MARSSONINA LEAF BLOTCH ON THE APPLE ORCHARD IN BATU, INDONESIA
Abstract: In Indonesia, apple
orchards are decreasing because of leaf blotch disease. Marssonina leaf blotch
has not been widely known and the problems are associated with the incidence of
the epidemic so they need to be studied. Research aimed to investigate the
biological aspect of Marssonina leaf blotch, the resistance of apple varieties
and the alternative host of Marssonina coronaria, and the interactions between
Marssonina leaf blotch and weather factors. The research was conducted in
laboratory, greenhouse and on apple orchard respectively. There are three
results in this research. First, fruit bodies (apothecia) are not produced by
fungus, but only conidia (imperfect form) are. Second, based on bioassay,
pathogen survives only on the apple. Finally, there are three formula can be
used to predict the leaf blotch disease, such as:1) Y=-37.91+19.98X6
(population of spores in the air),2) Y = -438.13 + 25.71X1 (temperature)
-3.05X2 (humidity) + 41.07X3(wind speed) -2.07X4 (sunlight) + 19.25X5
(rainfall), and 3) Y = -43.86-1.61 22.60 X5 (rainfall) + X6 (population of
spores).
Author: Ika Rochdjatun
Sastrahidayat, Hery Nirwanto
Journal Code: jppertaniangg160020