eChapters

9.1 Magnetic seed separator

These machines use a magnetic force to separate damaged seeds or other particles from the good seeds. This is used to solve special problems in seed lots that can not be taken out with our other basic seed cleaning equipment. Most of the time it is used for vegetable and field seeds that have problems in seed damage (fish mouth in cucumber or melon seeds / cracked radish or cabbage seeds), insect damage (beetle holes in cotton seeds) or contamination with soil or plant parts (white plant parts in onion seed) etc.

The processing operations are carried out based on the principle of physical differences found in a seed lot.

Mechanical damage is inflicted on seeds during harvesting, threshing drying, processing and handling. Injury may occur from any kind of physical abuse. Threshing abuse probably is most serious but, seed conditioning and handling also contribute to seed injury. High temperatures during drying or drying too quick or excessively can cause injury. Susceptibility to mechanical injury increases as the moisture content of the seed decreases. Effect of all individual impacts received by the seed appears to be cumulative in total seed damage. Cereals are largely immune to mechanical injury presumably because of the protective outer structures, the palea and lemma. Large sized legumes are more suscepitable. Small seeds tend to escape injury during harvest and seeds that are spherical tend to suffer less damage than elongated or irregularly shaped ones.

Methods in Seed Blending

For good seed blending there are three methods and details of which given as below:

The physical properties of seeds are a basic activity for designing processing equipments and precision planters. Since these characters vary with crop or variety, one needs to have the data handy to be used on shop floor. This data also helps to quantify processing efficiency, presence of dormancy and suitability for seed treatments for all existing and new crops or varieties.

Seed processing is specialized activity and also a tool to improve seed quality further to an acceptable standard. Seed quality parameters like germination, vigour or genetic purity can be improved using processing. Say a seed lot having a minimum standard of 90% germination, but the competition in the market offering seed quality 92 or 95 % then to meet the market demand we can process the seed lots using re-milling or re-conditioning techniques. Also sometimes simple techniques like liquid density separation which uses specific density of the seed to separate good seed from inferior quality can be considered.

1.1 Problem
    1.    Compare the seed quality at different physiological maturity stages
    2.    Compare the seed recovery in acid and fermentation method

1.2 Materials
    ·    Tomato fruits – 4 batches
    ·    Plastic bucket/ Beaker
    ·    Water

Visit to a seed processing unit and attending the following questionnaire to know firsthand information on operations of shop floor

Black pepper is popularly known as ‘King of spices’, it is the dried berry of the pepper vine, so important in the International Trade Market. The crop has its origin in the tropical rain forests of Western Ghats of India.  Kerala is the leading State in the production of black pepper with the ubiquitous presence of this crop in coconut, arecanut and coffee plantations. Chief pepper producing countries are Indonesia, Brazil, Malaysia, Cambodia, Sri Lanka and Vietnam.

Coconut is the most important palm of the wet tropics as a  major source of vegetable oil which also provides food, health drink, medicine, shelter, fuel, timber and fibre.  Because of its versatile nature, it is eulogised as ’Tree of Heaven’, ‘Tree of Life’, Kalpavriksha, Tree of Abundance, Natures supermarket and king of palms.  Oil is extracted from dried endosperm  which is called ‘copra’. The unopened flowering spathe, on tapping process, yields a delicious sap (Coconut Inflorescence Sap) rich in sugars and vitamin B, is called toddy from which sugar syrup and many products can be extracted.  An intoxicating drink called arrack can be prepared by distilling fermented toddy. The hard endocarps of fruits supply fuel and charcoal and mesocarp yields fibre for coir industry. Leaves are used for thatching houses.  Young unopened leaves are used to decorate festive places.

Onion is one of the most important commercial vegetable crops grown all over India. Onions are bulbous, biennial, herbaceous and are typically grown as annual, which give off a distinctive and pungent odour when the tissues are crushed. Characteristic pungency and flavour in onion are due to a volatile sulphur compound, allyl-propyl disulphide. This organo sulphur compound has potential for anticarcinogenic secondary metabolites. Pungency varies with cultivar, growing condition, stage of maturity and storage conditions.

