Paddy cultivation

Last year I had written a detailed post about paddy cultivation. This year also we did almost the same - with one change. Decided to bring some old technologies. Brought in Bangarappa's (our farm neighbour and farm helper) traditional skills and his animals for ploughing the field. It is lot of hard work both for human and the animals. But it is far less destructive compared to machines - they burn so much fossil fuel, throw lot of carbon into the air and also over-till the ground damaging the soil biology.

Last year I had borrowed seeds from Bangarappa. I did completely natural farming - I did not use chemicals and fertilisers of any kind. My crop had got some diseases. Plants resisted diseases and grew well. I got one generation of seeds grown without chemicals. Hopefully this year they will improve further in disease resistance and adaptation to local environment.

I should have treated seeds with biological agents like pseudomonas. My bad - I missed it because of my bad planning. I will for sure do it in the next season. I have to wait for one more year for that though :-(

We sowed seeds on 30-Jun. Saplings were transplanted on 16-Jun. We ran out of saplings though because of a minor mistake. Our saplings were little younger than the usual age transplanting. Transplanting workers did not consider that. They planted usual thickness of plants - ending up planting one or two extra samplings in each group. Because of that we ran out of saplings when one small terrace was still to be planted. Thanks to Bangarappa - he borrowed some saplings from another farmer who had some excess saplings and completed the job.

Will keep you posted about how it goes this year.

Monsoon time

It is the time of the year everybody in India is eagerly looking forward to - monsoon time. Monsoon not only brings lot of water; it also brings lot of interesting things (see below). It is the single biggest event of the year for farmers like me because it makes or breaks the plans for the next whole year. Everything gets delayed if monsoon is delayed. Year is ruined because of lack of water if monsoon is short. Lives and property lost if monsoon is in excess. Therefore, our lives hang in fine balance setup by monsoon!

So far (June-2017) monsoon had been disappointing for South India this year. Government statistics say our district (Shimoga district in Karnataka state) had 40% less rain this year compared to long term average. However, it has started raining well in last few days. Hopefully it will pick up now and cover up the shortage in rest of this monsoon season.

Some pictures of this monsoon:

One day came out of the house and found this beautiful orchid on a tree in front of the house. Such a beautiful creation of nature it is. See the close-up for more details of the compound flower. Pictures are not as good as I wanted them to be - continuous rain and less than satisfactory light conditions because of heavy cloud cover interfered with my efforts of taking better pictures.

Orchid in front of the house

Closeup

Very wet conditions created by the monsoon bring up lot of hidden life to visibility. See some amazing fungi found in our farm and around house.

Near our home

White fungi on dead coconut tree in the farm

Red fungi on dead coconut tree in the farm

Monsoon brings in its share of misery too. Here is one example of it - a tree fell on a 11,000 V electricity line bringing down the poles and wires to the ground. Luckily nobody was hurt. Electric equipment in the nearby homes were burnt to charcoal when the 11,000 V line touched 230 V domestic supply lines. Building behind the fallen tree is a school. Kids were inside the school when the incident took place. You can imagine what kind of disaster it would have been if this happened when the kids were walking out of school.

Tree fallen on electric line

Bhoomi Hunnime - day of earth worship

Bhoomi Hunnime is a festival for worshiping mother earth, say sorry for the digging and troubling her all round the year, offer delicacies to her and pray for a good harvest. For western people and people in cities it may look like a meaningless celebration. It is a natural thing and their own extension for people connected with the soil. Mother earth gives birth to us and supports our life in every way. That is why Indian farmers in our villages treat her as mother. This is the time when the crops are about to start flowering and producing grain. Therefore people treat earth as a pregnant lady. They worship her and offer many delicacies to her like we do in case of a pregnant lady. Some of these delicacies are buried in the soil and spread in the soil with the belief that it will satisfy pregnant mother earth's food craving. Even today many Indians don't look at earth as a 50x60 plot or a commodity to sell and buy. Earth is treated with greatest respect as a living being - which it is and it deserves that respect and royal treatment. No wonder, this festival is celebrated in India, the land where every living thing is treated as God. We are not at war with the nature like today's industrial farming, we are one with the nature and treat nature as God.

