In modern agriculture, the substrate industry prefers porous materials for plants to provide water and nutrients in soilless cultivation. Composted sawdust is such a substrate. The sawdust industry is interested in avoiding composting sawdust because it is time and labor-consuming. The study objective was to evaluate whether non-composted (fresh) Bombax ceiba (red cotton tree) sawdust with added nutrients could be an alternative to composted sawdust for okra production. The sawdust was mixed with nutrients in the form of banana peels (a potassium source), eggshells (a calcium source), and urea (a nitrogen source). We conducted two independent pot experiments. Treatments were viz.: T1: non-fertilized 100% sandy clay loam soil (control) (vol/vol); T2: non-composted 100% B. ceiba sawdust (vol/vol); T3: non-composted 80% B. ceiba sawdust + 20% banana peels (vol/vol); T4: non-composted 60% B. ceiba sawdust + 20% banana peels + 20% eggshells (vol/vol); T5: non-composted 60% B. ceiba sawdust + 20% banana peels + 20% eggshells (vol/vol) + urea (@ 91 kg N ha−1). In both experiments, the germination of okra seeds was unaffected by the sawdust mixtures. The phenological development of okra was significantly greater in non-fertilized clay loam soil than in any non-composted sawdust mixtures. Plant height, leaf relative water content, stability index of the membrane, root length, chlorophyll content index, root and shoot dry and fresh weight, stem diameter, and single leaf area of okra were lower in all non-composted B. ceiba sawdust mixtures compared to the control. In contrast to T2, T5 resulted in fewer days before the first flower developed, an increase in the number of pods plant−1, length of pod plant−1, the diameter of the pod, fresh and dry weight of pod plant−1, and the seed numbers pod−1. It is concluded that amending non-composted B. ceiba sawdust with banana peels, eggshells, and urea (T5) enhanced its perspective as a growth medium for okra. Nonetheless, the amendments were unlikely to establish an adequate yield of okra, as was the case with non-fertilized sandy clay loam soil.

Sawdust as a soilless growth substrate for plants is becoming popular in greenhouse production. However, fresh sawdust often requires time for decomposition before it is ready for use as a growth substrate. We studied whether amendments of banana peels (as a source of potassium), eggshells (as a source of calcium), and urea (as a source of nitrogen) in non-composted fresh chinaberry (Melia azedarach) sawdust could enhance its potential as a growth medium. In two pot experiments, the growth of okra (Abelmoschus esculentus (L.) Moench) was evaluated using mixtures of non-composted M. azedarach sawdust. The treatments were: (T1) 100% soil (control) (vol/vol); (T2) 100% M. azedarach sawdust (vol/vol); (T3) 80% M. azedarach sawdust +20% banana peel (vol/vol); (T4) 60% M. azedarach sawdust +20% banana peel +20% eggshell (vol/vol); and (T5) 60% M. azedarach sawdust +20% banana peel +20% eggshell (vol/vol) +91 kg N ha−1 (urea). There was no significant difference between the treatments regarding seed germination and okra emergence, but leaf area, chlorophyll content index, plant biomass, number of pods per plant−1, fresh pods, and dry weight were significantly lower in pots with fresh sawdust mixtures. Organic amendments of banana peels and eggshells improved the sawdust substrate. Adding a further 91 kg N hectare−1 improved the growth but was insufficient to produce the same yield of okra as in non-fertilized sandy clay loam soil. We cannot exclude that non-composted M. azedarach sawdust may be a potential growth substrate for okra, but the amendments added were not enough to obtain the same yields as when okra was grown in soil.