Germination sensitivity and seedling quality of mahogany (Swietenia macrophylla) in response to saline irrigation

Swietenia macrophylla or big-leaf mahogany is an exotic species from Central and South America. This tree has various benefits, so it’s used as an industrial plantation forest and afforestation in Indonesia. However, seed storage of mahogany is a major problem in cultivation, because it can reduce seed viability. The storability of seeds is influenced by seed and environmental conditions. Therefore, this study aimed to examine the effect of temperature and storage time on the viability of S. macrophylla seeds and to calculate the Seedling Quality Index (SQI). The experiment was carried out using a factorial Randomized Block Design (RBD) with 2 factors. The first factor was consisted of four levels of temperature treatment, namely room temperature (24), 4, 0, and -20°C. The second factor was the storage period treatment which consisted of 4 levels, namely 1 up to 4 weeks, with 1-week intervals. The results showed that the interaction between temperature and storage time affected mahogany leaves, primary and secondary roots, root/shoot ratio, and total wet weight of S. macrophylla seedlings. Mahogany seeds that were stored at room temperature for 1 week resulted in the highest seed viability, with SQI of 0.03-0.04.

Vesicular arbuscular mycorrhiza (VAM) is a symbiotic fungus accompanying with the roots of higher plants, playing a dynamic role in enhancing seedling growth and quality. It improves nutrient availability, particularly phosphorus, boosts chlorophyll content and fixes atmospheric nitrogen in leguminous species. These benefits make VAM a significant tool in forest nurseries for producing quality planting materials of economically and ecologically important tree species. This review highlights the potential of VAM, alone and in combination with other biofertilizers, in improving seedling growth, quality attributes, and soil fertility, emphasizing its role in sustainable nursery practices for the production of quality tree seedlings. The methodological approach involved reviewing studies that assessed the effects of VAM inoculation under controlled nursery conditions, either independently or combined with biofertilizers such as Rhizobium, phosphate-solubilizing bacteria (PSB), Azospirillum, Frankia, Phosphobacterium, and Azotobacter. Parameters such as seedling growth, nutrient uptake and quality attributes were analyzed. The effects of combining VAM with nutrient inputs like rock phosphate and NPK fertilizers were also evaluated. VAM inoculation alone significantly improved seedling quality in species such as Anthocephalus cadamba, Azadirachta indica, Dalbergia sissoo, and Swietenia macrophylla. Its combination with biofertilizers enhanced growth in species like Acacia catechu, Butea monosperma, Eucalyptus tereticornis and Tectona grandis. Integration with nutrient inputs further boosted the performance of species like Leucaena leucocephala and Acacia mangium. VAM is a promising tool for producing quality seedlings, contributing to sustainable afforestation and reforestation efforts by enhancing seedling growth, improving soil fertility and supporting environmental conservation.

Objetivou-se avaliar neste estudo o efeito de nitrogênio, fósforo e potássio no crescimento de mudas de mogno. As plantas foram cultivadas num Latossolo Amarelo Distrófico argiloso com seis níveis de nitrogênio (0, 50, 100, 125, 150 e 200 kg N ha-1), seis níveis de fósforo (0, 75, 150, 225, 300 e 400 kg P2O5 ha-1) e seis níveis de potássio (0, 40, 80, 120, 160 e 200 kg K ha-1), em condição de casa de vegetação. Aos 100 dias após o transplantio, as plantas foram colhidas para determinar as características de crescimento: altura, diâmetro, matéria seca da parte aérea e raízes e a concentração de nutrientes presentes na parte aérea e raízes. O desenvolvimento das mudas de mogno é pouco influenciado pelo fornecimento de doses crescentes dos nutrientes nitrogênio, fósforo e potássio, indicando uma baixa exigência nutricional da espécie na fase inicial de crescimento. Entre os nutrientes avaliados, a espécie parece ligeiramente mais exigente quanto ao potássio em relação aos demais. No entanto, a demanda da planta já seria satisfeita com uma pequena adição do respectivo nutriente. A adubação com nitrogênio e fósforo não promove melhora na qualidade das mudas de mogno.Palavras-chave: Espécies florestais; mogno; nutrição mineral; crescimento inicial. AbstractDevelopment of Swietenia macrophylla seedlings in response to nitrogen, phosphorus and potassium. A Greenhouse experiment was developed in order to investigate effects of nitrogen, phosphorus and potassium on the growth of mahogany seedlings (Swietenia macrophylla King). The plants were cultured in clayey dystrophic Red Latosol containing six nitrogen levels (0, 50, 100, 125, 150 and 200 kg N ha-1), six phosphorus levels (0, 75, 150, 225, 300 and 400 kg P2O5 ha-1) and six potassium levels (0, 40, 80, 120, 160 and 200 kg K ha-1). After 100 days of transplanting, the plants were harvest and processed for determine height, diameter, dry weight and nutrient concentration in roots and shoots. Addition of nitrogen, phosphorus and potassium did not affect the mahogany seedlings development. In contrast to N and P, the yield of plants was slightly greater with K fertilization. In general, results of this study clearly demonstrate the absence of a beneficial effect of these nutrients on the growth of mahogany seedlings. The nitrogen and phosphorus did not improve the quality of mahogany seedlings.Keywords: Forest species; mahogany; mineral nutrition; early growth.

