اثر توزيع يكنواخت و غير يكنواخت بر رشد، عملكرد و وضعيت تغذيه اي گوجه فرنگي در كشت هيدروپونيك

چكيده انگليسي :

Effect of Equal and Unequal Distribution of Salt on Growth Yield and Nutrition Status of Tomato Grown in Hydroponics Culture Abbas Dara abbas dara@ag iut ac ir Date of submission March Department of Soil Science Isfahan University of Technology Isfahan Iran Degree M Sc Language FarsiA H Khoshgoftarmanesh Assist Prof amirhkhosh@cc iut ac irH Shariatmadari Prof shariat@cc iut ac irAbstract Limitation of high quality water resources and expansion of saline soils are the main challenges foragricultural development in many areas of the world particularly in Iran The increasing need for foodproduction for the world growing population raised the importance of efficient management and application ofmarginal quality resources like saline waters The salinity related researches up to now have been directed intwo main aspects including increasing crop salt tolerance and introducing new management practices controllingthe effects of salt stress on plants On the other hand different researches show the positive effects of rootpartial drought stress on regulating some mechanisms improving the plant water use efficiency In this study theeffect of equal and unequal distribution of salt in tomato root media on water use efficiency was investigated The tomato seedlings were grown in a hydroponic system under four levels of equal and unequal salt dS m usingdistribution treatments In equal salt distribution treatments four salinity levels i e andNaCl applied in nutrient solution In unequal salt distribution treatments the root was physically divided in twoparts where one was placed in nutrient solution and the other part in NaCl solution with and dS m salinity levels Then the root and shoot biomass and the plant water consumption were determined at the earlyflowering and fruit set stages The plant nutrition status at flowering and some fruit quality parameters atmaturity were also studied In equal salt distribution treatments the salinity decreased the root and shoot dry and fresh weight Withincrease in salinity the plant water consumption was also decreased as such the consumed water per biomassremained unchanged for different salinity levels Calcium magnesium and potassium concentration in the plantroot and shoot decreased with salinity while the sodium concentration increased sharply On the other hand salinity improved some quality attributes such as acidity the dry matter weight and the dissolved solids in thefruits In unequal salt distribution treatments at lower salinity levels and dS m due to the reduced root growthand the absence of nutrient elements in NaCl solution the plant biomass decreased while at higher salinitylevels and dS m despite the root growth impairment and reduced nutrient absorption the plant biomasswas similar to the control Salinity on the other hand decreased the water consumption significantly that in turncaused an increase in water use efficiency as the consumed water per plant biomass Unequal distribution ofsalinity increased the calcium but decreased the potassium concentration in the tomato root and shoot Thetreatments did not significantly affect the plant iron magnesium and sodium uptake In conclusion the results ofthis investigation showed that a controlled partial salinity stress on plant root could considerably decrease theplant water consumption and improve the water use efficiency Regarding the expanding saline lands in thecountry salt distribution management in the root zone may be considered as a useful practice to improve theplant growth and water use efficiency Key Words Salinity Tomato Hydroponics Water Use Efficiency Nutrient uptake

دارا، عباس

اثر توزيع يكنواخت و غير يكنواخت بر رشد، عملكرد و وضعيت تغذيه اي گوجه فرنگي در كشت هيدروپونيك

تنش شوري , كارايي مصرف آب , جذب عناصر غذايي , PRD