Stress Therapy For Cocoa Trees
Plant Impact Plc, a UK agritech company, has recently announced the launch of BANZAI™ – a product designed to improve the yields of cocoa trees under stressful growing conditions. According to the BANZAI™ product flyer, “BANZAI™ is based on Plant Impact’s Alethea™ technology”. The product is described as actively promoting “the production and retention of pods and compensates for plant stresses including fungal disease”. If BANZAI™ can significantly reduce abscission (dropping) of cocoa pods when the tree is under the stress of a fungal infection, it will be a valuable tool for farmers.
Cocoa is very susceptible to fungal infections including:
- Witches’ Broom (Moniliophtora perniciosa)
- Frosty Pod, caused by the basidiomycete Moniliophtora roreri
- Black Pod – caused by three fungal species of the genus Phytophtora spp including:
- capsici (Latam)
- megakarya (Africa)
- Vascular-streak Dieback (VSD), caused by Oncobasidium theobroma – a particular nuisance in Oceania and South East Asia.
BANZAI™is a liquid product applied as a foliar spray. Plant Impact recommends 1.6 litres per hectare in a programme of at least 4 applications per season. The company notes that BANZAI™:
- Increases yields when applied under normal growing conditions and in the presence of Black Pod
- Supports bean quality
- Is environmentally safe.
- Has been trialled in Cameroon.
About Alethea™ Technology
Alethea is a Greek word meaning truth or verity, it is also the name of Plant Impact’s patent protected technology that may have significant potential for addressing biotic stresses to plants and the major causes of abiotic stress including:
- temperature variations
- higher than normal / acceptable salinity levels
- variation in levels of ultra violet light outside the acceptable range for a species.
Research undertaken by a renowned team of plant biologists at Lancaster University in collaboration with Plant Impact produced some startling results in trials with plants exposed to high levels of toxins, salinity and UV, when Hardman Agribusiness first came across the technology in 2011.
Jasmonic & Salicylic Acid & Arginine
The technology has been established around three botanical structures or analogues thereof, including jasmonic acid (JA), a known component of plant immune defences, salicylic acid and arginine, an amino acid that plays an important role in cell division, immune function, and the release of hormones. JA is a known plant signalling biochemical, possibly a hormone or hormone mimic. For example, JA is secreted by plants during attack by chewing insects. The effect of the acid is to produce tougher tissues with stronger cellulosic bonds. While JA or its analogues produce a series of well documented responses in plants, the potentially exciting action of the Alethea™ technology is a product of interaction between all three of its components, and it is this interaction that is the basis for the technology’s patent protection.
Alethea’s™ action is centred on restricting the build up of damaging reactive oxygen species [ROS] in plants during periods of stress. ROS are pretty much an unavoidable by-product of basic life processes. The photosynthetic processes that allow plants to fix carbon come with the cost that they produce ROS. Under normal conditions the plant keeps a balance between that ROS production and a series of antioxidant mechanisms that stop ROS building up to damaging levels (for example Vitamins C & E which are commonly sold as health supplements). However, under many types of stress that balance is undermined in plants, the antioxidants are not able to “keep up” with ROS production, so ROS builds up to damaging levels. The damage that is caused is quite wide-ranging because ROS attacks a very wide range of biological molecules, but damage to the cell membranes is very typical (so cells get “leaky” which lead to more damage, and so on). The way that the herbicide Paraquat works is to interfere with the photosynthetic processes in a way that diverts energy away from carbon fixation in to ROS production, so again the plant’s defence systems are over-whelmed. It is possible that the Alethea™ technology prompts plants to produce elevated levels of antioxidants such as cysteine during stress, and it is this response that suppresses the elevation of ROS.
The image below reveals damage to a tomato plant sprayed with Paraquat and beside it a plant sprayed first with Alethea™ and then Paraquat – this plant appears normal.
Ethylene levels may also increase in response to stress; although this is most commonly associated with fruit ripening. Ethylene produced as a result of stress may trigger the loss of calcium from the cellular tissues, which become thinner and weaker and thus becomes vulnerable to damage from both abiotic and biotic stresses, including the ingress of plant diseases.
By countering common causes of stress, Alethea™ is thought to have the potential to enable crops to thrive under conditions in which they might otherwise struggle to survive.
The remarkable slides below, being one component of the research conducted by Lancaster University on Alethea™, reveal the significant empirical differences in Alethea™ treated maize plants grown in soils with raised salinity levels. These plants were around five weeks old. They were treated with a foliar spray of Alethea™ on three occasions, when two, three and four weeks old, whereas the controls received only water plus the same wetting agent as included in the Alethea™ spray. For the salt treatments, controls simply received tap water, while the salt treatment consisted of a low concentration of salt (sodium chloride) designed to mimic poor quality irrigation water.