| This essay took Fruit Tree Fallen Leaves pears and apples as objects, andDangshan crisp pears, Jaderit pears and Gala apples as trying materials. The bagswere three-layer paper bag (yellow outside, black middle, white inside ), double-layerpaper bag (yellow outside, black inside ), single-layer yellow stripe paper bag andyellow plastic film bag, which are all often used by fruit farmers in the fruitproduction. Compared with non-bagging, this essay made a systematic study on bags'micro environment after bagging, fruits' growth and development, peel chlorophyll,peel anthocyanin, fruit surface rust spot, fruits' outer properties and innerproperties, the results as follow:1.Through survey the rate of light through different bags, temperature differenceand humidity difference inside and outside bags after bagging, this essay studied themicro environment in the bags. The results indicated that:1)The rate of light through three-layer paper bag and double-layer paper bag wasalmost zero, that of plastic film bag to the highest: 86.9%, and that of single-layeryellow stripe paper bag was 12.7%.2)Temperature changes inside and outside bags in the same day was dynamic.Generally, the temperature inside bag was higher than that outside bag during day, thetemperature outside bag was higher than that inside during night, and the temperatureabsolute difference during day was higher than that during night, the temperaturedifference of three-layer bag and double-layer bag was higher than that of single-layerbag and plastic film bag. The temperature difference maximum of three-layer bag anddouble-layer bag occurs at 2p.m and that of single-layer bag and plastic film bagusually occured at 10a.m.3)Humidity changes inside and outside bags in the same day was also dynamic.Generally the humidity inside bag was higher than that outside bag during day, andthe situation was on the contrary during night. The humidify absolute differenceduring day was bigger than that during night. The humidify difference maximum ofthree-layer bag and double-layer bag usually occured at 4p.m, and that of single-layerbag and plastic film bag occured at 2p.m. Among all the bags, the humidity difference inside and outside plastic film bags was the biggest and that of three-layer bag wasrather small.2.Through survey the volume of fruits growth of different bagging methods, thisessay studied fruits' growth curve and growth speed. The results indicated that:Different bagging methods don't change fruits' growth curve and the curve was stilldouble Scurve. But fruits' volume increased differently during the same survey time,that was to say, different bagging methods made growth speed different. The fruitsbagged in plastic film bag grow fastest and the volume increased by 40.9ml per 15days on average; The fruits bagged in three-layer paper bag grew most slowly and thevolume increases by 31.6ml per 15 days on average; The fruits bagged in double-layerpaper bag increased a little more slowly than that in three-layer bag and the fruitsbagged in single-paper bag increased at the same speed as that without bagging.3.Through survey volume increase amount and the average content of peelchlorophyll of bagging fruits and non-bagging fruits respectively 10 days aftergirdling of stock fruit, this essay studied the influence of peel pigment reducing onfruits growth in the same period of time at different stages after bagging. The resultsindicated that: After bagging, fruit growth was affected by peel chlorophyll reducingin affected extent and the influence was much more in the latter half time then in thefirst half time, which showed that peel chlorophyll had a certain effect on fruitgrowth.4.Through survey the contents of peel chlorophyll of different bagging methods,this essay studied the changing rule of peel chlorophyll contents and their differencesin different bags. The results indicated that: peel chlorophyll contents changed in acertain rule during the whole growth process. In this case, single-layer bagging andplastic film bagging were similar to non-bagging while peel chlorophyll contentsbagged in three-layer bags and double-layer bags showed the tendency of droppingexcept a small rise at the end of July and the beginning of August. Peel chlorophyllcontents in different bags were quite different, Chlorophyll content in double-layerbag was the lowest, only 0.013mg/g, much lower than that non-bagging 0.114mg/g,and the peel was yellow white; Chlorophyll content in plastic film bag was close tothat non-bagging 0.102mg/g, and the peel was green; Chlorophyll content inthree-layer bag was a little higher than that in double-layer bag and the peel wasyellow white; Chlorophyll content in single-layer bag was in the middle, and the peelwas light green.5.Through survey peel anthocyanin contents in different bags regularly, thisessay studied the changing rule of peel anthecyanin contents and their differenceswhen the fruits were picked. The result indicated: Bagging had certain influence onthe changing rule of peel anthocyanin during fruit growing proccess, but the influencewas not greet. Peel anthocyanin changing rule in single-layer bag and plastic film bagwas identical to that non-bagging and had little effect on fruit coloration, three-layer begging and double -layer bagging promoted fruit coloration obviously both in youngfruit period and before fruit picking. Peel anthocyanin contents in these two periodswere higher than that non-bagging. The anthocyanin contents in different bags werequite different after taking off the bags. Anthocyanin of the fruit bagged in three-layerand double-layer bag synthesized fast and the contents were high, 8.3U and 8.65Urespectively which was much better than non-bagging; Anthocyanin content of thefruit bagged in plastic film bag was also much higher than that non-bagging;Single-layer bagging didn't promote fruit coloration desirably, and anthocyanincontent was similar to that non-bagging.6.Through counting the rust spot index of Jaderit under the circumstance ofdifferent bagging methods, this essay studied on the influence of different bags anddifferent bagging time on rust spot forming and relevant. The results indicated thatamong different bagging methods, the rust spot index of pears bagged in plastic filmand double-lager paper bag was the lowest: 41.4. This bagging method had the besteffect. The rust spot index of pear non-bagged was the highest: 89.2. There wereobvious different among different bagging methods. As to bagging time. the indexwas the lowest: 37.0 if pears were bagged during the first ten days of may, and theindex was the highest during the late ten days of may. In short, it could prevent fruitrust effectively if pears were bagged with plastic film bag and double-layer bag duringthe front ten days of may, and other bagging methods and time would cause more rustspots at different degree.7.Through survey outer properties and inner properties of fruits bagged indifferent bags, this essay studied the influence of different bagging methods on fruits'outer and inner properties. The results indicated that three,layer bagging and double-layer bagging could improve fruits' outer properties, especially could make the peelcontain more anthocyanin, make fruits have higher coloration index, make fruit dotsmaller, peel thinner and fruit surface more smooth. But this method would reducesingle fruit's weight at a certain extent, Compared to three-layer and double-layerbagging methods had less effect on fruits' outer properties, but could prevent diseases,insect pets and pollution. Plastic film bagging could also increase single fruit's weight.As for fruits' inner properties, different bagging methods had certain effect on fruitsbut not remarkable. Compared with non-bagged fruits, bagged fruits contained lessmelting solid contents and melting sugar contents. Bagged fruits except fruit in plasticfilm bag contained higher acid content amount than non-bagged fruits, but thedifferent was not remarkable.
|
PDF Full Text Request