Effects of soil areation on trunk growth, yield and nut quality of pecan

Abstract

The effects of three soil aerators on trunk growth, yield, nut size, and percent kernel of pecan were studied at Frio, Medina, and San Saba Counties in Texas in 1993 and 1994. A complete randomized block design was used in each location to compare three different types of soil aeration equipment to a control. The Frio County study contained six replications on four 'Wichita' trees per treatment. The Medina County study contained seven replications on three 'Wichita' trees per treatment. The San Saba County study contained six replications on two 'Western' trees per treatment. The treatments included (A) Guin Root Feeder; (B) Savage aerator; (C) Aerway aerator; and (D) control, no treatment. The Guin Root Feeder is a manually-operated pneumatic aerator which injects air 15 cm into the soil. Each treated tree received 16 injections equally spaced in a 2 m square block design. The Savage aerator has 12 crescent-shaped spikes, arranged in three rows, which slices the soil every 70.78 cm to a depth of 40.6 cm. The model used in this study was 2.29 m wide. Each treated tree had three passes on two sides. The Aerway aerator has sixteen spikes, 1.27 cm thick by 20.3 cm in length, spaced 10.2 cm and mounted on two spindles. The model used in this study was the 1.7 m model with a wheel kit. Each treated tree had three passes on two sides. Treatments were applied and trunk diameters were measured in mid-May 1993 and 1994 at each location. In the fall of each year nut samples were collected from each treatment block, and nut yield was measured and analyzed for quality. Results of this study indicate that for these two years soil aeration did not increase trunk growth, nut yield, or quality. This could have been the result of a detrimental increase in water infiltration that saturated the clay soils and may have possibly destroyed roots since internal drainage was restricted. This study did continue for a third year and should give a better indication of effects of soil aeration on pecan.