Mr. Satyanarayana Bhat (foreground) and his wife (background)

This year I got an opportunity to attend some of these celebrations. Some pictures of earth worship are here. See how environment friendly they are - everything is bio-degradable or becomes food for some animal. Even the lamp is made up of coconut shell. This is how we all were few years back. Plastics and chemicals have invaded our lives only in recent years. There is urgent need to reverse the clock and go back few decades. Only then can we live happy and fulfilling life like our ancestors did.

Mr. Kiran (foreground) and his son Tejas (background)

After the worship we ate in the farm and came back. This experience will remain in our memory for a long time.

Environment friendly lamp made from coconut shell

An example of environment conscience our ancestors had. Even the lamp is made from used coconut shell. People use lot of coconut to cook the delicacies for the celebration. One of those shells becomes the lamp :-)

Car shelter

My friend Rajesh recently moved to a village near our farm. Being a village there are not many rented homes available here. Therefore he had to take a small house vacant at the time he moved here. Covered car parking is not available in that house.

It rains around 2000 mm here during monsoon. As per normal rain pattern here it rains heavily between June and August. Car remains wet for approximately 3 months in that time. It is a recipe for rust to invade the metal body of the car! Therefore he needed a car shelter to keep the pouring rain water away from the car and allow it to dry up. It was not wise to spend lot of money for the planned car shelter to be constructed in the rented premises; he will have to leave it there whenever he decides to move out of the rented house.

Minimum cost of conventional car shelter is above 20,000 Rupees. Our search for lowering the cost did not lead to any major cost reduction. Solution was elsewhere - it was there in a plant nursery. I noticed a low cost poly tunnel in a nursery. It is in the form of a tunnel with polythene sheet covering on PVC pipe skeleton. We decided to replicate that poly tunnel and use it as car shelter.

Poly tunnel skeleton - notice bent PVC pipes.
A car and a scooter are parked inside for testing.

My friend's poly house car shelter consists of 20 ft. long PVC pipes bent in semi-circular or parabolic shape. Two ends of the pipe are buried in the ground to a depth of 1 ft. and secured there using cement concrete. We used 6 such bent pipes at 3 ft. distance making the total length of poly tunnel 15 ft. We ensured width of the tunnel is enough (around 11 ft.) to comfortably open the car door when the car is inside the shelter so that the driver can get in/out of the car when the car is in the shelter.

Completed poly tunnel car shelter

Heavy wind can cause strong lifting force on the pipes buried in the cement concrete footings poured into the pits dug in the soil. Smooth PVC pipe secured using cement concrete can pull out of the concrete holding it to the ground. To be on the safer side we decided to glue PVC T joints at the end of the pipes buried in cement concrete to make it difficult for the wind force to pull the pipe out.

After this we draped UV stabilized polythene sheet on the skeleton. It is important to use UV stabilized sheet to avoid the sheet crumbling to powder because of UV component in sun light. Oh yes, we tied one pipe at the top center line to ensure skeleton pipes don't move away from their position. This is how it looks after completion.

Cost? Approximately 5,500 Rupees (+ some elbow grease - we did not put a value to that as it was fun doing it). That translates to 82 USD @ 67 Rs. conversion rate as of today. Probably a car shelter can't get any cheaper than that!

Growing a grain - paddy

Though we acquired our farm last year, it was too late to start the activity of sowing. Therefore we left the paddy fields fallow. Being the fertile land it is, it has given an opportunity for all sorts of weeds to grow. This year we decided to grow paddy in a part of the field. It was not possible to plough the field using animals because of thick weed cover. Therefore we decided to use a tractor to plough the land deep and keep it ready before it starts raining heavily. I will document the subsequent process here. Don't go away, keep coming back to this post :-)

Paddy field ploughed and ready to go to next step

Next step is preparing the seedlings to be transplanted in the field when they grow for around 20 days. This is how we did it:

• Select good quality rice seeds. We decided to take some seed (saved from the rice he had grown in last season) from our neighbor Mr. Bangarappa.
• Ensure good quality using salt water: Mix salt in water until uncooked hen's egg put in the water floats. Put the rice seeds in that water and mix it. Good quality seeds sink to the bottom. Bad quality ones float on top. Remove the floating seeds. Drain out water. Rinse in fresh water and dry the seeds in shade.
• We did not do salt water test because the seeds were good and germination rate was also very good. We knew it because Mr. Bangarappa had sowed the seeds in his field before us.
• Soak the seeds in fresh water for 24 hours.
• Take the seeds out of water. Wrap them in gunny bags and keep aside for germination. Another practice is spreading the seeds on wet floor and covering with gunny bags. Basically water soaked seeds should be kept wrapped with a wet cloth/bag to avoid water loss and be allowed to germinate.
• In 3-4 days rice seeds start growing roots and a small spec of green shoot.
• Make seedling beds in the field and sow them. Seedling bed making and sowing procedure is explained next.

