Seed Production for Hybrid Rice

Introduction To produce hybrid rice you need expert skills and strong knowledge of various practices to minimize costs and maximize returns. To produce hybrids, you also need: 1. A national seed production and distribution system, 2. A national quality assurance program, and 3. National expertise to oversee production of lines and seed.

What is "inbred rice seed"? Ordinary or inbred rice seed is produced when the egg inside the ovary is fertilized by pollen grains shed from: anthers borne in the same spikelet. anthers from other spikelets of the same plant. anthers from the spikelet of another plant of the same variety. When farmers plant an entire field to a single variety, they produce inbred seed.

How do you develop hybrid rice seed? Hybrid rice seed is produced when the egg is fertilized by pollen from the anthers of a rice plant from a different variety or line. Hybrid rice seed is the first filial (F1) generation of a cross of two rice varieties that are genetically different. In order to produce great quantities of hybrid seeds, two kinds of parental lines are needed: A male sterile line a rice variety without viable pollen. It is referred to as the female and accepts pollen from the male parent to produce the hybrid seed. A male (pollen) parent a rice variety with normal reproduction function. It is referred to as the male to provide pollen for the female parent in the same fields. A female plant X (left) and a male or pollen parent Y (right).

Some extra requirements to produce hybrid seeds Like any rice crop you need fertile soil. good water irrigation and drainage. sufficient sunlight for high seed yield. management of insects and soil-borne diseases. But, fields for hybrid seed production have some more important requirements: 1. Flowering time Both parents need to flower at the same time. So, planting dates of the two parents will sometimes be different. 2. Supplemental pollination To help the spread of pollen ropes or sticks are often used to improve the spread of pollen from the male to the female line. Using a rope to increase the spread of pollen in hybrid seed production fields. 3. Giberellic acid (GA) application GA increases the emergence of the female panicles from the sheath improving the ability of the female to accept pollen form the male. 4. Isolation of seed production plots to protect genetic purity What we mean by protecting genetic purity is that the seed parent (or A line) is only pollinated by the male parent chosen as the B line or the R line. If pollen from different rice cultivars are close to the seed production plots, they can contaminate the seed parent and lower the quality of the hybrid seed. Seed production crops should be isolated from other inbred rice crops in 3 ways: A. Rice pollen can be carried up to 100 meters in air, so no other rice crop should be grown within 100 meters of hybrid seed production plots. B. Change planting time to have different flowering times between the seed parent and other rice cultivars by at least 3 weeks. C. Any natural, artificial, or crop barrier over 2.5 m high can prevent contamination. Sesbania, rostrata or a healthy, tall crop of maize, sorghum, or pearl millet make a good barrier.

More information needed? To get a manual that describes and illustrates the many steps involved in hybrid rice seed production for both beginning and experienced seed growers, please visit http://www.knowledgebank.irri.org/hybridriceseed The authors have presented a complex topic in systematic, easy-to-understand terms that should appeal to trainers and growers alike.

Feeding Animals on Straw

Method of Treatment

The cultivation of cereals produces large quantities of residues in the form of straw. These residues are poor feed for cattle and are often wasted. However, straw can be a suitable feed if it is treated with a water solution of urea.

Straw as animal feed

The cultivation of rice or other cereals such as wheat, maize or sorghum often produces large quantities of residues in the form of straw and stalks. These residues are poor feed for cattle. buffaloes. sheer and goats and are often wasted. They may serve as maintenance fodder, but animals that are fed straw alone will probably lose weight for the following reasons:

• It is difficult for the animals to eat very much, as they have problems digesting the straw.
• Straw has a poor nutritional value.

However, straw can be a suitable feed if it is treated with a water solution of urea. The treatment enables the animals to improve their digestion of the straw, which permits them to eat more of it.

It has been demonstrated that even if as little as one third of the straw is treated, the animals will be stimulated to eat more of the untreated straw.

The differences between untreated and treated straw are as follows:

Untreated straw	Treated straw
- Poor-quality feed	- Reasonable-quality feed
- Unpalatable, so animals eat little	- Palatable so animals eat more
- Animals lose weight	- Animals gain weight
- Animals produce more milk

Treatment of straw

This section explains how cereal residues such as straw and stalks can be treated to become a suitable fodder for milk production and fattening. The method is simple:

A water solution containing 5 percent urea is applied to the straw.

- The straw is kept airtight for one to three weeks. It is then ready to use as feed.

Treatment is preferable where straw constitutes over half of the diet because other feeds are scarce and where higher levels of production are aimed at.

The method needs some planning, but it is not difficult. Straw, urea and water have to be mixed in the right proportion and correctly stored. This is explained later

To treat or not to treat

The decision to treat or not to treat is the farmer's. Farmers will be most interested in feeding treated straw to milking and fattening animals, which give an immediate monetary return.

