Intervention of Nutrient Imbalances

Growers Must Ensure Timely and Accurate Detection and Intervention of Nutrient Imbalances
By Benson Kibiru

The Kenyan floriculture industry has in recent decades grown at an exponential rate. This growth can be characterized by an increase in number of acreage of both indoor and outdoor cut-flowers, direct foreign investment to the industry as well as increased global market share. The flower industry is faced by myriad challenges such as changing climatic conditions, changing market dynamics, pests and disease. Growers therefore need to have relevant technical knowhow to achieve sustainable production.

Working smarter, not harder, to optimize productivity, maximize crop yields with minimal production cost is important. However, this does not happen without diligent efforts to prevent and overcome possible challenges. As a flower producer, how do you exercise the latter? Yield and quality are often considered important parameters to look at in crop production. For these to ensue however, it is important to consider a holistic crop production approach that considers the planting media, irrigation/fertigation water to be used, nutrients that have been absorbed by the plant tissue, crop protection among other parameters.

From an agronomist’s point of view, timely and accurate detection and intervention of nutrient imbalances can be achieved through routine soil, substrate, nutritive solutions and water analyses. The routine test results reveal nutrient credits from soil, irrigation/fertigation water and nutrient (stock) solutions. With the latter a good balance between elements in the nutrient solution can be achieved. For growers, it is worth noting that a, better low EC with a good nutrient balance than a high EC with a bad nutrient balance. This is due to the existing complex relationship between elements.

Foliar (tissue) analysis is one among the crucial crop management tools, for example, sometimes media & water analysis alone might not reveal the true picture of what is happening in the root zone. Adding knowledge on nutrient concentrations and ratios of essential elements found in indicator tissue reflect the true nutritional status of the plant. This it is therefore very important in developing and correcting nutrient program of a plant. During crop walks, often we encounter poor plant vigor despite a balanced nutrient program being implemented; in this case foliar analysis is one of the tools used to establish the cause among others.

Like any other plant, flowers are susceptible to attack by pest and disease causing pathogens. Economic importance of pests and diseases ranges from yield losses, cost of control, aesthetic losses and even environmental impact in the production areas. It is important to understand and differentiate between the two types of plant diseases; those whose primary causal agents are biotic (infectious) and those that are abiotic (not infectious). This would help understand how to target the diseases. The four major groups of microbial plant pathogens (fall under biotic diseases) are fungi, bacteria, nematodes and viruses which have a destructive effect on crop production. Screening and analysis of the growing media before planting is advised given the diverse sources and handling of the materials, while in soil previous land use activities are potential sources of the pathogens. Where either of the agents is suspected, screening of the growing media (soil& substrate) and the plant material is recommended and sometimes DNA check conducted as a diagnosis and the right control measures given.

Correct identification and quarantine of potentially harmful species of nematodes is important to the success of flower production. This is mostly in soil, substrate and irrigation water. Plant-parasitic nematodes attack almost every part of the plant including; roots, stem and leaves which in turn affects quality and quantity of crop yield. Symptoms of Nematode infestation include foliar discoloration when above aground, stunted growth, yellowing of leaves and root galling. As a result, nematodes are recognized as one of the greatest threat to crop production – popularly termed as the unforeseen enemy. Worth noting, apart from being parasitic, nematodes are also vectors of plant diseases and therefore timely control of their spread can reduce economic losses significantly.

In conclusion, a timely and well informed but efficient array of the above crop management tools will guarantee the flower growers good returns.

Benson Kibiru is an Agronomist with SGS (K) Ltd By Benson Kibiru