We had decided to grow rice in approximately 3/4th of acre land. For that we need around 15kg seeds. For that much seed approximately 50ft X 50ft area of field is needed for making seedling beds. You will see Mr. Bangarappa mixing in the soil preparing to make the seedling beds.

Sorry, I don't have video or pictures of in-progress process as I had thick layer of mud on my hand. What is the point in being arm chair farmer? I better get into the mud and actively work. Therefore muddy hands did not allow me to shoot the process :-)

Sowing work in progress

After the beds are made we walk in the trenches between the beds and sow the seeds thinly and uniformly over the beds. We should be careful to avoid seeds falling into the trenches to reduce wastage.

You can notice first 2 beds towards left side are smoother and uniform. Those are prepared beds on which we were sowing at that time. You can notice there are no pockets of water on these beds. 2 beds towards right are not yet completely ready for sowing. They are uneven and have water pockets.

3 of us are sowing (for the first time I am showing up in my blog pictures and videos; thanks to my friend Rajesh for being cameraman). After few seconds you see Mr. Bangarappa smoothing next bed for sowing.

After one day

Seeds are doing fine one day after sowing. Birds are the challenge at this stage - they come in big groups and finish off the seeds. Luckily for us there were only two birds in the field for first day. Therefore no damage to the seedling beds. May be they have eaten some, but insignificant damage.

You see some green shoots at this stage.

After 2 days

Green shoots are clearly visible now. Still there is a chance of bird damage. We were lucky to have no birds around on 2nd day too. Other animals also did not damage them.

After 5 days

After 3 days when the shoots grow up we hold water in the seedling beds - only enough to submerge the seeds, but not the growing up shoots. Birds and other animals don't like to get into water. Therefore holding water at this stage is for protecting the seedlings from animal/bird damage.

However, this protection technique should be applied only during day time. We drain the water in the evening for the roots to get some air. Otherwise roots rot and the whole bed can die.




Out of sowing experience - a word of advise for people going to attempt farming newly: I had gone to the paddy field with gumboots to avoid stepping into mud. It does not work, boots get stuck in the mud and it becomes a hassle to drag them around. I finally threw them aside and stepped into the mud bare footed. It has one problem though. Mud can get into the gaps between toe nails and cause infection. Wash your feet cleanly with soap. Use old toothbrush to clean around toe nails. Then disinfect your toe nails with diluted hydrogen peroxide.

Now we have to wait for the seedlings to grow for around 20-25 days. After that we pull them out and transplant them in prepared paddy field. Wait ... wait ... that is why I have heard someone saying - If you want to get the patience of a saint you should become a farmer!

Today is 14-July. Transplantation is going to happen around 05-Aug.



We prepare the paddy field for transplanting when the seedlings are growing. Bunds between the terraces are tidied up and prepared to hold water (water is held on need basis).

Here you see 3 farm helpers working to tidy up the bunds.

Seedlings ready for transplant

One day before transplant seedlings are pulled out, bundled and kept ready for transplant.












Using a power tiller we stir up the soil and prepare it for transplanting. This is done on the day of transplanting so that soil is little sticky and soft for transplant.



After this we hire a team of workers to transplant the seedlings. 2-3 seedlings are put together as one group with 8-10 inch distance between them (just guess work - they may fall little closer or farther).

As planned we did transplantation 20 days after sowing the seeds; on 05-Aug.

Immediately after transplant

We hold at least 4 inches of water in the paddy field after transplant. 2 problems come up if we don't hold water: (a) weeds start growing vigorously if there is no water. Being submerged in water kills the weeds and does not give them a chance to come up. (b) Buoyancy of water lifts up the seedlings little bit and allows them to get upright and grow. Without water they are knocked off by the breeze  and die.







This is how the field looks little more than a month after transplant:

Little more than a month after transplant

There should have been some standing water in the field. Unfortunately we had close to 40% rain shortage. So much for excess rain forecast from all weather agencies. If situation continues like this for some more days I may have to switch on irrigation pump to water growing rice plants.

