|Brown, Charles - Chuck|
Submitted to: 2000 Proceedings Washington State Potato Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/15/2001
Publication Date: 3/6/2001
Citation: BROWN, C.R., HOLLAND, E., CARDENAS, L., THORNTON, R. EL CORTE DE LA SEMILLA Y LA SIEMBRA CORRECTA DE LA PAPA. PROCEEDINGS OF THE 40TH ANNUAL WASHINGTON STATE POTATO CONFERENCE AND TRADE SHOW, FEB 6-8. P 127-138. 2001. Interpretive Summary: The farmworkers involved in preparation of seedpieces and planting of potato are often not aware of the most important principles that contribute to uniformity of stand and maximized profit in terms of size distribution of the harvested crop. First and foremost cutting of seed needs to be directed at obtaining seedpieces that lie between 1.5 and 3.0 ounces. The adjustment of the distances between sizing rollers that separate potatoes onto different belts and knife configuration is the most crucial consideration. Larger tubers must be placed on six-cut and eight cut belts while the smaller tubers should be on two-cut and three-cut belts. Workers must collect cut seedpieces, weigh them and determine what percent lie between the desired limits. Sometimes it is necessary to pre-sort seed into large, medium and small sizes in order to get the best profile. The driver of the planter must be aware that every planter has an optimum speed. At this speed seedpieces will have a consistent spacing, with very few skips and doubles. The tendency for the planter operator to plant as fast as possible to show time savings and efficiency to the employer must be discouraged. The objective of uniform spacing must be made very clear to planter driver. Proper seedpiece size and planter operation at the proper speed leads to a uniform plant stand, and will place a greater percentage of the yield in the desired size category that maximizes the profit derived from the contract with the buyer.
Technical Abstract: The effects of certain practices at planting on the agronomic performance of a potato planting are often not given much attention. The most important principle in the cutting of seed is to obtain a distribution of seedpiece sizes that lie within 1.5 and 3.0 ounces. If at least 80 percent of the seedpiece sizes lie within this range the uniformity of harvested tuber size will be enhanced. The best practice would be to use uncut single drop seeds. This is probably impossible to arrange with the present varieties, so the best alternative is specify to the seedgrower that the seed tubers should be small and not exceed 6 ounces. Achieving this, the seed could consist of single drop and single cuts. It is important for the grower to realize that apical seedpieces do not give the same performance as basal seedpieces. The second principle that needs to followed is that the planter must be run at the optimum speed. Suboptimal or supra-optimal planter speeds will result in uneven spacing. This includes long and short spaces, skips, and doubles. A plant that experiences crowding or lack of competition will produce undersize and oversize tuber sizes, respectively which will contribute to size categories outside of the most desirable contracted size. This also contributes to malformed tubers that will be scored as culls. Proper seed cutting to achieve high frequency of optimally sized seedpieces and planting at proper speed are two important principles to start a potato crop for maximum profitability.