Control of banana Fusarium wilt disease by reductive soil disinfestation Xinqi Huang Nanjing Normal University, China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application

Background——Banana Fusarium wilt

Bananageddon: Millions face hunger as deadly fungus Panama disease decimates global banana crop —— 《 The independent 》 2014 《 Nature 》 2013 Then, some mainstream media in China published the similar reports entitled “Banana AIDS”

Disease resistance cultivar Chemical fumigation Agronomic management Deep tillage Solarization Crop rotation …… Background——Current control methods

Reductive soil disinfestations (RSD), developed separately in Japan (Shinmura 2000) and the Netherlands (Blok et al. 2000) as alternatives to chemical soil disinfestations. In 2011, RSD was used for the improvements of soil acidification and secondary salinization in our lab. Then, we found the commendable disinfestation effect of RSD. RSD based upon supplying labile carbon to stimulate microbially-driven anaerobic soil conditions in moist soils covered with polyethylene mulch. Background——Reductive Soil Disinfestation

The objectives Population of pathogen Microbial community Disease incidence Microbial activity Yield RSD influences on

CKRSD untreated soil (CK1) disturbed soil without flooding (CK2) flooding disturbed soil (CK3) RSD incorporated with rice straw (LS, HS) HS plus lime (HSL) RSD incorporated with pig manure (PM) RSD with bagasse (BA) BA plus lime (BAL) flooding soil with lime (LI) Population of Fusarium oxysporum

Disinfestation mechanism The relationships among soil pH, the amount of toxic organic acids and pathogen population

Disinfestation mechanism Flooding: treated with deionized water Acetic: treated with 30 mM acetic acid Butyric treated with 30 mM butyric acid Ace+But: treated with 15 mM acetic acid and 15 mM butyric acid other elements, such as Fe 2+, Mn 2+, H 2 S and NH 3, might be also involved in the mechanism of RSD.

Soil microbial community Bacterial Fungi Relative abundance (%) of microbial phyla present in the soils of different treatments. CK, untreated soil. Flooding and RSD, soils treated by flooding and RSD, respectively. Flo-Ban and RSD-Ban, soils of Flooding and RSD treatments after planting banana, respectively.

Soil microbial community Bacterial Fungi Relative abundance (%) of microbial genera present in the soils of different treatments. Ruminococcus Coprococcus Fusarium Podospora

Soil microbial activity—N transformation CK: untreated soil Al-RSD: the soil after RSD treatment taking alfalfa as organic matters N fixation Nitrification Denitrification

Disease incidence of banana ControlRSD 2013 field experiment 2013 田间试验

Control Disease incidence of banana RSD 2014 field experiment 2014 田间试验

CK Disease incidence of banana 2014 field experiment 2014 田间试验 RSD

Disease incidence of banana Cultivar Treatments Disease incidence (%) Yield (t/ha) Disease sensitive RSD CK Disease resistance RSD CK field experiment

RSD CK Nanjing, Jiangsu Province Cucumber Fusarium wilt disease

RSD CK Pepper Fusarium wilt disease RSD CK Nanjing, Jiangsu Province

RSD CK Tomato bacterial wilt disease RSD CK Nanjing, Jiangsu Province

Yunnan Province Eustoma Fusarium wilt disease CK RSD

Conclusion RSD reduced the population of Fusarium oxysporum f. sp. cubense mainly through the production of toxic organic acids. Cellulose decomposition bacteria ( Ruminococcus etc.)and organic acids producers (Coprococcus etc.) were the dominant bacterial genera which might be responsible for the disinfestation effect of RSD taking solid plant residual as organic matters. The soil N transformation activities were enhanced by RSD. RSD significantly reduced the disease incidence of banana Fusarium wilt.