Fusarium root stalk of maize

Fusarium stalk rot is considered as major threat to production of maize, accompanied by small losses to total wipeout of the crop. This disease is more prevalent in area where water stress occurs after flowering stage of the crop.

1. Presented By Farjana Tumpa BKH1514045F FUSARIUM ROOT STALK OF MAIZE

2. introduction Fusarium stalk rot is considered as major threat to production of maize, accompanied by small losses to total wipeout of the crop. This disease is more prevalent in area where water stress occurs after flowering stage of the crop . Owing to its soil borne infection pathway, fungicidal control of Fusarium stalk rot is not effective. A number of quantitative trait loci have been identified which will help to expedite breeding program against Fusarium stalk rot.

3. DISTRIBUTION This is one of the most devastating soil-borne diseases of maize, occurring in all continents of the world, including USA , Europe,Africa ,Asia , and Australia. CAUSAL ORGANISM   Fusarium verticilioides  ( formerly called   Fusarium moniliforme   ) Systemic position Kingdom : Fungi Phylum : Ascomycota Class : Sordariomycetes Subclass : Hypocreomycetidae Order : Hypocreales Family : Nectriaceae Genus : Fusarium Species : Fusarium verticillioides

4. symptoms Rotting at roots, crown and lower internodes Plants wilt, take on a grayish-green hue , and then turn tan When split, inner stalk shows a light pink to tan discoloration , but no black specks (fungal fruiting bodies) in or on the stalk Pith disintegrates, vascular bundles remain intact Stalks feel spongy when squeezed and may be easily crushed or crimped at lower internodes Plants may lodge when pushed sideways or impacted by wind

5. Disease cycle

6. Factors affecting development of Fusarium stalk rot Fusarium verticillioides is more common in regions with hot and dry growing conditions , especially before or during pollination . Higher temperature reduces the time between wilting and lodging because heat increases the metabolic rate of fungi. The water stress at flowering and high soil temperature help in increasing of the magnitude of the stalk rot symptoms at post flower Disease incidence was greater in sandy soil than in loam or claying stage Stalk rot incidence and severity increase with increased fertility

7. CONTROL MEASURE Select hybrids with good stalk strength and resistance to leaf diseases Rotate crops. Do not plant corn after wheat infected with head scab, which is caused by same fungus Use a tillage system that chops and incorporates residue to break it down Do not use plant populations higher than recommended for the hybrid Soil test and follow fertilizer recommendations; maintain proper nitrogen to potassium balance Reduce stresses when possible -- stalk rots are favored by plant stress following pollination Control leaf diseases with fungicides if necessary Control corn rootworm and corn borer. Pioneer brand hybrids with Herculex ® Insect Protection traits are available to help manage these pests Scout preharvest to determine stalk condition. Schedule harvest based on stalk quality as well as grain moisture  

8. CONCLUSION The stalk rot usually occurs after flowering stage and prior to physiological maturity , which reduces yields in two ways : (i) A ffected plants die prematurely, thereby, producing lightweight ears having poorly filled kernels and (ii ) Plants with stalk rot easily lodge, which makes harvesting difficult, and ears are left in the field during harvesting Moreover , various chemical and biological control methods have been developed, but major emphasis is on development of maize cultivars with genetic resistance to Fusarium stalk rot for environment friendly control of the disease