1. Introduction
Geranium (
Pelargonium graveolens L’Hér) is one of the choicest ornamental outdoor plants and belongs to the family Geraniaceae [
1]. Geranium is an important, high-value perennial, aromatic herb and shrub that can reach to a height of 1.3 m and a spread (lateral growth) of 1 m. Its hairy stems are herbaceous when young and become woody with age, and the plant’s leaves are deeply incised, soft to the touch, and strongly rose scented [
2,
3,
4]. The geranium are native to South Africa [
5]. It is not to be confused with the household variety of geranium, which is a completely different species. There are over 700 varieties of cultivated geranium, however, most are grown for ornamental purposes. Moreover, geranium plants come in a variety of colors, white, pink, salmon, red, fuchsia, lavender, leaf patterns, round, segmented, lacy, flower size, single or double bloom, and leaf color, green, green and white, or multicolored. Geranium plants can be compact upright plants or graceful hanging vines. The vibrant Geranium flowers do not have an appealing aroma, but there are several Geranium varieties that have leaves with lovely scents such as rose, lime, peppermint, lemon, orange, or lime [
6]. Geranium Plants are a great addition to your indoor plant collection, but will only bloom if you keep them in very bright light or direct sun for at least 6–8 h a day.
The type of containers play a significant role for successful seed emergence of plant species [
6,
7]. Containerised seedling production has been widely used since the early sixties. This practice improved seedling survival and management as compared to bare-root seedling production [
7]. The primary function of any container is to hold a discrete supply of growing medium, which in tum supplies water, air, mineral nutrients and physical support to the seedling [
8]. Container based production of floriculture plants has competitive advantage over conventional (field) production. The advantages that are linked to container production included the less damage to root system of plants during the transplanting process and rapid establishment of root after transplantation. Moreover, less labour and land acquirement cost and increased availability and longevity of plant production in the market, all are the benefits of container production. In container plantation, plants are grown and transplanted with intact and functional root system thus enhancing the prospective of success ratio of transplanting.
Nursery practices are considered to have a large impact on seedling root development and this effect is likely to be maintained during the early establishment phase [
9]. The characteristics of the nursery culture and particularly the container type is among the most important determinants of seedling production and its quality [
10]. Besides that, container design also determines the morphological and physiological characteristics of seedlings, mainly in terms of their root systems [
11,
12,
13]. Moreover, container volume and container depth can determine root system growth including emergence of new roots and their length and survivability of seedlings as well [
14,
15,
16,
17].
Containers for the raising of the seedlings come in various forms, sizes, and in different materials such as polystyrene, polyethylene, root trainers, fiber, or paper. A common problem with all containers is the substrate. However, it is important to note that in developing countries like Pakistan the most commonly used substrates are soil and sand-based mixtures which are unsuitable for the development of an extensive fibrous root system. This type of substrate creates problems in various types of containers such a common problem with polybags is observed that plant roots tend to grow in spirals once they hit the smooth inner surface and root systems that lead to root girdling and weak performance after out planting [
18]. This inevitably leads to plants with restricted growth, poor resistance to stress and wind throw, and even early dieback due to ensnarled root masses or pathogens. This is a major drawback of the use of conventional polybags. As an alternative, root trainers are usually rigid containers with internal vertical ribs, which direct roots straight down to prevent spiral growth [
19,
20].
The type of container selected for growing depends on the plants to be raised [
21]. The most common container used for seedling production is black plastic trays [
22]. The black color has been found to absorb solar radiation and increase substrate temperatures [
23]. The ideal container for nursery plants should have an attractive appearance, structural strength, and good insulation value, the material should not be brittle or decompose rapidly, good durability during handling and shipping, promotes a healthy root system [
24]. Moreover, the container should be, light in weight, provide good drainage, be long-lived and affordable, creates no hazard for customers during planting and ease of disposal (sustainability) of product. Container type can significantly affect the root morphology of container-grown plants [
25]. By keeping all in mind, the present study is therefore designed to observe seed germination and seedling growth of the geranium in different types of containers.