It is such a unique vegetable, used throughout the year in the form of salad or condiment or for cooking with other vegetables. Onions are used for flavour, aroma and taste in preparation of vegetables and used in the form of dehydrated, freezing, canning and pickling. Onion salt is prepared by dehydration and used in flavouring.

Tomato, the ‘Apple of Love’ or ‘Golden Apple’ is one of the most popular, widely grown and highly praised vegetable in the world. In India, commonly referred as ‘Poor Man’s Orange’, has wider coverage in comparison to other vegetables. Tomato universally treated as ‘Protective Food’, is eaten raw or cooked or in processed form (soup, juice, ketchup, puree, paste and powder, green tomato - pickles and preserves) or it supplies vitamin C and adds variety of colours and flavours to food. It is a very good source of income to small and marginal farmers and contributes to nutrition of consumers. Tomato seed contains 24% oil used as salad oil and in manufacture of margarine. By virtue of its many attributes, it is considered as a favourite crop for research in physiology and cytogenetics, all over the world. Tomato is also rich in medicinal value. The pulp and juice are digestible, mild aperient, a promoter of gastric secretion and blood purifier. Tomato, a primary source of lycopene, showed significant association with low prostate cancer risk and cancers of digestive tract. It is one of the best vegetables which keeps our stomach and intestine in good condition. Tomato juice has become an exceedingly popular appetizer and beverage.

Citrus is the world’s leading tree fruit crop, comprising of mandarins, sweet oranges, grape fruit, limes and lemons. It is one of the most important fruit crops grown under varying agroclimatic conditions in India except in the high hilly temperature regions. Mandarin orange (Citrus reticulata) is the most important commercial citrus in India followed by sweet oranges and acid limes. Citrus fruits are not only delicious and refreshing but also they provide vitamins, minerals and other substances. Different species of Citrus have different chemical composition. In sweet oranges, principal constituents of edible portions are sugars (glucose + sucrose) and acids (primarily citric acid and a little of malic acid), the fruits of acid groups contain primarily acids in fruit juice. Rind of citrus fruits is rich in pectin and contains essential oils and glucosides (hesperidin, naringin). Citrus fruits are a good source of vitamin C (ascorbic acid - 25 to 85 mg/100 ml juice), besides vitamin B, A and D. World-wide demand of orange is as fresh fruits, but orange marmalade is an important product and is one of the main uses of sour and sweet oranges. Grape fruit and mandarins are also taken as fresh fruits. Citrus fruit can be utilized in a number of other ways as salads, juices, squashes, cocktails, syrup, concentrates and pickles. Peel of thick-rinded fruits can also be made to delicious candy. Lemon is used in many culinary purposes. Grape fruit is utilized in preparation of wines and brandies and also for flavour and in perfumery.

Mango occupies a pre-eminent place amongst the fruit crops grown in India and is acknowledged as the ‘King of Fruits’. Mango is the pride of the garden and one of the choicest fruits known to mankind. Mango possesses unique nutritional and medicinal qualities apart from being a rich source of vitamins A and C. Young and unripe fruits are utilized for culinary purposes, preparing pickles, chutneys because of their acidic taste as well as for extraction of tannin and other astringent products. Ripe fruits are a delicacy for the table and are utilized in preparing squash, juices, nectar, jam, cereal flakes, custard powder, baby food, mango leather and toffee. Canned mango slices and pulp are indeed very popular. The inside kernel of the stone being rich in carbohydrates, calcium and fat, can be used as a source of food for certain industrial purposes.

