Effects Of Partial Rootzone Irrigation On Growth And Physiological Characteristics In Apple And Water-saving Efficiency

In this article, a new economize irrigation technology-Partial Root zone Irrigation wasstudied. It included studying changes in physiology,growth and water-saving effect ofpartial root zone irrigation on apple. Using three-year pot apple trees called Royal Galawith their roots equably partitioned by a compound basin, which is binded by four plasticbasins with 20cm in both length and width and 36cm in height. The experiment designingof four irrigate quomodoes of root irrigation: 1/4 root zone irrigation (irrigating one fourthof the root),2/4 root zone irrigation (irrigating two fourths of the root zone),3/4 root zoneirrigation (irrigating three fourths of the root zone)and the whole root zone irrigation(irrigating the whole root zone),three different amounts of irrigation: 500mL per basinevery time,750mL per basin every time,1000mL per basin every time. The effects ofpartitioned root irrigation on LWP, Pn, Gs, new shoots, ABA content in root and leaf, trunk,root biomass and WUE were studied under 12 different treatments. The major results canbe summarized as below:1. Under the every amount of irrigation, LWP is notably different between one fourthof the root zone and the whole root zone irrigation treatment, but is not notably differentbetween two fourths and three fourths of the root zone irrigation treatment. It is not notablydifferent among two fourths, three fourths of the root zone and the whole root zoneirrigation treatments. The LWP in one fourth of the root zone irrigation treatment is at thelowest value all the time, while is at the biggest value in the whole root zone irrigation.Under the same irrigate quomodoes, the LWP at dawn isn't notably different among threeamounts of irrigation, but the LWP at noon is notably different between 500mL and1000mL amount of irrigation. The LWP under 500mL amount of irrigation is obviouslylower than that under 1000mL amount of irrigation.2. Under the every amount of irrigation, the photosynthesis in one fourth of the rootzone irrigation treatment is at the lowest value all the time, while is at the biggest value inthe whole root zone irrigation. The Pn is not notably different between four irrigatequomodoes under 750mL and 1000mL amount of irrigation. It is notably different betweenone fourth of the root zone irrigation and the whole root zone irrigation under 500mL amount of irrigation, while is not notably different among two fourths, three fourths rootzone irrigation and the whole root zone irrigation treatment. The photosynthesis in 500mLamount of irrigation treatment is at the lowest while is at the biggest value in 1000mLamount of irrigation treatment under the same irrigate quomodo, but they are not notablydifferent.3. Under the every amount of irrigation, the stomatal conductance in one fourth of theroot zone irrigation treatment is at the lowest value all the time, while is at the biggestvalue in the whole root zone irrigation. The stomatal conductance is notably differentbetween one fourth of the root zone irrigation and the whole root zone irrigation, while isnot notably different among two fourths, three fourths root zone irrigation and the wholeroot zone irrigation treatment. The stomatal conductance is not notably different amongdifferent amounts of irrigation under the same irrigate quomodo. The sequence of Gs underthree amounts of irrigation is: 1000mL＞750mL＞500mL.4. The growth of new shoots in one fourth, two fourths and three fourths of the rootzone irrigation are all inhibited more or less, furthermore the bigger the non-irrigation size,the stronger the inhibition becomes. The growth of new shoots is notably inhibited amongdifferent amount of irrigation under the same irrigate quomodo. The need of water is notsatisfied in one fourth of the root zone irrigation. The new growth of shoots is strictlyinhibited by 500mL amount of irrigation under the two fourths and three fourths root zoneirrigation. The growth of new shoots is increased by amount of irrigation under the wholeroot zone irrigation.5. Under the every amount of irrigation, the bigger the non-irrigation size the morecontent of ABA in leaf becomes. There is notably different between one fourth root zoneirrigation and the whole root zone irrigation. It is not notably different among one fourth,two fourths and three fourths of the root zone irrigation. The content of ABA in leaf isdecreased by amount of irrigation under the same irrigate quomodo. It is not notablydifferent among different amount of irrigation under one fourth and two fourths root zoneirrigation. It is notably different between 500mL, 750mL and 1000mL amount of irrigation,while it is not notably different between 500mL and 1000mL amount of irrigation underthree fourths root zone irrigation and the whole root zone irrigation.6. The ABA content of humid and droughty root is different under partial root zoneirrigation. There is not notably different among different irrigate quomodo under 500mLamount of irrigation. It is not notably different among different irrigate quomodo in humidroot under 750mL amount of irrigation. It is notably different between one fourth of theroot zone irrigation and three fourths root zone irrigation in droughty root under 750mLamount of irrigation. Under 1000mL amount of irrigation, it is not notably different indroughty root, but there is notably different among different irrigate quomodo. The contentof ABA in root is decreased by amount of irrigation under the same irrigate quomodo. It is not notably different among different amount of irrigation.7. Under 500mL amount of irrigation, the growth of basal trunk is not notably affectedby different irrigate quomodo. The growth of basal trunk is notably affected by threefourths root zone irrigation and the whole root zone irrigation under 750mL amount ofirrigation. It is notably affected by different irrigate quomodo under 1000mL amount ofirrigation. Under three fourths root zone irrigation and the whole root zone irrigation, thegrowth of basal trunk is notably affected by three amounts of irrigation.8. As the non-irrigation size become bigger, the growth volume of roots decreasesunder the same amount of irrigation. The smaller the amount of irrigation, the fewer thegrowth volume of roots. The growth of basal trunk is notably affected by 500mL and1000mL amount of irrigation.9. Without sacrificing the accumulation of biomass, the WUE under two fourths of theroot zone irrigation and 750mL amount of irrigation treatment is higher than that of othertreatments, but the biomass decreases only by 23.12% and water consumption reduces by50.61%, and the water-saving profit is significant.