Genetic estimates and trend analysis of some growth parameters of cashew (Anacardium occidentale L.) as influenced by nine nutrient combinations

摘要

Good seedling establishment has a positive impact on the productive capacity of tree crops. This study investigated the optimum combination of phosphorus and organic fertilizer (OF) for the growth of cashew seedling at the pre-flowering stage. Two cashew accessions of the same nut size category from two geographical sources (Ochaja and Oro, Kogi State of Nigeria) were evaluated to assess their responses to three types of phosphate fertilizer and three levels of OF. The eighteen treatment combinations were laid out in a randomized complete block design of three replicates. Two years monitoring of the growth of the cashew accessions resulted in significant (P ≤ 0.05) genotypic variation for most of the traits at quarterly intervals of measurement. Significant (P ≤ 0.05) variation existed among the three levels of OF at different stages of plant height, stem diameter and leaf area. Broad sense heritability was not consistent across the six quarters of the three growth parameters. It ranged from 0.16% (SDQ5) to 95.6% (HTQ1). The trend of growth of the stem diameter from quarter 1 to 6 was linear for the two accessions. However, the response of the same trait to the three levels of OF was negatively quadratic. The first two initial years of cashew development on the field falls within the actively growing period of the crop. This justifies the linear behaviour of the three quantitative growth parameters investigated, application of OF at 2.5 tonnes/ha could be optimum for young cashew.