Study On The Effect Of Application Of Possium Fertilizer On The Growth And Development In Fruiting Period Of Tomato In Substrate Culture

The research was to further explore the regulation of potassium fertilizer on the dry matter transport and distribution, nutrient absorption and distribution, and fruit quality indexes such as carotenoids content so that we can make more reasonable modes of topdressing potassium fertilizer.“Dongsheng T01”tomatos were used as test materials.And the drip irrigation system was used for potassium fertilizer treatments by 5 different amounts(The potassium fertilizer amount of every plant was 0 g,1.75 g,3.50 g,5.25 g and 7.00 g respectively)when the first inflorescence bloomed.The research method of source-sink growth unit(every tomato infructescence and the 3 leaves below the tomato infructescence were to form a source-sink growth unit)was used in the research.And the plants were divided into three source-sink growth unit.After analysing the effects of potassium fertilizer on the dry matter transport and distribution, nutrient absorption and distribution, and fruit quality indexes such as carotenoids content,the following main results were obtained:1.Potassium fertilizer had significant effects on the nutrient absorption and distribution of tomato.Topdressing potassium fertilizer had effects on N, P, K content(concentration)every tomato infructescence,total nutrient absorption of every source sink-growth unit and fruit nutrient distribution rate, but the degree of effects were changing with the time and the extent of effects existed differences among every tomato infructescence.The N, P, K content of every tomato infructescence increased with growth time.The effects of potassium fertilizer on N and K content of every tomato infructescence in each time period reached significant level, but the effects on P content did not reach significant level in later period. The total nutrient absorption of every source sink-growth unit and fruit nutrient distribution rate increased with advance in growing period,and the improvements on both of them were significant.2.Potassium fertilizer had significant effects on the dry matter accumulation and distribution of tomato.Potassium fertilizer had a very significant impact on dry matter accumulation of source-sink growth unit and translocation into the fruits duringthe blooming and fruit setting period. The amount of dry matter accumulation of every source-sink growth unit increased with time, and increased first and then decreased with the increase of the amount of potassium fertilizer.In addition, potassium fertilizer topdressing had significant improvements on the dry matter accumulation of every tomato infructescence,because it can not only improved dry matter of each source-sink growth unit translocation and distribution into every tomato infructescence, but also improved the fruit dry matter accumulation rate and prolonged the duration of rapid accumulation.3. Potassium fertilizer topdressing had different effects on each form index of tomato fruits.The potassium fertilizer topdressing had significant promotion on the horizontal diameter of the first and second tomato infructescence,but had not significant effect on the horizontal diameter of the third tomato infructescence in the later period.It only had significant promotion on the vertical diameter of every tomato infructescence in the early fruit setting period.It had weak influence on type index of every tomato infructescence,but the degree of influence did not reach the significant level.It had significant promotion on the fruit volume of first tomato infructescence in each period,but had significant promotion on the fruit volume of second and third tomato infructescence only in the early fruit setting.4. Potassium fertilizer had significant effects on the yield of tomato.Except for T1, the yield of per plant and plot under other potassium fertilizer treatments were significantly higher than those of CK, and those were the biggest under T3 treatment.But ti had different effects on the fresh weight of single fruit of every tomato infructescence during different growth periods. Potassium fertilizer had significant effects on the fresh weight of single fruit of the first tomato infructescence in each period,but had no significant effect on it of the second and third tomato infructescence in early fruit developing period.This effect law was same to the effect law of potassium fertilizer on fruit volume.5.Potassium fertilizer topdressing had different effects on three kinds of caroteinds of tomato fruits.The potassium fertilizer had significant inhibition on the lycopene content of every tomato infructescence,and the degree of the inhibition decreased gradually with the increased infructescence.In addition,there was an significant negative correlation between the treatments and β-carotene content,lutein content of the first infructescence,while they rarely affect β-carotene content and lutein content of the second and third infructescence through affecting nutrient absorption.6.Potassium fertilizer topdressing had certain effects on the VC, nitrate content and other quality indexs of tomato fruits. These nutrients content were influenced by a variety of factors.Although potassium fertilizer topdressing had certain effects in the blooming and fruit setting period,the effect of every tomato infructescence was different. And the influence lawof potassium fertilizer on the different nutrients content of the same tomato infructescence was different.The rational application of potassium fertilizer could significantly increase the VC content of second and third tomato infructescence, but the effect on the VC content of the first tomato infructescence was weak.Although it can significantly decrease the nitrate content of the first tomato infructescence,but the effect on the nitrate content of the second and third tomato infructescence was weak.It could significantly decrease the organic acid and increase soluble protein and soluble solid of every tomato infructescence.In terms of the yield,the optimum fertilizer amount was T3 treatment,equal to topdressing 5.25 g per plant.But in terms of dry matter accumulation and distribution,nutrient absorption and distribution,and fruits morphological indexes and so on,the optimum fertilizer amount were different among every tomato infructescence.The optimum fertilizer of the first tomato infructescence were generally T2 treatment,however the optimum fertilizer of the second tomato infructescence were generally T3 treatment,the optimum fertilizer of the third tomato infructescence were generally T3 or T4 treatment.When applying potassium fertilizer,we shoud decide the usage according to the development situation of each tomato infructescence.It was more conducive to the growth and development of tomato fruit, so that each tomato infructescence harvested can reach the standard of high quality and high yield.