木薯器官及其混合物水浸提液对橡胶树棒孢霉落叶病病菌的化感作用

采用生长速率法探讨不同浓度木薯器官及其混合物水浸提液于不同处理天数对橡胶树棒孢霉落叶病病菌的化感作用。结果表明:(1)根、叶水浸提液表现为化感抑制效果,浓度越大,效果越明显。(2)茎水浸提液在浓度为10~100 mg/mL时无明显化感效果;浓度达1 000 mg/mL时,处理后3~7 d时表现为显著的化感促进效果。(3)根、茎、叶比例为4:2:1的混合物水浸提液在10~100 mg/mL浓度时无明显化感效果,当浓度达1 000 mg/mL时,在处理后4~6 d表现为化感抑制效果。(4)茎、叶比例为2:1的混合物水浸提液在10 mg/mL浓度时化感效果不明显;当浓度达到100 mg/mL时,处理后2 d表现为显著的化感抑制效果,处理后3~6 d化感效果不明显;浓度达到1 000 mg/mL时,处理后2~3 d无明显的化感效果,处理后4~6 d则呈现显著的化感促进效果。建议间作木薯的胶园收获木薯后,应及早将茎干移出胶园,以减少橡胶树棒孢霉落叶病的发生。 

Allelopathy of Water Extracts From Cassava Organs and Their Mixtures to Corynespora cassiicola of Hevea brasiliensis

There is a controversy  for  whether  intercropping  cassava  will  result  in  occurrence  of  the  corynespora leaf fall disease of Hevea brasiliensis in academic circles. Allelopathy can affect the plant disease occurrence to a  certain extent. Used the growth rate method,  the  allelopathy  of  water  extracts  from  cassava  organs  and  the  mixtures on the disease at different concentrations and different days were  studied.  The  results  showed  that:  ⑴ Water extracts from the root and leaf of cassava could inhibit the growth  of  Corynespora  cassiicola  of  H.  brasiliensis, and the allelopathy inhibiting effect was more obvious with the concentration increased.  ⑵ The  allelopathy effect to water extracts from the stem was not obvious between 10 ~100 mg/mL, while there was a significantly positive effect at 1 000 mg/mL until 3-7 days. ⑶The effect of water extracts from the mixed organs in  the  ratio  of  the  root,  stem  and  leaf  of  cassava  4 ∶2 ∶1  was  not  noticeable  between  10 -100 mg/mL,  while the inhibiting effect was significant at 1 000 mg/mL until 4-6 days. ⑷The allelopathy effect of water extracts from the mixed organs in the ratio of the stem and leaf  2:1  was  not  obvious  at  10mg/mL,  while  at  100  mg/mL  the  inhibiting effect was significant after 2 days, but it was not obvious until 3-6 days. And then the concentrations  increased to 1 000 mg/mL, the effect was not obvious until 2-3 days, the positive effect was significant until 4-6      days. In order to reduce the occurrence of corynespora leaf fall disease, removing the stems of cassava should be removed from the rubber plantation as soon as possible after harvesting.