Hubungan Antara Keragaman Gulma dengan Penyakit Bulai pada Jagung (Zea mays L.) Stadium Pertumbuhan Vegetatif

Abstract

Weeds play an important role in the spread of downy mildew disease, competition, and lower crop
yields of corn. Research using the survey method in 3 locations of Sanur village, Denpasar City. Each
location is taken 5 samples, and each sample area was 1m2, which was arranged diagonally. For
weeds identification was using reference i.e. Weeds of rice in Indonesia, and identification of downy
mildew disease using reference i.e. Maize Disease: A Guide for Field Indentification and microscopically,
while the weeds diversity was determined based on Diversity Index of Shannon-Wiener. Relationship
between number of weed species and weed populations, and disease incidence were determined by
regression and correlation analysis. Weed diversity on ecosystem of maize in vegetative stage is very
low with the diversity index of 0.779, this means weed ecosystem unstable, and dominated by a particular
weed species was Paspalum commersonii Lamk. (Fam. Poaceae/Graminaceae) of 23.3%, with the
dominance index of 0.709. Relationship between the number of weed species and disease incidence of
the downy mildew disease was highly significant (P<0,01), while the relationship between weed population
and disease incidence of the downy mildew disease is not significant. Plant height and leaf number of
maize was influenced by the type of weed, but weed populations only affect plant height of maize in
vegetative stage (V3-V11).