Executive Summary of Nutramax Research At Penn State University

T. L. WATSCHKE AND J. A. BORGER

PROFESSOR EMERITUS OF TURFGRASS SCIENCE AND INSTRUCTOR OF TURFGRASS SCIENCE

HISTORY

Penn State’s turf program was originally contacted by Nutramax in late 1996 with regard to potential research projects. Early greenhouse work demonstrated that plants treated with several sequential applications of Macro-Sorb^® Foliar wilted slower and recovered quicker than non-treated turf. Turfgrass injury was never observed under any circumstances. This early research was positive enough to expand the greenhouse program and move several projects to field plots. (Sample study attachment #1)

SUPPLEMENT FOR HERBICIDES

One of the field trials conducted in 1997 was the use of Macro-Sorb^® Foliar with 2,4-D for dandelion control. It was found that control of dandelion with half rates of 2,4-D was equivalent to full rate applications of the herbicide. Subsequent research with an array of herbicides revealed similar results, except for dicamba (which is a root-absorbed compound). The most impressive and consistent results for Macro-Sorb^® Foliar/Herbicide combinations were found with combinations of Macro-Sorb^® Foliar with Acclaim Extra and Drive (postemergence summer annual grassy weed herbicides). Both herbicides provided satisfactory control of crabgrass at reduced rates (up to half rate) when combined with low rates of Macro-Sorb^® Foliar. Also, when the herbicides were used at full label rates in combination with Macro-Sorb^® Foliar, the level of crabgrass control was improved. These results were consistent from year to year at Penn State and at other research locations in the Northeast. (Sample studies attachment #2-4)

SUPPLEMENT FOR PGR’S

Our early research combining Macro-Sorb^®Foliar with Embark showed promising results, in that, seedhead suppression was enhanced at lower rates, which reduced the tendency of Embark to cause minor discoloration. In addition, several experiments were conducted over the years using Macro-Sorb^® Foliar and low rates of soluble nitrogen sources with Embark. Significant success was achieved in enhancing the level of seedhead suppression with increased safety to mixed creeping bentgrass and annual bluegrass swards. Macro-Sorb^® Foliar was also extensively researched as a supplement for other growth regulators (Trimmit, Primo Maxx, and Proxy). Intensive research using weekly height and weight measurements on creeping bentgrass maintained as a fairway turf revealed that the activity of Primo Maxx, in particular, could be significantly enhanced when the application was combined with Macro-Sorb^® Foliar. In almost all cases, half rates of Primo Maxx combined with Macro-Sorb^® Foliar provided similar growth suppression levels and longevity of activity to that of full label rates without using Macro-Sorb^® Foliar as a supplement. (Sample study attachment #5)

PRE-STRESS CONDITIONING

Nearly ten years of research has shown that Macro-Sorb^®Foliar, by itself, or in combination with Primo Maxx can be a very effective pre-stress conditioning strategy for cool-season turfgrasses. Greenhouse, growth chamber, and field trials have all shown that sequential applications containing Macro-Sorb^® Foliar prior to the onset of heat and moisture stress provide the treated turf with an enhanced ability for tolerating such stresses. In addition, there is also research evidence to support that turf treated with Macro-Sorb^®Foliar can also recover more quickly from mechanical stresses, as long as the Foliar applications are made sequentially prior to the onset of the mechanical stress. It was also found that Macro-Sorb^® Radicular, used in a mechanical stress study, was equal to applications of foliar, with respect to positive turf response (e.g., quicker recovery). Also, Macro-Sorb^® Radicular was found, in greenhouse and field studies, to enhance seedling development. In-depth basic research conducted by Dr. Gordon Kauffman at Penn State showed that Foliar was capable of eliciting hormonal responses in environmentally stressed turf. These responses improved the ability of the treated plants to maintain more stable photosynthetic and metabolic activity, under heat stress, than non-treated plants. (Sample studies attachment #6 & 7)

ENHANCEMENT OF NITROGEN SOURCES

Research over the past several years has shown that foliar applications of soluble nitrogen sources can be enhanced, with regard to plant response, when the applications are tank mixed with Macro-Sorb^® Foliar. It appears that the inclusion of Macro-Sorb^® Foliar either facilitates foliar absorption or movement within the plant after absorption or both.