Foreword India is the second largest producer of vegetables after China and also has a unique distinction of one of the most preferred destinations for vegetable seed production. The south India becomes hub for vegetable seed production of tropical vegetables in south-east Asia. This is because of presence of ideal weather conditions, soil and skilled labour force. The cost of production per kilogram is very low compared to Europe and Americas. Some of the well known seed corporations of the world are operating in this region with annual grower payments exceeding 100 million USD. This activity created jobs and has positive socio-economic impact. The seed processing is an important activity after production and to be taken care with utmost importance at the shop floor. Since there is wide diversity of vegetable hybrids or varieties, their processing requirements also vary. Each hybrid or variety may behave differently with respect to screens, processing machines, seed treatment etc. In this background an effort to give detailed information on vegetable seed processing, this book can be a valuable reference to students, academic and industry personnel associated with processing. I appreciate an effort of Mr. Rakesh C.Mathad, Dr.Basave Gowda and Dr. S B Patil, Seed Unit, UAS, Raichur in compiling such an valuable resource book for the shop floor.

1.1 Introducution Growing of vegetables is one of the most profitable allied activities of agriculture especially in small-medium land holdings and with limited water resources. Use of improved varieties and hybrids is very critical to make smaller land holdings profitable. Seeds of improved varieties and hybrids not only increase income to the tune of more than 30% but also reduce the use of plant protection chemicals. India being the second largest producer of vegetables in the world with 6.2 m ha of land and 85m MT production-use of improved seed is very important. The annual requirement of vegetables is estimated to be over 135m MT which can be only achieved through use of quality seed. India is predominantly vegetarian country and depends upon vegetables for their nutrients and minerals. Vegetable cultivation is labour intensive, gives high returns and ensures nutritional security. To ensure these the supply of quality seed is very vital. Apart from seed production, its processing for seed quality to give the end user is of high importance. Unlike seed processing of field crops, vegetable seed processing is very technology driven since the volume is less and involve costly material. Improved processing efficiency brings more income for the grower and seller. The vegetable seed being low volume needs better technology for upgrading, size grading, blending, conditioning, processing, treatment and packaging. Vegetable seed processing is set of activities as mentioned here each of having a special focus on the quality.

The vegetable seed production in India work on the principle of buy back or contract farming where the production agent or organizer distribute the plots of seed production to growers. The grower is responsible for the rising of seed crop till harvesting or pre-conditioning. The organizerguides the growers regarding the plant protection, roguing and pre-conditioning. The harvesting is entirely a responsibility of the grower but facility for pre-conditioning may be established by the seed organizer. The seed pre-conditioning includes activities like acid treatment on wet seed bases or operations which make seed ready for procurement. After the harvesting or pre-conditioning the seed will be procured by the organizer and head for the processing yard for grading & packaging. 2.1 Harvesting and Pre-conditioning The methods of harvesting and pre-conditioning various with crop to crop. There are mainly two types of vegetables in terms of type of harvesting.

Vegetable seed cleaning and processing are two important aspects of seed post-harvest management. These steps are very essential to maintain the quality of the seed till its next sowing season. The quality of seed produced is dependent on the moisture content and various admixtures. To provide quality seed to farmers, it is very essential to clean seed to its maximum quality. The seed quality attributes like moisture, free water activity, to be controlled in germination, vigor and viability are upgraded during seed cleaning. Seed cleaning is the term used as a part of processing means separation of admixtures from a particular seed lot. The physical characters like bigger clods, sand, soil, chaffy material, inert matter etc. will be removed during seed cleaning. Seed processing on the other hand is relatively broad term referring to the process of removal of dockage in a seed lot and preparation of seed for marketing is called seed processing. The price and quality of seed is inversely related to dockage, which should not exceed a maximum level permitted for different crops for seed certification. Due to the operation of processing the level of heterogeneity of seed lot gets narrowed down. The heterogeneity occurs in a seed lot due to following reasons:

The processing of the seed refers to mainly pre-cleaning and sizing. The sizing is up gradation of seed lots based on size, shape or length. In this chapter processing with main reference to sizing or upgrading is given. Sizing or upgrading is done by using different screens in an air screen cleaner, gravity separator, seed blower, indent disc cylinder, belt grader or some time colour sorter. Here specific tasks like use of screens in an air screen cleaner, rubber belt angles when using a belt grader, disc type when using indent disc cylinder or special arrangements in a gravity separator are given. The details of the machines or equipments with the principles of working were already covered in Chapter-3.

