Abstract: In order to understand the effects of  Cistanche deserticola  parasitization on  Haloxylon ammodendron growth, the activities of protective enzymes (SOD, POD and CAT) and the contents of osmotic adjustment substances (soluble protein, soluble sugar and free proline) in  H. ammodendron assimilating branches were measured, and the comprehensive drought-resistant capability of  H. ammodendron  under parasitized and un-parasitized conditions was evaluated by subordinate function values analysis. During the whole measurement period (from June to September), the test enzyme activities in  H. ammodendron  assimilating branches all decreased after an initial increase, and were lower in parasitized than in un-parasitized  H. ammodendron  in early period. After parasitized by  C. deserticola , the MDA content in  H. ammodendron increased significantly, soluble protein and free proline contents increased in different degrees, while soluble sugar content decreased. The parasitization of  C. deserticola  gave the host plant a stress environment, making an obvious damage on host’s protective enzyme system and osmotic adjustment system and the decrease of host’s drought resistance.

Key words: Coffea arabica, N, P, K, Fertilization strategy, Growth, Photosynthesis, Yield