3 weeks after transplant rice crop was attacked by some insects. They did some damage by cutting the leaves. Soon after that some birds showed up in the field and ate the insects. Damage control happened naturally.

7 weeks after transplant I see some symptoms of rice blast disease (a fungal disease). Neighboring fields have major damage. I am hoping this disease also is controlled naturally somehow. Have to wait and watch what happens.

Update: 26-Sep-2016

Some plants affected by rice blast disease (I believe it is rice blast, please comment if you are sure it is not rice blast). Some traditional farmers suggested me to spray chemicals for treating the disease. I decided not to spray and let the nature take care of it.

In hind sight certain environment friendly seed treatments could have avoided it or reduced it considerably. I will try it for the next crop (if I grow rice again).





Update: 12-Oct-2016

Nature did its job. Blast disease went away without doing anything :-) Conventional farmers don't have the patience to wait and also they have lost faith in nature. They start throwing chemicals at the slightest indication of a disease - thereby polluting the environment and poisoning their food.








Update: 23-Oct-2016

Rice grains - baby steps

It is great feeling when I see the rice grains on the plants in the field. Finally we are not depending on others for food - talk about "food security" ;-)

Harvesting is another month and half away. I have to wait .. wait .. wait!













Update: 14-Nov-2016

Growing rice grains

Grains are growing well. In the beginning grain sacs have milky substance inside - which grows and hardens to become rice grain. Now they have hardened and look like rice when we open the husk. Harvesting is another month away.










Update: 07-Dec-2016

Cut paddy kept in the field for drying

Finally harvest day arrives. Mr. Bangarappa (our farm helper) and team came to the field, cut the paddy grass and laid it on the ground to dry. It will be in the field for few days. After that we will move the stuff to flat clean ground for threshing and winnowing. Keep tuned for the last stage ...

I am few days away from eating 100% naturally grown food, grown by myself!

Paddy tied up for carrying to threshing yard

Update: 12-Dec-2016

Mr. Bangarappa moved harvested paddy to threshing yard today. Threshing is done in 2 different ways: (a) holding the base of the cut straw bunch and hitting the grain side against a hard surface. Grains fall down leaving only the straw in hand. (b) spreading the paddy in the threshing yard and running bullocks/cattle/tractor on them for some time. This separates grains from the straw. We took easy path of using a tractor to separate the grains from straw.



Update: 14-Dec-2016

Unfortunately a cyclonic storm named Varda threw major challenge for harvesting work. This cyclone hit Tamilnadu coast and became a depression causing continuous drizzle for a day in our area. We had just separated the grains from the straw. We could not carry them to a place safe from rain. We covered paddy in the threshing yard with plastic sheets. Straw was left in the open to soak up the rain! Hopefully very soon sun will show up and dry them before they rot down because of wet conditions. We need this straw for our cattle - it is their main food.

Such unpredictable weather is a major challenge for farmers. A farmer depending only on crops for the livelihood of whole year will be in major problem when such unfavorable weather events occur. Luckily for me I can tide through such situations even when there is 100% crop loss. Farmers have to change their farming practices to include some crops which are not so much dependent on weather or impacted so much by weather.

Update: 18-Dec-2016

Luckily there was no crop loss or damage because of un-seasonal/un-expected rains. Our farm help Mr. Bangarappa covered the crop with plastic sheets to protect them from rain. Today I received almost a tonne of paddy and a big pile of hay. This much paddy is enough for several years for my family of 3. Therefore I have decided to share it with friends and family so that people around me can taste pesticide free and chemical free food.


With total expenditure of approximately 8,000 Rs. I got paddy worth at least 12,000 Rs. and hay worth at least 3,000 Rs. Almost 100% profit margin - for those who look at everything from ROI perspective. However, chemical free food for us (and also for my cows) is invaluable. Health benefits of such chemical free food is worth lot more than straight forward ROI can calculate. Therefore look at it from any angle - farming is really worth the time, effort and money one spends on it :-)

Well ... well!

Plants in the farm need irrigation during hot and dry summer months. That needs a water source. Usual water source in this part of the world is a well. We have one well near the stream running adjacent to the farm. Though it was supposed to be a well, it did not remain a well more than 30 years after it was dug. It became a dirty water pond. This is how it looked when we bought the farm:

Pond? No, it is a well! Silt from the
stream converted the well to a dirty pond.

