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Author Juárez, H. S. ♦ Amaro, J. R. ♦ Rivera, M. D. ♦ Párraga, A. ♦ Hijmans, R. J.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Potato Late Blight ♦ Nitrogen Fertilization ♦ Kg Ha ♦ Disease Severity ♦ Little Effect ♦ Increased Lb ♦ Potato Variety ♦ Resistant Variety ♦ Foliage Development ♦ Net Effect ♦ Field Experi-ments ♦ Late Blight ♦ Phytophthora Infestans ♦ Potato Yield ♦ Intermediate Level ♦ Susceptible Variety
Abstract The effect of nitrogen (N) fertilization on the development of potato (Solanum tuberosum L.) late blight (LB) caused by Phytophthora infestans (Mont.) de Bary was studied in Huancayo and Oxapampa, Peru. We had field experi-ments in which three levels of N (0, 160, and 320 kg/ha) and three levels of fungicide were applied in all combinations on two potato varieties (18 treat-ments). In the absence of LB, more N led to more foliage development and higher yields. N had no effect on the disease when severity was very low or high. At intermediate levels of disease severity, increased N led to increased disease. In Huancayo, the net effect of N application (0 vs 160 kg/ha) on yield of the more susceptible variety was negligible because of increased LB. For the more resistant variety the presence of LB had little effect on yield, whether no N was applied or N was applied at the rate of 160 kg/ha. Doub-ling the N rate to 320 kg/ha did not increase yield in the absence of LB, and decreased it if no fungicides were applied. If farmers attempt to increase potato yields using N fertilizer, they may need to use more fungicides or
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study