Growth Response of Cashew Seedlings and Soil Properties to Cocoa Pod Husk and Cashew Leaf Litter Amendments at the Nursery Stage in South Western Nigeria
C. E. Ogbeide *
Agronomy & Soil Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria.
O. Aremu-Dele
Agronomy & Soil Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria.
F. E. Asowata
Agronomy & Soil Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria.
Y. M. Olugbemi
Agronomy & Soil Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria.
O. A. Akinyeju
Agronomy & Soil Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria.
S. A. Jude-Odia
Agronomy Division, Rubber Research Institute of Nigeria, P.M.B. 1049, Benin City, Edo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Cashew (Anacardium occidentale L.) is an important tropical plantation crop, yet productivity remains below potential due to poor nutrient management and underutilization of available organic residues.
Aim: The study aims to assess the influence of cocoa pod husk (CPH) and cashew leaf litter (CLL) on cashew seedling growth and soil properties.
Objectives: The objectives of the study were to: i. Determine the effects of different rates of cocoa pod husk and cashew leaf litter on the growth of cashew seedlings; ii. Assess the effects of the organic amendments on selected soil properties; and iii. Identify the amendment and application rate that gives the best response in cashew seedling growth under nursery conditions.
Study Design: A completely randomised design (CRD) was adopted. Seven treatments were evaluated: no organic amendment (control), 26.67 kg/t CPH, 40 kg/t CPH, 26.67 kg/t CLL, 40 kg/t CLL, 13.33 kg/t CPH + 13.33 kg/t CLL and 20 kg/t CPH + 20 kg/t CLL, each replicated three times. Data were collected on plant height, number of leaves, stem diameter and leaf area. Soil samples were analysed before and after the experiment.
Place and Duration of Study: A screen house experiment was conducted at the Cocoa Research Institute of Nigeria, Ibadan, Oyo State, for three months.
Methodology: The CLL was air-dried, milled and sieved prior to use. Polythene bags measuring 25 cm × 12.5 cm were each filled with 1.5 kg of topsoil, watered to field capacity, and arranged on a raised platform.
Statistical Analysis: Data were subjected to analysis of variance (ANOVA) using Minitab 17 statistical software, and treatment means were separated using Duncan's multiple range test (DMRT) at the 5% level of probability.
Results: The results showed that organic amendments improved seedling growth performance relative to the unamended control. Seedlings receiving 20 kg/t CPH + 20 kg/t CLL recorded the highest values for plant height, stem diameter and leaf area at 12 weeks after treatment application. Post-experimental soil analysis revealed notable improvements in organic matter, calcium and magnesium contents in most amended soils. Progressive seedling growth improvement was attributed to continuous nutrient release from decomposing organic materials and enhanced soil conditions.
Conclusion: The combined application of 20 kg/t CPH + 20 kg/t CLL demonstrated the greatest potential for optimizing cashew seedling growth and soil fertility, suggesting that it may be a viable organic nutrient management option for nursery production.
Keywords: Cocoa pod husk, cashew leaf litter, organic amendment, cashew seedlings, soil fertility