ComasOxapampa           package:agricolae           R Documentation

_D_a_t_a _A_U_D_P_C _C_o_m_a_s - _O_x_a_p_a_m_p_a

_D_e_s_c_r_i_p_t_i_o_n:

     Fifty-three potato varieties developed by the breeding program of
     the  International Potato Center and released in different
     countries around  the world were evaluated for their resistance to
     late blight in two locations  in Peru.

_U_s_a_g_e:

     data(ComasOxapampa)

_F_o_r_m_a_t:

     A data frame with 168 observations on the following 4 variables.

     '_c_u_l_t_i_v_a_r' a factor with 56 levels 

     '_r_e_p_l_i_c_a_t_i_o_n' a factor with 3 levels 

     '_c_o_m_a_s' a numeric vector

     '_o_x_a_p_a_m_p_a' a numeric vector

_D_e_t_a_i_l_s:

     The experimental design was a randomized complete block design
     with 3 replications  of 15 apical stem cuttings in Oxapampa and 10
     tubers in Mariscal Castilla. Plots were 11.9 x 18.5 m in size with
     30 cm in-row and 0.9 m between-row spacings. Spreader rows around
     plots were used at each site. Mancozeb was applied weekly until 30
     days after transplanting or planting, after which the plants were
     left to natural infection. Due to climatic conditions not
     conductive to the disease in Oxapampa, inoculum was enhanced with
     local isolate (POX 067, with virulence R1, 2, 3, 4, 5, 6, 7, 10,
     11) at a concentration of 5000-sporangia/ ml at 49 days after
     planting. Percentage of foliar infection was estimated visually
     every 3 days for 8 times in Oxapampa and every 7 days for 12 times
     in Comas, then values were converted to the relative area under
     the diseases progress curve (rAUPDC). rAUDPC rankings were
     analyzed for phenotypic stability with nonparametric measures.

_S_o_u_r_c_e:

     Experimental field, 2002. Data Kindly provided by Wilmer Perez.

_R_e_f_e_r_e_n_c_e_s:

     International Potato Center. CIP - Lima Peru.

_E_x_a_m_p_l_e_s:

     library(agricolae)
     data(ComasOxapampa)
     # Oxapampa (10 35 31 S latitude, 75 23 0 E longitude, 1813 m.a.s.l )
     # Comas, Mariscal Castilla (11  42  54  S latitude, 75 04 45 E longitude, 2800 m.a.s.l,)
     # cultivars LBr-40 (resistant), Cruza 148 (moderately resistant) and Pimpernell (susceptible)
     str(ComasOxapampa)
     means <- tapply.stat(ComasOxapampa[,3:4],ComasOxapampa$cultivar,mean)
     correlation(means$comas,means$oxapampa, method="kendall")

