The effect of a novel compound on yield and fruit quality in hydroponically grown tomatoes

Abstract

English: A company, Elementol (Pty) Ltd, requested the evaluation of their novel product, Pheroids. Pheroids is apparently a micro-emulsion that has the ability to act as a vehicle transporting phytologically beneficial substances over membranes. They further claim that Pheroids alone, has plant growth promoting qualities. However, little information on Pheroids was provided, as its patent registration is still pending. Lycopersicon esculentum (cv. Floridade) was used for this study as it is prone to developing a nutritional disorder, Blossom-end rot (BER), under circumstances that promote a calcium deficiency in fruits. It can reduce potential yield with up to 70%. The plants were cultivated in a controlled greenhouse environment in a drip hydroponic set-up using complete- and calcium deficient nutrient media. The plants cultivated in the calcium deficient nutrient medium markedly developed BER. In an effort to reduce the occurrence of BER, these plants were treated with additional calcium using 1% and 2% CaCl2 solutions, singly and mixed with Pheroids, as foliage sprays. The purpose of these treatments was to test the ability of Pheroids to act as a vehicle for the transport of additional calcium into the plants. Control plants cultivated in a complete nutrient medium were also treated foliarly with pure Pheroids to determine the possible stimulatory effect of Pheroids on plant growth. Reduced yield, and the subsequent high incidence of BER, as a result of the calcium deficiency, was prevented by supplying calcium stressed plants with additional calcium in the form of the 1% and 2% CaCl2 foliage sprays. These treatments improved yield above that of the calcium stressed plants, but failed to completely prevent the occurrence of BER. Mixing Pheroids with these CaCl2 solutions addresses its potential to transport additional calcium into the plants to improve cellular calcium concentrations. The 2% CaCl2 Pheroids mixture specifically proved to be a very efficient treatment in reducing the effect of a calcium deficiency on yield and the development of BER. Although BER was not completely prevented, the yield and income generated with this mixture compared favourably to that of control plants. The efficiency of this 2% CaCl2 Pheroids mixture as a preventative foliage spray for reducing the occurrence of BER, were also compared to a treatment where only the fruits of calcium stressed plants were treated with this mixture. Treating only the fruits reduced the occurrence of BER effectively, but yield and profit were markedly decreased, making it ineffective, unpractical and uneconomical. A further aim of this study was to investigate the ability of Pheroids to act as a growth promoting substance by spraying control plants with Pheroids. The data obtained suggested that Pheroids stimulated plant growth in general as it stimulated yield. However, its potential stimulatory response also promoted the development of BER, and subsequently a reduction in net yield and profit. Since general plant growth was stimulated by Pheroids under control conditions, it is recommended that Pheroids should be extensively tested on a variety of crops to evaluate its growth stimulating potential. In summary, it appeared that Pheroids has the potential to act as a growth promoting substance, but needs further detailed investigation. However, it did indeed act as a vehicle for the transportation of phytologically beneficial substances over membranes, especially in tomatoes grown under calcium stress conditions. Taking into consideration that most crops are grown in sub-optimal conditions, Pheroids might have numerous potential applications for the agricultural industry.

