Effect Of Wood Vinegar On Seed Germination And Growth Of Rapeseed And Its Application

As a byproduct of biochar processing,wood vinegar has multiple effects,such as promoting crop germination and growth,resisting stress,inhibiting bacteria,and killing insects.It can be used as a natural plant growth regulator similar to seed germination and coating technology,which is of great significance in solving the problems of low emergence rate and poor seedling quality of direct-sowing rapeseed.Therefore,exploring the effective components and mechanism of wood vinegar,and developing seed treatment technology that can effectively enter production and application,is of great significance for the large-scale promotion of machine sowing and aerial seeding in rapeseed production.This study used Huayouza 50 and Shengguang 165R as experimental materials to investigate the effects of 26 main components of wood vinegar on rapeseed germination and emergence,and screened out effective components and explored their mechanisms from the perspective of physiological metabolism;at the same time,seed germination,coating,and granulation technologies based on wood vinegar were developed with stable effects.Furthermore,these seed treatment technologies were validated and applied to cruciferous vegetables.The main results of the study are as follows:1.Most of the main components of wood vinegar had a promoting effect on rapeseed germination and emergenceSelecting 26 major components with relative content higher than 0.01%in wood vinegar for seed germination of rapeseed,various components could effectively promote the germination and emergence of rapeseed and the growth of seedlings.Among them,coumarin,2,5-dimethylphenol,and butyrolactone could significantly increase the emergence rate of rapeseed,with increases of 36.7%、30.0%,and 31.7%respectively;2-methoxy-4-methylphenol,resorcinol,and acetic acid could significantly improve the vitality of seedlings,with increases of 77.8%、74.1%and81.5%respectively.Combined with their effects on both germination and seedling growth,3-bromopentane,2-methoxy-4-methylphenol,and butyrolactone are recommended as preferred germination agents for rapeseed seed treatment.2.Using wood vinegar formula for seed germination,coating,and pelletization could promote the germination and emergence of rapeseed under stressful conditionsUnder drought,low temperature,and salt stress conditions,used the laboratory-optimized wood vinegar formula for rapeseed seed germination,coating,and germination+biomass char granulation treatment,the results showed that all three seed treatments significantly improved the germination rate and emergence rate under stress conditions,accelerated germination and emergence process,and promoted root growth and dry matter accumulation of rapeseed seedlings.Among them,the best-promoting effect was the seed germination+biomass char granulation treatment,which increased root length by 29.1%、48.8%,and 148.5%respectively,compared with the control,and increased total dry weight by 27.3%、39.3%and36.2%respectively.The vitality index of seedlings increased by 109.8%、238.1%and132.1%respectively.3.2-methoxy-4-methylphenol treatment significantly promotes rapeseed germination and enhances its drought resistance2-Methoxy-4-methylphenol treatment promoted rapeseed germination and seedling growth under normal and drought conditions.Compared with the control,the average germination time under normal conditions was shortened by 20.6%the vitality index of seedlings increased by 16.0%and root length and underground dry weight increased by 23.6%and 17.8%respectively.Under drought conditions,the average germination time was shortened by 46.4%the vitality index of seedlings increased by 74.3%and root length and underground dry weight increased by 22.1%and 13.8%respectively.Under drought stress,2-methoxy-4-methylphenol treatment could enhance the activities of catalase（CAT）and ascorbate peroxidase（APX）,decrease H₂O₂and O₂^·-content,increased proline and soluble protein content,increased photosynthetic pigments and net photosynthetic efficiency,and promoted dry matter accumulation of rapeseed.4.Seed treatment with wood vinegar formula significantly promoted rapeseed growth and increases field grain yieldThe use of formula germination,formula coating,and formula germination+biomass char granulation treatment could effectively improve the field emergence rate of rapeseed,promote plant growth,increase plant height,total number of leaves,green leaf number,leaf area,and dry matter weight,increase leaf area index,and improve the net photosynthetic rate and stomatal conductance.In terms of comprehensive promoting effect,the formula germination+biomass char granulation treatment performed the best.The field emergence rate of rapeseed was significantly increased,the growth process of seedlings was accelerated,the individual development was vigorous,and the final yield was increased by 21.1%-32.0%under normal sowing conditions and 37.7%-50.8%under late sowing conditions.However,considering cost and ease of operation,seed coating treatment was more suitable for large-scale promotion and application.5.The coating treatment of formula seeds significantly promoted the growth and yield of cruciferous vegetablesThe seed coating treatment with a wood vinegar formula was applied to six vegetable crops,including Shanghaicai,Suzhaocai,Shugu Xiaobai,Can Tai of rapeseed,radish,and radish sprouts.It was found that the treatment promoted various agronomic traits of field seedlings.Moreover,the performance of seed soaking+granulation treatment was better than that of seed coating treatment for rapeseed sprouts and radish.Both seed coating and seed soaking+granulation treatments for rapeseed sprouts increased the final yield by 44.4%and 102.2%compared to the control,respectively.For radish,the seed coating and seed soaking+granulation treatments increased the final yield by 27.9%and 37.4%compared to the control,respectively.The seed coating treatments for Suzhaocai,Shanghaicai,Shugu Xiaobai,and radish sprouts increased the final yield by 14.9%30.2%40.8%and 78.6%compared to the control,respectively.Therefore,the development of crop seed treatment technology using wood vinegar and biomass charcoal is not only beneficial for achieving cost-saving,stress resistance,and yield-increasing cultivation of crops but also for promoting the recycling of agricultural waste and promoting the sustainable development of low-carbon and green agriculture.