Potato Fertility Experiments

Transcription

1 25 Potato Fertility Experiments Trace Element Fertility Experiment: The trace element fertility experiment at the Weigand location was placed on the same plot location as the experiment in The plots were four rows wide with all measurements being made from the center two rows. The 1962 trace element treatments were sprayed on the soil while the 1963 treatments were applied as foliar sprays when the vines were approximately twelve inches high. The soil type at this location is a Deschutes sandy loam. A soil test in the same two-and-a-half acre block, but not in the immediate area of the experiment, indicated K20 was three hundred twelve pounds per acre, which is possibly low for potatoes. The other elements should have been in adequate supply. Prior to planting, 500 pounds of potassium sulfate per acre and 350 pounds per acre of fertilizer were surface applied and disced into the soil. Another 350 pounds per acre of was banded at planting time. In total this would be approximately 100 pounds of N, 62.5 pounds of K and 75 pounds of P205 in the form of and 22t pounds K as potassium sulfate. The potatoes were planted on Aay 30, 1963 and the trace elements Trace elements were applied at the following applied July 20, rates: Boron 1 Copper 1 Zinc 2 Manganese- --2 Molybdenum-4 Cobalt 8 pound of B as Solubar pound of Copper Chelate pounds of Zinc Chelate pounds of Manganese Chelate ounces of Molygrow ounces of Cobalt nitrate Proper cultural practices on this location were made difficult by seepage water from the head ditch. While no seepage water actually reached the experimental area of this location, the fact that water was in the field restricted cultural practices and encouraged weed growth and made uniform irrigation more difficult. As a result of these difficulties, the uniform conditions demanded by the experiment were not obtained. This is reflected in the variation in yield between replications of the same treatment shown in Appendix Table No. 17. When yields are placed in the plot design, it is easy to see that most of the highs and lows are more nearly associated with the irrigation pattern than treatment.

2 26 Table No 1L presents the average yield, average tuber size, average specific gravity and the percentage market grade for the experiment. The variation mentioned above is reflected in the high coefficient of variation 27.3% for yield. The highest yielding treatment was the manganese application. The average yield for the manganese treatment was about 3.25 tons per acre higher than the check and roughly 3.5 tons higher than the average of all treatments. This increase in tonnage was reflected in an increase in the average size of tuber. The tuber size determination was derived by dividing the sample weight, fifty pounds, by the number of tubers in the sample by actual count. The larger size was reflected in a higher percentage of No. 1 potatoes. Also there was a slight increase in the specific gravity of the potatoes. The manganese treatment tended to keep the foliage green to a later date in the fall, and was the only treatment that showed any consistent vegetative response. The reverse of these statements is generally found where manganese was omitted from the complete trace element application. Admitting the weakness of the experiment, from the vegetative response, it would appear worth while to continue experimentation with manganese, particularily on those soils that are heavily leached and are no longer high in ph. With the results from this and previous trials, it appears that with the trace elements under consideration, further study with cobalt and molybdenum is not justifiable. More work with copper, zinc and manganese is justifiable on the basis of this and other experiments. Boron applications should be made but preferably on sites lower in B by soil test than this site. Appendix Table No. 18 shows the average sized tuber weight by replicate; the specific gravity is shown on Appendix Table No. 19.

3 Table No. 14 Effect of Several Trace Element Fertilizer Treatment Combinations on the Yield, Average Weight of Tuber, Specific Gravity and Market Grade of Russet Burbank Potatoes Grown on the N. L. Weigand Farm, Powell Butte, Oregon Average Yield Tons/Acre Average Size Tuber Ounces Average Specific Gravity Average Market Grade Percentage No. 1 No. 2 Culls Base (1) Boron Copper t Zinc Molybdenum Manganese Cobalt,, Complete k 2 ) Complete - Boron Copper Zinc Molybdenum Aanganese Cobalt L.S.D.,,, ' 5% N.S. Coefficient of Variation 27.3% (1)Base treatment composed of: 500# Potassium Sulfate per acre disced in prior to planting. 750# of , 2 disced in prior to planting, i banded at planting. (2)Complete contains all of trace elements listed above.

4 77 Appendix Table No. 17 Effect of Several Trace Element Fertilizer Treatment Combinations on the Yield of Russet Burbank Potatoes on the N. L. Weigand Farm - Powell Butte, Oregon Yields are Shown in Tons Per Acre, By Replicate and Average Yield in Tons Per Acre By Replicate I II III IV Ave. Base (1) Boron Copper Zinc imlybdenum t Aanganese Cobalt,, Complete k 2 ) Complete - Boron Copper Line Molybdenum Aanganese Cobalt Significance N.S. (1)Base Treatment composed of: 500# Potassium Sulfate per acre disced in prior to planting. 750# , i disced in prior to planting, i banded at planting. (2) Complete contains all of trace elements listed above.

5 78 Appendix Table No. 18 Effect of Several Trace Element Fertilizer Treatment Combinations on the Tuber Size of Russet Burbank Potatoes on the N. L. Weigand Farm - Powell Butte, Oregon Average Sized Tuber Weight in Ounces I II III IV Ave. Base (1) i. Boron t Copper i Zinc t Molybdenum i Manganese Cobalt t Complete ( 2 ) , Complete - Boron Copper Zinc Molybdenum Manganese Cobalt Significance N.S. (1)Base Treatment composed of 500# Potassium Sulfate per acre disced in prior to planting. 750# , i diseed in prior to planting, i banded at planting. (2)Complete contains all of trace elements listed above.

6 79 Appendix Table No. 19 Effect of Several Trace Element Fertilizer Treatment Combinations on the Specific Gravity of Russet Burbank Potatoes on the N. L. Weigand Farm - Powell Butte, Oregon Specific Gravity Determinations Shown by Replicate and Average Average Specific Gravity of Sample By Replicate I II III IV Ave. Base (1) Boron Copper Line Molybdenum Manganese Cobalt, i Complete (2) Complete - Boron Copper Zinc Molybdenum Manganese Cobalt i L. S. D. e 5% N. S. Coefficient of Variation i.27; (1) Base treatment composed of: 500# Potassium Salfate per acre disced in prior to planting. 750# of , i disced in prior to planting, i banded at planting. (2) Complete contains all of trace elements listed above.