Afrikaans: ‘n Maatskappy, Elementol (Edms) Bpk, het die evaluering van hul produk, “Pheroids” onder gekontroleerde toestande aangevra. Pheroids is ‘n mikro-emulsie wat vermoedelik oor die vermoë beskik om die vervoer van fisiologies voordelige verbindings oor membrane te verbeter. Elementol (Edms) Bpk beweer verder dat Pheroids ook oor groeistimulerende eïenskappe beskik. Min inligting oor Pheroids is egter bekend aangesien die patentregistrasie nog nie afgehandel is nie. Lycopersicon esculentum (cv. Floridade) is in die studie gebruik aangesien die vrugte geneig is om blom-end-vrot (BEV) onder toestande wat ‘n kalsiumtekort in vrugte bevorder, te ontwikkel. Die voorkoms van BEV kan oesopbrengs met soveel as 70% verminder. Die plante is in ‘n kweekhuis verbou in hidroponiese drup sisteme met volledige- en kalsium-arm voedingsmediums. Daar is aangetoon dat ‘n hoë voorkoms van BEV by die plante wat in die kalsium-arm voedingsmedium verbou is, voorgekom het. In ‘n poging om die ontwikkeling van BEV te beperk, is die plante van addisionele kalsium voorsien in die vorm van blaarbespuitings met 1% en 2% CaCl2 oplossings, alleen of gemeng met Pheroids. Die doel hiervan was om die vermoë van Pheroids om fisiologies voordelige verbindings oor membrane in die sel te vervoer, te ondersoek. Kontroleplante is addisioneel met Pheroids bespuit om die moontlike groeistimulerende eïenskappe daarvan op plantgroei te bepaal. Kalsium-arm toestande het duidelik die oesopbrengs verlaag en die voorkoms van BEV verhoog. Daarenteen het behandeling van hierdie kalsium-arm plante met 1% en 2% CaCl2 oplossings die oesopbrengs verbeter en die voorkoms van BEV gedeeltelik beperk. Hierdie behandelings kon egter nie die effek van kalsium-arm toestande op oesopbrengs en die voorkoms van BEV ten volle ophef nie. Deur die CaCl2 oplossings met Pheroids te vermeng, is die potensiaal van Pheroids om addisionele kalsium na plantselle te vervoer, aangespreek. Die Pheroids teenwoordig in die 2% CaCl2-Pheroids-mengsel het moontlik die vervoer van addisionele kalsium verbeter aangesien dit die mees doeltreffende behandeling was om oesopbrengs te verhoog en die voorkoms van BEV beduidend te verminder. Alhoewel die voorkoms van BEV nie volledig met hierdie CaCl2–Pheroids-behandeling onderdruk was nie, het die oesopbrengs en winsgrense baie goed vergelyk met díe van die kontroleplante. Die doeltreffendheid van die 2% CaCl2-Pheroids-mengsel as ‘n voorkomende blaarbespuiting om die voorkoms van BEV te beperk, is ook vergelyk met ‘n behandeling waar slegs die vrugte van kalsium-arm plante met díe mengsel behandel is. Die direkte behandeling van slegs die vrugte het ook die voorkoms van BEV doeltreffend verlaag, maar dit het ook oesopbrengs en gevolglike winste, merkbaar verminder. Dus, om slegs die vrugte van kalsium-arm plante met die CaCl2-Pheroids-mengsel te behandel, is ondoeltreffend, onprakties en nie ekonomies nie. ‘n Verdere doel van die studie was om die groeistimulerende eïenskappe van Pheroirds te evalueer. Behandeling van kontroleplante wat reeds onder optimale voedingstoestande groei met Pheroids, het die oesopbrengs verbeter. Dit dui daarop dat Pheroids plantgroei in die algemeen kan bevorder. Pheroids het egter ook die voorkoms van BEV gestimuleer en gevolglik die oesopbrengs en winste verlaag. Daar word aanbeveel dat die groeistimulerende kapasiteit van Pheroids wat in hierdie studie waargeneem is, ook op ‘n aantal ander belangrike landbougewasse ondersoek word. Dit blyk dus dat Pheroids die potensiaal het om plantgroei te stimuleer, maar dit vereis verdere ondersoeke. Dit blyk ook dat Pheroids die vervoer van ander fisiologiese voordelige verbindings oor membrane bevorder, veral by plante wat aan spanningstoestande blootgestel is. As in ag geneem word dat die meeste gewasse in elk geval in sub-optimale toestande verbou word, wil dit voorkom of Pheroids verskeie toepassings in die landbouindustrie het. Verdere studies op ‘n verskeidenheid van landbougewasse, is dus noodsaaklik.