Abstract:
Purpose : To test the effectiveness of neem leaves in suppressing the development of Alternaria porri causing
purple blotch and to provide information about the use of neem leaves to control these purple blotch on
shallots
Research Method : The research was conducted at the Lembang Botanical Research Institute (BALITSA) at
altitude + 1,250 meters above sea level (masl) with average temperatures ranging from 19-24 0C, humidity
ranging from 39-90% and average rainfall of 2,207 , 5 mm / year. The trial period starts from the beginning of
November 2018 until January 2019. The study was conducted in the field using an experimental method with a
randomized block design (RBD) consisting of 6 treatments and 4 replications. These treatments are Application of
the extracted neem leaf with concentration of: (A) 150 g L-1, (B) 175 g L-1, (C) 200 g L-1, (D) 225 g L-1, (E) 250
g L-1, and (F) Control / without application.
Experimental data analysis was carried out based on a linear model for the Randomized Block Design
(RBD). The obtained data were statistically analyzed by variance analysis with the F test on variables.
The F test results showed significant differences. To differentiate the average of each conducted treatment,
further tests with Duncan’s multiple range method on real level of 5% is tested.
Findings : Neem leaves can act as a botanical pesticide that is easy to make and easy to apply for
farmers.The extracted neem leaf application with a concentration of 225 g L-1 is the best concentration
and is able to suppress the development of Alternaria porri causing purple spots on shallot plants.
Limitations : The secondary metabolite content of the mimba plant is found in parts of the seeds, but in
the west java area the neem tree does not produce seeds, so in this study only uses the leaves.
Value : The use of botanical pesticide derived from neem leaves is able to reduce the use of synthetic
pesticide, so as to reduce the effects of residual causes of environmental pollution.
