الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
This investigation was conducted during two successive
seasons, 1996 and 1997 to study the effect of different soil
management systems on weeds control, vegetative growth, fruiting
and fruit quality of bearing Anna apple trees. The trees were (15 years
old budded on MoIling Merton 106 rootstock) nearly similar in vigor,
and grown on clay loam soil. The treated plots were irrigated with
closed basin surface system and cleaned from all weeds before starting
the study, The trees were treated with the following treatments:
I-Clean cultivation which involved.
Twice cultivation, once clean cultivation and no cultivation.
11- Mulch cultivation: which included field crop residues and rice
straw.
111- Herbicide treatments: which comprised Glyphosate, Afalon’s and
paraquat. These, herbicides were used according to the
recommended rates.
Anyhow, these treatments were replicated three times and each
replicate was represented with two trees.
The present investigation included the following studies:
1- Weeds control.
2- Horticultural measurements: vegetative growth, leaf nutrients
content, fruit set and dropping, yield and fruit quality.
3- Herbicidal fruit residues.
4- Microbial organisms under mulch cultivation system: such study
involved bacteria, actinomycetes and fungi counts in the soil as
well as the decomposition of mulch materials used.
5 - Cost/benefit of different soil management systems used.
The results could be summarized as follow:
\11-1- Weeds control:
1- Annual weeds were completely controlled by mulching treatments
as compared with the other soil management systems used. Field
crop residues treatment was more promising than rice straw
mulch in decreasing dry weight of either broad or grassy weeds.
2- Twice clean cultivation (control) was more effective in weed
control parameters than other clean cultivation treatments used.
3- Glyphotosate herbicide treatment was more promising in get rid of
grassy weeds via decreasing dry weight and total dry weight of
weeds followed by Afalon’s.
VI..2 - Horticultural measurements:
VI-2-a- Vegetative growth:
1- Mulching treatments induced largest increase in number of shoots,
shoot length, leaf area and leaf dry weight, followed by clean
cultivation and herbicide treatments. Furthermore, rice straw
mulch treatment was most superior than field crop residues in
encouraging vegetative growth of trees.
2- Twice-elean cultivation treatment (control) was promising in
increasing number of shoots, shoot length and leaf dry weight as
compared with the other two clean cultivation treatments used.
While leaf area was only increased by one clean cultivation
treatment.
3R Trees treated with Glyphosate herbicide succeeded in increasing
number of shoots, shoot length and leaf dry weight than the other
two herbicide treatments.
VI-2-b-Leaf nutrient contents
I-As percentage and p.p.m,
1- Rice straw mulch succeeded in increasing leafN, K and Zn among
other treatments under study while failed to increase leafP, Ca,
Mg and Fe, simultaneously.
2- Clean cultivation treatments increased successfully leaf Mg and
Mn while they had intermediate effect on leafN, P, Ca, Fe and
Zn contents.
3- Twice clean cultivation treatment (control) induced an increase in
leaf Ca and K. nutrients while once clean cultivation treatment.
increased only Mg and Fe nutrients. No cultivation treatment, on
the other hand, stimulated statistically leaf Zn and Mn nutrients.
4- Herbicide treatments increased leaf P, Ca and Fe while failed to
increase leafN, Zn and Mn.
ll- As absolute value (mglleaf):
1- Field crop residues increased mostly leaf N, P, Ca, Mg and Fe
contents as compared with rice straw mulch.
2- Herbicide treatments succeeded only in raising up leafP nutrient. In
this respect; Glyphosate herbicide increased leafN and P, while
paraquat raised up leafK, Ca and Mg nutrients.
3 - Once clean cultivation system surpassed no cultivation treatment in
increasing leafN, P, Ca, Mg and Fe contents.
VI·2·e- Fruiting:
1- Fruit set and dropping.
1- Mulch treatments induced highest increase in fruit set and lowest
percentage of fruit dropping followed by clean cultivation and
herbicide treatments in a descending order. In this respect, rice
straw mulch treatment was more promising than filed crop
residues treatment in increasing fruit set and decreasing fruit
drop.
2- Twice clean cultivation treatment (control) surpassed the other two
treatments of clean cultivation under study in increasing. Fruit set
and decreasing fruit drop.
3- Afalon’s herbicide treatment was more preferable in increasing fruit
set and decreasing fruit DROP as compared with Glyphosate and
paraquat, herbicide treatments.
11-Yield and fruit quality
a- Yield
1- All treatments increased the yield. In this respect, mulch treatments
caused the highest effect in increasing the yield followed by
herbicide treatments. While the lowest increase was obtained
from clean cultivation treatments.
2- Significant difference was nil between field crop residues and rice
straw mulch.
3- Once clean cultivation treatment was the highest among the other
two clean cultivation treatments used
4- Glyphosate herbicide treatment succeeded in raising up the yield
significantly among the other two-herbicide treatments.
b- Fruit quality:
1- Fruit weight.
