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Many annual and perennial plants can be propagated from seeds. Although growing plants from seeds is relatively easy compared to other methods of multiplying plants, it can be challenging due to the specific germination requirements of certain seeds. In general, such requirements are related to overcoming various kinds of germination inhibitions. This publication provides information on how to germinate seeds and grow them into healthy plants.
Before you start, it will be helpful to learn about the seeds you’ll be dealing with so you can ensure the process of propagation goes smoothly and ask specific questions pertaining to seed propagation.
To a botanist, a “seed” is a specialized plant structure, complete with a tiny embryo, which is capable of growing into a new plant. Each seed has an embryo and food storage structures enclosed in a seed coat. Under conditions favorable for germination, the embryo develops into a mature plant as it is nourished by the food reserves in the storage structures, sometimes in tissue called an endosperm and sometimes in the cotyledons.
For a horticulturist, seed sometimes refers toany part of a plant capable of regenerating into a new plant. For example, in commercial cultivation of potato, the tuber is used as a vegetative propagule rather than the botanical seeds. Vegetatively propagated plants closely resemble their parent plants. To simplify, a potato tuber is referred to as a seed-tuber.
You know, if you put fresh cut flowers in water it will help keep them from wilting. If you have a packet of cut flower preservative from a florist or the store, it will help the flowers to stay fresh much longer. You can make cut flower preservative yourself, however. There are several good recipes, made using common household ingredient.
Keys to Keeping Cut Flowers Fresh
• Give them water.
• Give them food.
• Protect them from decay or infection.
• Keep them cool and out of direct sunlight.
The floral preservative provides flowers with water and food and contains a disinfectant to prevent bacteria from growing. Making sure your vase is clean will also help. Discard any decaying leaves or flowers, because the freshness of flowers is influenced by the gases and bacteria found on wilted or rotting plant material. Also, don’t set your flowers near ripe fruit, because the chemicals from the fruit (such as ethylene) will ‘ripen’ your flowers. If you can, keep your flowers in a cool location and out of sun. Minimize air circulation, since it speeds evaporation and can dehydrate your flowers. Trim the bottom ends of your flowers with a clean, sharp blade before arranging them in the vase containing the floral preservative. Cut the stems at an angle to increase the surface area for water and to prevent the ends from resting flat on the bottom of the container. In all cases, mix the floral preservative using warm water (100-110°F or 38-40°C) because it will move into the stems more effectively than cold water. Clean tap water will work, but if it is very high in salts or fluorides, consider using distilled water instead. Chlorine in tap water is fine, since it acts as a natural disinfectant.
some of the home-made preservatives are listed below:-
Some More Tips:
• Trim away any foliage which would be below the water line. The wet leaves encourage microbial growth that can rot your flowers.
• Remove any unnecessary leaves because they will accelerate dehydration of the flowers.
• Flowers with milky latex-containing sap require special treatment. Examples of these flowers include poinsettia, heliotrope, hollyhock, euphorbia, and poppy. The sap is meant to prevent water loss by the stem, but in a cut flower it keeps the plant from absorbing water. You can prevent this problem by dipping the bottom tips (~1/2 inch) of the stems in boiling water for about 30 seconds or by flashing the tips of the stems with a lighter or other flame.
With this we can keep the beauty of cut flowers for longer.
Weeds, defined anthropocentrically as undesirable plants that are growing ‘out of place’, have evolved numerous mechanisms to survive field conditions that are optimized for crops. Certain traits are generally associated with weedy plant species, including early germination, rapid growth from seedling to sexual maturity, and the ability to reproduce sexually and asexually (Baker & Stebbins, 1965; Baker, 1974). Baker hypothesized that the ‘ideal weed’ might exhibit a generalist genotype with a high level of phenotypic plasticity (Baker & Stebbins, 1965; Baker, 1974). However, weeds are known to evolve rapidly in several ways: from colonizers selected by agricultural practices; from hybridization between wild and domesticated cultivars; and from selection on abandoned domesticated cultivars (De Wet & Harlan, 1975). Thus, the question of whether weeds are phenotypically plastic, ‘Jacks of all trades’ (Richards et al., 2006), or possess single genes/traits that are responsible for weediness, remains unresolved.
There are many well-known examples of the appearance of new weeds or weed complexes following selection by a weed-control practice or cropping system. Annual tillage systems are known to select annual weeds and to disfavour perennial weeds, while perennial and no-till cropping systems generally select perennial weeds. Mowing often selects weeds with horizontal growth form and low-growing meristems, such as grasses and clovers, or prostrate phenotypes within the same species. In some systems weeds have evolved that mimic crops morphologically and phenologically, such as barnyardgrass (Echinochloa crus-galli) growing in rice (Oryza sativa) (Barrett, 1983). There are also many examples of biological agents that have had profound effects on weed floras, such as the increase in noxious thistles and other unpalatable species in response to grazing animals on rangelands. In some cases the result is simply a shift or a change in the species composition of a site, similar to succession in natural systems, while in other cases rapid weed evolution has occurred (Holt, 1997; Radosevich et al., 2007). As noted by Baker 1974 (1991), weeds are ‘potentially useful for studies of microevolution under human influence’.
This far we can say Weed adaptation to agricultural systems provides both a unique view into the process of evolution as well as a challenge to the global food supply. Understanding the mechanisms behind weed proliferation in cropping systems will require detailed knowledge of the processes and causes of weed adaptation, such as the evolution of herbicide resistance, gene flow between transgenic crops and weeds, and evolutionary ecology underlying traits that might be responsible for ‘weediness’. Ultimately, a better understanding of weed evolution in the context of human-caused selection could be the key to significant future advances in weed management in agroecosystems.