ELICITORS AND MINERAL CONTENT OF WATER EXTRACT FROM AUTOCLAVED SPENT MUSHROOM (PLEUROTUS TUBER-REGIUM) SUBSTRATE AND ITS EFFECT ON CASSAVA INOCULATED WITH AFRICAN CASSAVA MOSAIC VIRUS (ACMV)

Abstract

This study investigated the effect of the water extract from spent mushroom (Pleurotus tuber-regium) substrate (autoclaved) on the mineral compositions and resistant elicitors and on the growth, yield and management of African cassava mosaic virus. The treatments for this investigation comprised of cassava plants treated with autoclaved and unautoclaved water extract from spent mushroom substrate and untreated cassava plants as control. The treatments were applied 4months after culturing from meristem tip culture and inoculated with viral inoculum 7 days after treatment application and then transplanted. The experiment was laid out in a completely randomized block design with 3 replicates. The mineral compositions and elicitors in the treatments were analyzed using standard procedures. The data generated were subjected to analysis of variance(ANOVA) at (p=0.05). The results revealed significant differences in the values of elicitors: carbohydrate polymers (1.6-33.4%),glycoproteins (0.04-0.90%) and lipid molecules (0.2-18.0g).PTAWESMS had 15.52 mg/100g and 33.64mg/100g higher K and Nathan PTWESMS which had 8.94 and 24.21mg/100g for K and Na respectively which were significantly difference. PTAWESMS had6.3, 39.2 and 76.5 significantly higher number of stems, LAI and LAR than PTWESMS and the control while the other growth parameters were not significantly different. PTWESMS had 8.33 and 35cmsignificantly higher number of storage roots and storage root length when it was compared with PTAWESMS and the control, while Nigerian Journal of Plant Protection (NJPP) Vol. 32, No 1 June 201860PTWESMS and PTAWESMS had 17.3mm significantly higher root girth than the control. The control had 2.5 severity index at 4WAIsignificantly higher than PTAWESMS and PTWESMS, while at 28WAI, the control had 1.37 significantly higher severity index than PTAWESMS and PTWESMS. The result obtained from this investigation clearly revealed that PTWESMS and PTAWESMS significantly reduced ACMD severity when it was compared with the control. It also revealed that unautoclaved water extract SMS performed significantly better than the autoclaved in reducing ACMD severity. However, the reductions in ACMD severity did not translate to higher growth and yield of cassava. Therefore, it is recommended that ACMD management using water extract from P. tuber-regium should be complimented with the application of solid SMS in order to achieve the desired results.