الفهرس 
Response of Newhall Orange Trees to Different Agro-chemicals Foliar SpraysOnly 14 pages are availabe for public view
 |  | from | 96 |  |  |
| | | from | 96 | | |
Abstract
The present study was carried out during two successive seasons 2016 and 2017, on
8 years old ”Newahll” orange trees (Citrus sinensis, L.), budded on sour orange rootstock, trees were planted in sandy soil in the Agricultural experiential station at Rasheed area,
Beheira, Governorate, Egypt, the trees were spaced at 5×5 m apart and irrigated by surface irrigation system.
This study was aimed to evaluate the effect of foliar application of some agrochemicals;
boric acid, calcium chloride, amino star (Ca 11% + amino acid 21%), malty set (B 2%+ amino acid 16.84%), set (Ca11.4%+B 7%) and Calsostar (Ca 8% + amino acid 3%+ B 2 %) as well as spray with water as control on fruit set, fruit drop, fruit quality, yield and leaf
mineral contents of New hall navel orange trees.
Fifty six trees, as uniform as possible in size, productivity and appearance were
selected for this study and divided into two groups. The trees of the first group received the
following spraying treatments once a year at full bloom (80% flowering) as follows:
1- Control (sprayed with water only).
2- Boric acid at 300 ppm.
3- Calcium chloride (Cacl2) at 0.5%.
4- Amino star (Ca 11% + amino acid 21%) at 1%
5- Malty set (B 2%+ amino acid 16.84%) at 1%.
6- Set (Ca11.4%+B 0.7%) at 1%.
7- Calsostar (Ca 8% + amino acid 3%+ B 2%) at 1%.
The trees of the second group sprayed with the same above treatments twice a year at full bloom and after 21 days.
The treatments were arranged in split–plot technique in randomized complete block design (where the used agrochemicals presented the main plots and number of sprays devoted to the sub plots. Treatments were applied randomly with four replications of one tree each. So the total number of trees were 56 (7 spraying treatments X 2 number of
sprays X 4 replications).
84The result of this experiment could be
summarized as follows:
1-As for fruit set and retention % as well as, average No. of fruits / tree and total yield the
results showed that foliar application of different agro-chemicals through two sprays
significantly improved these parameters compared to control. In general, calsostar
treatment gave the best results in both seasons.
2 – As for the effect of spraying different agrochemicals on some physical fruit properties,
the data revealed that all agrochemicals significantly increased fruit length (cm), fruit
diameter (cm) and fruit volume (cm3) compared with the control. Moreover, in both
season, calsostar treatment gave the highest increase of this characters compared to other
agrochemicals, meanwhile the control treatment gave the lowest values in both seasons.
Regarding sprays number the results revealed that tow sprays significantly increased fruit length and fruit volume in both seasons and fruit diameter in the second season only compared to one spray. One spray increased fruit length/ diameter in both seasons and fruit
diameter (cm) in first season compared to tow sprays.
3- Spraying calsostar caused a significant increase in fruit weight (g), pulp weight (g) and juice volume (ml) as compared with all other chemicals in both seasons. Control treatment gave the highest value of peel weight (g) and peel thickness Cm) as compared with all other treatments. Moreover, tow sprays significantly increased fruit weight (g) pulp weight
(g) and Juice volume compared to one spray in both seasons. Meanwhile, one spray increased peel weight and peel thickness compared to tow sprays in both seasons. As for the interaction between different chemicals and number of sprays, data indicate that fruit
weight, juice volume and pulp weight showed the highest value with trees treated with calsostar through tow sprays in both seasons. The trees that treated with water only (control) in both seasons through one sprays recorded the significantly greatest values of
peel weight and peel thickness.
4 - The application of calsostar resulted in the highest values of total soluble solids (TSS), vitamin C (mg/100 ml juice) furthermore the lowest values of juice pH as compared with
other treatments in both seasons. Moreover, tow sprays gave the greatest values of total soluble and Vitamin C. contents as compared with one spray in both seasons, while, one 85
spray gave the greatest juice pH as compared with tow sprays in both seasons. Tress treated with calsostar through tow sprays in both seasons recorded the significantly greatest
values of TSS, V.C) and the lowest values of juice pH.