6 MASS. EXPERIMENT STATION BULLETIN 225. 



impaired to the extent tliat they cannot mature their fruit and grow new 

 foliage ;i.s normally growing i)lants can and conseciuently the fruit is pre- 

 maturely ripened. As cucumber plants grow older, especially with the 

 string method, they shade each other more,^ind for that reason the lower 

 leaves either drop off naturally or succumb to disease. Under such con- 

 ditions the plants are unable to carry to maturity the fruit which was pol- 

 linated when they were in a fairly healthy condition, and consequently 

 many yellow pickles appear. 



Soil Conditions and Yei^i.ow Pickle 



Ordinarily the soil in a greenhouse is so well manured^ that if it is 

 handled properly there will be suft'icient soil nutrients present to carry a 

 crop of cucumbers from nine months to a year, or as long as the vines 

 are able to produce a paying crop. There are, however, certain conditions 

 caused by poor drainage which tend to shorten the growing period of a 

 plant, and materially cut down the yield. After cucumbers are trans- 

 planted, a period of soil saturation with water follows so that the plants 

 are continually growing in a wet soil, which is usually too wet for healthy 

 growth. If good drainage is provided, as in benches, little damage will 

 result. If no drainage is provided, the soil becomes water-logged, 

 oxygen is excluded and practicall\' no nitrification takes place. The plant 

 does not receive suft'icient nitrates to make a healthy growth and a large 

 number of yellow pickles results. Even if compost manure or fertilizer 

 is ai)plied on the to]i of the ground and ke])t moist, the plant will not 

 function projjcrly as long as the soil is in a water-logged condition. This 

 undoubtedly has much to do with the longer growing period of cucumbers 

 when grown in benches. 



The cucumber plant needs a large (luantity of water, but it will not 

 thrive if the roots do not receive sufficient air in the presence of too much 

 water in the soil. Greenhouse growers claim that plants wilt if the soil 

 is not thoroughly wet down. This is true, but they will wilt even though 

 more than the necessary amount of water is added, the reason being that 

 the plants have received so much water from the time they were set in the 

 beds that the root system is not large enough to balance the upper part 

 of the plant. The roots remain near the surface and will not branch out 

 and down for water and food. They are near the surface where there 

 is air. It is the same condition found in a poorly drained field. If plants 

 wilt during hot dry weather, growth is interrupted to the extent that many 

 tucunibers become stunted and produce either nubbins or yellow pickles. 

 Proper watering after transplanting will prevent much of this trouble. 

 An excess of water from the time the seed germinates makes a soft plant 

 which requires a large amount of water. It is impossible to give such a 

 plant sufficient water during hot dry weather to ]irevent it from wilting, be- 

 cause the root system is not large enough to replace the water that is 

 given off by the leaves. Undoubtedly, cucumbers grown with less water 

 from the start are more lignified (less soft), have stift'er cell walls, and 

 do not droop as readily even when there is a slight water deficit. 



This condition of the soil has considerable influence on the health of 

 the plant. The number of yellow pickles will lie influenced by the con- 

 dition of the plant. 



