(Sharecast News) - Plant Health Care's shares jumped on Wednesday after it confirmed that three more agricultural and seed companies agreed to evaluate its PREtec crop improvement product candidates over three continents.The company, a provider of novel biological products to global agriculture markets, said the new collaborators are seeking novel, low-toxicity biological products such as PREtec to increase productivity with lower environmental impact.PREtec is based on peptides derived from natural proteins and designed to lead to higher crop yields and better protection against disease and environmental stresses such as drought, while remaining environmentally friendly.Corn and soy crops, which are grown on more than 375 million acres in North and South America, are a particular target for the product.Chris Richards, executive chairman and interim chief executive, said: "As we continue to generate positive results from our PREtec platform of peptides, we are delighted to expand our range of partners who will evaluate our technology on multiple crops in multiple regions during the 2019 growing season."Meanwhile, the London-listed outfit also confirmed that it is continuing field trials with the Innatus 3G peptide PHC279 against Asian Soybean Rust in Brazil.Plant Health Care's shares were up 17.02% at 11.38p at 1335 GMT.