Effect of shade intensity on root development, biomass accumulation (fresh and dry weight), and survival percentage of ornamental foliage plants

Introduction

Shade intensity is one of the most important environmental factors influencing the growth, development, and quality of ornamental foliage plants. Light regulates several physiological and biochemical processes, including photosynthesis, respiration, transpiration, and nutrient uptake, all of which directly affect plant growth. Since many ornamental foliage plants are naturally adapted to the shaded understory of tropical forests, providing an optimum level of shade is essential for maximizing their vegetative growth and aesthetic value. Root development is a key indicator of plant establishment and overall health. A welldeveloped root system enhances water and nutrient absorption, improves anchorage, and increases the plant's ability to tolerate environmental stress. Shade intensity can significantly influence root growth by altering the availability of photosynthates that are transported from leaves to roots. Excessive shade may reduce carbohydrate production, resulting in poor root growth, whereas moderate shade often promotes balanced shoot and root development in shade-loving ornamental species. Biomass accumulation, expressed as fresh weight and dry weight, is another important measure of plant growth. Fresh weight reflects the water content and succulence of plant tissues, while dry weight represents the actual accumulation of organic matter produced through photosynthesis. The amount of light available to plants directly affects biomass production, as it determines the rate of photosynthesis and the partitioning of assimilates among different plant organs. Appropriate shade levels can therefore improve both fresh and dry biomass, while excessive or insufficient light may adversely affect plant growth. Survival percentage is an important parameter for evaluating the adaptability and successful establishment of ornamental foliage plants under different shade conditions.

Higher survival rates indicate that the environmental conditions are favorable for plant growth and maintenance. Suitable shade levels reduce heat stress, minimize water loss through transpiration, and create a more favorable microclimate, thereby improving plant survival. Conversely, excessive shading or exposure to intense sunlight may reduce plant vigor and increase mortality. Therefore, evaluating the effect of different shade intensities on root development, biomass accumulation (fresh and dry weight), and survival percentage provides valuable information for identifying the optimum shade level required for the commercial production and maintenance of ornamental foliage plants. Such information is useful for nursery management, greenhouse cultivation, and landscape applications, ultimately contributing to improved plant quality and higher production efficiency. During the last decades, due to increased air temperature and intensity of solar radiation caused by climate changes, an increasing area of crops is being grown under shading materials of various types. Nets are commonly used in agricultural crops for specific modification of sunlight, improving microenvironment, and providing physical protection. They not only decrease light quantity but also alters light quality to a varying extent and also change other environmental conditions (Smith et al.,11). Cut greens grown under different shade-net gave better performance in terms of plant height, number of leaves, number of branches, leaf area, number of roots, etc. compared to control. Nettings, regardless of colour, reduce radiation reaching crops underneath which is directly proportional to the shade factor and modify microenvironment. Keeping these facts in view the present study was undertaken to observe the production and quality of dracaena under different colour shade-nets. Cut greens are an important component of the floricultural industry and are largely used for decoration as a-filler in floral compositions. They provide freshness, colour and variety to various decorations, arrangements and bouquets. Foliage plants are one of the important cut greens and are used widely for its beautiful foliage. Nets are commonly used in agricultural crops for specific modification of sunlight, improving microenvironment, and providing physical protection. They not only decrease light quantity but also alters light quality to a varying extent and also change another environment. Nets have three major uses in horticulture (i) shading, for protection from too much solar radiation; (ii) protection from environmental hazards such as strong winds, hail and sand storms; (iii) protection from flying pests like birds, fruit bats, etc. Study the effect of different shade levels on the growth and biomass production potential of Cactus (Opuntia ficus (L.) Mill.) under the arid Kachchh, Gujarat. Cactus in pots were grown for twelve months under 25, 50 and 75% shade; along with under full sun control. Shade level significantly affected plant response; the shading improved plant characters like height, number of leaves, leaf area, and overall plant weight. However, plant survival decreases at under high shade level (75%), mainly due to rotting. The plants grown in 25% and 50% shade levels produced the highest leaf area, no. of leaves and biomass than plants subjected to 75% shade and control. Plants grown under 75% shade level were taller, due to more longitudinal and less wide leaves (cladodes) along with more root length. Overall, up to 50% shading was found best for horti-based or agroforestry-based cactus pear cultivation or intercropping. ( Dev et al., 2018) [7] • To find out the effect of shade conditions on sprouting.

• To find out the effect of shade conditions on growth performance of ornamental foliage plants. • To find out optimum shade conditions for foliage plants.

Methodology

The field experiment was conducted at College of Horticulture, Mulde for successive three years (2020-2023) and laid out in Split plot design along with 4 green colour shade net conditions (main treatments) and 06 woody foliage plants (sub treatments) and replicated twice.

Number of roots

Conclusion

It can be concluded that different woody ornamental foliage plants exhibited superior overall growth performance under M₂ (50% shade) compared with the other shade treatments.

Plants grown under 50% shade showed better root development, higher fresh and dry biomass accumulation, and improved survival percentage, indicating that this shade level provided the most favorable microclimatic conditions for growth. The M₁ (25% shade) treatment ranked second in terms of overall performance, while the remaining shade levels were comparatively less effective. Therefore, 50% shade can be recommended as the optimum shade intensity for the cultivation and production of woody ornamental foliage plants, as it promotes vigorous growth, greater biomass production, and higher survival, ultimately improving plant quality and nursery production efficiency.

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