Itronics Inc. reported that a field trial on peaches using a high phosphate GOLD'n GRO liquid fertilizer in a foliar spray, conducted in cooperation with its California distributor in the spring and summer of 2012, demonstrated a significant increase in fruit size. The test was conducted to determine if the GOLD'n GRO 6-12-9 + 4% S, high phosphate fertilizer would improve fruit size for peaches as a follow up to the consistent multi-year improvement in size and quality obtained by a pomegranate growing customer.
The trial was conducted in three different orchards, one with five year old trees, one with 10 year old trees, and one with 20 year old trees. The test trees sprayed with GOLD'n GRO 6-12-9 + 4% S in the 10 year old orchard had an average increase in fruit size of 26.5 percent. The five year old trees increased 9.5 percent and the 20 year old trees increased 4 percent. The comparison is to standard grower practice.
Two GOLD'n GRO fertilizers, GOLD'n GRO 8-8-8 + 4% S and GOLD'n GRO 6-12-9 + 4% S, were compared. GOLD'n GRO 8-8-8 + 4% S has been used successfully as a foliar spray on cherry and apple trees in Utah with very satisfactory results for several years. Two secondary objectives of the trial were to see which of the two fertilizers might produce the best results and to determine if the spray applications would spot the fruit. Both peaches and nectarines are particularly sensitive to spotting by foliar fertilizer sprays and therefore this was an important part of the study.
There was no fruit spotting by either fertilizer. Both fertilizers produced an increase in fruit size, with the GOLD'n GRO 6-12-9 + 4% S generating the best results. The GOLD'n GRO 6-12-9 + 4% S was applied at a rate of two gallons in 100 gallons of water per acre. The GOLD'n GRO 8-8-8 + 4% S was applied at a rate of three gallons per acre, the rate used by the Utah fruit growers. Two applications of the fertilizers were made. The first was made about six weeks before harvest and the second application was made two weeks later. At the rate of two gallons per acre the GOLD'n GRO 6-12-9 + 4% S outperformed the GOLD'n GRO 8-8-8 + 4% S at each of the trial locations with one-third less fertilizer, an unexpected result.
This was the first foliar spray trial using GOLD'n GRO 6-12-9 + 4% S on fruit trees other than pomegranates. This year Itronics is working with its distributor to do foliar spray trials on other stone fruit including cherries, nectarines and plums. Trials may also be conducted on other tree crops including citrus and almonds. Using a high phosphate GOLD'n GRO liquid fertilizer is novel and will require more field trials to identify other crops on which the foliar spray will provide positive improvements in fruit yield and quality.
The GOLD'n GRO chelated micronutrient fertilizers have been used successfully in soil applications with consistent results for more than 10 years by peach growers in western Colorado to remedy "Yellow Peach Syndrome." The GOLD'n GRO chelated micronutrient fertilizers have been used successfully in foliar sprays for peaches, nectarines, plums and cherries for more than 10 years in Central California.
According to the United States Department of Agriculture, in 2012 the United States had 112,880 acres of peaches. In 2012 California had an estimated 47,500 acres of peaches, followed by South Carolina with 15,500 acres. California is presently the primary market for the GOLD'n GRO fertilizers.
"Peach growers and other tree crop growers whose production is valued based on size and quality stand to benefit from this new fertilizer application development," said Dr. John Whitney, Itronics President. "Development of an economical high phosphate fertilizer spray application that increases yield by increasing fruit size and quality provides a significant competitive advantage for the GOLD'n GRO fertilizers."