Feeding with treated straw costs money daily, but this cost can be balanced by a regular income from the sale of milk.

Income from fattening animals is not received until some time later. Fattening therefore requires farmers either to have their own money or to have credit for purchasing urea.

Farmers are usually less willing to spend money on better feed for bullocks, dry or sterile cows and young stock. The monetary return from feeding working animals treated straw will come much later, when the crop is sold. The other important point is that bullocks can sometimes do surprisingly well on basal diets of untreated straw.

If a sterile or dry cow is used for work, farmers may feed it like a bullock. This is acceptable for the sterile cow, but not the dry cow. If the dry cow is going to calve within two or three months, it must be well to have a healthy calf and more milk during lactation.

There are very good reasons to feed treated straw to working and milking cows. It will enable them to maintain their body condition and milk production. There is no doubt that calves and heifers will grow faster if they are fed treated straw. However, this is often a low priority for farmers because of a scarcity of ready money.

In all cases to make full use of the treated straw, the animals will require supplementation.

Supplementation

The way in which treated straw should be fed to animals depends on the situation. For moderate to high levels of milk production, animals require supplementation, preferably with oilseed cakes, cereal brans or polishings. Fattening animals also require feed supplements. Growing animals older than one year and working bullocks require only small quantities of supplements and, with straw of good quality, these two types of animal may require no supplement at all. However, it is best to feed them as much treated straw as they can eat.

Cows and fattening animals are used for work in several countries - at least during the most busy part of the cultivation season. To avoid a reduction in milk production and a reduced liveweight gain, while the animals are working they should be allowed to eat as much treated straw as possible. Supplements must also be added to the treated straw to get the full benefit. Supplements can be:

• cottonseed or other oilseed cakes;
• small quantities of green fodder, preferably from legumes, whether cultivated or from tree leaves;
• bonemeal.

It is also important that the animals receive sufficient water to drink.

Does it pay?

It costs money and labour to treat straw. Is it profitable? Not always. If animals have access throughout the year to enough grass, other green fodder or hay of good quality, there is no reason to feed them treated straw.

Straw as main feed

Where there is a scarcity of grass, green fodder or hay, but where there is plenty of straw, feeding with treated straw should be considered. In this case, straw is used instead of being wasted.

A larger herd

Farmers who want to keep more animals than they can feed with grass or green fodder can do so if they have enough straw of good quality. Here also, straw is put to good use instead of being wasted.

Whether it is profitable to feed treated straw will depend on local prices. The price of straw, supplements and urea as well as of milk, meat and labour is an important consideration.

How to treat straw

What tools are needed?

A scale to weigh the straw.

Weigh the straw

A typical basket or bundle of straw should be weighed with a spring balance or similar weighing scale.

containing 0.5 kg urea.

A measure

A 1 0- litre watering can or bucket.

A big barrel or trough which can contain a large quantity of water.

Which types of straw can be treated?

Straw from cereals. Straw from all types of cereal and even poor- quality hay - can be used. Rice straw is normally so soft that it can be used as it is. Wheat, barley and oat straw does not need to be chopped if it is compressed during treatment. This can be done by placing a layer of soil on top of the straw.

Stalks. Stalks of maize, millet and sorghum can be used but need to be chopped or extremely well compressed during treatment by placing a heavy layer of soil or stones on top of them.

Wet straw and stalks. Straw or stalks can become wet from rain but, if they are fresh, there are no problems in treating them. In fact treatment is a way to prevent them from being spoiled. Water can be saved and a stronger urea solution applied. Because of the high content of water in wet straw and stalks, the quantity of urea should be reduced to half. It is difficult to be completely accurate but the rule is that a 5 percent urea solution should be applied on an air- dried basis.

Mouldy or rotten straw and stalks. These must never be used. They will make poor and dangerous feed.

How much straw to treat?

Animals have different appetites, but you should use approximately 3 to 3.5 kg of treated straw daily per 100 kg of animal liveweight. Thus, an animal weighing 200 kg will need 3 to 3.5 x 2 = 6 to 7 kg. A young animal weighing 75 kg will only need 3 to 3.5 kg x 0.75 = 2 to 2.5 kg. If you plan to feed the animals as much as they will eat, you can expect them to eat one- third more treated than untreated straw. (See the following table.)

Untreated and treated straw feed quantities according to liveweight

Animal liveweight	Untreated straw	Treated straw
100 kg	2.0 - 2 5 kg	3.0 - 3.5 kg
200 kg	4.0 - 5.0 kg	6.0 - 7.0 kg
300 kg	6.0 - 7.5 kg	9.0 - 10.5 kg
400 kg	8.0 - 10.0 kg	12.0 - 14.0 kg

The urea solution

As an example, if you want to treat 10 kg of air- dried straw (straw that is dry enough for stacking), you need to dissolve 0.5 kg of urea in 5 litres of water. But if you want to treat 100 kg of air- dried straw, you need to dissolve 5 kg of urea in 50 litres of water. (See the following table.)

