Tunnel farming is also called “forcing” in which we grow especially grow winter vegetables twice a year. In Pakistan, tunnel farming is getting more value due to more production per year. It is necessary that tunnel farming awareness should be availed to each grower who wants to invest in this specific business. There are three kinds of tunnels that are used commonly in Pakistan which are “low tunnel”, “walk-in tunnel” and “high tunnel”. In this article, I will discuss the common problems and issues in tunnel farming with their suitable and efficient solution. There are the following outlines under which a whole article will be discussed,
- Tunnel structure
- Weeds inside the tunnel
- Less seed germination
- Death of nursery plant seedling
- Fungal disease problem
- Nitrogenous fertilizer issue inside the tunnel
- Maintenance of temperature and humidity issue
- Fog and frost danger in winter
- Pollination problem
- Rats problem in the tunnel
- Virus diseases especially in tomato tunnel farming
- Polythene puncture problem
It is necessary for the farmer or grower that tunnel structure should be good. There are two kinds of structures used wooden and iron. Iron structure is very commonly used due to longer structure sustainability. It is necessary to check the structure otherwise it may cause polythene puncture problems especially wooden structures which will influence the temperature and humidity problem inside the tunnel.
Weeds issue gets to appear in every field in each crop. It may control manually by hoeing as well as by a chemical spray of herbicides. It depends upon the condition that which method should apply. When the tunnel has a flood irrigation system then humidity gets higher and many weeds grow. It is suggested that manuring should be applied with well-rotten farmyard manure six months earlier so that manure should decompose earlier before crop plantation. Allow weeds to grow and irrigate the field so that it could be chopped as green manuring in the field. There is another technique used for controlling weeds which is the usage of black mulch or black polythene over the bed which conserves water as well.
Sometimes, the farmer gets lower seed germination which happens due to the older seed which has already lowered its germination capacity with the passage of time. It is suggested that get extra seed as well if farmers fear lower germination and grow in germination trays so that later plant gaps should be filled with these plants.
Preliminary measures of nursery seedlings
Nursery plant needs more there are many possibilities that may occur at the initial stage so it is very necessary that care should be taken. Soil-borne diseases are more common, it is suggested that seed should be dipped in the fungicides.
In tunnel farming, due to irrigation temperature rise and a higher percentage of humidity result in fungal diseases. It is very important in sunny winter day-time tunnel’s both sides should be open for ventilation so that humidity should be lower than a favorable threshold level and did not give the opportunity to fungus.
The negative impact of nitrogenous fertilizer
It is said by the agricultural experts that never use nitrogenous fertilizer especially urea in the tunnel. Nitrogenous fertilizer produces ammonia gas inside the tunnel and leads to suffocation for plant respiration system due to which plant’s death may occur. It is recommended that soil should be fertile already so that it can provide the nutrient supply organically. For this purpose, it is suggested that farmyard manure should apply as early as possible before crop plantation. Other chemical fertilizers like phosphorus and potash are not harmful, their schedule can be followed as per the condition.
Maintenance of temperature and humidity
The tunnel inside the atmosphere should be moderate and maintain. Flood irrigation increases the temperature, therefore drip irrigation is best recommended. The proper way of ventilation is also helping to maintain temperature and humidity. It is suggested that keep the meter for temperature and humidity measurement. Temperature between 15-35 degrees Celsius and humidity should be less than 80 % inside the tunnel environment for optimum results.
Temperature management during frost danger
It is also important for the farmer to maintain the temperature during the hard winter days. Normally, frost stress appears in February so that do not open the tunnels in the daytime to maintain the temperature inside the tunnels.
Mostly cucurbits and Solanaceae family members are cultivated in tunnel farming, which is crossed pollinated and needs an external source for flowering. It is necessary to create a ventilation environment so that different pollinators should be available to the crop. There are also some crops that need no pollination, those varieties are genetically modified and called parthenocarpic just like in cucumber.
Rats in tunnel
Rats and rodent issues are also not negligible in the tunnel in the case of cucurbits, which invade inside and destroy the mature crop. It is suggested that rat poison (ammonium sulfide) should be applied as per the condition. Always use the seed coated or dipped with fungicides or by any other poison which will help to keep rats and rodents away from the field.
Viral diseases problem is another most important in tunnel farming, especially in tomato. It is normally spread by whitefly. It is very indeed for the farmer to grow the tomato nursery after the mid of October so that the whitefly threat may not harm the seedling. Viral diseases appear due to vector so different insects are responsible for the spread of viruses. The recommended insecticides should be applied, and the infected plant should be uprooted and should be buried deeply in the soil. Try to isolate the infected plant by not touching other plants otherwise the whole crop may damage.
- Tunnel farming is profitable and a source of double production per year in summer vegetables.
- The tunnel structure needs to be safe and clear so that when the field covered with polythene then polythene may not scratch and puncture.
- Weeds should be controlled with black mulch which is most effective.
- Seed germination may be affected, so keep extra seeds and grow externally in germination trays to fill the plant’s gap.
- Excessive humidity due to flood irrigation systems and poor ventilation raises the temperature with higher-level moisture which leads to fungal diseases.
- Do not use the nitrogenous fertilizer which will produce ammonia gas and leads to plant suffocation.
- Pollination problems and fruit sets are poor in tunnel farming.
- Use ammonium sulfide to avoid the rats and rodent issues.
- Earlier plantation of tomato may lead to viral diseases in tomato in October, so keep nursery plantation when whitefly danger is gone long.
I hope this article helps you with tunnel farming common problems, feel free to express your thought in the comment section below. Stay tuned!