Two impact sprinklers, a traditional round-patterned design (Rain Bird Maxi-Bird) and a newly developed square-patterned design (Square Shooter) were tested under field conditions to compare the uniformity of their precipitation patterns. The Square Shooter sprinkler requires half as many sprinkler heads as the Rain Bird to cover the same area with head-to-head coverage. The Square Shooter sprinkler, with a coefficient of variation of 0.124, produced a more-uniform distribution of precipitation than the Rain Bird sprinkler, with a coefficient of variation of 0.215. Square Shooter also delivered water more accurately within the boundaries of the plot than Rain Bird, which had more of the total precipitation falling outside the plot area than Square Shooter. The new square-patterned design could allow installation of heads on only one edge of an area with the same, or better, uniformity of coverage as traditional perimeter installations.
T. Scott Starr and Gerald L. Klingaman
T. Scott Starr and L. F. Thompson
Interveinal chlorosis has been observed on the oldest leaves of several varieties of flowering crabapple (Malus sargentii Rehl). Our objective was to identify the cause of this disorder. Foliage and soil from 20 Sargent crabapple trees growing on 12 different sites were analyzed for possible nutrient deficiencies or excesses. Analyses showed N to be slightly low, Ca high, and Mg low in all leaf samples. Soil analysis showed Ca to be abnormally high at all sites. We concluded that the leaf discoloration was caused by a Mg deficiency due to Ca suppression of the Mg and that the low foliar N might be a contributing factor in the interveinal chlorosis.
Jon T. Lindstrom, James A. Robbins, Gerald L. Klingaman, Scott Starr and Janet Carson
The University of Arkansas established a new, replicated, woody ornamental plant evaluation program in 1999. Three sites were used across the state and these sites encompassed the three different USDA Plant Cold Hardiness Zones found in Arkansas, Zones 6, 7 and 8. In the first year, 17 different woody ornamental plants were established in the evaluation. Information obtained from performance in this evaluation will be used in Arkansas Select, a marketing program for customers and nurserymen in the state. Nonpatented and nontrademarked plant material will be made available for propagation purposes. Woody plants will be evaluated for 5 years and herbaceous perennials will be evaluated for 3 years.
Jon T. Lindstrom, James Robbins, Gerald Klingaman, Scott Starr and Janet Carlson
The Univ. of Arkansas initiated a statewide plant evaluation program in 1999. This trial will enable us to evaluate plants on a statewide basis, improve statewide marketing programs, and serve as a propagation source for nonpatented or non-trademarked material. Trees and shrubs will be evaluated for 5 years and herbaceous material for 3 years. Three test sites were established across the state, one in Fayetteville, Little Rock, and Hope, Ark. These sites correspond to the three USDA plant hardiness zones found in Arkansas (Zones 6, 7, and 8). A consistent planting protocol (e.g., distance between plants, irrigation system, bed width) is used at all three locations. Data collection consists of annual growth measurements and qualitative evaluations for factors such as time of flowering, length of flowering, and disease or insect problems. A standard protocol has been established for identifying future plants to be evaluated in the program. In the first year, 17 accessions were planted at each of the three different locations. Best plant growth on 15 of the 17 accessions occurred at the Little Rock site. This may be a reflection of the environment present at the sites in Hope and Fayetteville. Both of these sites are exposed, full-sun situations, whereas the Little Rock site receives some afternoon shade. Reception to this trial program has been favorable, with the Little Rock site gaining much attention from the Arkansas nursery industry.