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops cultivated in the world. It is used as raw in salads and also used as cooked vegetable in the preparation of curries. Processed items such as tomato puree, ketchup, pickle, chutney, whole peeled tomatoes and tomato powder are also consumed considerably. It is a rich source of Vitamins A & C. Lycopene and other flavonoids in tomato serve as good source of antioxidants. Tomato occupies 5 million hectares with a productivity of 34t/ha. in the world. In India it is cultivated in an area of 0.88 million hectares with productivity of 21 t/ha.

Mango (Mangifera indica L), the king of fruits, is cultivated throughout a wide range of frost-free climates (Litz 1998). It is commercially the most important fruit crop of India, accounting for more than 54% of the total mango production worldwide. The fruit of mango (Mangifera indica L.) is exceptional for its juicy, succulent, thick fruit pulp and nutrient abundance in terms of wide range of amino acids, sugars, organic acids, minerals including Ca, P, Fe, and K and vitamins. Out of several diseases which attack mango crop, mango malformation disease is a serious threat to its cultivation since it causes gross deformation of the vegetative and floral tissues (Ploetz et al., 2002; Kumar et al., 2011). Floral malformation is a major problem in mango, rendering mango cultivation unproductive in northern India and other regions of the world (Pandey et al., 1977; Ram, 1991).

Methylene-cyclo-propyl-glycine (MCPG), is a cyclopropyl derivative, grouped into the amino acids that have been isolated from the higher plants (Fowden, 1960). MCPG was identified to be closely related to two other cyclopropyl derivatives (Fig. 1), 1-aminocyclopropane – 1 – carboxylic acid from Vacciniumvitis-idaea and perry pears (Vahatalo and Viertanen, 1957; Burroughs, 1957) and â- methylenecyclopropyl alanine (MCPA or Hypoglycin A) from Blighia sapida (Hassall and Rayle, 1955; Anderson et al., 1958; Ellington, Hassall and Plimmer, 1958).

The orchids are commercially important group of flowering plants and their flowers are affluent in uniqueness in their shape, size and colour, exquisitely attractive, remain fresh condition for long period of time in comparison to other flowers. Orchidaceae is the second largest family among floriculture; about 25000 to 35000 species of orchids have been reported over the world (Rampal and Nagrare, 2006). India accounts for nearly 7 per cent of world’s orchids genetic diversity contributed 1300 species under 184 genera (Arora, 1983; Rampal and Nagrare, 2006) and 1150 species belonging to 164 genera (Satish Kumar, 1994) of which about 800 species are found in the North Eastern region of the country (Nagaraju et al., 2006) and many more are discovered year after year because of the prevailing congenial climatic conditions, diverse terrain and altitudinal variations, which provide suitable habitat for orchids.

The word Cymbidium has been derived from a Greek word ‘Kumbos’ meaning ‘hole or cavity’ referring to the structure of the base of the lip. The genus consists of 44 known evergreen species in the family Orchidaceae, subfamily Vandoideae, tribe Cymbidieae and sub-tribe Cryptopodiinae. It is distributed from northwestern India to China, Japan, south through the Malay Archipelago to the north and east Australia. (DuPuy and Cribb, 1988). Cymbidiums have been for over hundred years one of the most famous orchids in commerce.

Mango (Mangifera indica L.) is one of the most important tropical fruits of the world and is commonly known as the ‘King of fruits’ for its high quality fruits which are very popular among the Indians (Sharma et al., 2008). It is the oldest and extensively cultivated fruit crop in India having high socio-economic significance. India is the home of more than 1000 mango varieties, which originated in the Indo-Burma region (Mukherjee, 1958). India is the largest producer of mango, grown in about 2.3 million hectares with an annual production of 15.02 million tones. However, its productivity is only 6.5 tones per ha against 30 tones per ha in Israel (Bijay Jumar, 2010). Improvement of productivity in mango continues to be the foremost issue in mango production (Sauco, 1993). Of late, all the mango importing countries are considering the India as a source of quality mangoes due to its varietal wealth and availability. Hence, it is imperative to improve the productivity and quality of Indian mangoes to meet the global need (Balamohan et al., 2014).