Study On Substrate Selection And Lower Irrigation Limit For Tomato Planting In Factory

This experiment used’Qiyan Aifen’tomato as the experimental material to study the effects of different ratios of seedling substrates on the quality of tomato seedlings,and also explored the effects of different irrigation thresholds on the growth,development,and physiological characteristics of tomato seedlings,with a view to selecting suitable substrates for industrialized tomato seedling cultivation,reducing seedling costs,and cultivating healthy seedlings,providing a scientific,energy-saving Provide reference and technical basis for economically industrialized tomato seedling cultivation technology.The test results are as follows:1.The composite matrix composed of peat,vermiculite,perlite,and corn straw with a volume ratio of 3:2:2:2 and the matrix composed of peat,vermiculite with a volume ratio of 2:1,namely,T₃treatment and CK treatment,have excellent indicators such as unit weight,aeration porosity,biomass accumulation,seedling strength index,and root activity,significantly superior to other treatments.Moreover,T₃treatment can achieve or significantly outperform CK in plant height,stem diameter,biomass accumulation,photosynthetic parameters,and other indicators,indicating that T₃treatment can replace CK as a suitable substrate for tomato seedling cultivation.Compared with CK,reducing the amount of peat by 55.22%can meet the requirements of tomato seedling growth to a certain extent.2.From the perspective of various indicators in the comprehensive experiment,the treatment with a lower irrigation limit of 70%had the best biomass accumulation,seedling strength index,root activity,chlorophyll content,photosynthetic parameters,and chlorophyll fluorescence parameters,and performed well in growth indicators,soluble sugar content,and soluble protein content.Although the treatment with a lower irrigation limit of 80%had the best plant height,stem diameter,tissue water content,relative water content,and free water content Free water/bound water is significantly superior to treatments with a lower irrigation limit of70%,which to some extent leads to plant overgrowth and increases ineffective water transpiration.In addition,during the experiment,its irrigation amount and irrigation frequency are significantly higher than other treatments,reducing labor efficiency.Treatment with 50%and 60%lower irrigation limits resulted in slow plant growth,severe water deficit in leaves,inability to maintain normal cellular metabolic activity,and significant accumulation of proline,soluble sugar,and MDA,resulting in drought stress in tomato seedlings.Therefore,W₂treatment with a lower irrigation limit of 70%can achieve the goal of water-saving,efficient,and high-quality seedling cultivation,and can be used as an ideal lower irrigation limit for tomato seedling cultivation.3.To sum up,a composite substrate composed of peat,vermiculite,perlite,and corn straw with a volume ratio of 3:2:2:2 is used as the seedling substrate for tomato seedling cultivation at a lower irrigation limit of 70%.This substrate can ensure the normal growth of tomato seedlings and the normal progress of various physiological activities.Under mild drought stress,it can play a role in water conservation,water conservation,and fertilizer conservation,and cultivate strong seedlings.