نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction
Given the ongoing challenges of climate change and the increasing of shortages in water resources, there is an urgent need to reconsider conventional cropping systems. Promoting the cultivation of drought-tolerant and low water requiring crops such as legumes can substantially contribute to agricultural sustainability and food security. Chickpea (Cicer arietinum L.) is a major legume adapted to arid and semi arid regions, playing a vital role in improving soil fertility through biological nitrogen fixation. It is cultivated on approximately 17 million hectares worldwide. In Iran, although a large area is dedicated to chickpea cultivation, the average yield accounts for only about 30% of its potential capacity. Factors such as inadequate agronomic management, drought, high temperatures, and severe damage from pests and diseases—especially during early growth stages—are considered the main causes of such low productivity.
Direct seeding, which has long been the conventional method of chickpea establishment, often leads to poor and nonuniform seedling emergence under water-limited and harsh environmental conditions. In this context, transplanting represents a novel and promising approach to overcome these constraints by improving seedling establishment, optimizing water use, and enhancing tolerance to biotic and abiotic stresses. Therefore, this study aimed to evaluate the effects of seedling age and tray cell size on transplanting growth traits to identify effective strategies for improving transplant production and addressing challenges associated with water scarcity.
Materials and Methods
The experiment was conducted in February 2024 in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad, using a completely randomized design (CRD) with four replications. The treatments included two factors: transplanting age at three levels (4, 6, and 8 weeks) and tray cell size at three different volumes (24, 38 and 60 cm3). Chickpea seeds (cv. MCC770), obtained from the Faculty’s Research Farm, were sown in trays filled with a cocopeat–perlite substrate (7:3, v/v). To produce transplants of different ages, sowing was repeated at 2- and 4-week intervals following the initial planting. Transplants were grown under greenhouse conditions maintained at 17–23 °C with daily irrigation throughout the growth period. Nutrient application was carried out two weeks after sowing, at the two- to three-leaf stage, using a complete NPK nutrient solution (0.2%). Eight weeks after sowing, emergence percentage, leaf area, shoot and root dry weight, root surface area, and root length were measured
Prior to analysis, data were examined for normality and homogeneity of variances. Statistical analysis was performed using Minitab software (version 20), and means were compared using the LSD test.
Results and Discussion
The interaction between transplanting age and tray cell size was significant for all measured traits. In general, the highest leaf area and shoot dry weight were observed in 8 weeks transplants, whereas in the 4 weeks exhibited the greatest root surface area and root length. Increasing transplanting age markedly reduced the emergence percentage. However, 8 weeks transplants exhibited greater leaf area and shoot dry weight than 4 weeks transplants. This pattern indicates that spatial constraints during the nursery stage induced mild stress conditions, stimulating a compensatory growth response characterized by enhanced leaf expansion to improve post-transplant establishment. The observed negative correlations between emergence percentage and both leaf area and shoot dry weight further confirm this interpretation, suggesting that reduced transplants density allowed greater access to growth space and consequently promoted shoot biomass accumulation.
Correlation analysis revealed significant positive relationships among root dry weight, shoot dry weight, and leaf area, underscoring the pivotal role of root development in sustaining aboveground growth. Additionally, root surface area showed a positive correlation with emergence percentage, likely reflecting enhanced water absorption capacity in the lightweight and porous substrate. In contrast, its negative associations with leaf area and shoot dry weight suggest a shift in dry matter allocation toward root structures under spatial or resource limitations. Overall, these results highlight the necessity of maintaining a balanced root–shoot relationship to ensure vigorous chickpea seedling growth and successful transplant establishment.
Conclusion
The results revealed that increasing transplanting age decreased emergence percentage but improved growth traits such as leaf area and shoot dry weight. Cell size also played a crucial role in root development and dry matter distribution among plant organs. Transplanting aged 4 weeks exhibited stronger root systems, with greater root length and surface area, making them more suitable for field transplantation. Overall, optimizing transplanting age and cell volume can enhance chickpea transplanting quality by maintaining balanced root–shoot growth and improving establishment success after transplanting.
کلیدواژهها English
