Studies On Key Epidemic Links Of Tomato Leaf Mould Caused By Fulvia Fulva (Cooke) Cif.

In thesis, key epidemic links including germination of spores, spore production oflessions, incubation period and the rate of symptom appearance, spore spread, spacedistribution model, the resistiance to the pathogen of diffirent cultivars and fungicidescreening for tomato leaf mould caused by Fulvia fulva (Cooke) cir. On the base of aboveresearch, control measurements for the disease were put forward.Spores germinated easily in the pure water but the appressorium formation wasobserved. Surface substance of the leaves could stimulate spores germination. The sporeswere of the ability to resist dry conditions, but germinated spores died in 3～4 days under dryconditions. Optimmal temperature for germination was 23℃. Darkness was useful for thegermination of the spores. The higher the relative humidity was, the more the sporesgerminated. Optimal humidity for spores germination was in drip. The longer dew time wasuseful for the spores germination and infection. Three regression equations on the rate ofspore germination in relation to dew time, temperature and relative humidity were established.When more water was penetration into the leaves and relative humidity reached to81%-85%, lesions could sporulate. Suitable temperature for the sporulation of lesions was10～25℃, and 23℃was the optimal temperature. Lesions did sporulate under 4℃and over35℃. Lesions sporulated either in dark or scattered light, but more sporulation produced indark than in scattered light. Capacity of producing spores was influenced by differentchemical fertilizer. Nitrogen were stimulative to spores production but Phosphor Kalium wereinhibitory to them.6-9 d lesions could produce more spores, but 1-2 d lesions could hardlysporulated. The larger lesions were, the more spores produced.Incubation period of the disease was affected by the varieties and the humidity period.Different seeding time had number effect on the incubation period and the period ofsymptoms appeared in the disease. The regressive equation was established between theaccomulated symptomatic appearance in relation to the rate of every day symptom appear andthe rate of accumulated symptom appear. Infection against ability of tomato were effected bythe kinds of fertilizers. P could decresed the infection ability and K could increased the infection ability.In the same condition of simultaneous and equal quantity of iNumberculation, the lesion number ofsingle plant was effected by the varieties. The plants had resistance diversity under the different chemicalfertilizers levels. The plant of supplied P fertilizers could reduce infection than supplied K fertilizers.Thegrowth stage of the plants did Numbert effect the resistance to the tomato leaf mould.Spores spread mostly in the evening. Distribution model of the disease was established.Through Inhabition zone and conidia germination screening indoor, effective pestides were chosenout such as Thiram 900×, Carbendazo 900×, Previcur-n 900×, Nustar 8500×, Polyram 700×, the controlefficacy of these fungicide in the field were 90.2%, 91.76%, 91.67%, 91.02%, 91.39% respectively.