Problem statement: Rubber has been grown more than a century in South East Asia, who has been the largest producer of natural rubber. Demand of natural rubber increases steadily due to increasing demand particularly from developing countries. Water has been a limited and invaluable resource especially in agriculture. This resource has to be used wisely and there is a need for a detailed study pertaining to water requirement of rubber plants. This study provides details about rubber plants growth in relation to water stress. Approach: Two new latex timber clones from Malaysia Rubber Board (MRB), RRIM 2005 and RRIM 3001 were used in this study with soil from Haplic Ferralsol used as planting media. Five levels of treatment were used; plants irrigated for every 2, 5, 10 and 15days and everyday which acted as control. The experimental design used was a Completely Randomized Block Design (RCBD) with four replications. Results: Results showed treatment well watered for clone RRIM 2025 (T6) had most the turgidity with high mean value in stomata conductance and chlorophyll content. RRIM 2025 also more resist to water stress compared to RRIM 3001. All plants in treatments with extreme different in water regimes cannot survive and dead due to severe stress. Conclusion: This study found rubber clones RRIM 2025 and RRIM 3001 cannot survive with acute deficiency of water. Rubber cannot be planted in dry areas with low water regimes which will retard the plant growth and plant will die under severe water stress

Problem statement: Rubber, Hevea brasiliensis, has been traditionally planted in the humid tropics, which is characterized by high rainfall throughout the year. However, due to an increase in world's demand for rubber, future planting will be established in dry areas, characterized by prevalence water stress. Utilizing limited resource, in dry areas or to use water wisely is very important. This study provides a detail evaluation of morphological and physiological responses of rubber trees at nursery stage in relation to different water stress. Approach: Two new latex timber clones from Malaysia Rubber Board (MRB), RRIM 2001 and RRIM 3001 were used in this study. Five levels of treatment were used; plants irrigated for every two days, five days, 10 days, 15days and everyday which acted as control. The experimental design used was a Completely Randomized Block Design (RCBD) with four replications. Results: Fundamental changes of plant growth and physiological responses showed that treatment with well watered for clone RRIM 2001 (T1) had higher values than other treatments. Harvest index highest in well watered (T1) with mean 20.73, while T5 were lowest with the mean 5.03. Stomata conductance showed significant difference between T6 with 0.161µmol m -2 s -1 compared to under stress treatments with 0.00 µmol m -2 s -1 . There was treatment failure to adapt to water stress at treatments withholding water for 15days followed by treatments 10days and five days. Conclusion: RRIM 2001 and RRIM 3001 clones had responded to water stress by indicating changes in morphological and physiological responses. This indicated that Hevea brasiliensis cannot withstand water stress.

Rubber is currently the second major industrial crop in Malaysia after oil palm. The use of bokashi fertilizer (BF) on industrial crops is still not popular, and farmers rely mostly on chemical fertilizers (CFs) that are costly and hazardous to the environment. This research was conducted at Hevea plantation, Universiti Putra Malaysia, between August 2020–October 2021. The study was to assess the short-term effects of BF with reduced NPK fertilization on soil fertility, growth, and yield of rubber. Seven treatments (T) were involved. T1, T2, and T3 denote 4, 8, and 12 kg BF per pit. T4 was 1 kg NPK as control, whereas T5, T6, and T7 denote 4, 8, and 12 kg BF + 500 g NPK per pit, respectively. The variables observed included total nitrogen (TN%), total phosphorus (TP%), organic carbon (OC%), organic matter (OM%), exchangeable cations, microbial counts, tree girth, and dry rubber yield. The major findings indicated that applying 12 kg BF has raised the soil’s TN%, OC%, and OM% by 165, 171.4, and 172.0%, respectively, compared to NPK control. Also, adding 4 kg BF + 500 g NPK has increased the soil’s cation exchange capacity and TP% values by 107.8 and 42.9%, respectively, compared to the control. Adding sole bokashi increased the bacterial population by 22.2–133.3%. Rubber yield was better on trees treated with 12 kg BF, though this did not differ significantly from other treatments. Therefore, applying 12 kg BF or 4 kg BF + 500 g NPK can improve soil fertility and save costs from using inorganic fertilizer by at least 50%.