This study characterized a green-waste-derived biochar from date palms and ghaf trees and investigated its potential as a soil amendment with halotolerant Bacillus spp. to improve tomato seedling quality under dual stress of salinity and nutrient deficiency. Biochar was produced through pyrolysis at 450°C and then characterized for yield, pH, electrical conductivity, proximate analysis, surface morphology, energy-dispersive X-ray spectroscopy, and heavy-metal content. Its effectiveness was tested both alone and in combination with a Bacillus sp. mix, using a completely randomized design with varying NPK fertilizer levels and saline irrigation. Tomato seedlings were evaluated 45 days after planting for various vegetative, morphological, physiological, and nutrient content indicators. Under normal conditions, applying biochar combined with a Bacillus mix at 0% NPK greatly enhanced all measured parameters, often exceeding values observed with 100% NPK fertilization. This approach was especially effective under saline irrigation, resulting in significant increases in morphological parameters (40-150%), physiological parameters (51-94%), and nutrient content (34-63%) compared to control plants that received 100% NPK. Additionally, this treatment resulted in a 42% decrease in sodium accumulation. Using the biochar with the Bacillus mix effectively replaces chemical fertilizers and enhances salinity tolerance, supporting sustainable farming through waste recycling and less dependence on fertilizers.

The present investigation was aimed at adopting organic production, promoting forest nurseries for sustainable tree plantation, and exploring Swietenia macrophylla King for timber purposes in present times for local conditions. The experiment was designed to assess the growth and vigour of big-leaf mahogany seedlings amongst various organic manures (FYM, Vermicompost, Neem cake, and Poultry manure) in different combinations with red soil and drenching of various biofertilizers (Azotobacter, Azosprillum, Acetobacter, PSB, Pseudomonas, VAM) in early stages of the nursery in comparison to control (Red soil). Among different organic manure treatments, red soil + poultry manure (2:1) exhibited fair qualitative as well as quantitative responses in growth parameters whereas, the maximum seedling quality index was found in Vermicompost treatment. In another aspect of the study, the results showed the highest growth and vigour were recorded in seedlings drenched with VAM @ 10 ml plant-1.

Swietenia macrophylla King is one of popular tree species for timber product in Java. In order to increase the productivity of planting stock production at nursery, this research was conducted. The objectives of this research was to study the influences of sowing method and NPK fertilizer application on the growth of mahogany seedlings at nursery. The treatments were sowing methods (with and without pricking out), types of NPK fertilizer (grain and solution) and the dosages of NPK fertilizer (0, 0.2, 0.4 and 0.6 gram/seedlings). The result showed that sowing methods and type of NPK fertilizer did not give significant effect on the growth of mahogany seedlings. The dosages of NPK fertilizer caused significant different on the variation of height, diameter, total dry weight and seedling quality index. The application of NPK fertilizer at 0.6 g/seedlings/month showed the best result i.e: the seedling heigth (42 cm), stem diameter (5.15 mm), total dry weight (5.28 g) and seedling quality index (0.38).