Study On The Key Cultivation Measures And The Yellowing Characteristics Of Baking Of Yunyan 99 In Luzhou Tobacco Area

In order to better understand the key cultivation measures and the yellowing characteristics of Yunyan 99,through the method of single factor and camera Obscura test.A comparative test was carried out between this variety and the main Cultivar Yun 87,and experimental study on nitrogen application rate(7Kg/667m~2,6Kg/667m~2,5Kg/667m~2),transplanting date(April 15,April 25,May 5),planting density(1200 plants/667m~2,1100 plants/667m~2,1000 plants/667m~2),leaf number(20,18,16),harvest maturity(suitable,underripe,over ripe)and yellowing characteristics.The main resecrch results are as follows.1.This variety is generally superior to Yunyan 87,and the agronomic traits during the growing period of the field are generally superior,and the leaf area is larger than that of the control variety.The appearance quality of flue-cured tobacco is better than the control variety.The output value per mu is 235.27 yuan higher than that of the control variety.It is suitable as a promotion or reserve variety in the local production area.2.After topping of Yunyan 99,the number of effective leaves in the high-fertilization treatment is more than 2 pieces higher than that in the low-treatment.And Yunyan 99 has the highest yield and the highest output value of tobacco leaves under the use of 7 kg/667m~2of pure nitrogen.Under the experimental conditions,the variety should be applied pure nitrogen of 7 kg/667m~2.3.The effects of different transplanting treatments on the agronomic traits of Yunyan 99 in the field were not obvious.However,treatment 2 that planted at April25 was the highest output value,and the proportion of first-class tobacco was also high.The results show that,under the natural ecological conditions of Luzhou tobacco area,this variety is better planted at April 25.4.The effect of transplanting density on the agronomic traits of the variety is not obvious at the planting stage,the difference in the agronomic traits of tobacco plants after the prosperous period,and after topping,Tobacco plants with lower density have higher plant height,thicker stem circumference and longer pitch,but the output value is relatively low.In order to obtain better economic benefits,the planting density of this variety is 1100 plants/667m~2?5.The treatment with different number of leaves left had a certain effect on the agronomic traits of the tobacco plant after topping.With the increase of the number of leaves,the height of the flue-cured tobacco increased,and the stem circumference decreased,and the yield increased,and the output value decreased.It can be seen that for Yunyan 99,in order to obtain better economic benefits,18 leaves are best.6.From the test point of view,the economic benefits and tobacco quality of the mature harvest of this variety are higher than those of under-mature and over-mature.The proportion of the middle and lower part in the under-harvest variegated is the lowest,and the upper part is the highest,while is opposite when harvested overmaturation.Therefore,it is necessary to harvest the lower leaves when they are slightly mature,while the upper leaves should be harvested when they are more mature,but not when they are mature.7.The middle and lower leaves of this variety turn yellow faster and are easier to bake,but the lower leaves turn Brown faster,the middle leaves a little slower and the upper leaves turn yellow and turn Brown more slowly.8.The experiment shows that after the leaves lose part of the water,it is beneficial to roasting yellow Discoloration,better roastability.When the lower leaf loses 40%of water,the increase in yellowing slightly slows down.So,the lower leaves of this variety are suitable for baking at a slightly higher temperature and humidity,and the middle and upper tobacco leaves can be roasted normally according to the"three-stage"roasting theory.