Study On Biological Characteristics And Related Control Theory Of Sagittaria Trifolia L.

Rice is one of the main crops in Heilongjiang Province,S.trifolia L.as one of the most important malignant weeds in rice paddy field,how to completely eliminate has been a thorny problem that you want to solve.S.trifolia L.has two breeding ways,seed propagation and corm propagation.Due to the depth of distribution of corms in the soil layer is different,the emergence time of S.trifolia L.was longer,which increased the difficulty of prevention.S.trifolia L.alias phylum,triangular cut,water taro.Perennial aquatic or marsh herbs.Leaf shape changeable,with leafy leaves,oval leaves and arrow type leaves three leaf shape.Underground rhizomes crossed,apex bulge was corms.In this paper using outdoor potting method,the biological characteristics and related control technology of S.trifolia L.were systematically and objectively studied,which provided a theoretical basis for the more scientific and effective control of S.trifolia L.The main results were as follows:1,The average per plant of corm propagation S.trifolia L.can be bolted 1.00-2.35,up to 6 bolting;can produce rhizomes 1.03-4.84,up to 9,rhizome sheaths 1.88-4.85,up to 9,newborn corms 1.00-3.73,up to 6.The arrow type leaves of corm propagation S.trifolia L.to reach 6-7 tablets,the underground rhizome began to occur.The number of rhizomes and the number of bolting were most relevant,followed by the number of leaves,temperature is an important factor.The number of newborn corms and the number of bolting,number of rhizomes,number of rhizome sheaths were most relevant.2,The emergence of corm propagation S.trifolia L.in the absence of water had a long duration.With water treatment,the emergence time was neat.The depth of the water layer had little effect on the emergence time and emergence rate.Corm sowing the more shallow,the earlier emergence time,sowing deeper,the lower the emergence rate,sowing depth of 20 cm or more,the emergence rate was very low.No water treatment,sowing depth of 5-20 cm range,with the sowing increased,the number of leaves and bolts decreased.No water treatment between different sowing,the number of rhizomes,number of rhizome sheaths and number of newborn corms were no significant difference.Sowing depth of 15 cm with water treatment,the largest number of leaves,bolts,rhizomes,rhizome sheaths and newborn corms of S.trifolia L..3,Distribution depth of newborn corms of corm propagation S.trifolia L.was 3-37 cm,10-30 cm depth within the maximum number of corms.Corms size diameter of 0.63-1.20 cm,longitudinal diameter of 1.65-2.30 cm.Overyear investigated the number of newborn bulbs decreased,distribution was more concentrated,but the size was not reduced compared with the second year survey.4,Emergence characteristics of corms and seeds of S.trifolia L.:(1)When the temperature conditions at 25/10 ? or more,that was to meet the corm propagation S.trifolia L.emergence of the temperature requirements.The higher the temperature,the smaller the temperature difference,the faster the emergence,the faster the leaf growed and growing the better.Under low temperature conditions,the seedlings growed faster than the roots,under high temperature conditions,the roots growed faster than the seedlings.The root growth was more affected by the temperature.(2)Under different light intensity conditions,the emergence rate and growth of corm propagation S.trifolia L.were similar,only the plant stem intensity was different.Completely shading treatment can also emergence,but the survival time was not long.(3)The terminal buds of S.trifolia L.corms after destruction can not germinate.(4)Seed sowing depth of 1cm and 2cm with the highest emergence rate of S.trifolia L.,the emergence time of 3cm and 4cm was later than that of sowing depth of 1cm and 2cm,the seed can not germinate at sowing depth of 5cm and 6cm.5,The application of herbicides before the S.trifolia L.formation the corm can reach the purpose of eradication of two kinds of propagation ways.The best effect of two kinds of herbicides with MCPA-sodium or MCPA-sodium-bentazon.The effect of controlling the number of newborn corms of application herbicides after formation the corm was not better than application herbicides before the formation the corm.The best effect of controlled the number of the corms was MCPA-sodium,the best effect of controlled the size of the corm was MCPA-sodium-bentazon.