4. Discussion
Nursery practices are considered to have a large impact on seedlings root development during the nursery phase, this effect is likely to be maintained the early establishment phase [
9]. The characteristics of the nursery culture and particularly container types are among the most important determinants of the cost of seedling production, as well as of seedling quality [
10]. The ideal container for nursery plants should possess attractive appearance, structural strength, the material should not be brittle or decompose rapidly, good durability during handling and shipping, promotes a healthy root system, efficient storage (nesting) potential, light in weight and provide good drainage. Moreover, container be long-lived and affordable, create no hazard for customers during planting and ease of disposal (sustainability) of product. It is important to note that plants don’t grow in containers naturally, so this environment is unnatural and different from field-grown or native conditions [
26].
Different type of containers plays a significant for seed emergence and healthy growth and development of seedlings [
24]. In general, a relationship has been observed between container size or shape and seedling growth [
27]. The use of deep containers in the nursery does not necessarily produce excessive height, growth, adequate control of watering and fertilization could modulate seedling height and growth [
28].
The most common container used for nursery production is the black plastic container, while these containers tend to be inexpensive (though cost depends on current petroleum prices), they have benefits and drawbacks. Black plastic containers are lightweight, durable, familiar to growers, well-suited for mechanization, and can be reused or recycled. These containers are made from many different plastic types, melted and remolded for the desired shape and size. In the present study different types of containers were used to observe germination and seedling growth of geranium. Nonwoven fabric bags were observed as the best container for germination and seedling growth of geranium. The use of nonwoven fabric bags was observed better for transplantation of the seedlings as these bags can be transplanted directly in containers or soil without removing the bag, reducing the risk of damage to the roots during the moment of transplanting. Similar reports were also observed by the [
29]. These bags are made from natural fibers such as grasses, cotton, sisal, etc. [
30] reported that biodegradable containers required more frequent watering than those in polythene bags under light tree shade and shade nets but less frequent in polythene chambers. Seedlings produced in polythene tubes had higher growth rates in the nursery, but when transplanted to the field, they were overtaken by those grown in the biodegradable containers due to transplanting shock after the polythene containers were removed. In a study, better seedling growth observed in 600 mL and 1500 mL polybags than in the 1000 mL polybag [
31]. This might be due to a greater ratio between length and diameter in the 1000 mL polybags (2.00) compared with the 600 mL (1.57) and 1500 mL (1.60).
With the development and improvements made in production technologies, nonwoven geotextiles are gaining more and more advantages over traditional agro textiles [
32]. Nonwoven agro textiles are used effectively for optimizing the productivity of crops, gardens, and greenhouses. Some examples where nonwovens are used are as crop covers, plant protection, seed blankets, weed control fabrics, greenhouse shading, root control bags, biodegradable plant pots, capillary matting, landscape fabric, lawn coverings, bio-based and compostable nonwovens for multi-season mulching and other short-term and long-term agricultural applications [
33]. Nonwoven fabrics present many advantages over conventional fabrics with one main clearest benefit, cost savings. Properties of nonwoven agro textiles depend on the fibers made of and on the type and conditions of production. The nonwoven agro textile can be made from natural or man-made fibers and their blends. As a natural fiber, jute is mostly used, while polypropylene is the most common choice for nonwoven agro textiles made from man-made fibers. [
34] reported that the use of deeper containers produced seedlings with better above-ground characteristics. [
12] reported that white or light containers have the potential to reflect solar radiation and eliminate heat stress. He said heat-sensitive plants will benefit from being grown in white containers or painting the outside of the container white for improved root growth. [
20] observed that plastic containers were better than polybags. Seedlings produced in black plastic containers had a total dry weight of 1.8 g, shoot dry weight of 0.96 g, root dry weight of 0.89 g, and quality index of 0.23.
Different types of containers are used for successful production of ornamental plants [
35]. Container size is a vital for satisfactory growth and development of nursery plants [
36]. It has been widely reported that small size pots/container had a negative effect on plant growth and biomass production [
37]. Since small size pots comprises of less amount of soil that causes reduced availability of water and nutrients to the plants. Thus, eventually lead to poor growth and development of plants [
38]. Pot/container also effect the photosynthetic activity in plants. Available evidences have revealed that low photosynthetic rate was observed in small size plants [
39]. Since small sized pots contains small fraction of soil in which plant nutrients quantity specially nitrogen and phosphorus is decreased [
40]. Nitrogen and phosphorus are vital for enhancing the photosynthetic rate [
41]. The low photosynthetic rate in the small sized pots might be attributed to less contents of nitrogen and phosphorus in the soil [
42].