- Plant Growth Regulators – Plant growth regulators (PGRs) are compounds that effect major physiologic functions of plants, such as growth rate, seed germination, bolting, fruit set and ripening, branching and many others. They may be naturally-occurring or synthetically manufactured to mimic the function of the natural substance. Many are plant hormones, but there are also other compounds that have an impact on plant growth, including a variety of secondary metabolites produced by plants and some plant-associated microbes. As the benefits of PGRs have become better understood by growers, their use has increased. They provide value through their ability to maximize productivity and quality, improve consistency in production and to overcome genetic and abiotic limitations to plant productivity. There are five major classes of natural plant hormones. Under each class there are a number of PGR products that play specific roles in optimizing crop yield and quality. Gibberellins, Cytokinins, Abscisic acid, Ethylene and Auxins .
There are a variety of concrete examples of how PGR’s meet the needs of growers in the fresh produce market. These include:
- .Improved fruit quality: Gibberellins reduce russet on apples, improve firmness in cherries and rind quality in citrus. Abscisic acid enhances the red colour on red grapes and ethylene aids in ripening of fruit crops.
- Improved yield: Gibberellins increase the fruit size of cherries, table grapes, pineapple and bananas.
- Gibberellins also improve fruit set on citrus and many other crops and the leaf size and yield are increased on spinach and other leafy vegetables. Cytokinins also increase the berry size of table grapes and ethylene modulation increases fruit set on walnuts.
- Overcoming genetic limitations: Gibberellic acid improves seed germination of dwarf rice varieties and increases berry size on seedless table grapes. Both gibberellins and cytokinins can also increase fruit size in small apple varieties.
Application rate: ratio 1:4 Litres ARATI PGR®
- Reduce labor costs: Cytokinins and auxins induce thinning of flowers and fruits. Ethylene modulation allows growers to manage the timing of fruit maturity, and therefore, the harvest. Gibberellins also allow growers to delay the harvest on citrus and cherries.
- Extend post-harvest life: Ethylene management and ethylene receptor blockage can enhance
the shelf life of fruit. Gibberellins extend the green life of bananas and lemons during shipping and storage.
- Insect Growth Regulators -Most chemical insecticides work by killing insects outright, often targeting the nervous system. Often, beneficial insects are killed as well. Insect growth regulators (IGRs) use a different and more selective mode of action; they disrupt the growth process of insects, preventing them from the reaching reproductive stage. The direct impact of IGRs on target pests combined with the preservation of beneficial insects and pollinators aids growers in maximizing yield and product quality. IGRs can be divided into two broad categories: those that disrupt the hormonal regulation of insect metamorphosis and those that disrupt the synthesis of chitin, a principle component of insect exoskeletons.
Agricultural applications currently focus on the first category of compounds, also known as “hormone mimics.” The most widely used IGR is azadirachtin, which structurally mimics the natural insect molting hormone ecdysone. Immature insects exposed to azadirachtin may molt prematurely or die before they complete a properly timed molt. Insects that survive exposure are likely to develop into a deformed adult incapable of feeding or reproducing. Since beneficial insects do not feed on the treated foliage, biopesticide insect growth regulators are considered “soft” on beneficial insects such as honeybees, ladybugs, green lacewings and parasitic wasps.
Organic Acids – Peracids are highly effective sanitizing agents used for controlling algae and pathogens. Peracids can be used for sanitation of greenhouse surfaces, shock applications for tanks and piping, continuous application at a low concentration and as a bacterial or fungicidal application to plant foliage or roots. A further advantage is that when peracids degrade, the byproduct is oxygen, which is safe and beneficial.
Plant Extracts – In order to protect themselves from insect, animal and fungal predators, plants have devised numerous biochemical defences. Some discourage feeding by insects and herbivores, some have anti-bacterial or anti-fungal activity that provides protection or even immunity from some pathogens, and others have a detrimental effect on nearby plants in order to reduce competition for resources. By studying the diverse chemistries of many different plant species, scientists have discovered many useful compounds that can be used as biopesticides. These are called plant extracts and provide pest control in a variety of ways.