EFFECT OF TIMING OF BASAL FERTILIZER APPLICATION ON YIELD OF THREE RICE (Oryza sativa L.) VARIETIES IN GUINEA SAVANNA ECOLOGICAL ZONE

Abstract

A field experiment was conducted at Nyankpala, in the northern region of Ghana, during the 2018 cropping season. The experiment was a 3 x 4 factorial experiments which was conducted with three (3) varieties at four (4) different times of fertilizer application. This was conducted using Randomized Complete Block Design (RCBD). It was twelve (12) treatments and replicated three (3) times which sum up to thirty-six (36) experimental units. The study was aimed at investigating the response of three rice varieties (C93, Gbewaa and Tox 3107) to four fertilizer application timings. The fertilizer application timings were; (1) farmers practice (3WAP basal application + 6WAP top dressing), (2) 1WAP basal application + 5WAP top dressing, (3) 2WAP basal application + 6WAP top dressing and (4) 3WAP basal application + 7WAP top dressing, were combined factorial with three rice genotypes; C93, Gbewaa and Tox 3107. Parameters measured were plant height, chlorophyll content, leaf area, tiller count, number of seeds per panicle, 1000 grain weight, biomass yield, grain yield and harvest index. Yield components were grain yield of the genotypes were significantly affected by the fertilizer application timing. Average grain yields of C93 and Tox 3107, which are varieties yet to be released, were similar to Gbewaa. Averagely, 2 WAP basal application + 6 WAP top dressing recorded the highest influence on grain yield relative to the remaining fertilizer application timing. The varieties varied in their response to the various fertilizer application timing. Biomass and grain yield of C93 were maximised by 1 WAP basal + 5 WAP top dressing, yield of Gbewaa and Tox 3107 were maximized by 2 WAP basal + 6 WAP top dressing and 3 WAP basal + 7 WAP top dressing respectively. Grain yield was highly positive correlated with 1000 grain weight (r=0.76**). The study recommends 2 WAP basal + 6 WAP top dressing for optimize yield in the selected three rice varieties. However, 1 WAP basal + 5 WAP top dressing for C93, 2 WAP basal + 6 WAP top dressing for Gbewaa and 3 WAP basal + 7 WAP top dressing for Tox 3107 respectively of fertilizer are recommended for yield maximization in rice production.