The Effect Of Four Fungicides Sprayed In A Row To Soil And Sapling Growth Of Replant Apple Tree

This test is aimed to define the effect of chemical fungicide pesticide sprayed several times to replant apple tree and find a supporting application technology. A pot experiment which chemical fungicides mixed with soil was carried out to explore mancozeb, fludioxonil, thiram, carbendazim which sprayed in the first year%successively sprayed2years and successively sprayed3years in a new replanted apple orchord by testing the population of Fusarium, fruit tree growth, root activity, chlorophyll content of leaves and soil enzyme activity to determine the optimal frequency of four fungicides used.1. In field trials, four kinds of fungicides against harmful fungi(Fusarium oxysporum and Fusarium moniliforme) showed significant inhibitory effect which fludioxonil appeared the most obvious effect, mixed with soil when transplanting pesticide treatment, Fusarium inhibition rate of42.1%-53.7%sprayed in the first year and inhibition rate of52.4%-74.8%sprayed2years in a row. Followed by mancozeb, inhibition rate of36.3%-44.9%sprayed in the first year and inhibition rate of42.7%-66.4%sprayed2years in a row, the effect of carbendazim was relatively weak, but also significantly reduced the amount of harmful fungi and improve rhizosphere microenvironment. Two consecutive years spraying could have better inhibitory effect on the growth of Fusarium.2. There were significantly contribution to the growth of succession cropping young trees, enhancement on root activity of young trees and chlorophyll content of saplings, promotion of the growth of fruit trees and obviously ease of cropping obstacles, after treated soil with the four fungicides. Two consecutive years spraying of the four fungicides could have better growth-promoting effect on the fruit trees. Among of them, mancozeb worked best. The four fungicides all could improve root activity of the cropping fruit tree, and the fludioxonil performaed best. Fludioxonil, mancozeb and thiram all have significant improve on chlorophyll content of leaves in the fruit trees.3. Four fungicides investigation on soil enzyme in continuous cropping orchards, all the treatment on catalase, urease, sucrase and neutral phosphate in the soil have shown a "first suppression-after activating " dynamic changes. Among them, mancozeb could activate the activity of invertase and urease in cropping orchard soil, and the highest activation rates were 71.3%and48.1%sprayed2years in a row. Fludioxonil on soil catalase and invertase showed better activation activation and the highest rate was39.5%and79.5%sprayed2years in a row. Thiram showed bets activation on soil neutral phosphatase and the rate was62.2%sprayed2years in a row. Whether continuous spraying could improve soil enzyme activity for different agents had different results.4. According to the2011and2012survey results found that mancozeb to promote fruit cropping most obvious. The survey in2013showed that treatments for three consecutive years could further reduce the number of Fusarium which was close to the number of non-cropping soil. But the survey for the trees’ growth showed that spraying pesticide forl year or2years and3years successive, the moderating effect for fruit trees differed slimly which indicated that spraying mancozeb only once at the time of transplanting would be able to achieve better regulation effect, spraying for2consecutive years could gain small improvement on trees’growth. Moreover, trees’ growth was close to non-continuous cropping orchards. Therefore, mancozeb for controlling apple obstacles, spraying1or2times was best.