{'fraction_non_alphanumeric': 0.0358553151160954, 'fraction_numerical': 0.016269151792765755, 'mean_word_length': 4.583774250440917, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 2, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Evaluation of the Effects of Organic and Mineral Fertilizers with Mycorrhiza on the Dry Matter Yield and Nutrient Uptake of Theobroma Cacao in Ibadan, Nigeria

A greenhouse trial was conducted at Cocoa Research Institute of Nigeria, Ibadan, to evaluate the effects of organic and mineral fertilizers with and without Mycorrhiza on the dry matter yield and nutrient uptake of CRIN Tc-1 and F3 Amazon cocoa seedling in Ibadan. The treatments consist of cocoa pod husk (CPH), Tithonia diversifolia leaves (TD) , combination of CPH and TD (CPH+TD) and NPK fertilizer which were applied to F3 amazon and Tc1 hybrids of cocoa at two levels of mycorrhiza (with and without) inoculation, to supply 10Kg N/ha respectively and laid out in completely randomized design (CRD) in three replicates. All the fertilizer treatments with mycorrhiza were significantly (p<0.05) higher than the treatments without mycorrhiza for N uptake except for NPK and control. Application of sole CPH under mycorrhiza inoculation significantly (p<0.05) enhanced phosphorus uptake in TC1 relative to the control. Potassium uptake was significantly(p<0.05) enhanced by CPH and CPH+TD without mycorrhiza. CPH with mycorrhiza gave the highest leaf and root dry matter yield (DMY) which were significantly higher than the control for Tc-1, while for F3Amazon, TD with mycorrhiza gave the highest root DMY relative to the control. It can therefore be concluded that optimal and sustainable growth and dry matter yield of cocoa seedlings could be achieved by the use of organic fertilizer materials such as TD and CPH in combination with mycorrhiza.


Materials and Methods
The experiment was conducted in the greenhouse at the Cocoa Research Institute of Nigeria, Ibadan. Top soil (0-15cm) used for the study was collected from a cocoa plot, air-dried to pass through a 2mm sieve and 5kg soil was weighed into each pot. Representative soil sample was analyzed in the laboratory for routine physical and chemical properties. The pots were watered to field capacity and two cocoa beans sown directly into each pot. The experiment was factorial laid out in a completely randomized design and replicated three times. The three factors were mycorrhiza at two levels (with and without mycorrhiza), fertilizer types at five levels (CPH, CPH +TD, TD, NPK and the control) and cocoa varieties (F3 Amazon and Tc 1). There were 60 experimental units altogether. The fertilizer type used were Cocoa Pod Husk (CPH), Tithonia diversifolia leaves (TD), a combination of CPHand TD (CPH+TD) and NPK fertilizer. The organic materials were applied two weeks before sowing while NPK was applied two weeks after sowing. The seedlings were thinned to one per pot one week after emergence, watering was done three times a week. The experiment was terminated at six months after sowing. The plants were harvested and separated into leaves, stem and roots. The plant samples were oven dried at 70 0 C until a constant weight was obtained, weighed, milled and analyzed for the nutrient content. The nutrient uptake was then calculated using the formula: Nutrient Uptake = Yield (Kg) × Nutrient Content (%).
All data generated were subjected to statistical analysis using ANOVA and significant means were separated using Duncan Multiple Range Test.

Results and Discussion
The physical and chemical properties of soil used for the greenhouse experiment are shown in Table 1. The soil was slightly acidic (pH 6.0). The critical soil nutrient recommended for optimum production of cocoa in Nigeria are: Organic Carbon (OC) -18g/kg -1 , Total Nitrogen (N) -1.0gkg -1 respectively (Egbe et al., 1989). Available Phosphorus -5.5mgkg -1 , Exchangeable K -1.2gkg -1 , Ca -8.0cmolkg -1 and Mg -0.8cmolkg -1 .However, the test soil was low in OC, N, P, K, Ca and Mg and the values fall below the critical level for optimum production hence the need for nutrient amendment.
The nutrient composition of the cocoa pod husk and the Tithonia diversofolia are also shown in table1. The CPH had 25.7g/kg N, 242.6g/kg OC, 2.9mg/kg P, 8.8cmol /kg K, 2.0cmol/kg Ca, 0.3cmol/kg Mg. While TD had 27g/kg N, 140g/kg organic carbon, 3mg/kg P, 4.1cmol/kg K, 9.8cmol/kg Ca and 0.35cmol/kg Mg. This shows their potential for use as fertilizers.
The effect of CPH +TD and CPH both with mycorrhiza (+M) inoculation produced similar effect on the K uptake in Tc1although CPH with mycorrhiza gave a higher K uptake. The two treatments were significantly higher than the control. Also TD +M, CPH+TD+M and TD without mycorrhiza (-M) recorded similar effects on K uptake in F3 Amazon cocoa seedlings (Table2). Calcium uptake for CPH+TD, CPH, TD and control was significantly higher than that of NPK. Inoculation with mycorrhiza significantly affected the Ca uptake in Tc1 variety with CPH and CPH +TD and the control. Also, Mg uptake by Tc 1was the highest for CPH+TD fertilizer material under mycorrhizal inoculation and was significantly higher than NPK and control.  The Dry Matter Yield (DMY) followed the order leaf> stem>root (Table 3). The shoot DMY was higher than the root DMY. CPH with mycorrhiza gave the highest leaf and root DMY which was significantly higher than the control for Tc-1. While for F3 Amazon, TD with mycorrhiza gave the highest root DMY which was significantly higher than the control. CPH +TD, CPH in combination with mycorrhiza gave the highest TDMY which was significantly higher than the control for both Tc1 and F3 Amazon. This could be as a result of increased microbial activities that led to increased mineralization of organic matter from the natural source in the soil and availability of nutrients in the soil for the plant use leading to increased dry matter accumulation as indicated by Akanbi et al 2013. In Tc1, inoculation with mycorrhiza significantly increased the root DMY and the TDMY for CPH +TD, CPH. This observation is consistent with that of Akanbi et al (2014) who reported an increase in cocoa seedling growth and dry matter yield using cocoa pod ash and oil palm bunch ash.

Conclusion
The study shows that application of organic materials and mycorrhiza increased the nutrient uptake as well as the total dry mater yield of cocoa. Hence, CPH, CPH +TD could serve as an alternative for NPK which is expensive and not readily accessible to low income farmers.

References
i