Author: admin

Description
Downy mildew is a fungal disease that causes destruction of leaves, stems, and flowers of the infected plant. Downy mildew causal organism is called Peronosporasparsa and as the scientific name indicates, the production of spores is sparse and therefore this disease is difficult to diagnose and control.

• Downy mildew (Oomycete fungi) are referred to as a high risk pathogens because of the following factors;
• Oomycetes fungi are able to spread in an explosive manner under favorable conditions.
• Short development cycle (8-10 days under optimum conditions)
• High potential for reproduction (high quantities of spores)
• Wide propagation by water and wind
• Damage is not reversible: The damaged tissues die in general leading quickly to substantial losses at harvest
• High genetic variability: Rapid appearance of strains less sensitive to specifically acting fungicides possible.

In the last 10 years biocontrol in Kenya has grown from a concept and wish, to a major crop protection strategy in reality. This transition

Scientific facts in cold chain management
Although a scientific approach of post harvest technology for fruits, vegetables and flowers goes back to the 1970’s, many partners in the logistic chain still lack awareness and knowledge of basic principles. All efforts that the producer has made to reach top quality products may be lost within 24 hours by mismanagement of the cold chain. The small gain made by saving on the cold chain is negligible compared to the loss of value it will cause. Proper cold chain management from farm till buyer is an essential condition for the preservation of the quality and the value of a perishable product.

The respiratory metabolism
Cut flowers, harvested fruits and vegetables are still alive and carry on characteristic processes of all living things. The most important process is the respiratory metabolism. It is a natural process of ripening, senescence and deterioration of the plant. The bio-chemical reaction (for 1 mole): C6H12O6 + 6O2 + 6CO2 + 6H2O + 686 kcal 294 kcal of the produced energy is used for internal processes but 392 kcal is heat. Cut flowers, beans and the vast majority of Kenyan fresh produce are climacteric plants and have a very high respiration rate. The respiration is triggered by ethylene, a self-regulatory hormone produced by the plant itself.

By Ernest Muriu and Floriculture Staff

Export Processing Zone (EPZ) program was established in 1990 to provide an attractive investment opportunity for export-oriented business ventures within designated areas or zones. This sought to help the economy through increased productive capital investment, jobs generated, technology transferred, backward linkages developed and diversified exports.

However, to date no one has ever answered, why is flower growing not included in the program. The sector which is predominantly an export oriented business continues to struggle with a stringent tax regime which has slowed foreign direct investment for the last five years and a relocation of a number of investors to the more lucrative Ethiopia. All this has happened under the government’s watch.

By Issabella Wanjiru Drip irrigation is a type of micro-irrigation that has the potential to save water and nutrients by allowing water to drip slowly

Rose growers from across the East African region are naturally clamoring for new interesting varieties to include in their production lines. Kordes Roses’ new white codes have drawn a lot of interest from growers. Most have visited their show case recently and discussed some of the varieties that are quite promising. These varieties have been the most popular in trial selections inline with indications that growers are looking premium varieties.

To solve the freshwater problem we must first understand how much water is actually available, how much we use, to what purpose, using what system, in what condition, and with what realistic capacity given rapid climate change and its visible and continuing catastrophic effect.

By Peter Neil
To solve the fresh water problem we must first understand how much water is available and how it is being used.

The new water paradigm should begin not at the top of the user pyramid, but at the bottom. It needs a better calculation of our own water footprint, a measure of the amount used to produce each of the goods and services we use, directly and indirectly, including “virtual” water and externalities. There is an excellent online tool to help us understand this process—the Water Footprint Network , founded in the Netherlands by Professor Arjen Hoekstra, and intended to assist individuals, companies, municipalities, and governments with water assessments, to design stewardship plans, and to offer training for new methodologies and project implementation under this new aquacentric approach.

Lake Naivasha is a freshwater lake in the Kenyan Rift Valley. It is unique in that it is home to both an internationally renowned environmental treasure as well as a blossoming agriculture industry that exports high value fresh vegetables and cut flowers to European and English markets.

The Lake is currently under intensive scrutiny over concerns about how its environmental integrity can be maintained whilst still supporting a valuable and growing economy and society. Agricultural activity in the basin has expanded dramatically in terms of both the rural smallholder farmers in the upper catchment and the high value exported commercial horticulture around the Lake and this sector anchors a local economy that supports almost 650 000 people.

The two most valuable crops in the Naivasha basin are cut flowers and vegetables. The vegetables grown in Lake Naivasha contribute approximately KSh6.65 billion ($95 million) to the Kenyan economy. Whilst predominantly focused on producing for the local market, smallholders are increasingly able to access high value export markets through their association as “out growers” with the commercial vegetable farms.

In Africa, and especially in Kenya, sodium is one of the major causes of yield losses, quality reduction and crop failure in irrigated agriculture. Writes Ruth Vaughan.

Soils with a high percentage of sodium in the soil are called sodic soils. Sodic soils negatively impact plant growth for several reasons:

1. Specific ion toxicity to sodium sensitive plants.
2. Nutrient deficiencies or imbalances in the plants.
3. High soil pH – resulting in lock up of phosphates, iron and other micronutrients.
4. Dispersion of clay and silt particles in the soil – collapsing the soil structure and blocking soil pores.