Potato an alternative to tomato

In first John 2:17, the Bible gives an assurance that the world is passing away and so are its desires, but the one who does  the will of God will remain forever. Those that lived thirty years ago and are still living to date will agree with the Bible because of what is happening and many things are being fulfilled.


Ten years ago, it was very difficult for many farmers to cultivate tomato and there were very few farmers growing the crop. Today, there are so many farmers growing it and this has led to the crop going to waste because there are no supporting marketing infrastructure to anchor activities beyond production. These are activities which will promote value addition to increase the shelf life of the product. Farmers are still mourning the low commodity price for tomato. There are still some more fruits to be brought to the two key markets in Zambia – Soweto and Chisokone. This trend will continue till late December and hopefully throughout the rainy season unless the reports we are receiving that the region might experience a drought or longer dry spells – much drier than what we experienced last production season. The fact is that we have to be in production regardless of what happens. Besides, the mines, which were our main industry, are in the hands of Chinese and Indian brothers who are busy sending the money back to their countries. Zambian farmers and smallholders in particular have learned the art of growing tomatoes. They are producing quality tomatoes that can sell anywhere on the planet. Now that we are all growing tomato, what else can we diversify into as farmers?
Tomatoes belong to the family of Solanaceae and crops that belong to this family are potato, chilli, egg plants, pepper, tobacco and others. When we scan the environment for agricultural products, one will agree that Zambia has more shopping malls than manufacturing plants. These malls have shops selling clothes from China and South Africa as well as fast foods outlets for ‘junk’ foods. These fast foods will need tomato but not as much as they will need potatoes for making French fries. This is an opportunity that tomato growers have. Those that have grown tomato can easily grow potatoes because the diseases and pests that attack both crops are similar. This is an opportunity some of the tomato growers can diversify into off the rainy season. The advantage of the potato is that it has a longer shelf life than the tomato. Potatoes are mainly grown from tubers and these tuber seeds can easily be bought from Buya Bamba in Lusaka. The choice of the seed variety is very important because some are more prone to diseases than others. The size of the tuber is also critical because the size determines the number of stems in addition to the crop as larger tubers have more eyes and stores more carbohydrates, nutrients and water which are critical to sustain the young seedling. The crop is grown on ridges for easy harvesting and the planting of the seeds can start as early as March in this part of the globe. The planting and specifications of the ridges will depend on the variety and size of tuber seeds.
Potatoes should be grown in soils that are friable and easy to work with and they prefer pH range of 5.5 to seven.  Therefore, a pH that is too acidic will render certain nutrients, especially the macro ones, to be unavailable. One of the key nutrient to watch for under acidic condition is phosphorus which will be unavailable or locked as we call it in agronomy. A pH range of six to seven promotes the availability of most plant nutrients while on the other end, very high pH of over eight will limit the availability of iron, magnesium and boron. Knowing your soil status is not only important in cultivation of potatoes but other crops as well.


It is also important that the soil should contain adequate amounts of organic matter as this acts as a reservoir of carbon and helps to store water as well. Potato needs a higher requirement for phosphorus, potassium and nitrogen. These should be readily available as you may know that these are also important for protein formation as the crop is high in this element. It also requires some secondary elements like  magnesium which is an important constituent of chlorophyll for photosynthesis, calcium and sulphur but not as important as the micronutrients such as manganese, iron, boron, zinc, and copper, including molybdenum. This is the reason why it is important to apply foliar fertilisers in the production of potatoes because these might be locked in the soil, especially if we are not monitoring our soil nutrition. This is a crop that has a highest susceptibility to phosphorus deficiency. This can be seen on the leaf as well as root size, ultimately affecting the tubers size, quality and number of tubers formed. This element is only second to nitrogen in the effective growth of a potato plant. However, it is important to note that no nutrient is more important than the other. The absence of one nutrient, either micro or macro, will be the limiting factor in the effective production of the crop and it is the reason that farm managers should closely monitor crop nutrition.


The second aspect of the effective production of potatoes, just like tomatoes, is managing the diseases and pests. One of the most devasting disease for potato is early blight. This can easily wipe out the field if not controlled. The only good news that we have is that there are a couple of products that can be used to control this and one of the products I have come to like both for tomato and potatoes is Bellis. This is a must have product. The other most important disease which caused famine in Ireland and killed over a million people in 1800 is the dreaded late blight. It is a fungal disease caused by a group of fungi called the Oomycetes. Normally in the growth of potatoes, just like tomatoes, the late blight sets in early and the other one late but it doesn’t mean the opposite cannot happen. Again, there are so many products that can control these diseases but what is important is to spray preventatively, as the saying goes:  prevention is better than cure. Other diseases of economic importance are black rot, brown spot, fusarium wilt, powdery mildew and scab, verticillium wilt and other viral diseases. It is important to note that just like in humans, there is no pesticide that can control viral disease. What is important is to control the vectors which carry and transmit these diseases such as aphids and grasshoppers. On the pests, look out for the dreadful red spider mites, especially now that it is hot and whiteflies, potato tuber moth, the leaf miner and the nematodes. On the other hand, you will agree with me that marketing of potatoes is slightly easier than tomatoes because of the shelf life.


My fellow farmers, let’s not cry about the loss we have incurred from tomato; that is how business is – you win some and lose some. What is important is to soldier on, whether FISP is there or not. Zambian farmers are so resilient and I know that they will produce even without FISP. Mind you, the Minister of Agriculture does not know when the inputs will be distributed and in less than six weeks, farmers will be planting. How I wish his  salary can be withheld until he assures the farmer of the date when the fertiliser will be distributed.

This author is an agribusiness management consultant. Your feedback is most welcome; keep those emails coming on ftembo2001@gmail.com.

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