1- Fruit weight of mulched trees was heaviest remarkably as
compared with both clean cultivation and herbicide systems
2- Rice straw mulch gave fruits heavier in weight than those of field
crop residues.
3- Once clean cultivation treatment succeeded in producing fruits
heaviest in their weight comparing with those of other two clean
cultivation treatments used.
4- Glyphosate herbicide treatment produced fruits heaviest in their
weight followed by Afalon’s.
11- Fruit size.
1- Mulch treatments increased fruit size visually followed by clean
cultivation treatments. Herbicide treatments, on the other hand,
failed to realise any success in this respect.
2- Field crop residues surpassed rice straw mulch in increasing fruit
SIze.
3- Under no cultivation, trees gave smallest fruits in their SIze as
compared with both twice-clean cultivation and once clean
cultivation treatments.
4- Paraquat herbicide succeeded in increasing fruit size than those of
both Ghyphosate and Afalon’s herbicides.
111-Fruit firmness:
1- Fruit firmness did not affect with different soil management,
systems used.
Nevertheless,
a- Rice straw mulch treatment gave fruits more soft than those of field
crop residues.
b- Once clean cultivation treatment gave fruits more soft as compared
with both twice-clean cultivation and no cultivation treatments.
c- Herbicide treatments had no statistical effect on fruit firmness.
2- Chemical properties
a- Titratable acidity.
1- Mulch and. herbicide treatments gave generally lowest values of
acidity as compared with clean cultivation treatments.
2- Rice straw mulch gave fruits with lowest values in respect of those
of field crop residues.
3- Once clean cultivation treatment succeeded in decreasing acidity in
fruits followed by twice clean cultivation treatment.
4- Trees received Glyphosate herbicide gave fruits poorest in acidity
comparing with the other two herbicide treatments.
b- T. S. S.
1- No significant difference was noticed between fruit T. S. S. values
of the three soil management systems.
However,
a- Rice straw rnulch gave fruits with higher values ofT. S. S. than the
corresponding ones of those treated with field crop residues.
b- No significant difference was noticed between clean cultivation
treatments.
c- Glyphosate herbicide treatment produced fruits with higher values
of T. S. S. as compared with the other two herbicides used in this
study, which were statistically similar in their values.
c- Total soluble sugars.
1- Mulch treatments caused highest increase in fruit total soluble
sugars content in respect of both herbicide and clean cultivation
systems, which they were more or less similar in their values in
this concem. In addition, rice straw mulch gave fruits with higher
amount of total soluble sugars than those of field crop residues.
2- Fruits of once clean cultivation treatment had highest amounts of
total soluble sugars as compared with the other two treatments in
this field
3- Afalon’s augmented total soluble sugars comparing with the other
two herbicides under study.
d- Starch.
1- Mulch treatments gave lowest values among the other two systems
of soil management which they (as average) nearly similar in
their values. In this concern, fruits of field crop residues treatment
were higher in starch content comparing with those of rice straw
treatment.
2- Twice clean cultivation treatment had fruits with highest amounts
of starch as compared with the other two clean cultivation
treatments under study.
3- Paraquat herbicide treatment increased fruit starch among the other
two herbicides used.
e- Starch/sugars ratio.
1- Mulch treatments gave lowest values of starch/sugars ratio as
compared with both clean cultivation and herbicide systems.
Moreover, field crop residues increased starch/sugars ratio over
rice straw mulch.
2- No cultivation treatment gave the highest value of starch/sugars
ratio as compared with other clean cultivation treatments used.
3- Paraquat herbicide treatment gave mostly fruits with higher
starch/sugars ratio in respect of the other two herbicides under
study.
VI-3- Herbicidal fruit residues.
Both Glyphosate and Paraquat herbicides had, no residues in
Anna apple fruits. On the contrary, residues of Afalon’s herbicide was
obtained in fruits of treated trees.
VI-4- Soil microbial organisms.
1- Mulch trea.tments increased the activity of bacteria in the soil as
compared. with twice clean cultivation (control) treatment.
2- Field crop residues mulch was more effective in increasing total
bacterial and actinomycetes counts in the soil than rice straw
mulch, which was more promising in increasing fungi activity.
3- Growth period of total bacteria and actinomycetes counts in
mulched soil increased till 120 days and 150 days in fungi then
decreased afterwards up to 180 days under control treatments.
Growth period of actinomycetes and bacteria was extended up to
120 days, while it was 150 days in fungi.
4- e/N ratio in mulch sources used in this study was high during
January and February then decreased gradually till June.
5- Rice straw mulch had higher elN ratio than, the field crop residues
mulch mainly during the period from April to June.
VI·5..Costjbenerrt of different soil management systems:
1- Mulch system was more profitable for Anna Apple growers
followed by herbicide treatments as compared with clean
cultivation treatments.
2- Field crop residues gave highest net return than rice straw mulch.
3- Glyphosate herbicide surpassed the other two herbicides used in
this study in the highest net return while paraquat herbicide took
the other way around in this respect.
4- Once clean cultivation treatment was most superior in increasing
net return among other two clean cultivation treatments under
study.