Effects Of Artificial Culture Substrates On Growth And Development Of Rhododendron

Peat is one of the main cultivation substrates for potted plants,and it is a non renewable resource.The quantity of peat is limited.The use of agricultural waste to replace peat can greatly reduce the cost of matrix and is beneficial to environmental protection;rhododendron has a high ornamental value,but due to the inappropriate physical and chemical properties of the substrate,the growth of Rhododendron is poor.This experiment took "Baifeng 4" Rhododendron as experimental material,and studied the effects of 4 organic substrates,rice straw,corn straw,cottonseed shell and sawdust of pine tree,on the growth,physiology and development of Rhododendron in potted plants,in order to screen out the suitable culture matrix for the potted Rhododendron,for the protection of peat resources and the agricultural and forest waste reuse to provide theoretical reference.The results of the test are as follows:1.Compared with the original soil,the content of nutrient elements N,P,K,Cu,Zn,Fe,Mn and Mg in the substrate was generally high,the total N content was up to 12.78%,the effective P reached 81.23 mg/kg,and the effective K was up to 7353.66.The content of effective Cu?Zn?Fe?Mn?Mg,358.05,75.50,17.80,respectively,respectively,75.50 mg/kg.2.The two groups of composite substrates that fermented rice straw and cottonseed shell significantly promoted the plant growth of Rhododendron seedlings.The plant height,plant size and diameter of seedlings of rice straw composite substrates were 39.98 cm,22.40 cm and 7.15 cm respectively,which were significantly higher than those of other groups.The number of new leaves,the number of new branches,the fresh weight of root,branch and leaf in the cottonseed shell composite substrate were significantly higher than that of the other groups,66 new leaves,7 branches of new branches,fresh weight 15.22 g of root,11.39 g of fresh shoots and 9.86 g fresh weight,followed by the compound matrix of corn straw and rice straw,and there were significant differences between each group.3.The root activity of the Rhododendron seedlings cultivated with cottonseed shell as the main component was 631.46,followed by the cultivation matrix of the rice straw as the main component 538.73,the corn straw group,the pine sawdust group in turn and the control group was 169.01,and there was a significant difference between each group.4.The chlorophyll content of the Rhododendron with cottonseed shell composite substrate was 50.17 mg/g,which was significantly higher than the other groups,and there were significant differences.The content of fluorescent pigment F0,Fv and the ratio of Fv/F0 and Fv/Fm were also higher than those of the other groups,but the difference was small.5.In the weak light greenhouse,the protective enzyme activity of SOD and POD of Rhododendron with cottonseed shell composite substrate was significantly higher than that of other groups,and the soluble sugar content of the leaves was significantly higher than that of other substrates,which indicated that the Rhododendron cultivated in the cottonseed shell composite substrate had a stronger resistance to light resistance,followed by rice straw.And corn stalk compound matrix.6.The nutrient elements in the leaves of Rhododendron were determined after 120 days in different substrates.The results showed that the highest total nitrogen content was 2.6994% in the leaves of the Rhododendron plants cultivated by the cottonseed shell composite matrix,and the rice straw compound matrix,the corn stalk compound matrix and the pine sawdust composite matrix decreased in turn,and the lowest total nitrogen in the control group was contained.1.3403%,there was a significant difference between each group.The total phosphorus content in the leaves of the rice straw composite matrix was the highest,0.2302%,the other four groups were slightly lower,the significant difference between the groups was smaller,the highest potassium content in the sawdust group of the pine tree was 0.1151%,and the other four groups decreased in turn,and there was no significant difference between the groups.7.Four different composite substrates had certain effects on flowering of Rhododendron seedlings.The single branch of the cottonseed shell group was 17 branches per plant,and the rice straw group branched 12 branches / plants,but the number of bud number of rice straw was the highest,the average 8 per plant,the cottonseed shell group were 6 / plants,and the three groups of corn straw,pine sawdust and original soil decreased in turn,except for rice straw and cottonseed hull,there was no significant difference among the groups.In the flowering period,the flowering rate of the rice straw composite matrix was 100%,the flower amount was 8~17,the single flower diameter was 74.06 mm,the flowering rate of the pine sawdust group was 66.7%,the flower amount was 2~8,and the single flower diameter was 69.08mm;the flowering rate of the control group was 50%,the flower amount was 3~5,the single flower diameter was 65.27 mm,the maize straw stalk compound matrix and the cottonseed shell composite matrix bloomin,the rate is 16.7%,the flower volume is 1 and 7,and the single flower diameter is 74.06 mm and 69.44 mm respectively.From the flowering condition,the mixed substrate of rice straw group is more suitable for potted plants of Rhododendron.To sum up,combined with the comprehensive effects of substrate on the growth and development of Rhododendron plants,the fermented rice composite substrate is most suitable for potted plants of Rhododendron.The above experimental results have important guiding significance for searching for peat substitutes for agricultural and forestry wastes in potted flowers and recycling of agricultural and forestry wastes.