Efforts to manually de-silt this pond failed because the silt was very slippery and soft. It was almost like quicksand - a worker entering this drowned few feet of depth and came out fearing for his life! There was no way I could have pumped out water for irrigation from this dirty pond. Therefore I decided to convert it to a proper well so that we can use it easily.

Soft soil all around the well needs reinforcement to hold the sides of the well in place. In earlier times people used to line such wells with a stone wall (round shaped stone wall). That works only if the sides of the wall are strong enough to stay until the well is dug and the lining work is completed. Also, stone lining means there is very less chance for further deepening the well if need arises in future. Modern solution to the problem is using concrete rings for lining. Well diggers place the concrete ring liner as soon as they find soft soil. Therefore there is no danger of the well collapsing at any time. Expert well diggers can dig under the concrete ring and deepen the well further if need arises. Digging under the ring and sinking them vertically is an art form well diggers have perfected over the years. But it all comes at a cost - they demand a premium for risking their life for this kind of work.

Concrete rings cast on site and ready to go into the well

I decided to use 10 ft diameter concrete rings for the well. Ring height is 1 ft and thickness is 5 inches. Obviously they are very heavy with all the steel reinforcement inside and the concrete. Therefore they are almost always cast on site and placed into the well after curing the concrete.

Well diggers don't dig such large diameter wells manually now. They use earth moving equipment to dig such large diameter wells up to 25-30 ft depth (provided there is enough space around the well for the earth moving equipment to move around and work). They use the same equipment to lift and place the rings into the well.

Earth moving equipment digging the well

We had our well ready after 10 hours of heavy digging, moving the soil, dropping the rings into the well, adjusting the rings for proper alignment and filling gravel between the rings and outer wall of the well. Gravel is filled between rings and outer wall of the well for the oozing ground water to filter through and enter the well. We started at around 10:00 am and it was well past mid night when we finished. This is how finished well looks:

Finished well, photographed almost at the
same angle as the pond photograph above.

Best part of the well is - water; it has lot of water. We saw water oozing from all sides of the well when the work was in progress. It started filling up as the work was progressing. There was close to 8 ft standing water in the well by the time we finished the work. When I saw next morning water level was around 5 ft from ground level (10 ft deep water in the well) - means ground water table is at a depth of 5 ft in this land. According to my back-of-the-envelope calculation this well is holding approx. 25000 liters of water. Even if I completely empty the well it fills up overnight. Imagine such a good source of water at this peak summer after a drought year. It was worth spending close to 150,000 INR for the well. That too not heeding the advice from several "well wishers" of drilling a tube well. I got a well which can be recharged instead of exploiting the water stored thousands of years back deep under earth surface.

DIY AA to D battery converter/adapter

A powerful torch light (well, it is flashlight for US guys) is necessary for a farmer to see things after it gets dark. There are 2 types of torch lights - conventional incandescent bulb and LED light. More than a century old energy inefficient incandescent bulb torch lights have been superseded by modern LED lights outperforming incandescent bulb in every department. Therefore LED torch light is the way to go. Fenix is a popular brand when it comes to high end LED flashlight. However, the price is insane - it costs several thousand Indian Rupees for a light! I need a practical solution, not an expensive "brand" I can flaunt. Therefore I started looking around for a lower cost option. Found some lower priced torch lights in the cost range of 1000-2000 Indian Rupees on Amazon and eBay. Still it looked too much to pay for a torch light. My search for a practical torch light continued. I found an unknown brand torch light in a small electrical shop in Sagara town. Best things of this light were throw of light and the cost. Cost was just 500 Rs., that too with 4 numbers of D size zinc-carbon batteries included. I thought I can very well risk 500 Rs. instead of risking 2-4 times of that money on some other torch light. Therefore I bought this torch light for experimenting. I pointed it to the road outside and switched it on after it got dark. Wow - it could light up several hundred meters distance easily. This was the practical torch light I was looking for - good light at reasonable price. Probably this torch light stands at the top position when it comes to light/price ratio.

No doubt this torch light is good for seeing outside things after it gets dark. It has also worked well as replacement for candle light when there was power failure in the night. Just switch it on and point it to the roof. Reflection from the white painted roof illuminates the room pretty well. Little bit of reflective paint on the roof can make it really nice.

