In the Northeastern United States, when harvest is begun very 

 early in the season, 2 difficuhies are encountered: (1) Ahhough the 

 quality (DDM value) per unit of forage harvested is high, the quantity 

 (tons) of forage harvested per acre is very low, and (2) the number of 

 rainy days is usually high at this time of the year (May 30 to June 10) .^ 



Weather Pattern 



The sequence of clear and rainy days that occur during the har- 

 vesting season is of great importance because of its influence on the 

 length of the harvest period and the quantity of rain-damaged hay. The 

 average number of clear days, occurring during the 2-month period of 

 June and July at Concord, New Hampshire, for example, varied from 

 a low of 31 to a high of 50 days over the last 50 years." 



The weather pattern influences the quality and quantity of forage 

 harvested in the following manner: First, if rainy days are numerous 

 during the harvesting period, harvesting is prolonged, providing time 

 for the quantity (yield per acre) of the forage to increase while the 

 overall quality decreases. Second, if clear days are numerous during the 

 harvesting period, harvesting occurs relatively fast and the quality of 

 each unit harvested is relatively high while the quantity harvested tends 

 to be low. While the absolute number of clear days determines the 

 number of days of harvest operations, the sequence of clear days alters 

 the quality and quantity of hay harvested. The quantity of rain- 

 damaged hay is greater for systems requiring a longer field drying 

 period. For any particular weather sequence the date harvesting com- 

 mences also influences the quantity and quality of forage harvested. By 

 changing the date that harvesting begins, a different sequence of clear 

 and rainy days is encountered during forage harvest. For example, Fig- 

 ure 1 shows that: (1) if starting date 1 is used, only 2 out of 6 mowings 

 are harvested without getting wet; (2) if starting date 2 is used, 3 mow- 

 ings are harvested without getting wet; and, (3) if starting date 3 is 

 used, only 1 of the 6 mowings would get wet. 



Equipment Complement 



The working speed of the equipment complement influences the 

 quality and quantity of the forage harvested by affecting the time re- 

 quired to harvest a unit of forage. Each equipment complement has a 

 specific input-output relationship, and changing from one set of equip- 

 ment to another changes the resources used and products produced from 

 a given number of acres. 



f' For the last 49 years, 4 out of the first 10 days of June were rainy on the 

 average with a range from zero to 8. 



^ Local Cliniatological Data with Comparative Data, Concord, New Hampshire, 

 U. S. Department of Commerce, Weather Bureau, 1914 through 1962. 



