INT. J. BIOL. BIOTECH., 16 (3): 703-708, 2019. DISTRIBUTION OF STALK ROT OF MAIZE IN PUNJAB, PAKISTAN Ateeq Tahir, Arshad Javaid, * Salik Nawaz Khan and Muhammad Riaz Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan. * Corresponding author’s email: salik_nawaz@yahoo.com ABSTRACT Surveys of 8 districts of Central Punjab, Pakistan namely Sialkot, Narowal, Gujranwal, Hafizabad, Shekhupura, Lahore, Okara and Sahiwal; and five districts of South Punjab namely Khanewal, Multan, Muzaffargarh, Vehari and Lodhran were carried out during April 2014 to assess the distribution of stalk rot of maize (Zea mays L.). In each district three sampling sites were selected. From each site data were collected from three fields well apart from each other. Disease prevalence (DP) was calculated on the basis of presence or absence of disease at each visited site. Disease incidence (DI) was calculated on the basis of number of infected plants out of total plants. Likewise, disease severity index (DSI) was recorded on the basis of plant area infected or damaged. Stalk rot disease was found in all the surveyed areas showing 100% prevalence. Disease incidence varied from 41 to 51% in different districts. The highest DI was recorded in Sialkot and Sahiwal. DSI ranged from 17.4% in Hafizabad to 30.2% in Sahiwal. Different species of Fusarium namely F. vericeiliodes (Sacc.) Nirenberg, F. oxysporum Snyder & Hansen, F. prolifiratum Nirenberg ex Gerlach & Nirenberg, F. moniliforme J. Sheld., F. bullatum Sherb., F. thapsinum Klittich, Leslie, Nelson & Marasas, F. incarnatum (Desm.) Sacc. and F. acchari (Butler & Khan) Gams were found associated with maize plants infected with stalk rot disease. Key-words: Central Punjab, Fusarium spp., Maize, Stalk rot. INTRODUCTION Maize (Zea mays L.) is a short duration cross pollinated crop cultivated in spring and summer for grain as well as for fodder purpose in Pakistan. It is economically important cereal crop next to wheat and rice, widely grown in the world due to its adaptability to a wide range of climatic conditions (Gerpacio and Pingali, 2007; Mubeen et al., 2017). The crop is utilized as a food for human consumption, as a fodder for livestock, as a feed for poultry and as a raw material in industry (Mahuku, 2010). It contains 72% starch, 10% proteins, 4.8% oil, 8.5% fiber, 3% sugar and 1.7% ash (Farhad et al., 2009). It is cultivated on an area of 140 million hectares with 577 million metric tons production in the world (Ahmad et al., 2015). Maize is successfully cultivated in nearly all agro ecological zones of Pakistan and is cultivated in all of its provinces. Punjab and Khyber Pakhtunkhwa are the major maize growing provinces, contributing 39 and 56% of the total area under maize and 30 and 63% of total production. The total cropped area occupied by the maize in Pakistan for year 2016-17 was 1334 thousand hectares (Anonymous, 2017). Sialkot, Narowal, Gujranwala, Hafizabad, Sheikhupura, Lahore, Okara, Sahiwal are major maize growing districts in central Punjab. Pakistan is far behind in term of average yield per hectare than developing countries like America, Ireland, Australia, China. Both biotic and abiotic factors are constraints that reduce the maize yield per hectare and deteriorate the quality of the crop even in the presence of high yielding cultivars. Stalk rot is a serious biotic constraint (Fig.1), reported in all major maize growing countries in the world (Mir et al., 2018). Stalk rot of maize is caused by a complex of several fungal pathogens and secondary colonizers (Afolabi et al., 2008). In the Asian tropics, Fusarium stalk rot, Macrophomina stalk rot and late wilt are prevalent (Khokhar et al., 2014). Stalk rot disease attacks vascular bundles and causes internal decay and discoloration by blocking translocation of water, nutrients and can result in death and lodging of the plant during the cropping season. In South East Asia, hot and humid weather favors the disease development (Khokhar et al., 2014). Geographical location and cultural practices including planting date, crop rotation, tillage and fertilizer application also affect the disease index of all Fusarium species causing stalk rot of maize (Munkvold, 2003). Stalk rot of maize in Pakistan received little attention and scanty information are available on occurrence and distribution of the disease in Central Punjab, Pakistan. Therefore, the objective of present study was to carry out an extensive survey to document the distribution of stalk rot disease in maize growing areas of Central Punjab, Pakistan. MATERIALS AND METHODS Survey The survey for stalk rot of maize was conducted during April 2014, in 8 maize growing districts of Central Punjab, and 5 districts of South Punjab, Pakistan. These included Sialkot, Narowal, Gujranwala, Hafizabad,