This was going great until last month. For last few days I started feeling the light is not as bright as it used to be. Either the LED is going bad OR the batteries are getting weak. With today's LED technology it is rare for the LED to go bad so early. Therefore battery was the suspect. To test it I pulled out the battery and put a multi-meter across the battery. It read dismal 1.1 V indicating battery is dead. This battery is hopeless because open circuit voltage of 1.1 V means it will perform far worse when loaded.

D size battery (left) and AA size battery (right)

What are my options for the batteries? 4 numbers of D size Duracell batteries cost approximately 600 Indian Rupees - more than the price of the torch light. Therefore using rechargeable batteries is sensible option. However, rechargeable D size batteries cost several times more than conventional batteries. More over it is hard to find D size battery chargers in India. Therefore that is not a practical option for me. Only option I have is using widely available rechargeable batteries - which are AA size batteries. I have to somehow use AA size batteries in a D size battery torch light. Say, I have to adapt AA size batteries to a D size battery - either individual batteries or as a set of 4 batteries connected in series (as they are used inside the torch light).


There are AA to D size battery adapters available in the market. They are D size plastic shells inside which 1-3 AA size batteries fit in. After fitting the AA size batteries and closing the shell it looks like a D size battery - both in size and voltage (in theory). I am saying voltage is in theory because voltages measured with adapter may be slightly less than without adapter - simply for the reason that each adapter adds at least 2 more contact points, thereby increasing the contact resistance and resulting voltage drop. Using 4 such AA to D size adapters will make it possible to use AA size batteries in the torch light. Again, cost came in the way. On Amazon I found one such AA to D size adapter at 350 Rs. Paying so much for just a plastic shell does not make any sense. Making such an adapter does not need any complicated technology. Manufacturing cost of each adapter should not be more than 2 or 3 Rs. Selling price is nonsense even if I assume manufacturing cost is 10 Rs. Definitely seller/manufacturer (or both?) are making insane profit. I hate such businesses ripping off their customers. I will not buy it!

How about making my own AA to D adapter? It need not be a fancy thing like the ones sold online. It should do the job without major inconvenience for me to use it. A DIY adapter will do the job if it satisfies following requirements:

• Should have same outer diameter as that of D size battery - 33.2 mm +/- 1 mm.
• Should have same length as 4 D size batteries put together - 61.5 mm * 4 = 246 mm.
• Should have same voltage as 4 D size batteries connected in series - 1.5 V * 4 = 6 V. I have tested my torch light even with 4.5 V. It works well as long as around 300 mA current is supplied even at 4.5 V. Therefore voltage between 4.5 V to 6 V is fine.

I decided to use AA size Ni-MH batteries because they are widely used in digital cameras, it is easy to source them and it is easy to find a charger for them. Though a new fully charged Ni-MH battery gives out 1.4 V, average voltage is 1.2 V. Therefore they can be a good replacement for zinc-carbon batteries having 1.5 V. 4 numbers Ni-MH batteries in series are almost equivalent to 4 zinc-carbon batteries in series. Challenge is battery size - AA size batteries are much thinner and shorter than D size batteries. One way of solving the problem is:

• Add something around AA batteries to get outer diameter of 33.2 mm. Very high accuracy is not needed. Approximate size is enough. 1 or 2 mm tolerance is good enough.
• Put the batteries in series to reach same length as that of 4 numbers D size batteries put in series. AA size batteries have a length of 50 mm approx. 4 numbers AA batteries in series make only 200 mm (+/- 2 mm). We fall short of 46 mm when compared to 246 mm (see the requirement list above) length of 4 numbers D size batteries. How to manage that? Simple, use some kind of filler to take up 46 mm length.

23 mm inner (29 mm outer) dia uPVC pipe (above)
18 mm outer diameter PVC pipe (below)

Being a farmer I also have many pipes (used for watering the plants) and one them happened to be a uPVC pipe with 23 mm inner diameter and 29 mm outer diameter (though the label on the pipe reads 1 inch / 25 mm inner diameter). This is the closest dimensions I could manage to reach the goal of 33 mm outer diameter of D size battery. I cut out a 200 mm piece of the pipe - which is the length of 4 numbers AA batteries connected in series minus 2 mm (you will read later why 2 mm less). Next challenge is filling the gap between AA battery diameter and the 23 mm inner diameter of the uPVC pipe I chose. For that I chose 18 mm external diameter PVC pipe used as electrical wiring sheath. I took 200 mm length of this pipe and fitted it inside the uPVC pipe. Remember - this electrical sheath pipe should fit concentrically inside uPVC pipe; therefore their length should be equal: 200 mm.

