Abstract
1 ABSTRACT
Pineapple (Ananas comosus L. Merr) is an important fruit crop in Uganda. Pineapple
production in Uganda is devastated by pineapple heart rot disease (PHRD) which is
associated with serious economic and yield losses. Therefore, this study quantified yield
loss on five pineapple cultivars to pineapple heart rot disease in central Uganda. Five
cultivars (Smooth Cayenne, Victoria, Sasilimu, MD-2 hybrid and Red Spanish) were tested
for latent infection by planting the suckers in buckets containing 10 kilograms of sterile soil
for four month. Disease free suckers, four month old, of average size from the five cultivars
were planted in pots containing 10 kilograms of sterile clay-loam soil in the screen house in
2016/2017 in a completely randomized design (CRD). Treatments consisted of protected
pots, un-protected pots and control pots respectively. Pineapple plants in the protected pots
had their suckers dipped for three minutes in a solution of Metalaxyl (Active Ingredients:
methoxyacetyl)-N-(2, 6-xylyl)-DL-alaninate 8%) before planting and later sprayed with a
solution of Fosetyl Al (Active Ingredients: Aluminum tris 80%) using a backpack sprayer
with Hardir flat spray nozzles three weeks after planting. Pineapple plants in the unprotected pots were not treated with any fungicide. The suckers in protected and
unprotected pots were inoculated with 108ml of zoospores using needle-mediated leaf base
wound technique. Control pots were not inoculated. Data on pineapple heart rots caused by
the pathogen was collected from all the pots and thus used to compute yield loss per
cultivar. Data was analyzed usin analysis of variance (ANOVA) of the GenStat computer
program (15th edition). Pineapple heart rot disease (PHRD) significantly (P<0.001) reduced
pineapple yield in the un-protected pots across all the five cultivars evaluated in both trial
one and trial two. Metalaxyl (Ridomil) and Fosetyl Al treatment significantly (P<0.001)
reduced yield losses in all the five cultivars used in the Protected pots in trial one and trial
two respectively. The highest and lowest yield loss was recorded in cultivar Victoria and
Smooth Cayenne respectively. PHRD can cause 100% yield loss. Metalaxyl (Ridomill) and
Fosetyl Al is recommended for the control of PHRD in Uganda
Publisher
Elewa Biosciences, F.a.C.T Ltd (K)
Reference33 articles.
1. Agrios, G. (2005) Plant Pathology. 5th edition. Elsevier Academic Press. San Diego, CA.
2. Bartholomew, D.P., Paul, R.E., Rohrbach, K.G. (2003). The pineapple: botany, production and uses. CABI Publishing, Wallingford, UK. pp 1-301.
3. Bua, B. Karungi, J. and Kawube, G. (2013). Occurrence and effects of pineapple mealy bug wilt disease in central Uganda. Journal of Agricultural Science and Technology, 3:410-416.
4. Cabral, J.R.S., Matos, A.P.d. and Coppens D’Eeckenbrugge, G. (1985) Segregation for resistance to fusariose, leaf margin type, and leaf colour from the EMBRAPA pineapple hybridization programme. In Martin-Prevel, P. and Hugon, R. (eds) Proceedings of the Second International Pineapple Symposium. Acta Horticulturae, Trois-Ilets, Martinique, pp. 193–200
5. Darwis, S.N. (1992) Phytophthora in relation to climate and coconut cultivar. Paper presented at the Coconut Phytophthora Workshop, Manado, Indonesia.