14 EXPERIMENT STATION BULLETIN 351 



The list of fertilizers offered has l)ccn reduced, hut it is found that 

 savings are still availahle through advance orders and cash purchases, and 

 b\^ purchases in ton or carload lots. 



Savings in the purchase of feed arc not as readih' availahle because of 

 increased demand and reduced supplw Farmers should continue to scru- 

 tinize values carefull\' and not adopt the "get it at any price" psychology. 



The first publication will be on "Purchasing Fertilizers." 



L. A. Dougherty, D. Hosken 



AGRICULTURAL ENGINEERING 



Potato Storage Construction 



This project was continued, using three bins each holding about 300 

 bushels of potatoes. "All w ere equipped with flues leading to the bottom 

 of the bins to permit the entrance of cool air for fall cooling, and to pro- 

 vide for an outlet to remove the warm air from the top of the bins. There 

 also was provision for recirculation of the air \\ithin each bin after the 

 desired temperature of 40°F. had been reached. Loss of ^\'eight was noted 

 for the bottom, center, and top of each bin. 



Little difference in loss of weight was evident between the bin 

 equipped \\ith a central flue at the bottom and the bin in w^hich the en- 

 tire bottom \\as constructed of slats. Two recommendations are appar- 

 ent: 



( 1 ) Cool the bins in the fall by causing cool air to pass under and 

 up through the potatoes 



(2) Have flues at the top to carry oft' the warmer air 



Two of the bins were constructed so that fall cooling was obtained 

 by natural draft or gravit\' and the other was obtained by use of a suction 

 fan. The suction fan cooled the bin to the desired temperature in about 

 ten days, whereas the gravity method required four to five weeks. After 

 the bins were cooled to the desired temperature (38°F. to 40°F.), the 

 flues were closed to exclude outside air. However, each bin had a false 

 partition in the back to circulate the same air within the bin. 



The bins cooled by gravity had a smaller loss of weight than the one 

 cooled more rapidh' by suction fan. This sho\\ s that as long as the pota- 

 toes in the bin can be cooled in four or five weeks, the results are satis- 

 factory. The average weight loss for gravity-cooled bins was 1.79 per 

 cent and for the bins cooled by suction fan the loss ^^■as 2.81 per cent. 

 Obviously, it is important to cool the bins, but rapid cooling \\'ith rapidly 

 moving air tends to dry the potatoes. Further evidence that outdoor air 

 has a drying effect is the fact that potatoes at the bottom of each bin had 

 a greater loss of weight than those at the top of the bin. 



The storage period covered in this experiment was from five to eight 

 months. The tubers selected were free from bruises. Length of storage 

 period had little effect on the loss of weight, provided that the potatoes 

 were cooled reasonably soon to about 38 or 40°F. and held as near that 



