular bundles turn brown, and the leaves turn yellow, wilt and die. Sometimes, when only one side is infected, it appears as disease and death on only one side. When moist, the affected parts have pink mold-like growth. The pathogen of this disease overwinters in the soil, in diseased plant residues, or inside and on the surface of seeds. The disease begins in June and peaks in August. Continuous cropping of sesame fields, poor soil fertility, and high field humidity all favor the occurrence and spread of the disease.
Sesame prevention and control techniques
1. Choose disease-resistant varieties and treat seeds. Choose varieties with good quality, high yield, waterlogging tolerance and strong disease resistance, such as Yuzhi No. 8 and Yizhi No. 1. Before sowing, soak the seeds in 55°C warm water for 10 minutes or 60°C warm water for 5 minutes, then dry them and sow. Or mix seeds with pentachloronitrobenzene plus thiram (1:1), using an amount equal to 0.5-1% of the seed weight; or soak the seeds in 0.5% copper sulfate solution for half an hour. All of these give fairly good control.
2. Agricultural control. Soil-borne diseases and insect pests of sesame are serious, and continuous cropping is most avoided. Rotating sesame with cotton, sweet potato and grass-family crops for 3-5 years can control the occurrence and spread of the disease fairly well. After harvesting sesame, promptly remove diseased residues from the field, burn them in a concentrated manner or bury them deeply to reduce overwintering inoculum. Promptly pull out diseased plants and carry them out of the field for destruction to prevent the pathogen from spreading. Strengthen fertilizer and water management, apply more base fertilizer; the base fertilizer should be mainly medium- and slow-release organic fertilizer, mixed with phosphorus and potassium fertilizer; apply no or little nitrogen fertilizer at the seedling stage, so as to cultivate healthy seedlings and make it harder for the pathogen to invade. Use high-ridge cultivation and promptly clear ditches and drain water to prevent standing water in the field and lower field humidity.
3. Chemical control. The control of sesame diseases should be based mainly on agricultural control; chemical control should be by spraying for protection before the disease occurs, or by applying chemicals at the early stage of disease. Control agents include 37% Fusarium wilt Lik WP 800-fold solution, 40% carbendazim suspension 700-fold solution, 50% thiophanate-methyl WP 800-1000-fold solution, 80% copper sulfate WP 800-fold solution, and so on.
What is sesame stem spot blight
Sesame stem spot blight is also called sesame stem blight, sesame black root madness, and so on. It mainly harms sesame stems, roots and seedlings. When disease occurs at the seedling stage, the aboveground part of the diseased seedling wilts and dies, and the roots turn brown and die. After the stem is affected, the diseased stem first shows yellowish-brown water-soaked spots that develop rapidly into encircling spots; in the late stage the lesions become dark brown, after which the stem becomes hollow and breaks easily. After the roots are affected, the main root and branch roots gradually turn brown, and a large number of black sclerotia form in the root cortex, causing the roots to die. The pathogen of this disease overwinters as sclerotia on seeds, in soil and on diseased plant residues. The following year, conidia spread in the field by wind, rain and air currents, and mainly invade and cause damage from the stem base, roots and leaf stalks of the plants. Sesame is most susceptible at the seedling stage and the full flowering stage. Diseased plants can produce conidia that spread and infect again. High temperature, high humidity and abundant rain favor the occurrence and spread of the disease; excessive nitrogen fertilizer, overly dense planting and continuous cropping fields make the damage worse.
Sesame sowing methods
Sesame has three methods: dibbling, broadcasting and drilling. The seed rate per mu is 400 grams for broadcasting, 350 grams for drilling and 250 grams for dibbling. In fields with high soil fertility, few diseases and insect pests, and high water content, the sowing rate can be appropriately reduced.
1. Broadcasting: broadcasting is the traditional sowing method in the Jianghuai region and is suitable for sowing to catch soil moisture. When broadcasting, the seeds are evenly scattered and the soil cover is shallow, so seedlings emerge quickly, but it is not conducive to field management.
2. Drilling: drilling can control row and plant spacing, allows rational close planting, facilitates field management such as thinning seedlings and intertillage, and is suitable for mechanized operations.
3. Dibbling: dibbling uses 5-7 seeds per hole. Regardless of the sowing method, shallow sowing and even sowing, with a depth of 2-3 cm, are preferable.
In the process of growing sesame, disease prevention is very important. If diseases are well controlled, the yield can be greatly increased. Therefore, mastering sesame cultivation techniques and also mastering some methods of disease prevention are both very important.