Modelling Integrated Control for Maize Smuts in the NWFP

Abstract

Maize is apt to the attack of smut diseases at the high altitudes in the North West Frontier Province (NWFP) of Pakistan which reduces its productivity by approximately 25% every year. With no proper control of diseases, it is assumed that these losses may increase year after year on account of number of reasons. Farmers generally plant susceptible varieties that not only reduce the crop yields but also helps in increasing the diseases inoculum. Dense planting for dual purpose of food and feed provides conductive environment for the disease development. Sub-optimal levels of fertilizer make the plants weak and liable to the attack of smuts. Again, the minimal use of fungicides in maize for control of seed/soil borne smuts may increase the disease infection. It is why important that fool-proof methods should be involved to warrant effective control of maize smuts. These include the use of resistant varieties, balanced soil fertility, optimum plant density and seed treatment with fungicides, the main objectives of this research were to identify such best controls and to study their synergistic effect into an Integrated Disease Management Model (IDMM) in the NWFP.

During the first two years of project research, several replicated experiments were laid out, in Hazara and Malakand division, to ascertain the validity of various maize genotypes, fertilizers, seed dressing fungicides and plant density levels in reducing common smut attack and yield loss in maize. In each experiment data were recorded on the disease incidence, grain yield, stalk yield and percentage of barren plants.

Out of 16 different genotype cv. Pahari showed the best performance. In the variety common smut was the lowest and the grain yield was the highest. Cv. Pahari is a short duration variety and its high disease resistance and yielding capability shall make it the best fit into the cropping pattern of the area where farmers generally demand early maturing varieties. Among different NPK combinations, 100:50:0 kg/ha was the best. This fertilizer can be applied with less investment of labour, time and money. Common smut attack but also serve the dual purpose of grain and fodder production. The result of maize seed treatment with fungicide Dithiane M-45 were the most satisfactory. The practice shall be encouraged among the farmers to minimize most of seed/soil borne inoculum of the disease.

During the second phase oof the project research, theses best controls were integrated into a disease management model (IDMM) abd compared with other treatments. the result of multilocation experiment showed the superiority of the proposed model comprising of improved variety plus improved practices over other treatments. The synergistic effect of different control measure into IDMM was more significant than their single effect in decreasing common smut incidence, percentage of barren plants and increasing grain and stalk yield. the successful testing of the model under different agroecological zones in the NWFP indicated that the proposed model, if adopted properly, shall help in reducing smut losses and increasing/ stabilizing maize productivity in this province.