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1.黄麻根腐病为黄麻新的问题,目前了解的主要分布地区为浙江省沿钱塘江两岸的肖山、杭州市郊、原杭县等麻区。1954—1957年各地黄麻圆果种的平均发病率在14.7—24.6%以上。2.本病为害黄麻根及莖基等部分,使形成褐腐。病部不收缩,或微现收缩。后期病菌侵入输导组织,木质部形成黄褐色。8月下旬后,在病部出现大小约0.63×0.36毫米扁平不整形的黑色菌核,为本病的重要标志。3.本病以为害黄麻成株期为主。从6月下旬开始渐次出现病株,高峯期为8月下旬至9月下旬。在沙壤土中,地温(5厘米)平均在28—30℃,每旬降雨量在70毫米左右可以诱致严重发病。在一定温度下,雨量多少关系于发病程度极重要。4.经接种证实,本病为真菌Papulospora sp.所致,在病组织及普通培养基上不见分生孢子。生长发育以25—30℃为最适。矿物营养在缺碳时生长最差,缺氮时生长无大影响,迅速形成大量菌核;如加入蛋白腖,菌丝不复变色(白色),菌核不能形成。钾及磷对病菌生长发育的影响仅次于碳。5.含粘粒在10%以下的轻松土壤为最有利的发病环境。连作或轮作,对发病关系极为明显,多年连作地发病率较多年轮作或2—4年轮作地高7—53倍。6.笨麻主要是受不良环境影响的生理病态。在这种生长较衰弱的笨麻上最易遭病菌侵害而发生根腐病。所以笨麻中病株率极高,特别在病原菌大量积累的轮作地为甚。7.在接种或多年连作地上肥料施用不合理,可以导致发病而減产。油粕作为基肥有减轻发病的趋势,效果并不显著,但可视为对生物防治的一种启发。8.病组织中的菌核,在10及20厘米深度砂壤土,历时15个月以后,粘壤土11个月以后,即失去生活力;而放置土面的,在3年测定中仍具生活力。9.以人工接种法测定本病原菌对浙江省麻区主要作物寄主范围的结果,除黄麻圆果种为最主要寄主外,黄麻长果种、花生、苜蓿、洋棉、中棉、蚕豆等均可以不同程度的被感染。在自然情况下,黄麻长果种、花生、苜蓿等均可以被寄生而发病。10.严重病区或病地进行3年以上的轮作,深耕15厘米以上,同时清洁病地等措施都很必要,尤其在多肥(氮素30斤以上/亩,密植25,000株以上/亩)时更为重要。严重病地苜蓿必须在地温15℃以下即耕入土壤。
1. Jute root rot is a new problem of jute. At present, the main distribution area for jute root is Xiao Sha, Hangzhou suburbs and Yuan Hang County along the Qiantang River in Zhejiang Province. From 1954 to 1957, the average incidence of jute round fruit variety was above 14.7-24.6%. 2. The disease damage jute roots and stems and other parts, so that the formation of brown rot. Disease does not shrink, or micro-contraction. Later pathogens invade the lead tissue, forming xanthophyll xylem. In late August, in the diseased part of the size of about 0.63 × 0.36 mm flat non-plastic black sclerotia, an important indicator of this disease. 3. The disease to harm jute into plant-based. From late June gradually began to diseased strains, the peak period from late August to late September. In sandy loam soil, the average ground temperature (5 cm) is between 28 and 30 ° C, and a daily rainfall of around 70 mm can cause serious morbidity. At a certain temperature, the amount of rainfall is very important in the degree of disease. 4 confirmed by vaccination, the disease caused by the fungus Papulospora sp., In the diseased tissue and normal medium no conidia. Growth and development to 25-30 ℃ for the most appropriate. Mineral nutrition is the worst growth in the absence of carbon, no significant effect on the growth of nitrogen deficiency, rapid formation of a large number of sclerotia; such as adding protein 腖, mycelium no longer change color (white), sclerotia can not form. Potassium and phosphorus on the growth and development of bacteria impact second only to carbon. 5. Containing clay in less than 10% of the soil as the most favorable environment for the disease. Continuous cropping or rotation, the incidence of the relationship is extremely obvious, even for many years the incidence of rotation compared to many years or 2-4 years crop rotation 7-53 times. 6 stupid linen is mainly affected by adverse environmental physiological pathology. In this weaker growth of stupid on the most vulnerable bacteria and root rot. Therefore, stubborn plant disease rate is extremely high, especially in a large number of pathogens accumulate rounds staggering. 7.Inoculation or years of continuous use of fertilizer on the ground unreasonable, can lead to disease and cut. Oil meal as a base fertilizer to reduce the incidence of the trend, the effect is not significant, but can be regarded as a biological control of a kind of inspiration. 8. Sclerotia in diseased tissues, sandy loam at depths of 10 and 20 cm lasted for 15 months and the clay loam lost its viability after 11 months; on the other hand, force. The result of artificial inoculation method to test the main crop host range of this pathogen in the area of Zhejiang province showed that except for the main host of jute circle fruit variety, all the varieties of jute, peanut, alfalfa, foreign cotton, cotton, Can be infected in varying degrees. In natural conditions, jute longan fruit species, peanuts, alfalfa, etc. can be parasitic and disease. 10. Severe ward or disease for more than three years of rotation, deep plowing more than 15 cm, while cleaning the disease and other measures are necessary, especially in more fertilizer (nitrogen more than 30 pounds / mu, dense planting more than 25,000 / mu) When more important. Severe land alfalfa must be below 15 ℃ in soil temperature that is plowed into the soil.