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. Various case studies on processing to improve seed quality are given here.

The term seed blending is nothing but seed mixing done based on certain principles. It is simply combining two or more seed lots of same variety or hybrid of specified quality. The blendingmayinvolve lots which mayhave different quality in terms of germination. Usually individual seed lots are much better compared to blended lots but from the point of efficient inventory management blending is advisable. The main purpose of blending is to pool all the variable lots in to a larger bulk and mix the constituents effectively so that each pocket of seed has a uniform quality.

Seed treatment is one of the important activities of the shop floor. The seed should be treated with various insecticides, fungicides and additives to protect it up to establishment. Some timesenhance quality parameters like vigour which is critical for better establishment. Since vegetable seeds are of very high value and low volume, investment on seed treatment will yield better not only for the seed seller but to the grower also. More number of plants in a field brings moreincome per unit area. Hence the farmer or grower who buys seed is ready to bear the cost of seed treatment making it an important aspect of seed processing. Seed treatment refers to the application of fungicide, insecticide or both to the seeds to disinfect(deep seated) and disinfest (over seed coat) them from seed borne or soil borne pathogenic organisms and storage insects. It also refers treating seed for enhancing quality by subjecting the seed to solar energy exposure or immersion in hot water or dry heat treatment or priming also.

Vegetable seed drying is the most critical stage for any shop floor activities. Only properly dried seed will be taken for processing and all the other activities from seed receipt to storage. Seed producers harvest the seed which will have more moisture than packaged seed. For example onion seed harvested when its moisture at 60% but eventually dried to 10-12% for safe storage and packaging. Seed drying is highly skilled and specialized activity without affecting the seed quality. Proper drying procedures are vital for storage and field performance of seed lots. Drying prevents germination of the seed, the growth of bacteria and mould and it reduces the conditions for development of insects. The moisture content of a seed is influenced by the humidity of the air because they are very hygroscopic in nature. The more moisture in the air, the higher the moisture content of the product. If seed are harvested during warm, humid weather, the moisture content of the seed will be high because the relative humidity of the air is high as well. It is necessary to dry the seed before it can be stored safely. The method of drying depends on the local conditions (climate, season, volume of the seed, type of seed etc)

Vegetable seed drying is the most critical stage for any shop floor activities. Only properly dried seed will be taken for processing and all the other activities from seed receipt to storage. Seed producers harvest the seed which will have more moisture than packaged seed. For example onion seed harvested when its moisture at 60% but eventually dried to 10-12% for safe storage and packaging. Seed drying is highly skilled and specialized activity without affecting the seed quality. Proper drying procedures are vital for storage and field performance of seed lots. Drying prevents germination of the seed, the growth of bacteria and mould and it reduces the conditions for development of insects. The moisture content of a seed is influenced by the humidity of the air because they are very hygroscopic in nature. The more moisture in the air, the higher the moisture content of the product. If seed are harvested during warm, humid weather, the moisture content of the seed will be high because the relative humidity of the air is high as well. It is necessary to dry the seed before it can be stored safely. The method of drying depends on the local conditions (climate, season, volume of the seed, type of seed etc)

