EFFECTS OF GUANO MANURE ON HEIGHT GROWTH AND FOLIAR NUTRIENT CONCENTRATIONS OF SELASIH (OCIMUM TENUIFLORUM L.)

Abstract

The herbal industry in Malaysia is facing problem of scarcity of the natural herbs due to excessive exploitation of natural forest. It is therefore necessary to cultivate these herbs and research is urgently needed on its agronomic aspects. A pot trial study was therefore carried with the following objectives: (i) to determine the effects of different organic fertilizer rates on height growth, and (ii) to measure selected foliar and soil nutrient concentrations. Treatments evaluated were: (i) 10% of guano manure mixed with 90% of soil (T1), (ii) 20% of guano manure mixed with 80% of soil (T2), (iii) 30% of guano manure mixed with 70% of soil (T3), (iv) 40% of guano manure mixed with 60% of soil (T4), (v) 50% of guano manure mixed with 50% of soil (T5), (vi) 60% of guano manure mixed with 40% of soil (T6), (vii) 70% of guano manure mixed with 30% of soil (T7), (viii) 80% of guano manure mixed with 20% of soil (T8), (ix) 90% of guano manure mixed with 10% of soil (T9), and (x) Soil without guano manure (control) (T10). The experiment was conducted using a Completely Randomize Design (CRD) with five replications. Plant height for each treatment was recorded on monthly basis for four months duration. Selected nutrient concentrations in the plant leaves after harvest and in the soil before planting and after harvest along with the soil pH were analysed. Soil total N was determined using Kjeldahl method while total P was determined using Aqua regia method. The exchangeable K, Ca, Mg, Zn, Cu, and Na were extracted using double acid method and their concentrations determined using atomic absorption spectrophotometry (AAS). Dry ashing method was used for the determination of P, K, Ca, Mg, Zn, Cu, and Na concentrations in plant leaves while total N concentrations was determined using Kjeldahl method. Guano manure showed significant effects on plant height, and concentrations of total N, total P, Ca, Mg and Zn in the leaves. The T3 recorded significantly higher plant height at 76.50 cm while the lowest was in T9 at 50.60 cm. The concentrations of K, Cu and Na on the other hand recorded no significant effects. Nutrient concentrations in the soil after harvest decreased compared to before planting while soil pH increased as level of manure increased in the soil before planting and after harvest. It is advisable to conduct field trial experiment for further study.