Layer of foam tape on inner (black) pipe.
I have applied few layers of electric
insulation tape over foam tape for proper fit.

However, there is a gap between the outer pipe (white one) and the pipe (black one) fitted inside it. You have to somehow fill this gap so that the inner pipe is concentric when fitted inside the outer pipe. I used foam tape to fill the gap. One layer of foam tape was enough to fill the gap. I applied the foam tape on both ends of the pipe and in the middle. If you want feel free to apply the tape all along - does no harm but not needed, why waste the tape? I could source only double sided foam tape (are the foam tapes always double sided? May be ...). Be careful not to peel off the outer backing tape on the foam tape to avoid the foam sticking to the outer pipe when you are inserting the thinner pipe (black one) inside the thicker pipe (white one). Fret not if you peeled it off by mistake, just apply a layer of cello tape on it to cover up the glue layer.

Note: Depending on exact thickness and diameter of the pipes you are using there may be some slack between the inner pipe and outer pipe even after applying foam tape. In that case apply few layers of cello tape or electrical insulation tape on top of foam tape to fill the gap. Be creative and use what you have to reach the goal!

Now comes the challenge of achieving outer diameter of 33 mm. Foam tape comes to rescue again. I applied a layer of foam tape on the outer pipe (white one) to get 33 mm outer diameter. Well, in my case it turned out to be little more than 33 mm. But that is okay - torch light barrel has adequate tolerance to take slightly bigger diameter battery too.

Outer pipe of 29 mm outer diameter with foam tape to convert it to 33 mm outer diameter

Then I put 4 numbers AA size batteries in the newly made holder and tested it. Positive terminal of the first battery and the negative terminal of last battery extend 1 mm outside the 200 mm long holder. That is perfect fit because it is necessary for both the terminals to extend little bit outside the holder for establishing proper connection. This is the reason why I had cut 200 mm long piece of pipe instead of 202 mm needed for 4 numbers of AA size batteries.

Cut and split pipe pieces for fitting inside the
ends of 18 mm PVC pipe

However, there was a small problem. There was some gap between the batteries and 18 mm pipe containing the batteries. That much of little gap may not cause any problem. But I wanted to be more accurate. So I filled that gap using small pieces of 18 mm PVC pipe pieces. For that cut 15-20 mm long piece of 18 mm pipe and remove around 6 mm on its side. Then press it so that the cut ends meet and push it inside the pipe. You may have to remove more than 6 mm or less than 6 mm or even file the inside of the cut piece depending on the thickness of the pipe you are using. Just make sure AA batteries slide in comfortably after fitting in the filler pieces. Filler pieces have a tendency to slide inside the pipe. Therefore glue it to the outer pipe using PVC cement or any quick curing adhesive. Lightly file (use a circular or semi circular file) or sand the inside of the ends If at all you find that it is little too tight for inserting AA batteries.

Thin black layer outside the white outer cover of battery
is the filler piece

Just 2 pieces at each end of the 200 mm length of 18 mm diameter pipe is enough because any gap inside the pipe does not matter much. Filling the gap at the 2 ends of the pipe ensures positive terminal of first battery and negative terminal of the last battery are at the center of the battery adapter.

Filler battery to fill 46 mm shortfall

Now the challenge of making up for the 46 mm short fall between the total length of 4 numbers D batteries and 4 numbers AA batteries connected in series. For that I cut out a 30 mm length of the 29 mm diameter uPVC pipe. Then I harvested the top and bottom ends of the spent D size battery and attached them to the ends of the pipe. It should look like a 46 mm long mini battery. It should act like a filler battery to fill that space conducting the electricity through it. Solder a wire connecting both ends of this "filler battery" to conduct electricity from one end to the other end. In the picture you don't see soldered wire because I have put the wire inside.

Now open the torch light, drop the filler battery to the bottom, fill batteries in the battery holder pipe and drop it on top of the filler (make sure polarity of batteries are all correct). Close the torch light. Switch it on. You should see it lighting up fully bright :-) Don't worry when the brightness of the light goes down. Just pull out the batteries, charge them and put them back. It restores full brightness.

After this experiment I felt confident of handling D to AA conversion. Ordered one more much better torch light for further experiments :-)