Seeds are having a ability to survive and start a new generation when favourable conditions exists. However like other form of life, they cannot retain their viability indefinitely and eventually deteriorate and die. To retain viability and germination it is important to store in proper storage. Seeds harvested may not be useful for packaging thus making it to store for a period till the need for packaging arises. Seed storage is very critical task of seed processing. The success of seed processing is determined by safe storage. Since the vegetable seeds are expensive need modern techniques of storage. Based on the seed shelf life or longevity vegetable seeds can be divided into two types: Orthodox Seeds : Orthodox seeds are long-lived seeds. They can be successfully dried to moisture contents as low as 5% without injury and are able to tolerate freezing temperatures. Most orthodox seeds come from annual temperate species adapted to open fields. At physiological maturity they contain moisture content of 30 – 50%. Most of the vegetable seeds are orthodox and hence there is lot of scope for proper storage. E.g-Tomato (6.0 %) and Peppers (7.0% Recalcitrant Seeds : They are short - lived seeds, which cannot be dried to moisture contents below 30% without injury and are unable to tolerate freezing. They are difficult to ore successfully because of their high moisture content encourages microbial contamination and results in more rapid seed deterioration. Storage of these seeds at subzero temperatures causes the formation of ice crystals, which disrupts cell membranes and causes freezing injury. These seeds are from perennial trees in the mois t tropics such as coconut, coffee, cacao, citrus etc. These seeds mature and exists in their fruits and are covered with fleshy or juicy ariloid layers and impermeable testa. At physiological maturity they contain more moisture content (50- 70%) than orthodox seeds, even though their embryos are only about 15 % of the size of an orthodox seed embryo. In general recalcitrant seeds never go into dormancy but instead continue their development and progress towards germination.

Inventory management system is a computer based system for creating work orders at a processing plant, tracking inventory levels in the go downs, , sales and seed movement out of the processing plant. These modern systems avoid book maintenance and save lots of space. It will also tool for avoiding overstock or delay in movement of seed material for packaging. In most of the processing plants SAP is the most popular inventory management tool which is more efficient than others. SAP is basically a tool of enterprise resource planning which help in material management. The customised software can be used very effectively in a processing plant for the following operations.

11.1 Planning Upon receipt of production program verify that crop sowing dates fall into crop windows identified for the particular area and allot accordingly. Check the quality of lots produced in previous season, if available. Assign crop location (Open field, Green house, Insect Proof Net / Cage etc) according to crop needs, site conditions and degree to which these conditions can be manipulated efficiently to meet the crop needs. Always adhere to optimum crop conditions. Identify material and personnel needs based on the production program and coordinate timely arrival of both. Material and personnel must meet standards established by the production site. Identify material quality like A, B, D (First, Second and Dirty) based on the specs. Refer standard procedures or formulate some of them. Do not proceed if proper documentation does not exist. Plan training for laborers regarding crossing, flower morphology, anthesis, time of stigma receptivity etc.

A After-ripening. The physiological maturation processes which occur in e.g. seeds and fruits after harvest or abscission. After-ripening is often necessary for immature seeds to become germinable. Also used for the seed handling process itself. Application Rate: The application rate of Seed Treatments, Seed Treatment Products and/or Seed Treatment Components. For liquid Seed Treatment Products, rates are typically expressed in ml or in mg ai/kernel on the label. Aspirator or blower: A processing equipment in which when a seed mixture is introduced in to a upward moving air stream, light particles with a low terminal velocity are carried along with the flow where as heavy seed falls through. B Batch: A defined quantity of seed material, packaging material or product processed in one process or series of processes so that it could be expected to be homogeneous. Bio-priming : is a process of biological seed treatment that refers combination of seed hydration (physiological aspect of disease control) and inoculation (biological aspect of disease control) of seed with beneficial organism to protect seed. It is an ecological approach using selected fungal antagonists against the soil and seed-borne pathogens. Biological seed treatments may provide an alternative to chemical control. Batch number (or lot number): A distinctive combination of numbers and/or letters which specifically identifies a batch. Bulk Seed: Any seed lot or batch which has completed all seed processing stages up to, but not including, final packaging.