Feedback: What makes mango trees drop flowers and how to correct defect

CAUSES OF FLOWER DROP IN MANGO TREES

Every mango flowering season I keep losing almost all the flowers. They end up having black spots, white powder, and then they dry and eventually drop.

From my observation, the problem occurs only on one particular species of mango trees.

I have used fungicides and pesticides in vain. Please give me the possible causes and the remedial measures.

Vincent

This could be powdery mildew, one of the most serious diseases of mangoes. The characteristic symptom of the disease is the white superficial powdery fungal growth on leaves, stalk of panicles, flowers and young fruits.

The affected flowers and fruits drop pre-maturely reducing the crop load considerably or might even prevent the fruit set.

Rains or mists accompanied by cooler nights during flowering are congenial for the disease spread.

Control: Alternate spraying of Wettable sulphur (0.2 per cent, 2g Sulfex/litre), Tridemorph (O.1 per cent, 1 ml Calixin/litre) and Bavistin (0.1%) at 15 days interval can effectively control the disease.

The first spray should be applied at the panicle emergence stage.

Carol Mutua,
Department of Crops, Horticulture, and Soils, Egerton University.

****

DAIRY CONSULTANTS

I have a farm on Kiambu Road, where I keep dairy cows though it has been challenging on milk production.

I would kindly request if you can recommend consultants who advise me on dairy farming.

Michael Kariuki

Kindly send an email to [email protected] and you will be provided with more details.

Tom C. Owino,
Department of Crops, Horticulture, and Soils, Egerton University.

****

GROWING MAIZE AND POTATOES

I want to venture into potato and maize farming on small-scale in Ol Kalou, Nyandarua. What are the best steps, varieties, fertilisers and pesticides?

Solomon Nderitu

Maize variety information would depend on the purpose for which you are growing the crop, that is to sell as green maize for roasting or dry maize for making ugali, otherwise facts on varieties grown in the area, fertiliser rates and any localised pests, check with the local agrovet shops or extension officers for detailed information.

However, fall armyworm has been the greatest nightmare to farmers but can be contained through spraying especially on small-scale as you intend to do.

For agronomy on potatoes, check the Seeds of Gold issue of August 12.

Tom C. Owino,
Department of Crops, Horticulture and Soils, Egerton University.

****

CALLIANDRA SEEDS

Please help me to get calliandra seeds.

David 

Most certified tree seeds can be obtained from Kefri.

The following email and phone contacts could be useful: [email protected] (0722157414); [email protected] (020-2172567); [email protected] (0713687975) and [email protected](0718232226).

Tom C. Owino,
Department of Crops, Horticulture, and Soils, Egerton University.

****
HYDROPONICS FODDER

I am Eric Mureithi from Githurai 45. Please advise on how I can grow hydroponics fodder?

Hydroponics is simply a method of growing plants without soil.

Plants’ growth and productivity is controlled by the type and amount of nutrients added to water; and can be used to grow both fodder and vegetables in a much faster way.

Fodder grains sprout in very little water and get ready in just seven days. Crops grown include barley, although alfalfa, oats and sorghum are possible grains to use.

The seeds for any of these crops must be clean, have no overgrowths, free of chemicals and unbroken. Using broken seeds may certainly not germinate and then begin to mould in the system.

Mouldy sprouts are also caused by poor hygiene conditions of both hydroponics unit and sprouting trays, warm and moist environment created within the unit, making it conducive for fungi to flourish.

The seeds are then spread in a wide channel or trays and kept moist then they start sprouting in a few days and in a week or so, fodder is ready, provided other management factors not limited to hygiene, and flow of air are observed.

While hydroponics is an exciting technology and sounds quite appealing, it is rather expensive to set up but other affordable materials can be used.

Apart from being costly, the resulting fodder contains very high moisture with little dry matter, meaning it may be difficult to feed ruminant animals that require considerable amounts of crude fibre for effective rumen function.

Nonetheless, hydroponics fodder should not fully replace conventional pasture or feed rations.

Felix Akatch Opinya,
Department of Animal Science, Egerton University.

****

OILSEED PROCESSING

I am Prince Kakis and I want to venture into oilseed processing on small-scale. Please advise me on the following:
a)What’s the seed with high oil content I can do process apart from sunflower and palm?

Canola, soybean and rapeseed.

b)How can I plan to acquire raw materials throughout. Should I import to get low prices from the biggest producer of sunflower or have in place a group of farmers growing for me?

You can contract a group of farmers, then buy the seeds from them to ensure a constant supply.

It is good to deal with a group of farmers rather than an individual farmer.

c) Will I require any training for the processing?  If yes, where should I go for it?
You can visit farmers who are already in the processing business and get some training from them.

d) What are the kind of machines I need? I want my product to meet the national standards and later export it.
You will need an oil press and a refining machine for good quality oil.

e) What are the sources of good machinery? Estimated price please if possible.
Machines are available from China and the price ranges from Sh100,000 to Sh300,000.

f) What should I do so that I can stand out from the big players?

Ensure that your oil is of high quality.

g) What are the by-products of sunflower I can get after pressing oil?

Sunflower cake is a by-product which you can also sell to be used as an animal feed by farmers.

Carol Mutua,
Department of Crops, Horticulture, and Soils, Egerton University.