Rid your vegetables of pests and diseases

Vegetables are increasingly becoming an essential component for food and nutrition security in the country.
Vegetable production provides a promising economic opportunity for reducing rural poverty in farming communities in Uganda and elsewhere in Africa.
There are various types of vegetables grown by farmers across the country with priority of specific types according to the regions.

However farmers in the various regions tap economic opportunities at various levels. The pest and disease challenge infesting the vegetables is more or less similar.
Some farmers are engaged in growing exotic hybrid vegetables mainly of Asian origin with the target of foreign consumers living in the country as a major market potential while the rest grow indigenous varieties.

Agricultural scientists in the country regard vegetables as essential sources for micronutrients needed for healthier diets. They contain nutrients such as potassium which helps to maintain blood pressure, while fiber content reduces blood cholesterol levels and may lower the risk of heart diseases. They also contain folate (folic acid) which helps reduce the risks of birth defects and vitamins A and C.
As such Seeds of Gold caught up with experts to discuss the importance of farmers growing vegetables, its consumption as health diet and the challenges of pests and diseases and below are the details.

Varieties
Central
Dr Idd Ramathan the in charge of vegetable breeding at the National Crops Resources Research Institute (NCRRI) explains that his team has established on-farm screening of high value Korean vegetables for enhanced productivity. This method is also resistant to pests and diseases.
The field trials were done in the districts of Nakaseke, Mukono and Masaka.
The vegetables included two varieties of tomato namely pinktop and tenten, two varieties of eggplants – Heukmi and Miggeuni and two varieties of Kales – Jeil Guijok and Matjang.

Other varieties tested included cucumber (Gangryuk-samchok and Shinbinakhab varieties), local cabbage (YR Hogirl and YR Onnuri varities) and Chinese’s cabbage (Noranja and Bul-am 3HO varieties).
Other varieties which farmers are already growing include Amaranthus dubius (dodo), Gynandropsis gynandra (African spider), African eggplant and, nakati and tomatoes

East and north
Farmers in these regions grow Hibiscus sabdariffa (malakwang), Crotalaria ochroleuca (alayu), Hibiscus esculentus (okra), Jute mallow (otigo lwoka), Vigna unguiculata (cow pea leaves), Manihot esculentum (cassava leaves) and Cucurbita maxima (pumpkin leaves).
There are more than 300 different species of African traditional vegetables that have been eaten in East Africa for many years. These vegetables are known for their nutritive as well as medicinal value.
African traditional vegetables were a big part of people’s diet and culture until modern vegetables such as cabbage and carrots were introduced.

Field trial experience
Basing on a recent survey, Dr Monica Kansiime, a scientist working with the Centre for Agricultural Biosciences International (CABI) in Nairobi, Kenya says farmers in central region prefer growing nakati, amaranth and Africa spider.
Those engaged in growing these vegetables allocate 0.2 acres of their land for the same but for the last five years; many farmers are beginning to grow them due to the awareness exercise carried out by different development partners about its nutritive importance. Many farmers prefer to sell their vegetables on farm in bundles of 70 kilogrammes to 100 kilogrammes with each bundle costing between Shs300,000 to Shs700,000 depending on the season.

Pests and diseases
Most farmers are faced with similar pest and disease challenge with exception of a few.
Farmers growing both local and exotic varieties are mainly faced with the challenge of pests invading their fields and they are of different types.

Vegetable pests
It is the dream of every farmer to sell their produce for higher returns. However, many face phytosanitary and technical challenges that lead to rejection of their vegetables especially the export market.
Dr Kansiime breaks down the pests and diseases that stop farmers from exporting their produce and how to overcome them.

Moth
This is a major pest, because the larvae of the moth feeds on a wide range of crops.
The brown insect originated from Sub-Saharan Africa, but has also been detected in Europe and US. It thrives under warm and humid conditions and can produce up to five generations annually.
One should observe good sanitation conditions, destroy wild and cultivated hosts and apply recommended insecticides, which could be done aerially or from the ground. Scout at least twice a week for early detection and work with your agronomist to apply the necessary pesticides.

Leaf miner
It is the larva of an insect that lives and eats the leaf tissue of plants. Adult leaf miners are small, active, black and yellow.
Leaf miners attack numerous horticultural crops including tomatoes, cucurbits, peas and beans.
They can be detected by seeing mines on leaves. Manage them through crop rotation and use of abamectin-based chemical. However, the leaf miner is resistant to many chemicals.

Whiteflies
These are small pests that feed on the undersides of plant leaves. They have the ability to carry and spread diseases, thus, they are a huge threat to food security globally.
White flies spread diseases such as African cassava mosaic virus, bean golden mosaic virus, tomato yellow curl virus and tomato mottle virus.
They have needle-like mouth parts used to sack sap from phloem and they excrete honey dew, a sugary liquid from plant stems and leaves.
If in large population, white flies can cause leaves to turn yellow, wither and fall off.

Use reflective mulches which repel them especially in vegetable gardens as well as yellow sticky traps.
Other pests include aphids, webworm, diamond black moth flea beetles, cutworms and cabbage lopper. These mainly affect cabbage fields as well as other leafy vegetables such as spinach, Sukuma wiki, and nakati among others.

Diseases
Diseases that attack vegetables include anthracnose, powdery mildew, black leg, downy mildew, club root, sclerotinia rot, soft rot, leaf spot, black rot and root- knot nematodes. These cause rotting of the vegetable plant leading to its collapse.
Others are late blight mainly affecting tomatoes caused by soil borne bacteria roslstonia solanacearum.
The factors leading to pests and disease burden in farmer fields are usually heavy rains, heavy dew which favour their multiplication and participation in destroying the leaves.