Common wheat "Triticum compactum", but in India "T. sphaerococcum") are closely related to common wheat, but have a much more compact ear. Their shorter rachis segments lead to spikelets packed closer together. Compact wheats are often regarded as subspecies rather than species in their own right (thus "T. aestivum" subsp. "compactum"). Common wheat Common wheat ("Triticum aestivum"), also known as bread wheat, is a cultivated wheat species. About 95% of the wheat produced is common wheat, which is the most widely grown of all crops and the cereal with the highest monetary yield. Numerous forms of wheat have evolved under human selection.
Cover crop ("Sinapis alba") and radish ("Raphanus sativus"). They can be grown after a main (cereal) crop and trap nematodes, for example the beet cyst nematode and Columbian root knot nematode. When grown, nematodes hatch and are attracted to the roots. After entering the roots they cannot reproduce in the root due to a hypersensitive resistance reaction of the plant. Hence the nematode population is greatly reduced, by 70-99%, depending on species and cultivation time. Other cover crops are used to attract natural predators of pests by providing elements of their habitat. This is a form of biological control known as habitat