Whitefly , aphids , and thrips can also cause problems with cucumber crops , though they produce symptoms many growers don ’ t associate with these pests . Thrips feeding on young cucumber fruit results in fruit deformities that become apparent long after the insect has moved on . Thus , early monitoring for these pests is vital . Blue sticky traps can be used to check for the presence of thrips infestations . Aphids and other sucking insect pests can carry a wide range of cucumber viruses that can cause a number of strange and serious symptoms such as leaf mottling , leaf and fruit deformities , plant stunting , and lack of fruiting . The most common , however , is cucumber mosaic virus , which causes ‘ shoestring ’ growth . This is when new leaves grow out thin , twisted , thickened , and alien-looking , and the entire plant becomes extremely stunted . As such , selecting cultivars with some degree of resistance to cucumber mosaic virus is recommended if aphids and other pests are an issue . Many modern greenhouse hybrids also have genetic resistance to other significant disease issues such as cucumber vein yellow virus , powdery mildew , target spot , scab , and fusarium root rot , making crop production much more reliable .
WILTING
Under warm conditions , cucumbers may naturally wilt slightly during the warmest part of the day , but regain turgor at night . However , long-term , severe wilting is a sign that root zone or environmental conditions are causing plant stress and need adjustment . Cucumbers seem to be more prone to wilting than any other hydroponic crop . This is largely due to the size of the leaves , which have a high rate of transpirational water loss , particularly in low humidity conditions . This transpiration can result in a rise in EC in the root zone or nutrient system , which can lead to even more progressive wilting . Other conditions such as certain nutrient deficiencies , root rot disease , and excess temperature may also be the cause . Under hot growing conditions , the EC can be dropped back slightly , particularly if the plants are wilting under overhead lights . Wilting can also point to issues in the root zone , though it is not necessarily a sign of a lack of moisture . In hydroponics , wilting it is more commonly caused by overwatering , which results in a lack of oxygen in the root zone .
Despite what may seem like a long list of checks and precautions when contemplating cucumber cultivation , most crops are usually trouble-free , high-yielding and thoroughly rewarding . Still , as with all hydroponic plants , it pays to know what to look out for with specific species , and a little background knowledge always goes a long way in preventing any major problems . Maximum Yield USA | December 2016 137