Two field experiments were carried out at El-Ismailia Agricultural Research Station, Agricultural
Research Center, Giza, Egypt during 2013/14 and 2014/15 seasons in the sandy soil under sprinkler irrigation
system to study the effect of weed management and plant nutrition practices on weed biomass, growth
characters and bulb yield of onion (Allium cepa L.). Weed management practices included eight weed control
treatments i.e. (Pendimethalin, pyraflufen-ethyl, tepraloxydim, fluazifop-p-butyl) alone application of herbicides
or combinations (pyraflufen-ethyl + tepraloxydim or + fluazifop-p-butyl), hand hoeing twice and unweeded
check. The crop was fertilized with four levels of N, K fertilizers as follows (75 kg N + 25kg K, 75kg N+50 kg K,
150kg N+25 kg K and 150 kg N+50 kg K) and without fertilization by N and K under the recommended rate of
super phosphate fertilizer (150 kg/faddan). The results indicated that weed management and N, K fertilizer levels
had a significantly effect on dry weight of weeds and onion bulb yield. The best reduction of total dry weight
of weed and bulb yield increase was obtained with spraying pendimethalin at 2 L/faddan (one faddan = 0.42ha)
and Pyraflufen at 200 cm3/faddan + Tepraloxydim at 600 cm3/faddan. The best reduction percentage of total
weeds was 81.7% and 75.9% resulted from pendimethalin in 2013/14 and 2014/15, respectively, compared to
unweeded check. The highest bulb yield/faddan (9.51 and 12.98 t/faddan) was obtained from weed control by
pyraflufen-ethyl +tepraloxydim in the first and second season, respectively. Increasing level of fertilizer
applications increased the dry weight of total weeds. Application of 150 kg N + 50 or 25 kg K/faddan
significantly increased bulb yield by 88.6% in the first season and 57% in the second season. The interaction
effect between the combination of pyraflufen–ethyl+ tepraloxydim or + fluazfop-p-butyl and 150 kg N + 50 kg
K was most productive (13.73, 13.36 and 14.6, 14.1 t/faddan compared with unweeded check and without N, K
fertilizer was 2.73 and 3.1 t/faddan in the 1st and 2nd seasons, respectively. |
