Host status effect of cowpea and sunflower on the populations of Meloidogyne java']javanica and Rotylenchulus reniformis

A highly susceptible cowpea, Vigna sinensis cv. Baladi plants were tested as trap plants for either Meloidogyne javanica or Rotylenchulus reniformis under greenhouse conditions. The plants were gathered by cutting them above the surface of the soil or by uprooting them, 1/2, 1, 3, 6, 12, 24, 36 and 48 days after nematode inoculation. Both of the mentioned nematodes began to mature and lay eggs after the 12th day from their inoculation. Hence, it is advised to pull up cowpea plants from 3-12 days after nematode inoculation. After planting sunflower, Helianthus annus cv. Miak replacing cowpea, the nematode populations were higher, in most cases, on sunflower plants replacing cutting cowpea than those on Sunflower replacing uprooted cowpea. The highest percentages of nematode reduction were 98.55 and 99.57 for M. javanica and 95.09 and 92.90% for R.reniformis on sunflower plants replacing cutting and uprooted cowpea plants after 12 days from nematode inoculation, respectively. M. javanica and R. reniformis decreased the length and weight of sunflower plants as affected by planting time and method of cowpea harvest. This method of nematode control is cheaper, easy and pollution free.