الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
Effect of some nitrogen fertilization and weed control
treatments on growth and yield of onion
Two field experiments were carried out at the Research and
Experimental Center of the Faculty of Agriculture at Moshtohor, Zagazig
University, Benha Branch each during the two successive seasons of
1991/ 92 and 1992/93.
The first study was aimed at studying the effect of different weed
control treatments on the quality of transplants in the nursery while the
aim of the second one was to study the combined effect between
different levels of nitrogen fertilizer and some post- transplanting weed
control treatments on the production and quality of onion bulbs as well
as associated weeds.
Results obtained may be sunnnarized as follows :
1- Mold-board plowing the nursery soil followed by spraying nursery
soil with tribunil at the rate of 750 gI fed. 2 weeks after seedsowing
led to good seedlings of the best quality.
2- Similar findings were found in case of discarded seedlings.
3- The combined effect of anyone of the three used pre- sowmg
Treatments combined with spraying the nursery with either tribunil
at the rate of 750 g! fed. 2 weeks after- sowing as post sowing
treatment resnlted in good seedlings of the best quality (highest
numberof leaves) .
4- Number ofleaves per discarded seedlings was not affected by the preand
post- seed sowing weed control treatments.
5- Best weed competition by onion transplants in onion nnrsery was
obtained with either mold- board ploWing before seed sowing or
spraying nursery soil 30 days before seed- sowing with lancer (4
htres/ fed.) followed by either tribunil at 750 g i fed 14 days after
seed- sowing or with goal at 200 or 400 em’ i fed. three weeks after
seed Sowing. These treatments showed the lowest values of either
fresh or dry weight of weeds.
6- Combinations between nitrogen application at 60 kg Ni fed. and
spraying one litre of goal as post- transplanting resulted in the
highest average weight of bulb.
8- Best weed control in onion farms was obtained by the application
at 60 - 90 kg Ni fed. and spraying either one litre or 750 em’ goal
or ronstar at 1.7 U fed. as post transplanting treatments. Such
treatmentsresulted in the lowest fresh weight of weeds.
9- Similarly, application of750 em’ or one litre! fed. goal 14 days after
transplanting in combination with fertilization with 60 kg N/ fed.
showed the lowest values of dry weight of weeds.
Generally, it may be concluded that best transplants of onion may
be obtained when the soil of the nursery is plowed with the moldboard
plower or sprayed with lancer one month before seedsowing
in combination with spraying the seedlings with tribunil at
750 g! fed. as a post-seed - sowing treatment 2 weeks after seedsowing.
Concerning onion bulb yield and quality.
It may be stated that fertilization of onion plants with 100- 200 kg
ammonium nitrate resulted in the highest onion bulb yield and
quality and associated with the highest killing effects of weeds when
combined with post- transplanting treatments of goal at either 750
crrr’ or one litre! fed. or ronstar at 1.7 L! fed.