Agriculture Reference
In-Depth Information
the soil preparation. These amounts of fertilizers were divided into three doses and
applied during the vegetative growth, during flowering and fruiting stage under gated
pipe irrigation system, while 14 equal doses were fertigated in both drip and low-head
bubbler irrigation systems (one dose every two weeks).
20.2.4 MEASUREMENT METHODS
20.2.4.1. SOIL MOISTURE DISTRIBUTION
Soil moisture percentage was determined gravimetrically on oven dry basis before
and after irrigation from planting to harvesting. On each sampling date, duplicate soil
samples were taken from soil at 0-15, 15-30, 30-45, 45-60 cm depths and at 0-15,
15-30,30-45 cm distance away from grape tree. The samples were immediately trans-
ferred into tightly closed aluminum cans to the laboratory. They were weighed, dried
in an electrical oven at 105 °C for 24 h then reweighed and the soil moisture contents
on the dry weight basis (
w
) were determined. The data were analyzed by SURFER
program under Windows computer application. The “Kriging” regression method was
used for analysis and contour maps were developed.
20.2.4.2 PLANT MORPHOLOGY
Leaf area (L
2
) by digital planimeter and leaves dry weight at 70 °C in (gm) were de-
termined [15]. Both length (cm) and dry weight (gm) of branches were determined in
the field after crop harvesting. The pruning weight per vine was determined in gm per
vine.
20.2.4.3 YIELD AND QUALITY PARAMETERS
Grape clusters were harvested when the total soluble solids (TSS) reached about 16 to
17 (prix) in berry juice [24]. Yield per vine was recorded in kg.vine
-1
at harvest time
during July of each season. Yield productivity (kg.fed
-1
) was determined by the fol-
lowing formula:
Yield product (kg/fed) = (Average Number of Clusters per vine ´ average weight
cluster ´ Number of vine per fed) (9)
A sample of 100 berries was randomly selected from different bunches for each irriga-
tion system. The berries were weighed and the average weight of berries per treatment
was recorded. Volume of berries was determined by immersing the 100 berries in a
graduated cylinder containing water at a fixed mark (V
1
). Water level was recorded
after immersion (V
2
). The volume of berries in cm
3
was calculated as (V
2
- V
1
). Juice
volume was determined by blending 100 grams of berries for each irrigation method
and by filtering through a fine muslin cloth. The pomace was pressed by hand until
no more juice was obtained. Juice volume in cm
3
was then measured in a graduated
cylinder. All observations were replicated thrice.
Sugar percentage (prix number) was carried out for the fresh extracted juice, which
was obtained by blending 100 berries, and total soluble solids content was also ob-
served using a hand refractometer [15]. The juice was thoroughly stirred and few of
drops were mounted on the clean stage of the refractometer after which the readings
were recorded.
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