Positive products for control of rice blast disease

1. Positive products for control of rice blast disease Mwangi J.K, - UOK Wanjogu R.K,Owilla B.P.O, -MIAD

2. Introduction • Rice is one of the world’s most important cereal crop and its protection from disease is vital to the many million dependants on it as their staple food. • Rice: 3rd most important cereal crop in Kenya ; Consumption: 400,000MT p.a • Production constraints; • Abiotic : drought and floods, temparature, soil fertility • Biotic: insect pests, and diseases (Fungal and bacterial) • Primary constraint;- Rice blast. • Rice Blast Causal organism • Perfect stage: Magnaporthegrisea • Imperfect stage(anamorph): Pyriculariaoryzae • The fungus infects plant by the spore germinating and forming an appresorium (a thick fungal cell) on the plant surface and then exerting a haustoria (feeding structure) into the plant cells. • A minimum of 8 hrs moisture is needed for infection to occur. • Most plant parts are susceptible to infection except the roots. .

3. Symptoms caused by Magnaporthe grisea on rice plants Leaf blast Collar blast Neck rot Panicle blast

4. Node symptom Node blast White heads' caused by neck rot Panicle blast

5. Introduction cont. • Yield losses due to blast;- Approximately 60% - 100% • Rice blast was first reported in Kenya in the 60’s mainly in the Western regions. • It has also been reported since 2008 in Mwea the main rice growing area in the country where it caused 20- 30% yield loss. • The blast problem has threatened rice production and also the national food security. • Use of resistance varieties against rice blast pathogen alone has been found to be unreliable and sometimes disappointing. • Breeding for these resistant lines takes time before they reach the farmers. • It thus seems that chemical control can offer greater promise and will constitute an important weapon in reducing crop losses. • The objective of the trials is to evaluate the efficacy of different fungicides from different companies in the control of rice blast.

6. Fungicides presented thro PCPB for trials

7. Experimental design • The experiments were laid out in a randomized complete block design with six treatments replicated three times. • The treatments consisted of; The varieties used were Basmati 370 and Basmati 217

8. Data at harvest; • Number of tillers per hill • Number of productive tillers/hill • Number of grains/panicle • Number of empty grains/panicle • 1000 grain weight at 14% MC

9. RESULTS Rice blast disease incidence/severity and effect on some yield parameters

10. Effect on grain yield

20. Conclusion • From the results; • It is evident that the new fungicides have an effect on rice blast. • Severity in plots sprayed with the new fungicides were not significantly different from those sprayed with Bavistin (standard check) and Goldazim (local check). • Similar trend was observed on the filled grains, 1000 grain weight and biomass per plant. • The fungicides have therefore been recommended for registration by PCPB for use by farmers in the control of rice blast.

22. Thank you for listening End