Towards management of fertilization to control wheat crown rot caused by Fusarium culmorum.
IPNI-2014-MAR-3
22 May 2017
2016 Annual Interpretive Summary
Fusarium crown rot of wheat, caused by Fusarium culmorum, has become a yield-limiting disease in the dryland wheat-production areas in Morocco, and is usually enhanced in water-stressed plants due to imbalanced fertilization with nitrogen (N). This project was initiated in 2014 with the objective to investigate: i) the relationship between wheat crown rot and fertilization (N forms and potassium), and ii) develop a fertilizer management package to control this disease in durum wheat. Field experiments were established in November 2015 at three locations Sidi El Aydi, Jamaat Shaim, and Khemis Zemamra, all in the semi-arid regions of Morocco. Within each experimental station, two trials were undertaken: one each in irrigated and rain-fed conditions. The experimental design was a strip plot with four blocks, where treatments were seed inoculation, inoculated and non-inoculated seeds. The inoculation treatment was crossed with fertilizer treatment of six levels: diammonium phosphate (DAP), DAP+potassium sulfate (KS), DAP+ammonium nitrate (AN), DAP+Urea, DAP+KS+AN, and DAP+KS+Urea.
The severe drought in the cropping season of 2015-16 (less than 150 mm cumulated rainfall) gave favorable conditions for root rot disease to reach epidemic levels as early as in the tillering stage under rain-fed condition. As a consequence, all rain-fed experiments in Jemaa Shaim and Khemis Zemamra were destroyed. In Sidi El Aidi station, results under rain-fed conditions showed that application of DAP+AN and DAP+Urea in inoculated plots enhanced the number of whiteheads, but these numbers were reduced by 44% and 75% respectively with the application of DAP+AN+KS and DAP+Urea+KS. Similar results were observed under supplemental irrigation where the addition of KS to DAP+AN and to DAP+Urea reduced the number of whiteheads by 27% and 81%, respectively. At the Khemis Zemamra station, results under fully irrigated condition showed no significant effect of fertilizer treatments on the severity of Fusarium crown rot of wheat.