Temperature Effects on Development and Reproduction ofHeterodera cajani on Pigeonpea uri icon

abstract

  • Effects of constant and fluctuating temperature on development and reproduction ofHeterodera cajani were studied on pigeonpea cv. ICPL 87 in growth chambers at 10, 15, 20, 25, and30 C and in a greenhouse fluctuating between 22.2 and 37.8 C. Nematode penetration was greatest(P = 0.001) in roots at 25 C; there was no penetration at 10 C. The basal threshold temperature fordevelopment was calculated to be 11 C. Completion of one H. cajani generation required 17, 28, 35,and 66 days (323, 392, 315, and 264 degree-days) at 30, 25, 20, and 15 C, respectively, and 19 days(356 degree-days) at a fluctuating temperature. Survival was greater at 20 and 25 C than at 15 and30 C. The greatest (P = 0.05) number of females (17.9 females per root) were produced at 25 C,compared with 13.2 at 20 C, 7.9 at 30 C, and 2.5 females at 15 C. Nematode reproduction was 1.6to 7.1 times greater at 25 C than at other temperatures. Emergence of juveniles from egg sacs andcysts was greater at 25 and 30 C than at 15 and 20 C. Equations were developed to predict nematodedevelopment rate, cumulative juvenile emergence from egg sacs and cysts, and population increasesas influenced by temperature

publication date

  • 1994