LIBRO-CONGRESO-CITRUS

S11
composition, and growth parameters of ‘Fino 49’ lemon trees grafted on two rootstocks, Citrus macrophylla
and sour orange, were studied. This study was carried out in Santomera (Murcia) over a four-year period (2008-
2011) using seven-year old trees at the beginning of the experiment. Shade screen had similar effect in trees
grafted on both rootstocks. Shading increased the height and canopy perimeter producing trees with a greater
canopy volume than that under full sunlight (increase of about 60% compared with full sunlight trees). Despite
that, shading reduced fruit production. Trees under full sunlight produced in total 81 and 45 kg/tree, while
trees under shade produced 70 and 33 kg/tree, respectively for C. macrophylla and sour orange. Leaf water
status according to leaf water potential (Ѱw) and relative water content (RWC) was greater in trees under
shade screen. Shading affected the physical characteristics of the fruit from trees on C. macrophylla as fruits
under shade had less fresh weight and smaller width than fruits from trees under full sunlight. Leaf mineral
concentration was not affected by shading, except for B and Mn where the concentration increased by shading.
S11P06
Effect of liquid fertilizer applied by injection into the soil on quality of ‘Tarocco’ blood orange
He J., Chen K.L., Guan B., and Liu J.J.
Horticulture Research Institute, Sichuan Academy of Agricultural Sciences (HRI, SAAS), Centre of Fruit Research, China.
chen-kl@163.com
Experiments using four different treatments of liquid fertilizer (No. 1 to No. 4) and one treatment of compound
fertilizer (N:P 2 O 5 :K 2 O = 15:15:15) (No. 5) were conducted continuously for 3 years to compare the fertilization
effect on fruit quality of ‘Tarocco’ orange. The liquid fertilizer (containing humic acid and dissolved N, P, K)
was injected into the soil by pressure increasing device to a depth of 20 cm-30 cm. The results indicated that
the fruit of all liquid fertilizer treatments had higher content of total soluble solids (TSS) and total sugars
than those of compound fertilizer. The content of TSS increased by 13.5%, 14.4%, 7.2% and 2.7% and total
sugars increased by 25.9%, 24.7%, 11.5% and 6.7%, respectively for treatments No. 1, 2, 3 and 4, compared
to those of fruit from treatment No. 5. The content of total acid for liquid fertilizer was different. Treatment
No. 1 and No. 2 produced lower total acid content in fruit than did treatment No. 5 while treatments No.
3 and No. 4 produced higher total acid content. The fruits of treatments No. 1, 2, 3 and 4 also had higher
vitamin C content than fruit from No. 5 treatment. In short, the fruit quality of ‘Tarocco’ blood orange could
be improved by liquid fertilizer injection into soil.
S11P07
Effect of branch girdling and ringing on carbohydrates, chlorophyll fluorescence and SPAD index
in leaves of ‘Tahiti’ acid lime
Santos D. 1 , Siqueira D.L. 1 , Salomão L.C.C. 1 , and Cecon P.R. 2
1 Universidade Federal de Viçosa (UFV), Fitotecnia, Brazil; and 2 Universidade Federal de Viçosa (UFV), Estatística, Brazil.
lsalomao@ufv.br
This work evaluated the effects of girdling and ringing on the dynamics of carbohydrates, chlorophyll
fluorescence and SPAD index in leaves of ‘Tahiti’ acid lime. Three year-old trees cultivated in the subtropical
climate of Minas Gerais, Brazil, were used in the experiments. These practices were applied at 8 dates: June
30th 2009, July 15th 2009, July 30th 2009 and August 14th 2009 and June 15th 2010, July 5th 2010, July
25th 2010 and August 14th 2010 plus a control (not girdled nor ringed). Girdling and ringing were both
performed on the main branches of the trees, 10 cm above their insertion on the trunk. Greater contents of
starch were observed until 50 to 60 days after girdling on both 2009 and 2010 crops, returning to normality
around day 120 due to the reestablishment of phloem transport. Unlike girdling, the responses obtained
with ringing were mostly similar to those observed in control trees. Girdling reduced the ratio of variable to
maximal chlorophyll fluorescence (Fv/Fm relationship) in the 2009 and 2010 years. In 2009, trees subjected
to ringing presented maximum values of Fv/Fm similar to the ones of control trees on day 90 after incision.
In 2010, plants subjected to ringing did not present variation in Fv/Fm relationship over time, similar to the
control plants. Regarding SPAD index, results presented similar trends in both years. In the 2009 treatments,
all girdled trees presented a reduction in the index, reaching minimal values around days 80 to 90 after
incision. In 2010 treatments, those values were reached around days 100 to 110.
182 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012