Ultrasol® K Plus and Speedfol™ Pecan SP Substantially Increase Pecan Grower's Net Income.
"In 2009, SQM along with the University of Georgia, field tested the effects of foliar applied Ultrasol® K Plus and Speedfol™ Pecan SP on pecan (Carya illinoensis) to assess the N, K, Zn, and B levels in the leaves, yield in terms of % kernel, kernel size (nuts/ lb), and % nut retention. Compared with the standard nutrition programme, the plots treated with Ultrasol® K Plus raised the grower's net income by 13%; those treated with Speedfol™ Pecan SP added an extra 43%" reports Sam Carruth (Sales & Business Development Manager Specialty Plant Nutrition, SQM North America). The trial was conducted in a commercial "Desirable" pecan orchard as a randomized block design with 3 treatments and 4 replications (Table 1). The treatments were applied with an air blast sprayer from mid April and continued approximately every 2 weeks throughout the season.
Treatment 1: 8 sprays of Ultrasol® K Plus at a rate of 7 lbs/100 gallons/acre + 3 sprays of grower Zn+B programme at a rate of 1/16 lb B/acre applied with a 6% B solution and Zn(NO3)2 (17%) at 2 lbs/acre (0,34 lbs Zn/acre).
Treatment 2: 8 sprays of Ultrasol® K Plus (13,7046,3) at a rate of 4 lbs/100 gallons/acre + Speedfol™ Pecan SP (100 34 + 7 Zn + 0,7 B) at a rate of 10 lbs/100 gallons/acre for a total volume of 14 lbs/100 gallons/acre.
Treatment 3 (control): 3 sprays of only the grower's standard Zn+B programme at a rate of 1/16 lb B/acre and Zn(NO3)2 (17% Zn) at 2 lbs/acre.
Table 1. Total lbs of foliar nutrients applied per acre throughout the entire season.
Treatments

N

K_{2}O

B

Zn


Lbs/acre

T1

Ultrasol® K Plus + Zn, B (grower)

7,7

25,9

0,18

1,0

T2

Ultrasol® K Plus + Speedfol™ Pecan SP

12,4

42

0,56

5,6

T3

Control

0

0

0,18

1,0

Figure 1. In the USA there are 255.000 acres of pecans. On the left the Mahan variety; on the right the Stuart variety.
As can be observed in Table 2, Treatment 1 significantly increased leaf K in the May samples, compared to the control (T3). The July samples did not reflect the results observed in May, possibly due to transport of K from leaves to nuts during this period. Nut retention was numerically greater in T1 and T2, suggesting a greater crop load on treated trees, which would require greater K transport from leaves to nuts.
The treatment with Speedfol™ Pecan SP (T2) statistically significantly increased leaf Zn in May and July, probably because a greater total dose rate was applied in T2 (5,6 lbs Zn/ acre) compared to T1 and T3 (1,0 lbs Zn/acre). Furthermore, T1 showed statistically significantly greater leaf Zn levels than T3 in May, although the same amount and source of Zn was applied, which suggests higher availability compared to the grower's formulation.
However, the greater dose rate of B in T2 (0,56 lbs B/acre) compared to T1 and T3 (0,18 lbs B/acre) was not reflected in statistically significantly higher leaf B levels in T1 and T3.
Table 2. Effect of the treatments on leaf element concentration in May and July, and, on pecan yield characteristics.
Leaf element concentration

Pecan yield characteristics


May 2009

July 2009


Treatments

N
%

K
%

B
ppm

Zn
ppm

N
%

K
%

B
ppm

Zn
ppm

Nut
retention
%

Nuts/lb

%kernel

T1

Ultrasol® K Plus (7 lbs/acre) + Zn, B (grower)

3,11 a

1,34 a

21,5 a

99,8 b

2,57 b

1,23 a

53,8 a

77,5 b

54 a

60,3 a

55 b

T2

Ultrasol® K Plus (4 lbs/acre) + Speedfol™ Pecan SP

3,09 a

1,27 a

22,0 a

174,0 a

2,80 a

1,20 a

52,3 a

198,0 a

71 a

59,4 a

57 a

T3

Control

3,10 a

1,18 b

21,5 a

81,8 c

2,46 b

1,32 a

54,5 a

74,5 b

51 a

73,2 a

56 ab

Picture 2. Pecan in hull, still on the tree.
Picture 3. The treatments were applied with an air blast sprayer.
Although no statistical differences were observed within plots (most likely due to high variation), the control plot (T3) produced more nuts per lb compared to the plots treated with Ultrasol® K Plus (T1) and Speedfoltrade; Pecan SP (T2). This indicates that nuts were larger in treatments 1 and 2 compared to treatment 3. In addition, % kernel was enhanced by Speedfol™ Pecan SP (T2).
Both nut size and % kernel are the two most important yield characteristics, as these parameters determine the price the grower obtains for his harvested nuts. A good price for the treated plot (60 nuts/lb, 57% kernel) would be $1,60/lb versus the control plot (73 nuts/lb, 56% kernel) at $1,40/lb. The higher price/lb coupled with the increased yield (i.e. greater nut retention) resulted in a 13% increase in farmer net income for T1 and 43% increase in farmer net income for T2 (Table 3).
Table 3. Economic aspects of the trial.
Treatments

Yield

Obtained price

Gross income

Treatment costs

Net income

Difference to T3

lbs/acre

US$/lb

US$/acre

US$/acre

US$/acre

US$/acre

%

T3

Control

2000

1,40

2.800

13

2.787

0

0%

T1

Ultrasol™ K Plus

2.120

1,50

3.180

34

3.146

359

13%

T2

Speedfol™ Pecan SP

2.560

1,60

4.096

99

3.997

1.210

43%
