Manure and Soil Zinc Application to ‘Wichita’ Pecan Trees Growing Under Alkaline Conditions

Abstract

<jats:p>The effect of cattle manure or combined manure and zinc (Zn) application on Zn uptake, mineral composition, and yield and nut quality in pecan trees [<jats:italic>Carya illinoinensis</jats:italic> (Wangenh.) C. Koch] was evaluated. In 2006, treatments evaluated were: manure (12 ton/ha; M), manure plus Zn (12 ton/ha plus 129 kg Zn/ha as ZnSO<jats:sub>4</jats:sub>; MZ), and an untreated control. During 2007, two more treatments were added with doubled manure and Zn rates. New treatments were manure 2× (24 ton/ha; M2) and manure 2× plus Zn 2× (24 ton/ha plus 258 kg Zn as ZnSO<jats:sub>4</jats:sub>; M2Z2). Manure was broadcast on the soil in a 2.5-m wide band 2 m from the trunk. Zinc sulfate was broadcast over the manure, and then manure and Zn were disked into the top 10 cm of soil. In 2008, in five of nine sampling dates, significant treatment effects were detected on leaf Zn concentrations. On all of the dates, M2Z2 had the highest foliar Zn levels. During the Summer 2008 (17 July) foliar Zn in M2Z2, treatment reached 66 μg·g<jats:sup>−1</jats:sup>; the control treatment level was 45 μg·g<jats:sup>−1</jats:sup>. Nut yields were higher in treatments receiving manure, with or without Zn in the first year, and highest in the untreated control the second year. No differences were observed in trunk growth, leaf area, leaf weight, or nut growth. Kernel percentages were over 61.4 in the 3 years of study in all treatments. Largest differences among treatments in nut size were found in 2007; nut weight in the control treatment was 7.5 g per nut and in M was 8.0 g per nut. Nut weight was smaller during 2008 when nut yield was high, and the untreated control nuts were smaller than those from treated trees. The manure and manure plus Zn treatments increased foliar Zn levels in pecan trees after 3 years of annual applications. In 2008, significant differences in leaflet Zn concentration among treatments were detected with M2Z2 having the highest concentrations.</jats:p>

Foliar Fertilization with Zinc in Pecan Trees

“…These low leaf Zn concentrations were similar to those reported in pecan trees by previous studies conducted in the same area (Núñez-Moreno et al, 2009b;Ojeda-Barrios et al, 2009. The optimal critical levels of Zn in pecan trees have been established in the range of 20 to 60 mg • kg -1 Zn (Favela et al, 2000;Núñez-Moreno et al, 2009a;Ojeda-Barrios et al, 2012). In the last sampling of 2007 (19 July), the average Zn concentration in the treated trees was 10.6 mg • kg -1 Zn, i.e., 87% higher than that in the untreated controls (5.7 mg • kg -1 Zn).…”

Zinc Content and Fruit Quality of Pecan as Affected by Application of Zinc Sulfate

“…Zn nutrition is critical for pecan growth and nut production (Ojeda-Barrios et al, 2014;Walworth et al, 2006). It is instrumental in improving fruit set because it is involved in the metabolism of auxin, which is responsible for fruit set and growth (N uñez-Moreno et al, 2009). Zn deficiency causes pecan leaf disease and reduction in nut yield, resulting in serious economic losses (Hu and Sparks, 1990;Sparks, 1993).…”

Pecan Tree Productivity, Fruit Quality, and Nutrient Element Status using Clover and Poultry Litter as Alternative Nitrogen Fertilizer Sources

“…Also, because Zn deficiency results in incomplete shoot development of pecan, yield is drastically reduced (Sparks, 1989). Nunez-Moreno et al (2009) found that cow manure increased pecan leaf Zn concentration 3 years after application began. During the current study, treatment effects on leaf Zn were observed each year after study Year 1; however, poultry litter failed to increase leaf Zn over that of the control except in the presence of clover in 2010 (Table 2).…”