inside the egg. The eggs hatch in 8 to 10 days. The juvenile molts three times to reach the immature stage. The immature female parasitizes the root for one to two weeks. During this time the male deposits sperm, which the female stores until her gonads mature. The nematode can also reproduce via parthenogenesis, without fertilization. Upon maturity the female exits the root and lays up to 200 eggs in a gelatinous matrix. Host-parasite relationship When the immature female penetrates the root, a feeding tube forms from stylet secretions. Reniform nematode infestations can be hard to detect, as they do not cause galls or other obvious symptoms. Instead, it causes symptoms in the host plant that resembles those of moisture and nutrient deficiencies. Reniform nematode cause hypertrophy in the pericycle cells of seedling roots and in the periderm cells of the roots of older plants. Root growth slows and secondary root development is limited. Root necrosis has been observed in pineapple and banana. Shoot growth suppression and reduction of fruit quality has been observed in crops such as pineapple. In sweet potato, early infection of reniform nematodes results in tuber cracking leading to poor storage quality. Infested plants can become stunted and chlorotic. Wilt disease can follow when opportunistic fungi such as Fusarium and Verticillium infect the plants, a process observed in cotton. Secondary fungal infection can also cause root decay. Damage from R. reniformis is directly related to the number of nematodes present when the crop is planted. Variation among nematode populations, hosts, environmental conditions, and soil types may alter the threshold or economic injury level across the geographic distribution of the nematode. Management Management can be challenging, as reniform nematodes have been found in depths greater than 1m in soil and appear to become dominant over other nematodes such as southern root knot nematode (M. incognita). Some plants are resistant to this nematode. In susceptible taxa, chemical control is one of the most common management practices. Nematicides before and after planting can be effective. Intercropping and crop rotation, especially with resistant or non-host plants, is used as cultural control to improve soil, increase antagonistic microorganisms, and reduce nematode populations. French marigold (Tagetes patula) and sunn hemp (Crotalaria juncea) are recommended for these uses. The fungus Purpureocillium lilacinum has been used as an agent of biological pest control against the nematode in chickpea. References Tylenchida Plant pathogenic nematodes Nematodes