Yield losses of cotton seedlings disease damage , wilt disease and foliar disease

1. Cotton ( Gossypiumbarbadence ) is the one of the most ancient important commercial crops next only to food grains and is the principal raw material for a flourshing textile industry. Yield losses of cotton seedlings disease damage , wilt disease and foliar disease

2. However , the production potential of the crop has been fully Exploited due to several factors. Biotic factorsA biotic Microorganismfactors Fungi Yield losses to cotton seedlings disease damage , wilt disease and foliar disease

3. the cotton crop suffers from many fungal disease . foliar disease, seedborne and soilborne Black mold , alternaria wilt disease seedling disease Yield losses on cotton

4. seedling disease complex of cotton , causes annual economic losses . the seedling disease complex is composed of several fungi which cause seriouse problems whatever cotton grown.the soil borne pathogens most commonly involoved in the seedlin disease complex in Egypt includinesRhizocotniasolani, and species of Fusarium , Pythium and Macrophominasp. fusaruim wilt and Verticilium wilt , there are the most imporatant disease of cotton probably causes greater economic losses in that crop in many different places in the world . seedborne and soilborne disease

5. the cotton growth and devlopmentmodle= dPp / dt dPp= number of plants per mater dt= time the population models for cotton growth and development is composed of separate models for the population of indiviual plants ,and each plant has a population of leaves (L), stems (S), roots, and fruits (number = F ,mass = M ) for estimation of crop loss due to soilborne pathogen

6. leaves Growth modle= ąL / ąt + ą L / ą a ąL= no of leaves ąt = plant at time ą L = no of leaves in same age ą a = plant at same age Roots Growth modle = ąR / ąt + ą R / ą a Stems Growth modle = ąS / ąt + ą S / ą a Fruits Growth modle = ąF / ąt + ą F / ą a Mass of pool modle = ąM / ąt + ą M / ą a models for the population of indiviual plants

7. Effect of verticillium or Fusarium wilt on plant growth and development dФs / dt=[(1- 1.3 x 10-5 pv2 + 1.6 x 10-3 pv – 4.5 x10-4) z ] / 100 dФs= the percentage of plants showing foliar symptoms pv = inoculum density z= pathotype severity (Gutierrez et al 1983) for estimation of crop loss due to verticillium or Fusarium wilt pathogen

8. Estimating Yields loss YT = YH (1- ∑ni=1ΔФi )+ ∑ni=1yiΔФi YH=expected Yields of helthay in all plants ΔФi= plants becoming diseased yiΔФi= Yields of diseased plants (Gutierrez et al 1983)∑ estimation of crop loss due to verticillium or Fusarium wilt pathogen

9. incidence and severity of symptoms on cotton percentage plants with root disease index 1 2 3 4 5 6 1 = no of healthy seedling 2- 5 =no of browning to necrosis roots 6 = no of died plants estimation of crop loss due to seedlings disease

10. Losses of crop = A / B X 100 A= Percent disease index B = Percent disease over control % increase in yield over control = C/ D X100 = kg pooled C= Pooled yield ( kg /area ) in disease plant D = Pooled yield ( kg /area )in plant over control (Chattannavaret al 2010) estimation of crop loss due to foliar disease