Amount of urea solution required

Straw	Water	Urea
50 kg	25 litres	2.5 kg
100 kg	50 litres	5.0 kg
200 kg	100 litres	10.0 kg

and stir until the urea has completely dissolved.

Mix the urea and the water

The urea solution should be distributed evenly, using a watering can or something similar.

Storage during treatment

There are different ways to store wet straw that is undergoing treatment. The best result is obtained when the straw is kept airtight. This condition can be achieved in several ways. Following are some examples.

Trampling the wet straw carefully before sealing the stack is an important first step.

Trampling the wet straw carefully

The straw can be stacked against a wall or in a corner and covered with old bags, banana leaves or bamboo mats and a layer of soil or clay to ensure airtight conditions.

The smaller the quantity of straw, the greater the care needed to make it airtight.

Make it airtight

The straw can be stacked in a separate heap and sealed with a mud plaster.

Separate heap

Chicken- wire or welded wire mesh can be used to make a stack, lined with used plastic sheets or old fertilizer bags.

Make a stack

The straw can be stacked in smaller or bigger clamps made of locally available materials.

Smaller or bigger clamps

Depending on the site where treatment is actually taking place there may be other possibilities. The point is that every effort should be made to keep the straw in an airtight condition during treatment.

Treatment time

The straw should now be kept in an airtight condition for one to five weeks before it can be fed to the animals. A short treatment time can be used when it is hot (25 to 30°C) and a long treatment time when it is cold (below 15°C). Urea as a source of ammonia does not work below 5 to 10°C. A way to bypass this problem is to treat large quantities before it gets too cold.

Following are the signs of successful treatment:

- The straw has changed colour to dark yellow or brown.
- The straw has a strong ammonia smell.
- The straw is softer than untreated straw.
- The animals - after adapting - eat one- third more treated than untreated straw.

Adapting the animals

You can adapt animals to the treated straw over a week or ten days by gradually mixing more and more of the treated straw into the fodder they are used to. Adaptation can be quicker if animals are used to eating straw and if the treated straw is left out in the fresh air for some hours before it is eaten. This practice should only be required during the first week to ten days. It should then be stopped and the straw taken directly from the stack for feeding.

Rice Clam Culture

Corbicula fluminea is a species of freshwater clam, an aquatic bivalve mollusk in family Corbiculidae.

This species is of originally mainly Asian origin and thus it is often commonly called Asian clam or Asiatic clam. In the aquarium and koi pond trade it is often call Golden Clam or Golden Freshwater Clam. In Southeast Asia it is known as the prosperity clam or good luck clam.

Native species clam originally occurs in Russia, Thailand, Philippines, China, Taiwan, Korea, Japan, but also in parts of Africa.

Clams (Agihis in Hiligaynon)

Clams grow naturally in many rice paddies and rural people have traditionally harvested them. This was true until chemical use in rice paddies resulted in the elimination of these clams in many areas. Intentional culturing of clams simply adds one extra step to the traditional clam harvesting -the seeding of clams.

From work with farmers in Quirino province, it was found that:

· Clam culture in rice serves as a buffer against unforeseen crop losses due to flooding or diseases like tungro.

· Clam production serves as a source of additional income (in 1 hectare paddy the average yield was 226 kg marketable clams valued at P1,800/ha.)

· In addition to extra income, the clams serve as a source of protein and minerals for the farmer's family.

PROCEDURE:

1. 20-25 days after planting, increase the irrigation water in the paddies to the maximum tolerable depth proportionate to the rice plant (approximately 5 cm depth). If the crop needs weeding, the rotary weeder can be used before irrigation.

Increase the irrigation water in the paddies

 2. Let the water stand for 2 days to soften the soil and to neutralize sold toxicity or pesticide residues.

Let the water stand for 2 days

 3. On the third day, drain the water and replace it with fresh irrigation water to the depth mentioned above.

Drain the water and replace it with fresh irrigation water

 4. Evenly broadcast baby clams along the rice furrows. Seeding should be done in every other furrow.

Evenly broadcast baby

 5. Harvest the clams as soon as they reach the desired marketable size (size of the new P50 coin) or just before harvesting the rice.

Harvest the clams

Note:

· Avoid using chemical insecticides; as a substitute, use botanicals.
· Don't introduce carp into the paddies seeded with clams. Carp eat clams.
· Faster growth of clams is attained when fields are fertilized with organic materials.
· Medium- to long-maturing rice varieties should be used in clam-rice culture. This allows the clams   to stay longer in the paddy field.
· Rice-clam system is best suited to areas where there is a continuous supply of water.

Clams Recipe